Association of Serum Uric acid and Gamma-glutamyltransferase with Obesity Related Metabolic Derangements in a Cohort of Children with Obesity in Sri Lanka

Introduction: Gamma-glutamyltransferase (GGT) and serum uric acid (UA) are known to be associated with cardiovascular disease in obese children. Objectives: To determine the association of serum UA and GGT with components of metabolic syndrome (MetS) in a group of obese children and determine the validity of UA and GGT in predicting MetS. Methods: Cross sectional analytical study was conducted among 205, 5-15 year old obese children. After a 12- hour overnight fast, blood was drawn for glucose, lipid profile, alanine aminotransferase (ALT), aspartate aminotransferase (AST), insulin, UA and GGT. Oral glucose tolerance test (OGTT) was done with 2 hour plasma glucose. Height, weight, waist circumference, blood pressure and fat mass were measured. USS of abdomen was performed to assess hepatic steatosis. Results: Chi square test showed statistically significant associations between GGT and UA with triglyceride, insulin resistance (HOMA-IR), AST, ALT, AST/ALT ratio and fatty liver. Additionally UA showed a significant association with the OGTT. With existing cut offs (GGT >30 U/L and UA >330 μmol/L) the sensitivity and specificity of GGT in predicting MetS was 19% (95% CI, 13.63-24.37) and 88.4% (95% CI, 84.02-92.78) respectively while for UA was 28.6% (95% CI, 22.42-34.78) and 80.2% (95% CI, 74.75-85.65) respectively. A new cut off value of 19.5 U/L (sensitivity 56% and specificity 55%) for GGT and 275.5 μmol/L (sensitivity 61% and specificity 54%) for UA predicted MetS with greater accuracy. Conclusion: GGT and UA are strongly associated with metabolic derangements and these biomarkers are rather weak in predicting MetS