Associations of uric acid and gamma-glutamyltransferase (GGT) with obesity and components of metabolic syndrome in children and adolescents.

Summary What is already known about this subject Associations between concentrations of uric acid and cardiovascular risk factors are known. The associations between gamma-glutamyltransferase (GGT) levels and cardiovascular disease are also known. But no study has ever investigated the combined effects of both GGT and uric acid in cardiovascular risk factors in adolescents. What this study adds Our study is the first to date reporting a significant combined effect of uric acid and GGT in association with cardiovascular risk factors in the youth populations. The results of our study add to our knowledge regarding the relationship between uric acid, GGT and cardiovascular risk factors. Based on our results, measurements of these biochemical markers should be considered in the cardiovascular risk stratification in children and adolescents. The results of our study also raise the alertness of clinicians in identifying at-risk young individuals for primary prevention of cardiovascular diseases. 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.