8970641
Atherogenic subfractions of lipoproteins in the treatment of metabolic syndrome by physical activity and diet – the RESOLVE trial
BackgroundWe aimed to comprehensively evaluate lipoprotein profile including lipid particle size following a lifestyle intervention in metabolic syndrome (MetS) volunteers and to assess the associations between lipoprotein subfractions and carotid-intima-media-thickness (CIMT) – a surrogate indicator of atherogenesis.Methods100 participants (50–70 years) from the RESOLVE trial, underwent a one-year follow-up beginning with a three-week residential program combining high exercise volume (15-20 h/week), restrictive diet (-500 kcal/day), and education. For baseline references, 40 aged-matched healthy controls were recruited. Independent associations between subfractions of lipoproteins and CIMT were evaluated using a generalized estimating equations model accounting for variation in correlations between repeated measures. The lipoprotein subfractions profile was assessed using Lipoprint® electrophoresis allowing to separate: the very low-density lipoprotein (VLDL) fraction, then the intermediate-density lipoprotein (IDL) C, B and A, the low-density lipoprotein (LDL) with subfractions 1 and 2 as large LDL and subfractions 3 to 7 as small dense LDL (sdLDL), and the high density lipoprotein (HDL) subfractions categorized into large, intermediate, and small HDL. Apolipoproteins A1 and B were also measured.Results78 participants completed the program. At baseline, apolipoproteins B/A1, VLDL, sdLDL and small HDL were higher in MetS than in healthy controls; IDL, LDL size, large and intermediate HDL were lower. Despite time-related regains during the follow-up, lipoprotein subfractions traditionally involved in cardiovascular risk, such as sdLDL, improved immediately after the residential program with values closest to those of healthy controls. CIMT improved throughout the lifestyle intervention. Using a generalized estimating equations model, none of the subfractions of lipoproteins nor apolipoproteins were linked to CIMT.ConclusionsLipoprotein subfractions traditionally involved in CVR, decreased after the 3-week residential program. During a 12 month follow-up, the time-related regains remained closer to the values of healthy controls than they were at baseline. CIMT improved throughout the lifestyle intervention. However, we failed to demonstrate a link between some lipoprotein subfractions and the atherogenicity directly measured from the wall thickness of arteries (CIMT). Further investigations are required to explore the atherogenicity of lipoprotein subfractions.Trial registrationNCT00917917
205537962
The metabolic syndrome and cardiovascular risk a systematic review and meta-analysis.
OBJECTIVES
We sought to conduct a systematic review and meta-analysis of the cardiovascular risk associated with the metabolic syndrome as defined by the 2001 National Cholesterol Education Program (NCEP) and 2004 revised National Cholesterol Education Program (rNCEP) definitions.


BACKGROUND
Numerous studies have investigated the cardiovascular risk associated with the NCEP and rNCEP definitions of the metabolic syndrome. There is debate regarding the prognostic significance of the metabolic syndrome for cardiovascular outcomes.


METHODS
We searched the Cochrane Library, EMBASE, and Medline databases through June 2009 for prospective observational studies investigating the cardiovascular effects of the metabolic syndrome. Two reviewers extracted data, which were aggregated using random-effects models.


RESULTS
We identified 87 studies, which included 951,083 patients (NCEP: 63 studies, 497,651 patients; rNCEP: 33 studies, 453,432 patients). There was little variation between the cardiovascular risk associated with NCEP and rNCEP definitions. When both definitions were pooled, the metabolic syndrome was associated with an increased risk of cardiovascular disease (CVD) (relative risk [RR]: 2.35; 95% confidence interval [CI]: 2.02 to 2.73), CVD mortality (RR: 2.40; 95% CI: 1.87 to 3.08), all-cause mortality (RR: 1.58; 95% CI: 1.39 to 1.78), myocardial infarction (RR: 1.99; 95% CI: 1.61 to 2.46), and stroke (RR: 2.27; 95% CI: 1.80 to 2.85). Patients with the metabolic syndrome, but without diabetes, maintained a high cardiovascular risk.


CONCLUSIONS
The metabolic syndrome is associated with a 2-fold increase in cardiovascular outcomes and a 1.5-fold increase in all-cause mortality. Studies are needed to investigate whether or not the prognostic significance of the metabolic syndrome exceeds the risk associated with the sum of its individual components. Furthermore, studies are needed to elucidate the mechanisms by which the metabolic syndrome increases cardiovascular risk.
1984484
Obesity‐related Changes in High‐density Lipoprotein Metabolism
Obesity is associated with a 3‐or‐more‐fold increase in the risk of fatal and nonfatal myocardial infarction ( 1 , 2 , 3 , 4 , 5 , 6 ). The American Heart Association has reclassified obesity as a major, modifiable risk factor for coronary heart disease ( 7 ). The increased prevalence of premature coronary heart disease in obesity is attributed to multiple factors ( 8 , 9 , 10 ). A principal contributor to this serious morbidity is the alterations in plasma lipid and lipoprotein levels. The dyslipidemia of obesity is commonly manifested as high plasma triglyceride levels, low high‐density lipoprotein cholesterol (HDLc), and normal low‐density lipoprotein cholesterol (LDLc) with preponderance of small dense LDL particles ( 7 , 8 , 9 , 10 ). However, there is a considerable heterogeneity of plasma lipid profile in overweight and obese people. The precise cause of this heterogeneity is not entirely clear but has been partly attributed to the degree of visceral adiposity and insulin resistance. The emergence of glucose intolerance or a genetic predisposition to familial combined hyperlipidemia will further modify the plasma lipid phenotype in obese people ( 11 , 12 , 13 , 14 , 15 ).
11334632
Small, dense low-density lipoprotein particles as a predictor of the risk of ischemic heart disease in men. Prospective results from the Québec Cardiovascular Study.
BACKGROUND
Case-control studies have reported that patients with ischemic heart disease (IHD) have a higher proportion of small, dense LDL particles than do healthy control subjects. The extent to which the risk attributed to small LDL particles may be independent of concomitant variations in plasma lipoprotein-lipid concentrations remains to be clearly determined, however, particularly through prospective studies.


METHODS AND RESULTS
Baseline characteristics were obtained in 2103 men initially free of IHD, among whom 114 developed IHD during a 5-year follow-up period. These 114 case patients were matched with healthy control subjects for age, body mass index, smoking habits, and alcohol intake. LDL peak particle diameter (PPD) was measured a posteriori in 103 case-control pairs by nondenaturing gradient gel electrophoresis of whole plasma. Conditional logistic regression analysis of the case-control status revealed that men in the first tertile of the control LDL-PPD distribution (LDL-PPD < or = 25.64 nm) had a 3.6-fold increase in the risk of IHD (95% CI, 1.5 to 8.8) compared with those in the third tertile (LDL-PPD > 26.05 nm). Statistical adjustment for concomitant variations in LDL cholesterol, triglycerides, HDL cholesterol, and apolipoprotein B concentrations had virtually no impact on the relationship between small LDL particles and the risk of IHD.


CONCLUSIONS
These results represent the first prospective evidence suggesting that the presence of small, dense LDL particles may be associated with an increased risk of subsequently developing IHD in men. Results also suggest that the risk attributed to small LDL particles may be partly independent of the concomitant variation in plasma lipoprotein-lipid concentrations.
13091164
Association of small low-density lipoprotein particles with the incidence of coronary artery disease in men and women.
OBJECTIVE
To investigate the prospective association of low-density lipoprotein (LDL) particle diameter with the incidence of fatal and nonfatal coronary artery disease (CAD).


DESIGN
A nested case-control study.


SETTING
Cases and controls were identified from a population-based sample of men and women combining all of the 5 cross-sectional surveys conducted from 1979 to 1990 of the Stanford Five-City Project (FCP).


PARTICIPANTS
Incident CAD cases were identified through FCP surveillance between 1979 and 1992. Controls were matched by sex, 5-year age groups, survey time point, ethnicity, and FCP treatment condition. The sample included 124 matched pairs: 90 pairs of men and 34 pairs of women.


MAIN OUTCOME MEASURES
LDL peak particle diameter (LDL size) was determined by gradient gel electrophoresis on plasma samples collected during the cross-sectional surveys (stored at 70 degrees C for 5-15 years). Established CAD risk-factor data were available from FCP baseline measurements.


RESULTS
LDL size was smaller among CAD cases than controls (mean +/- SD) (26.17 +/- 1.00 nm vs 26.68 +/- 0.90 nm; P<.001). The association was graded across control quintiles of LDL size. The significant case-control difference in LDL size was independent of levels of high-density lipoprotein cholesterol (HDL-C), non-HDL cholesterol (non-HDL-C), triglyceride, smoking, systolic blood pressure, and body mass index, but was not significant after adjusting for the ratio of total cholesterol (TC) to HDL-C (TC:HDL-C). Among all the physiological risk factors, LDL size was the best differentiator of CAD status in conditional logistic regression. However, when added to the physiological parameters above, the TC:HDL-C ratio was found to be a stronger independent predictor of CAD status.


CONCLUSION
LDL size was significantly smaller in CAD cases than in controls in a prospective, population-based study. These findings support other evidence of a role for small, dense LDL particles in the etiology of atherosclerosis.
17173613
The relationship between high density lipoprotein subclass profile and plasma lipids concentrations
HDL particles posses multiple antiatherogenic activities and the identification and differentiation of individual HDL subclasses may be useful in documentation and understanding of metabolic changes of different HDL subclasses. The major plasma lipids exist and are transported in the form of lipoprotein complexes. Hence, alterations in plasma lipids levels can interfere with the composition, content, and distribution of plasma lipoprotein subclasses that affect atherosclerosis risk. The research review major discussed the relationship between plasma lipids levels and HDL subclasses distribution. The general shift toward smaller size of HDL particle size in HTG, HCL and MHL subjects, and the changes were more prominent with the elevation of TG and TC levels which imply that HDL maturation might be abnormal and RCT pathway might be weaken, and these changes were more seriously in MHL subjects. Plasma contents of small sized HDL particles significantly higher, whereas those of large sized HDL particles were significantly lower with elevation of TG/HDL-C and TC/HDL-C ratios. Increased in the TC/HDL-C ratio alone did not influence the distributions of HDL subclasses significantly when the TG/HDL-C ratio was low (TG/HDL-C ≤ 2.5). Hence, the TG/HDL-C ratio might be more sensitive to reflect the alteration of HDL subclass distribution than the TC/HDL-C ratio. In LDL-C/HDL-C ≤ 2.3 group, the pattern of distribution in HDL subclass was in agreement with the normolipidemic subjects. Moreover, considering the relative ease of measuring TC/HDL-C, TG/HDL-C and LDL-C/HDL-C ratios, as opposed to measuring HDL subclasses, these 3 ratios together may be a good indicator of HDL subclass distribution. The protective effect of increased apoA-I levels against the reduction of HDL2b caused by elevated TG concentration. On one hand, plasma HDL-C and apoA-I appear to play a coordinated role in the assembly of HDL particles and the determination of their contents among the total subjects. On the other hand, the apoA-I level might be a more powerful factor than HDL-C to influence the distribution of HDL subclasses in hyperlipidemic subjects. At the same time, from point of HDL subclasses distribution, the plasma lipids, apos concentrations and apos ratios should be considered while assessing the CHD risk. Abnormality of HDL subclasses distribution may result in accelerated atherosclerosis, therapeutic normalization of attenuated antiatherogenic HDL function in terms of both particle number and distribution of HDL particles is the target of innovative pharmacological approaches to large-sized HDL particles rising, including enhanced apoA-I levels.
36967515
High-Density Lipoprotein Particle Size and Concentration and Coronary Risk
Context High-density lipoprotein (HDL) particles are heterogeneous in size and composition. Contribution This nested casecontrol study found that both HDL size and HDL particle concentration were associated with risk for coronary artery disease (CAD). High-density lipoprotein size was strongly associated with risk factors characteristic of the metabolic syndrome, such as triglyceride and apolipoprotein B levels. Adjustment for those factors explained the association between HDL size and CAD risk, but not the association between HDL particle concentration and CAD risk. Implication High-density lipoprotein size and HDL particle concentration are differentially associated with cardiovascular risk factors and CAD risk. The association between HDL size and CAD risk may be explained by metabolic parameters. The Editors The strong inverse relationship between high-density lipoprotein (HDL) (see Glossary) cholesterol levels and risk for coronary artery disease (CAD) is well established (1). However, at any given level of HDL cholesterol (see Glossary), HDL particle concentration (see Glossary) and HDL size (see Glossary) distribution may differ substantially between individuals. The atheroprotective role of HDL cholesterol is believed to be mediated mainly by its role in reverse cholesterol transport, the biological pathway that facilitates removal of cholesterol from macrophages in the arterial wall back to the liver (2). Substantial evidence suggests that HDL particles are heterogeneous in their efficacy to facilitate adenosine triphosphatebinding cassette A1 (see Glossary)mediated cholesterol efflux from macrophages and scavenger receptor class B1 (see Glossary)mediated hepatic uptake of cholesterol from HDL particles. In particular, this heterogeneity has been associated with HDL particle size (35). Accumulating evidence suggests that, in addition to their role in reverse cholesterol transport, HDL particles have anticoagulant, antioxidative, and anti-inflammatory properties that contribute to the antiatherogenic capacity of HDL cholesterol. In fact, HDL particles were recently shown to carry a wide array of proteins that mediate these properties (6). The binding affinity of these proteins to the surface of HDL particles may depend on their size (7, 8). Under certain conditions, HDL particles may lose their antiatherogenic capacity and become dysfunctional (9, 10). As a consequence, various HDL subpopulations may differ substantially in their capacity to play an atheroprotective role. Despite this functional heterogeneity, HDL has thus far been regarded as a single entity in epidemiologic studies, and the amount of cholesterol transported by HDL particles is traditionally being used for this purpose. However, we have recently shown that higher HDL cholesterol levels may not necessarily be associated with lower cardiovascular risk (11), and the HDL cholesterol levelincreasing drug torcetrapib has been shown to have detrimental effects (12). These findings emphasize that a broader perspective on HDL metabolism is warranted. We hypothesized that HDL particle concentration and HDL size distribution are differentially associated with cardiovascular risk factors and with cardiovascular risk. We tested these hypotheses in a casecontrol study nested in the EPIC (European Prospective Investigation into Cancer and Nutrition)-Norfolk cohort. Methods We performed a nested casecontrol study among participants of the EPIC-Norfolk study, a prospective population-based study of 25663 men and women age 45 to 79 years living in Norfolk, United Kingdom, who completed a baseline questionnaire survey and attended a clinic visit (Figure). Participants were recruited from agesex registers of general practices in Norfolk as part of the 10-country collaborative EPIC study, which was designed to investigate dietary and other determinants of cancer. Additional data were obtained in EPIC-Norfolk to enable the assessment of determinants of other diseases. Figure. Study flow diagram. ApoAI = apolipoprotein A-I; ApoB = apolipoprotein B; CRP = C-reactive protein; EPIC = European Prospective Investigation into Cancer and Nutrition; HDL = high-density lipoprotein; LDL = low-density lipoprotein; NMR = nuclear magnetic resonance. *Individual case patients and control participants may have several missing variables. The design and methods of the study have been described in detail (13). Eligible participants were recruited by mail. At the baseline survey between 1993 and 1997, participants completed a detailed health and lifestyle questionnaire. Nonfasting blood samples were obtained by venipuncture into plain and citrate bottles. Blood samples were processed for assay at the Department of Clinical Biochemistry, University of Cambridge, Cambridge, United Kingdom, or were stored at 80C. All individuals have been monitored for death certification at the United Kingdom Office of National Statistics, with vital status ascertained for the entire cohort. In addition, hospitalized participants were identified by their unique National Health Service number and data linkage with the East Norfolk Health Authority database, which identifies all hospital contacts throughout England and Wales for Norfolk residents. Coronary artery disease was defined as codes 410 to 414 according to the International Classification of Diseases, Ninth Revision. Participants were identified as having CAD during follow-up if they had had a hospital admission or had died with CAD as the underlying cause. Previous validation studies in our cohort indicate high specificity of such case ascertainment (14). We report results with follow-up to November 2003, an average of about 6 years. The study was approved by the Norwich District Health Authority Ethics Committee, and all participants gave signed, informed consent. Participants We have previously described other analyses within this prospective, nested casecontrol study (14, 15). We excluded all individuals who reported a history of heart attack or stroke or use of lipid-lowering drugs at the baseline clinic visit. Case patients were individuals who developed fatal or nonfatal CAD during follow-up until November 2003. Control participants were study participants who remained free of cardiovascular disease during follow-up. We matched 2 control participants to each case patient by age (within 5 years), sex, and time of enrollment (within 3 months). We performed the current analysis on all participants who had a complete data set available for baseline characteristics, apolipoproteins A-I and B, gradient gel electrophoresis (GGE)measured HDL size, and lipoprotein nuclear magnetic resonance (NMR) spectroscopy. We selected 1138 persons who were apparently healthy at baseline but did develop CAD during follow-up. For every case patient, we aimed to select 2 control participants who were healthy at baseline and remained free of cardiovascular disease during follow-up. From the original data set of 1138 case patients and 2237 control participants, 270 case patients and 430 control participants were excluded because at least 1 value was missing for any of the parameters mentioned. We excluded 46 case patients because they had no matching control participants and 406 control participants because they had no matching case patients. The analyses are therefore based on a data set of 822 case patients and 1401 control participants (243 case patients were matched with 1 control participant each, and 579 case patients were matched with 2 control participants each). Measurements We obtained data on smoking and alcohol consumption by health questionnaires at the baseline clinic visit. We obtained information on physical activity with a physical activity questionnaire (13). In the original cohort, we classified smoking into current cigarette smokers, former smokers, and those who never smoked. In the present study, we recorded smoking as yes or no. We divided physical activity into 4 categories: inactive, moderately inactive, moderately active, and active. We defined use of large amounts of alcohol as more than 21 units of alcohol per week. Diabetes mellitus and use of hormone replacement therapy was self-reported. We asked participants about medical history with the question, Has a doctor ever told you that you have any of the following?, followed by a number of choices, including diabetes. We recorded blood pressure by taking 2 measurements of diastolic and systolic blood pressure by using the Accutorr sphygmomanometer (Datascope, Huntingdon, United Kingdom) after 3 minutes of resting. We measured serum levels of total cholesterol, HDL cholesterol, and triglycerides on fresh samples with the RA 1000 (Bayer Diagnostics, Basingstoke, United Kingdom). We calculated low-density lipoprotein (LDL) cholesterol levels with the Friedewald formula to closely approach current clinical procedures. We measured plasma concentrations of C-reactive protein with a sandwich-type enzyme-linked immunosorbent assay as previously described (16). We measured serum levels of apolipoprotein A-I and apolipoprotein B by using rate immunonephelometry (Behring Nephelometer BNII, Dade Behring, Marburg, Germany) with calibration traceable to the International Federation of Clinical Chemistry primary standards (17). We measured serum concentration of myeloperoxidase (see Glossary) by using a commercially available enzyme-linked immunosorbent assay (CardioMPO Test, Prognostix, Cleveland, Ohio) (15). We measured paraoxonase 1 (see Glossary) activity as previously described (18). We measured HDL size by 4% to 30% nondenaturing polyacrylamide GGE as previously described (19). We measured lipoprotein subclass particle concentrations and average size of particles by proton NMR spectroscopy (LipoScience, Raleigh, North Carolina) as previously described (20). In brief, we obtained particle concentrations of lipoprotein subclasses of different size directly from the measured amplitudes of t
10201798
The relative atherogenicity of VLDL and LDL is dependent on the topographic site[S]
To evaluate whether the relative atherogenicity of VLDL and LDL is dependent on the topographic site, atherosclerosis was compared at four topographic sites in homozygous LDL receptor (LDLr)-deficient rabbits fed normal chow and in heterozygous LDLr-deficient rabbits with the same genetic background fed a 0.15% cholesterol diet to match cholesterol levels. VLDL cholesterol was significantly higher and LDL cholesterol significantly lower in LDLr+/− diet rabbits compared with LDLr−/− rabbits. Intimal area in the ascending thoracic aorta and in the abdominal aorta at the level of the renal arteries was 1.4-fold (P < 0.05) and 1.5-fold (P < 0.05) higher, respectively, in LDLr−/− rabbits than in LDLr+/− diet rabbits, whereas no significant difference occurred in the descending thoracic aorta and in the abdominal aorta just above the bifurcation. Differences remained statistically significant after adjustment for plasma cholesterol, triglycerides, and sex. Compared with LDLr+/− diet rabbits, higher intimal lipoprotein lipase (LPL) and apolipoprotein (apo) B levels were observed in LDLr−/− rabbits only at the level of the descending thoracic aorta. Intimal apo E levels in LDLr−/− rabbits were significantly lower in sites with a larger intima than in LDLr+/− diet rabbits. In conclusion, the relative atherogenicity of VLDL and LDL is dependent on the topographic site.
1014351
Relative importance of different lipid risk factors for the development of myocardial infarction at a very young age (≤ 40 years of age)
Eur J Clin Invest 2012; 42 (6): 631–636
19418023
Apolipoprotein Measurements: Is More Widespread Use Clinically Indicated?
Apolipoprotein (apo) B may be a more sensitive measure of atherogenicity than low‐density lipoprotein cholesterol (LDL‐C) and a better index for assessing cardiovascular risk. The refined risk assessment provided by apo B may be important in patients at high cardiometabolic risk such as those with diabetes mellitus or metabolic syndrome, as these conditions are often associated with normal LDL‐C values but increased numbers of small, dense low‐density lipoprotein (LDL) particles (indicating increased levels of apo B). Although apo B is not currently a treatment target in the United States cholesterol‐lowering guidelines, a consensus conference endorsed by the American Diabetes Association and the American College of Cardiology recently recommended that apo B be added as a therapeutic target in patients at high cardiometabolic risk and in patients with clinical cardiovascular disease or diabetes. Suggested target goals are < 90 for high risk and < 80 mg/dL for highest risk patients. Current clinical data indicate that intensive statin therapy can lower apo B to meet this aggressive goal. While the proatherogenic/antiatherogenic ratio of apo B/apo A‐I is a better risk discriminator than the single proatherogenic measurement (apo B), clinical trial data are lacking regarding the impact of increasing apo A‐I and high‐density lipoprotein on outcomes. Copyright © 2009 Wiley Periodicals, Inc.
45189606
Metabolic Syndrome and Carotid Intima-Media Thickness in Young Adults: Roles of Apolipoprotein B, Apolipoprotein A-I, C-Reactive Protein, and Secretory Phospholipase A2: The Cardiovascular Risk in Young Finns Study
Objective—Aberrations in apolipoprotein (apo) metabolism and increased systemic inflammation associate with the metabolic syndrome (MetS) and may contribute to its atherogenicity. We examined whether the association between carotid atherosclerosis and MetS in a population of young adults is mediated by apoB and apoA-I and/or by inflammatory markers C-reactive protein and type II secretory phospholipase A2. Methods and Results—We used cross-sectional and 6-year prospective data from the cardiovascular risk in young Finns study. In young adults (aged 24 to 39 years), apoB, C-reactive protein, and type II secretory phospholipase A2 enzyme activity were significantly higher and apoA-I lower in subjects with MetS (N=325) than in subjects without MetS (N=1858). In prospective analysis (N=1587), both MetS and high apoB predicted (P<0.0001) incident high carotid intima-media thickness, defined as carotid intima-media thickness >90th percentile and/or plaque. The association between MetS and incident high carotid intima-media thickness was attenuated by ≈40% after adjustment with apoB. Adjustments with apoA-I, C-reactive protein, or type II secretory phospholipase A2 did not diminish the association. Conclusion—High levels of apoB, C-reactive protein, and type II secretory phospholipase A2 and low levels of apoA-I associate with MetS in young adults. The atherogenicity of MetS in this population assessed by incident high carotid intima-media thickness appears to be substantially mediated by elevated apoB but not inflammatory markers.
25448587
Influence of 4 weeks' intervention by exercise and diet on low-density lipoprotein subfractions in obese men with type 2 diabetes.
Insulin resistance is associated with dyslipoproteinemia characterized by increased serum triglycerides, reduced high-density lipoprotein 2 (HDL2) cholesterol, and increased small, dense low-density lipoprotein (LDL) subfraction particles. Physical activity and weight reduction are known to improve insulin resistance and dyslipoproteinemia, but their influence on LDL subfractions in diabetic patients is unknown. Therefore, we investigated the effect of a 4-week intervention program of exercise (2,200 kcal/wk) and diet (1,000 kcal/d: 50% carbohydrate, 25% protein, and 25% fat; polyunsaturated/saturated fat ratio, 1.0) on glycemic control and HDL and LDL subfractions in 34 obese patients with non-insulin-dependent diabetes (age, 49 +/- 9 years; body mass index [BMI], 33.1 +/- 5.1 kg/m2). Reductions in body weight (P < .001) and improvements in fasting blood glucose, insulin, fructosamine (P < .001), and free fatty acids (P < .01) by intervention were associated with reductions in serum cholesterol and apolipoprotein B (apo B) concentrations in very-low-density lipoprotein (VLDL) (P < .01), intermediate-density lipoprotein (IDL), and small, dense (>1.040 g/mL) LDL particles (P < .001). These data underlie the positive influence of weight reduction induced by exercise and diet on insulin resistance and lipoprotein metabolism in obese diabetic patients, particularly showing improvements of the LDL subfraction profile with a decrease of small, dense LDL particles. This is of particular importance, as these particles have been shown to be associated with coronary artery disease.
43167078
Endurance exercise training raises high-density lipoprotein cholesterol and lowers small low-density lipoprotein and very low-density lipoprotein independent of body fat phenotypes in older men and women.
Endurance exercise training improves plasma lipoprotein and lipid profiles and reduces cardiovascular disease risk. However, the effect of endurance exercise training, independent of diet and body fat phenotypes, on plasma lipoprotein subfraction particle concentration, size, and composition as measured by nuclear magnetic resonance (NMR) spectroscopy is not known. We hypothesized that 24 weeks of endurance exercise training would independently improve plasma lipoprotein and lipid profiles as assessed by both conventional and novel NMR measurement techniques. One hundred sedentary, healthy 50- to 75-year-olds following a standardized diet were studied before and after 24 weeks of aerobic exercise training. Lipoprotein and lipid analyses, using both conventional and NMR measures, were performed at baseline and after 24 weeks of exercise training. Relative and absolute maximum oxygen consumption increased 15% with exercise training. Most lipoprotein and lipid measures improved with 24 weeks of endurance exercise training, and these changes were consistently independent of baseline body fat and body fat changes with training. For example, with exercise training, total cholesterol, triglycerides, and low-density lipoprotein cholesterol (LDL-C) decreased significantly (2.1+/-1.8 mg/dL, P=.001; -17+/-3.5 mg/dL, P<.0001; and -0.7+/-1.7 mg/dL, P<.0001, respectively), and high-density lipoprotein cholesterol subfractions (HDL3-C and HDL2-C) increased significantly (1.9+/-0.5 mg/dL, P=.01, and 1.2+/-0.3 mg/dL, P=.02, respectively). Particle concentrations decreased significantly for large and small very low-density lipoprotein particles (-0.7+/-0.4 nmol/L, P<.0001, and -1.1+/-1.7 nmol/L, P<.0001, respectively), total, medium, and very small LDL particles (-100+/-26 nmol/L, P=.01; -26+/-7.0 nmol/L, P=.004; and -103+/-27 nmol/L, P=.02, respectively), and small HDL particles (-0.03+/-0.4 micromol/L, P=.007). Mean very low-density lipoprotein particle size also decreased significantly (-1.7+/-0.9 nm, P<.0001) and mean HDL particle size increased significantly with exercise training (0.1+/-0.0 nm, P=.04). These results show that 24 weeks of endurance exercise training induced favorable changes in plasma lipoprotein and lipid profiles independent of diet and baseline or change in body fat.
8304489
Studies of low density lipoprotein molecular weight in human beings with coronary artery disease.
Low density lipoprotein molecular weight (LDL MW) correlates positively with coronary artery disease in cholesterol-fed nonhuman primates. To evaluate this in human beings with coronary artery disease (CAD) we measured LDL MW in 93 volunteers undergoing coronary angiography (47 controls and 46 CAD patients). LDL MW of CAD patients was less than that of controls (patients, 2.79 +/- 0.17 g/mumol; controls, 2.93 +/- 0.19 g/mumol; P less than 0.001). However, LDL MW decreased as plasma triglyceride increased and concentrations of triglyceride were greater in CAD patients than in controls. Since decreased LDL MW is likely to result, in part, from increased plasma triglyceride concentrations, we attempted to determine the effect of triglyceride on the relation of LDL MW to CAD in this study. After covariance adjustment for triglyceride, there was no LDL MW difference between CAD patients and controls. Because LDL heterogeneity has been identified in other studies and was apparent on inspection of agarose column profiles of LDL of these volunteers, we sought differences in the profiles that might distinguish coronary disease cases from controls. No differences could be found. In addition, we used density gradient ultracentrifugation to characterize LDL in more detail in a subset of volunteers who had a wide range of plasma triglyceride concentrations (50 mg/dl to 900 mg/dl). LDL mean hydrated density was inversely related to LDL MW and increased as triglyceride increased. The increase in peak density was reflected in an increase in percent of total protein in LDL found to have d greater than 1.045 g/ml and a decrease in protein in LDL of d 1.035-1.040 g/ml. These interrelationships were not apparently influenced by coronary artery status.
2071833
Low-density lipoprotein subclass patterns and risk of myocardial infarction.
The association of low-density lipoprotein (LDL) subclass patterns with coronary heart disease was investigated in a case-control study of nonfatal myocardial infarction. Subclasses of LDL were analyzed by gradient gel electrophoresis of plasma samples from 109 cases and 121 controls. The LDL subclass pattern characterized by a preponderance of small, dense LDL particles was significantly associated with a threefold increased risk of myocardial infarction, independent of age, sex, and relative weight. Plasma levels of high-density lipoprotein cholesterol were decreased, and levels of triglyceride, very low-density lipoproteins, and intermediate-density lipoproteins were increased in subjects with this LDL subclass pattern. Multivariate logistic regression analyses showed that both high-density lipoprotein cholesterol and triglyceride levels contributed to the risk associated with the small, dense LDL subclass pattern. Thus, the metabolic trait responsible for this LDL subclass pattern results in a set of interrelated lipoprotein changes that lead to increased risk of coronary heart disease.
1216715
Low density lipoprotein particle size and coronary artery disease.
Decreased plasma low density lipoprotein (LDL) particle size has been associated with premature coronary artery disease (CAD). We examined LDL particle size by 2-16% gradient gel electrophoresis in 275 men with CAD (greater than 75% cross-sectional-area stenosis) and 822 controls. Seven major LDL size bands (with LDL-1 [d = 1.025-1.033 g/ml] being the largest and LDL-7 [d = 1.050-1.063 g/ml, the smallest]) were identified. Because most subjects had two or more adjacent LDL bands, an LDL score was calculated for each subject, with the relative area in each band taken into consideration. Four major LDL particle size groups were classified in the present studies: large LDL, intermediate LDL, small LDL, and very small LDL. The use of beta-blockers was significantly associated with smaller LDL particles. After adjusting for use of this medication, small LDL particles were still more prevalent in CAD patients (39%) compared with controls (27%). The prevalence of large LDL particles was lower in CAD patients (3%) than in controls (24%). Intermediate LDL particles were the most prevalent in both groups, 49% in CAD patients and 46% in controls. The difference in LDL particle size between CAD patients and controls was not independent but was highly associated (p less than 0.0001) with elevated triglyceride levels and decreased high density lipoprotein (HDL) cholesterol levels. Significantly higher LDL cholesterol levels were found in subjects with intermediate and small LDL particles than in those with large or very small LDL particles.(ABSTRACT TRUNCATED AT 250 WORDS)
29376273
The relevance of a protein-enriched low density lipoprotein as a risk for coronary heart disease in relation to other known risk factors.
The significance of a decreased low density lipoprotein cholesterol/apolipoprotein B ratio (LDL-chol/LDL apo B), or protein-enriched LDL, to predict atherosclerosis was studied in 121 males with angiographically defined coronary artery disease (CAD) and compared to 98 male controls, without history or complaints of vascular disease. Controls were selected for similar age, smoking habits and relative body weight characteristics compared to the CAD group. Covariance analysis with adjustment for hyperlipoproteinemia, apoprotein E phenotype, smoking, age and relative body weight revealed that high density lipoprotein (HDL)-cholesterol was the only parameter that differed significantly between both groups. By logistic regression analysis HDL-cholesterol had the highest predictive power for the development of CAD. The LDL-chol/LDL apo B ratio appeared significantly different between controls and CAD patients (3.1 +/- 0.7 vs. 2.9 +/- 0.6 mmol/g, P less than 0.05), indicating a predominance of subjects with protein-enriched LDL in the CAD group. However, within the group of CAD patients with normal LDL-cholesterol levels no clear distinction could be found between patients with normal and increased LDL apo B levels. Furthermore, it appeared that the LDL-chol/LDL apo B ratio correlated significantly with age (p = -0.24), serum triglycerides (p = -0.24), and HDL-cholesterol (p = 0.24). Thus, the LDL-chol/LDL apo B ratio cannot be considered an independent risk factor for CAD. When adjusted for age, smoking habits and relative body weight the significance of protein-enriched LDL as a risk factor for coronary heart disease diminishes, and HDL-cholesterol appears to be the best indicator for CAD.
34489090
Association of plasma triglyceride concentration and LDL particle diameter, density, and chemical composition with premature coronary artery disease in men and women.
Low density lipoprotein (LDL) physical-chemical characteristics were studied as nontraditional risk factors of coronary artery disease (CAD) in a well-characterized population of 98 men aged < or = 50 and 100 women aged < or = 60 who underwent elective diagnostic coronary arteriography. The average LDL diameter was determined by gradient gel electrophoresis, chemical composition (%w/w) was measured, and the density of the major LDL peak was determined by equilibrium density gradient ultracentrifugation. Logistic regression was used to examine the association of various LDL characteristics with CAD before and after adjustment for other covariates. Smaller, cholesterol-poor LDL particles were associated with CAD independently of traditional risk factors (age, sex, smoking, diabetes, LDL and HDL cholesterol concentrations), other than the plasma triglyceride concentration. These characteristics were generally more strongly associated with CAD when measured on the major LDL subfraction (defined as the density gradient ultracentrifugation fraction with the highest LDL concentration) than the average characteristics of the more heterogeneous parent LDL (d 1.019-1.063 g/ml). The associations with CAD among men and women were generally similar. These data show that a broad range of LDL characteristics are associated with CAD before, but not after, adjustment for the plasma triglyceride concentration. These data further indicate the importance of hypertriglyceridemia and LDL heterogeneity in premature CAD.
26559185
LDL particle size: an important drug target?
Low density lipoprotein (LDL) is the main carrier of plasma cholesterol and a major component of atherosclerotic plaque [1]. Lowering LDL cholesterol reduces coronary events and mortality from coronary artery disease (CAD) [2–4], however, the relation between LDL cholesterol concentration and (CAD) is complex. Many patients with CAD have plasma LDL cholesterol concentrations in the normal rangefor the general population [5]. Thus, it could be that coronary risk goes beyond LDL cholesterol concentration to the characteristics of the LDL particles themselves. The purpose of this communication is to address the issue of whether LDL particle size and density influences its atherogenecity and how this might be modified by drug therapy.
30931314
Predominance of large LDL and reduced HDL2 cholesterol in normolipidemic men with coronary artery disease.
Previous studies have indicated that a predominance of small, dense LDL particles is associated with coronary artery disease (CAD) risk. In the present study we examined the LDL peak particle diameter (determined by lipid-stained 2% to 16% gradient gel electrophoresis) in 92 normolipidemic men with CAD (total cholesterol < 200 mg/dL and triglyceride < 250 mg/dL) and 92 matched healthy controls. Plasma triglyceride, LDL cholesterol, and apo B levels were similar in subjects with CAD and in control subjects, whereas subjects with CAD had decreased HDL2 cholesterol levels (mean +/- SEM, 10 +/- 0.7 compared with 15 +/- 0.7 mg/dL in control subjects; P < .0002). Mean LDL particle diameter (+/- SEM) was increased in the subjects with CAD compared with control subjects (26.8 +/- 0.08 and 26.4 +/- 0.08 nm, respectively; P < .001). The association between large LDL size and CAD was significant (P < .0001) after adjustments were made for age, body mass index, HDL cholesterol levels, and VLDL cholesterol levels. An LDL particle size distribution characterized by a predominance of the largest of three classes of LDL particles (> 26.8 nm) was more prevalent among subjects with CAD (43%) than among control subjects (25%) (P < .002). Among subjects with this LDL size profile, subjects with CAD had significantly higher (P < .05) VLDL triglyceride, VLDL cholesterol, and VLDL apo B levels and significantly lower (P < .0001) HDL2 cholesterol levels than controls.(ABSTRACT TRUNCATED AT 250 WORDS)
36710648
Substitution of vegetable oil for a partially-hydrogenated fat favorably alters cardiovascular disease risk factors in moderately hypercholesterolemic postmenopausal women.
OBJECTIVE
Compared to vegetable oils in their unmodified state, partially-hydrogenated fat is associated with less favorable effects on cardiovascular disease (CVD) risk factors. Acceptable alternatives must be adjudicated. Our objective was to assess the effect of a recent commercial fat substitution, corn oil for partially-hydrogenated soybean oil.


METHODS
Using a double-blind cross-over design, 30 postmenopausal women >or=50 years with LDL-cholesterol concentrations >or=120 mg/dL were randomly assigned to each of two 35-day phases; all food and beverage was provided to maintain body weight. Corn or partially-hydrogenated soybean oil was incorporated throughout the diet and contributed two-thirds of fat. Primary outcomes included fasting and non-fasting lipid, lipoprotein, apolipoprotein, and fasting high sensitivity C-reactive protein (hsCRP) concentrations; secondary outcomes included fasting small dense LDL (sdLDL)-cholesterol, remnant lipoprotein cholesterol (RemLC), glycated albumin, adiponectin and immunoreactive insulin concentrations, and endogenous cholesteryl ester transfer protein (CETP) and lecithin:cholesterol acyl transferase (LCAT) activities.


RESULTS
Relative to the partially-hydrogenated soybean oil enriched diet, the corn oil enriched diet resulted in lower fasting total cholesterol (7%; P<0.0001), LDL-cholesterol (10%; P<0.0001), VLDL-cholesterol (7%; P=0.052), apo B (9%; P<0.0001), lipoprotein (a) [Lp(a)] (5%; P=0.024), sdLDL-cholesterol (17%; P=0.001), and RemLC (20%; P=0.007) concentrations, and no significant effect on the other outcomes. Changes in postprandial (4-h post-meal) lipid, lipoprotein and apolipoprotein concentrations were similar to the fasting state.


CONCLUSION
The replacement of partially-hydrogenated soybean oil with corn oil favorably affects a range of CVD risk factors and is an appropriate option to decrease cardiovascular disease risk factors in moderately hypercholesterolemic individuals.
41808835
Small Dense Low-Density Lipoprotein Concentration and Oxidative Susceptibility Changes after Consumption of Soybean Oil, Rice Bran Oil, Palm Oil and Mixed Rice Bran/Palm Oil in Hypercholesterolaemic Women
The effects of a diet containing soybean oil (SBO), rice bran oil (RBO), palm oil (PO) or a RBO/PO (3:1) mixture on the composition and oxidation of small dense low-density lipoproteins (sdLDL) in 16 hypercholesterolaemic women were investigated. During the 8-week control period, participants consumed a free-choice weight-maintaining diet comprising carbohydrate (55% energy), protein (15% energy) and fat (30% energy) with < 300 mg/day of cholesterol. During each 10-week study period, participants consumed this same diet but with the addition of one of the three test oils or the RBO/PO mixture. Total cholesterol and low-density lipoprotein (LDL)-cholesterol levels were significantly reduced during SBO, RBO and RBO/PO consumption, while high-density lipoprotein cholesterol was significantly decreased by SBO consumption. There was a significant reduction in sdLDL-cholesterol levels only after using SBO and it tended to be reduced during RBO/PO consumption, whereas it was significantly increased following PO consumption. The sdLDL oxidation lag time was significantly increased during PO, RBO/PO and RBO consumption, but significantly reduced following SBO. The results for the RBO/PO mixture suggest that this oil mixture might further reduce the risk of atherosclerosis.
20294859
Effects of a low-calorie diet associated with weight loss on lipoprotein-associated phospholipase A2 (Lp-PLA2) activity in healthy obese women.
INTRODUCTION
Platelet-activating factor acetylhydrolase (PAF-AH or Lp-PLA(2)) is a Ca(2+)-independent phospholipase A(2) primarily associated in plasma with low density lipoproteins (LDL), especially with small dense LDL (sdLDL) particles. Increased plasma Lp-PLA(2) levels have been associated with increased cardiovascular risk in large clinical trials.


AIM
To assess the effects of weight loss on Lp-PLA(2) activity and to examine the association of Lp-PLA(2) activity changes with the alterations of sdLDL, the primary carrier of Lp-PLA(2) in plasma.


METHODS
Twenty-eight obese, non-diabetic women participated in a weight reduction program. Anthropometric parameters were assessed and parameters of glucose metabolism, lipid profile, Lp-PLA(2) activity, and LDL phenotype (using a 3% polyacrylamide gel-tube electrophoresis method), were determined at baseline and after 4months of weight loss.


RESULTS
A 10% diet-induced weight loss resulted in significant improvement in most parameters of lipid and glucose metabolism. Moreover, Lp-PLA(2) activity was significantly reduced (-10.2%, p<0.01). Mean LDL particle diameter did not change after the weight loss program. The cholesterol levels of very low-density lipoprotein (VLDL) and large-buoyant LDL particles were significantly reduced, but neither the cholesterol levels of sdLDL particles nor the % proportion of the sdLDL-cholesterol over the total LDL-cholesterol were changed after the intervention program. Interestingly, the changes in Lp-PLA(2) activity were correlated with the changes of VLDL-cholesterol (r=0.39, p<0.05), but not with the changes of anthropometric or other lipid variables.


CONCLUSIONS
A low-calorie diet associated with weight loss in obese women resulted in the significant reduction of the plasma levels of Lp-PLA(2), the potentially new predictor for incident atherosclerotic disease.
30892626
Influence of alpha-linolenic acid and fish-oil on markers of cardiovascular risk in subjects with an atherogenic lipoprotein phenotype.
We tested the hypothesis that dietary alpha-linolenic acid (ALA) can exert effects on markers of cardiovascular risk similar to that produced by its longer chain counterparts in fish-oil. A dietary intervention study was undertaken to examine the effects of an ALA-enriched diet in 57 men expressing an atherogenic lipoprotein phenotype (ALP). Subjects were randomly assigned to one of three diets enriched either with flaxseed oil (FXO: high ALA, n = 21), sunflower oil (SO: high linoleic acid, n = 17), or SO with fish-oil (SOF n = 19) for 12 weeks, resulting in dietary intake ratios of n-6:n-3 PUFA of 0.5, 27.9 and 5.2, respectively. The relative abundance of ALA and EPA in erythrocyte membranes increased on the FXO diet (p < 0.001), whereas both EPA and DHA increased after fish-oil (p < 0.001). There were significant decreases in total plasma cholesterol within (FXO -12.3%, p = 0.001; SOF -7.6%, p = 0.014; SO -7.3%, p = 0.033) and between diets (p = 0.019), and decreases within diets after 12 weeks for HDL cholesterol on flaxseed oil (FXO -10%, p=0.009), plasma TG (-23%, p < 0.001) and small, dense LDL (-22% p = 0.003) in fish-oil. Membrane DHA levels were inversely associated with the changes in plasma TG ( p= 0.001) and small, dense LDL (p<0.05) after fish-oil. In conclusion, fish-oil produced predictable changes in plasma lipids and small, dense LDL (sdLDL) that were not reproduced by the ALA-enriched diet. Membrane DHA levels appeared to be an important determinant of these fish-oil-induced effects.
535732
Different modalities of exercise to reduce visceral fat mass and cardiovascular risk in metabolic syndrome: the RESOLVE randomized trial.
BACKGROUND
Opinions differ over the exercise modalities that best limit cardiovascular risk (CVR) resulting from visceral obesity in individuals with metabolic syndrome (MetS). As little is known about the combined effects of resistance and endurance training at high volumes under sound nutritional conditions, we aimed to analyze the impact of various intensities of physical activity on visceral fat and CVR in individuals with MetS.


METHODS
100 participants, aged 50-70 years, underwent a diet restriction (protein intake 1.2g/kg/day) with a high exercise volume (15-20 h/week). They were randomized to three training groups: moderate-resistance-moderate-endurance (re), high-resistance-moderate-endurance (Re), or moderate-resistance-high-endurance (rE). A one-year at-home follow-up (M12) commenced with a three-week residential program (Day 0 to Day 21). We measured the change in visceral fat and body composition by DXA, MetS parameters, fitness, the Framingham score and carotid-intima-media-thickness.


RESULTS
78 participants completed the program. At D21, visceral fat loss was highest in Re (-18%, p<.0001) and higher in rE than re (-12% vs. -7%, p<.0001). Similarly, from M3, visceral fat decreased more in high-intensity-groups to reach a visceral fat loss of -21.5% (Re) and -21.1% (rE)>-13.0% (re) at M12 (p<.001). CVR, MetS parameters and fitness improved in all groups. Visceral fat loss correlated with changes in MetS parameters.


CONCLUSION
Increased intensity in high volume training is efficient in improving visceral fat loss and carotid-intima-media-thickness, and is realistic in community dwelling, moderately obese individuals. High-intensity-resistance training induced a faster visceral fat loss, and thus the potential of resistance training should not be undervalued (ClinicalTrials.gov number: NCT00917917).
33352640
Role of plasma triglyceride in the regulation of plasma low density lipoprotein (LDL) subfractions: relative contribution of small, dense LDL to coronary heart disease risk.
The concentration of plasma LDL subfractions is described in four groups of normocholesterolaemic (total plasma cholesterol < 6.5 mmol/l) male subjects consisting of men with and without coronary artery disease (CAD+/-), as determined by angiography, post-myocardial infarct survivors (PMI) and normal, healthy controls. The CAD(+) and PMI groups were distinguished from the CAD(-) and controls by raised concentrations of plasma triglyceride, very low density lipoprotein (VLDL) cholesterol, small, dense LDL (LDL-III density (d) 1.044-1.060 g/ml) and lower concentrations of high density lipoprotein (HDL) cholesterol and large, buoyant LDL (LDL-I d 1.025-1.034 g/ml). In all groups, a subfraction of intermediate density, LDL-II (d 1.034-1.044 g/ml), was the predominant LDL species but was not related to coronary heart disease risk. Plasma triglyceride showed a positive association with LDL-II (r = 0.51, P < 0.001) below a triglyceride level of 1.5 mmol/l. Above this threshold of 1.5 mmol/l, LDL-II and LDL-I showed significant negative associations with triglyceride (LDL-II r = -0.5, P < 0.001; LDL-I r = -0.45, P < 0.001). Small, dense LDL-III showed a weak positive association with triglyceride that became highly significant above the 1.5 mmol/l threshold (r = 0.54, P < 0.001). While age was positively related to LDL-II within the control subjects (r = 0.3, P < 0.05), there was no difference in the percentage abundance or concentration of LDL-III within control and CAD(-) subjects above and below the age of 40 years. Smoking was associated with a relative deficiency of the LDL-I subfraction (LDL-I to LDL-III ratio in smokers = 0.77, in ex-smokers = 0.95, in non-smokers = 1.89; P < 0.01), as was beta-blocker medication (% LDL-I, users vs. non-users, P < 0.05). Both of these effects could be explained by their primary influence on plasma triglyceride. Analysis of the frequency distributions for the three LDL subfractions revealed the concentration of small, dense LDL-III to be bimodal around a concentration of 100 mg (lipoprotein mass)/100 ml plasma. The calculation of odds ratios based on this figure indicated relative risk estimates of 4.5 (chi 2: P < 0.01) for the presence of coronary artery disease and 6.9 (chi 2: P < 0.001) for myocardial infarction.(ABSTRACT TRUNCATED AT 400 WORDS)
19803644
Investigation of low density lipoprotein subfractions as a coronary risk factor in normotriglyceridaemic men.
There is an increasing interest in low density lipoprotein (LDL) subfractions since some of them are associated with a higher risk for coronary artery disease (CAD). Small LDL particles are particularly atherogenic and more of those are produced in hypertriglyceridaemia. However, high triglyceride concentrations are not the only explanation for the predominance of small LDL particles and other influences, including genetic factors, are also responsible for LDL particle size. We investigated LDL subfraction profiles in two groups: 46 men with and 21 men without CAD proven angiographically. For the separation of LDL subfractions, we used continuous disc polyacrylamide gel electrophoresis (PAGE) that is rapid and easier to perform than the other methods usually used which, although more precise in terms of measuring particle diameter, are much more demanding of time and equipment. The described method is suitable for routine use in assessing large numbers of patients. All studied men had triglyceride concentrations below 2.3 mmol/l. LDL scores were calculated on the basis of all LDL subfractions present in a particular profile; the higher the score, the greater the proportion of small LDL particles. LDL cholesterol (P < 0.05) and LDL score (P < 0.001) were the only significant discriminators between two groups. LDL score was significantly correlated with CAD, even after adjusting for triglyceride and HDL cholesterol concentrations and it was the best discriminant factor for the presence of CAD.
17074056
Comparison of effects of diet versus exercise weight loss regimens on LDL and HDL particle size in obese adults
BackgroundObesity is associated with an atherogenic lipid profile characterized by a predominance of small LDL and HDL particles. Weight loss, by dietary restriction or exercise, increases LDL particle size. Whether these interventions can augment HDL size in conjunction with LDL size remains unknown.ObjectiveThis study compared the effects of alternate day fasting (ADF), calorie restriction (CR), and endurance exercise on LDL and HDL particle size in overweight and obese subjects.MethodsIn a 12-week parallel-arm trial, adult subjects (n = 60) were randomized to 1 of 4 groups: 1) ADF (75% energy restriction for 24-h alternated with ad libitum feeding for 24-h), 2) CR (25% energy restriction every day), 3) exercise (moderate intensity training 3 x/week), or 4) control.ResultsBody weight was reduced (P < 0.001) by ADF, CR, and exercise (5.2 ± 1.1%, 5.0 ± 1.4%, 5.1 ± 0.9%, respectively). Plasma LDL cholesterol decreased (P < 0.05) with ADF (10 ± 4%) and CR (8 ± 4%), whereas HDL cholesterol increased (P < 0.05) with exercise (16 ± 5%). Integrated LDL particle size was augmented (P = 0.01) by ADF and CR. The proportion of small LDL particles decreased (P = 0.04) with ADF only, and the proportion of large HDL particles increased (P = 0.03) with exercise only.ConclusionThese results indicate that dietary restriction increases LDL particle size, while endurance training augments HDL particle size, with minimal weight loss. None of these interventions concomitantly increased both LDL and HDL particle size, however.
27016302
Relationships between exercise-induced reductions in thigh intermuscular adipose tissue, changes in lipoprotein particle size, and visceral adiposity.
Small LDL and HDL particle size are characteristic of a proatherogenic lipoprotein profile. Aerobic exercise increases these particle sizes. Although visceral adipose tissue (VAT) has been strongly linked with dyslipidemia, the importance of intermuscular adipose tissue (IMAT) to dyslipidemia and exercise responses is less well understood. We measured exercise-associated changes in thigh IMAT and VAT and examined their relationships with changes in LDL and HDL particle size. Sedentary, dyslipidemic, overweight subjects (n = 73) completed 8-9 mo of aerobic training. Linear regression models were used to compare the power of IMAT change and VAT change to predict lipoprotein size changes. In men alone (n = 40), IMAT change correlated inversely with both HDL size change (r = -0.42, P = 0.007) and LDL size change (r = -0.52, P < 0.001). That is, reduction of IMAT was associated with a shift toward larger, less atherogenic lipoprotein particles. No significant correlations were observed in women. After adding VAT change to the model, IMAT change was the only significant predictor of either HDL size change (P = 0.034 for IMAT vs. 0.162 for VAT) or LDL size change (P = 0.004 for IMAT vs. 0.189 for VAT) in men. In conclusion, in overweight dyslipidemic men, exercise-associated change in thigh IMAT was inversely correlated with both HDL and LDL size change and was more predictive of these lipoprotein changes than was change in VAT. Reducing IMAT through aerobic exercise may be functionally related to some improvements in atherogenic dyslipidemia in men.
9930265
Effects of supervised aerobic exercise training on serum adiponectin and parameters of lipid and glucose metabolism in subjects with moderate dyslipidemia.
AIM
To examine the effects of supervised aerobic exercise training on serum adiponectin and lipids, including triglyceride (TG)-rich lipoproteins, in moderate dyslipidemic subjects.


METHODS
Twenty-five dyslipidemic patients [mean body mass index (BMI)=24.6 kg/m²; mean age= 39 years; mean total cholesterol=226 mg/dL; mean TG=149 mg/dL] without metabolic syndrome, diabetes, and hypertension underwent supervised aerobic exercise training (60 min/day, 2 to 3 times/week) at an intensity of 60-80% of age-predicted maximal heart rate for 16 weeks. Lipoprotein cholesterol levels were measured by our established anion-exchange HPLC method.


RESULTS
Aerobic exercise training significantly decreased BMI, cholesterol levels of LDL- and IDL-, and markedly reduced VLDL-cholesterol at week 8 (-45%) and week 16 (-50%), but changes in TG and HDL-cholesterol were not significant. Adiponectin significantly increased by 51% and HOMA-R was significantly decreased at week 16, although changes in these parameters were not significant at week 8. There was no significant relationship between changes in adiponectin and in VLDL- or IDL- cholesterol, but changes in adiponectin were inversely but insignificantly associated with changes in BMI (r=-0.343, p=0.095).


CONCLUSIONS
These results suggest that supervised aerobic exercise training two to three times/week in the presence of body weight loss increases serum adiponectin with an improved lipid profile and insulin sensitivity at week 16 in non-obese moderate dyslipidemic patients, and that VLDL-cholesterol is markedly decreased by supervised aerobic exercise training.
39088575
Predominance of large VLDL particles in metabolic syndrome, detected by size exclusion liquid chromatography.
OBJECTIVE
To study size heterogeneity of triglyceride rich lipoproteins (TRL) in metabolic syndrome (MS).


DESIGN AND METHODS
Thirty MS patients and 14 healthy subjects were included. In fasting serum we measured: lipid profile, free fatty acids (FFA) and adiponectin; TRL were isolated (d<1.006 g/mL) and analysis by size exclusion HPLC followed by UV detection was performed; each subfraction was expressed as percentage of total TRL.


RESULTS
MS patients, even those with normal triglycerides, presented higher proportion of very large VLDL (90 nm diameter) and large VLDL (60 nm) and slightly lower of typical VLDL (37 nm) (p<0.04); increased FFA (p=0.04) and lower adiponectin (p=0.001). FFA correlated with large VLDL% (r=0.58; p=0.003), independently of insulin-resistance and waist. Furthermore, the lower the adiponectin, the greater the predominance of large VLDL (r=-0.40; p=0.04).


CONCLUSION
MS was associated with large VLDL, described as more atherogenic beyond triglyceride levels. Size exclusion HPLC would represent a useful tool for assessing subfractions' lipoprotein profile.
2052591
Effects of Electronegative VLDL on Endothelium Damage in Metabolic Syndrome
OBJECTIVE Biochemical heterogeneity governs functional disparities among lipoproteins. We examined charge-defined VLDL subfractions in metabolic syndrome (MetS) to determine whether their increased electronegativity is associated with increased cytotoxicity and whether high concentrations of highly electronegative subfractions render VLDL harmful to the vascular endothelium. RESEARCH DESIGN AND METHODS Plasma VLDL of normal individuals (control subjects) (n = 13) and of those with MetS (n = 13) was resolved into subfractions with increasing negative charge (V1–V5) by anion-exchange chromatography. Human aortic endothelial cells were treated with V1–V5 or unfractionated VLDL. RESULTS Compared with the control subjects, individuals with MetS had a significantly higher percentage of V5 VLDL (V5/VLDL%) (34 ± 20 vs. 39 ± 11%, respectively; P < 0.05) and plasma V5 concentration ([V5]) (5.5 ± 4.4 vs. 15.2 ± 8.5 mg/dL, respectively; P < 0.001). Apolipoprotein (apo)B100 levels decreased and apoC levels increased from V1 to V5, indicating that V5 is apoC-rich VLDL. Regression analyses of all 26 individuals showed that [V5] was positively correlated with total cholesterol (P = 0.016), triglyceride (P < 0.000001), and V5/VLDL% (P = 0.002). Fasting plasma glucose, but not waist circumference, exhibited a positive trend (P = 0.058); plasma HDL cholesterol exhibited a weak inverse trend (P = 0.138). V5 (10 μg/mL) induced apoptosis in ~50% of endothelial cells in 24 h. V5 was the most rapidly (<15 min) internalized subfraction and induced the production of reactive oxygen species (ROS) in endothelial cells after 20 min. Unfractionated MetS VLDL, but not control VLDL, also induced ROS production and endothelial cell apoptosis. CONCLUSIONS In populations with increased risk of diabetes, the vascular endothelium is constantly exposed to VLDL that contains a high proportion of V5. The potential impact of V5-rich VLDL warrants further investigation.
23912592
Vascular reactivity at rest and during exercise in middle-aged obese men: effects of short-term, low-intensity, exercise training
Objective:Although increased blood flow (BF) in exercising muscles is thought to be impaired in obese subjects and may contribute to physical inactivity, data are scarce in this regard and the involvement of endothelium dysfunction remains partly hypothetical.Methods:A total of 16 middle-aged obese men (body mass index, BMI⩾30 kg m−2) and 16 normal-weight men (BMI<25 kg m−2), matched for age, were recruited. We used ultrasonography to compare intima-media thickness (IMT) and distensibility of the carotid artery, flow-mediated dilation (FMD), nitrate-dependent dilation (NDD) and peak BF during post-ischemic hyperemia in the brachial artery (a conduit artery), and leg BF during knee-extensor exercise (indicative of resistance vessel function) in obese and in normal-weight men. In addition, 10 obese men participated in an 8 week individualized low-intensity training program.Results:Compared with normal-weight men, obese men had higher carotid IMT (0.50±0.01 vs 0.62±0.04 mm, P<0.05) but lower carotid distensibility (0.26±0.03 vs 0.11±0.03 mm Hg−1 10−2, P<0.05), FMD (5.7±0.4 vs 3.3±0.5%, P<0.05) and peak BF during post-ischemic hyperemia (398±52 vs 229±24%, P<0.05), despite similar maximal shear rate, without NDD differences. Lower limb BF (ml min−1 100 g−1) increased significantly from rest to maximal exercise in both groups with lower values in obese men (at peak power, 36.9±1.6 vs 31.5+2.2 ml min−1 100 g−1, P<0.05). Exercise training normalized carotid distensibility (0.14±0.04 before vs 0.23±0.03 mm Hg−1 10−2 after training, P=0.09) and FMD (2.7±0.4 before vs 4.8±0.5% after training, P<0.05), but did not improve brachial post-ischemic peak BF or exercising leg BF.Conclusions:In obese men, conduit and resistance vessel reactivity is depressed, but a short-term low-intensity exercise training improves distensibility and endothelium dependent vasodilation in the large conduit artery, but not post ischemic or exercise muscle BF.
40159280
Correlation between glucose fluctuations and carotid intima-media thickness in type 2 diabetes.
AIMS
To evaluate the relationship between blood glucose fluctuations and carotid atherosclerosis (AS) in type 2 diabetic patients.


METHODS
A case-control study included 36 patients with type 2 diabetes and 10 controls. According to the levels of carotid intima-media thickness (CIMT), 36 diabetic patients were classified into two groups, the diabetes mellitus without atherosclerosis (DM-AS, n=20) and diabetes mellitus with atherosclerosis (DM+AS, n=16). The glucose excursions were assessed by the following parameters obtained from continuous glucose monitoring system for 72h: the mean blood glucose (MBG) and its standard deviation (SD), the area under the ROC curve when the blood glucose was higher than 7.8mmol/L (AUC7.8), the mean amplitude of glycemic excursion (MAGE), the mean of daily differences (MODD), and the largest amplitude of glycemic excursion (LAGE).


RESULTS
The levels of MBG, SD, MAGE, LAGE, and AUC7.8 were gradually increased with the progression of atherosclerosis (P<0.05). The Spearman's correlation analysis showed that the CIMT was correlated to the age (R=0.58, P<0.001), the duration (R=0.50, P<0.001), the MAGE (R=0.34, P=0.021), and the LAGE (R=0.31, P=0.035).


CONCLUSION
These results suggest that glucose fluctuations may accelerate atherogenesis in older type 2 diabetic patients who had a longer duration.
19441583
Small dense low-density lipoprotein in familial combined hyperlipidemia: Independent of metabolic syndrome and related to history of cardiovascular events.
INTRODUCTION
It is unclear whether small dense low-density lipoprotein (sdLDL) are associated with familial combined hyperlipidemia (FCHL), independently of the metabolic syndrome (MS). It is also unclear whether sdLDL are related to history of cardiovascular (CVD) events in FCHL patients, independently of MS.


PATIENTS AND METHODS
Serum levels of sdLDL, expressed as percentage of total LDL cholesterol (LDL score), were determined in 137 probands with FCHL and in 133 normolipidemic, normotensive, normoglycemic healthy subjects.


RESULTS
In binary logistic regression age- and gender-adjusted LDL score values above the 90th and 95th percentiles of the values in the control group (10.23 and 13.11%, respectively) were found to be significant predictors of FCHL status, independently of MS diagnosis (p=0.007 and p<0.0001, respectively). Values of the LDL score above the 90th and the 95th percentile of the control group resulted to be significantly related to FCHL status, even after adjustment for the components of MS (p=0.006 and p=0.001, respectively). Among FCHL patients, values of the LDL score above 95th percentile of the values in the control group were found to be significantly related to personal and/or family history of CVD events, independently of age, gender, total cholesterol, apolipoprotein (apo) B, and MS status (p=0.016). The same significant relationship was found adjusting for all components of MS (p=0.034).


CONCLUSIONS
High concentrations of sdLDL are highly specific markers of FCHL, independently of concomitant MS. In FCHL patients high levels of sdLDL are related to history of CVD events, independently of MS, total cholesterol and apo B.
12545334
High pre-beta1 HDL concentrations and low lecithin: cholesterol acyltransferase activities are strong positive risk markers for ischemic heart disease and independent of HDL-cholesterol.
BACKGROUND
We hypothesized that patients with high HDL-cholesterol (HDL-C) and ischemic heart disease (IHD) may have dysfunctional HDL or unrecognized nonconventional risk factors.


METHODS
Individuals with IHD (Copenhagen University Hospital) and either high HDL-C (n = 53; women >or=735 mg/L; men >or=619 mg/L) or low HDL-C (n = 42; women <or=387 mg/L; men <or=341 mg/L) were compared with individuals without IHD (Copenhagen City Heart Study) matched by age, sex, and HDL-C concentrations (n = 110). All participants had concentrations within reference intervals for LDL-C (<1600 mg/L) and triglyceride (<1500 mg/L), and none were treated with lipid-lowering medications. Pre-beta(1) HDL and phospholipid transfer protein concentrations were measured by using commercial kits and lecithin:cholesterol acyltransferase (LCAT) activity by using a proteoliposome cholesterol esterification assay.


RESULTS
Pre-beta(1) HDL concentrations were 2-fold higher in individuals with IHD vs no IHD in both the high [63 (5.7) vs 35 (2.3) mg/L; P < 0.0001] and low HDL-C [49 (5.0) vs 27 (1.5) mg/L; P = 0.001] groups. Low LCAT activity was also associated with IHD in the high [95.2 (6.7) vs 123.0 (5.3) micromol x L(-1) x h(-1); P = 0.002] and low [93.4 (8.3) vs 113.5 (4.9) micromol x L(-1) . h(-1); P = 0.03] HDL-C groups. ROC curves for pre-beta(1) HDL in the high-HDL-C groups yielded an area under the curve of 0.71 (95% CI: 0.61-0.81) for predicting IHD, which increased to 0.92 (0.87-0.97) when LCAT was included. Similar results were obtained for low HDL-C groups. An inverse correlation between LCAT activity and pre-beta(1) HDL was observed (r(2) = 0.30; P < 0.0001) in IHD participants, which was stronger in the low HDL-C group (r(2) = 0.56; P < 0.0001).


CONCLUSIONS
IHD was associated with high pre-beta(1) HDL concentrations and low LCAT levels, yielding correct classification in more than 90% of the IHD cases for which both were measured, thus making pre-beta(1) HDL concentration and LCAT activity level potentially useful diagnostic markers for cardiovascular disease.