Associations of uric acid and gamma-glutamyltransferase (GGT) with obesity and components of metabolic syndrome in children and adolescents.
BACKGROUND
The combined effect of uric acid, gamma-glutamyltransferase (GGT) and cardiovascular risk factors clustering in the youth remains under-explored.


OBJECTIVE
The objective of this study was to examine the association between uric acid, GGT, obesity and the individual components of metabolic syndrome in children and adolescents.


METHODS
We performed a cross-sectional observational study of 2067 children and adolescents (875 boys and 1192 girls) aged 6-20 years who were healthy volunteers and were recruited from primary and secondary schools in Hong Kong between 2007 and 2008. Subjects were divided into two strata (75th percentile as cut-off) for comparison between odds of cardiovascular risk factors.


RESULTS
After adjustment by multivariable logistic regression, subjects in upper stratum, i.e., >75th percentile, of either serum uric acid or GGT levels were associated with obesity, low high-density lipoprotein cholesterol (HDL-C) level and high blood pressure (adjusted odds ratios [AOR] ranged from 1.63 to 5.82, all P < 0.005) compared with those in the lower stratum. There were combined effect for upper stratum of both uric acid and GGT in the association with obesity, low HDL-C and high blood pressure (AOR ranged from 2.60 to 10.69, all P < 0.05) after adjustment for age, sex and body mass index z-score (except for obesity status) as well as body height (for high blood pressure).


CONCLUSION
Uric acid and GGT have combined effect in association with obesity and other cardiovascular risk factors in children and adolescents.