Association of fatty liver with serum gamma-glutamyltransferase and uric acid in obese children in a tertiary care centre.

Abstract

Background: Obesity among the young is an emerging health problem with many metabolic changes including liver damage. Our objective was to investigate the association of fatty liver with serum uric acid (UA) and gamma-glutamyltransferase (GGT) in a cohort of obese children in Sri Lanka.

Methods: A cross-sectional analytical study was conducted among 5-15-year-old obese children (based on WHO 2007 standards). After a 12-hour overnight fast, blood was drawn for glucose, lipid profile, alanine aminotransferase (ALT), aspartate aminotransferase (AST), insulin, UA and GGT. Height, weight, waist circumference, blood pressure and fat mass were measured. Ultrasound scan of abdomen was performed to determine fatty liver.

Results: We studied 146 obese children with a mean age (SD) 9.86 (2.1) years. The fatty liver group showed significantly elevated levels (p < 0.05) of UA, oral glucose tolerance test (OGTT), triglycerides (TG), AST, ALT, GGT, insulin resistance (HOMA-IR) and a reduced AST/ALT ratio, compared to the non-fatty liver group. Chi square test showed statistically significant associations between fatty liver and AST, ALT, AST/ALT ratio, HOMA-IR, UA and GGT. With existing cut offs, GGT (> 30 U/L) and UA (> 330 µmol/L) the sensitivity and specificity of GGT in predicting fatty liver was 26.9% and 94.1% respectively while for UA it was 38.5% and 83.8% respectively. A cut-off value of 18.5 U/L (sensitivity 76.9% and specificity 52.9%) for GGT, 277µmol/L (sensitivity 70.5% and specificity 57.4%) for UA, 27.5 U/L (sensitivity 70.5%, specificity 51.5%) for AST, 21.5 U/L (sensitivity 80.8% and specificity 61.8%) for ALT, a ratio of 0.99 (sensitivity 77.9% and specificity 55.1%) for AST/ALT and 2.02 (sensitivity 73.2%, specificity 58.5%) for HOMA-IR predicted fatty liver.

Conclusion: GGT and UA are associated with fatty liver and these biomarkers can be used to predict fatty liver disease.