Rheumatoid arthritis is associated with increased cardiovascular morbidity and mortality. We performed a systematic review of the literature and a meta-analysis to look for differences in the prevalence of traditional cardiovascular risk factor between RA patients and controls.
Medline database was searched to identify studies evaluating the prevalence of traditional cardiovascular risk factors in rheumatoid arthritis patients and controls. Studies were selected and reviewed by two investigators. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated and pooled using a random-effects model. Statistical heterogeneity was evaluated through the use of Chi2 and I2 statistics.
Fifteen case-control studies with a total of 2956 patients and 3713 controls met the inclusion criteria. The prevalence of smoking was increased in RA patients in comparison with controls: OR (95%CI) 1.56 (1.35-1.80) (P < 0.00001). The prevalence of hypertension did not differ: OR (95% CI) 1.09 (0.91-1.31) (P = 0.35). The prevalence of diabetes mellitus was increased in RA: OR (95%CI) 1.74 (1.22-2.50) (P = 0.003). The prevalence of hypercholesterolemia did not differ: OR (95%CI) 0.84 (0.67-1.04) (P = 0.11). HDL cholesterol levels were lower in RA patients: weighted mean difference -17.72 mg/dl (-18.35 - -17.08) (P < 0.00001). Significant heterogeneity among studies was found for diabetes mellitus and HDL cholesterol levels.
Some traditional cardiovascular risk factors, such as smoking, diabetes mellitus or lower HDL cholesterol levels, appear more prevalent in rheumatoid arthritis patients and could contribute to the increased cardiovascular morbidity and mortality observed in rheumatoid arthritis.