Prevalence, clinical & biochemical correlates of non-alcoholic fatty liver disease in overweight adolescents

Background & objectives: Non-alcoholic fatty liver disease (NAFLD) characterized by excessive accumulation of fat in the liver, which can progress to inflammation, and cirrhosis, has emerged as an important complication of obesity in adults as well as children. This study was undertaken to assess the prevalence of NAFLD and its correlation with clinical and biochemical parameters in overweight Indian adolescents. Methods: In this cross-sectional study, 218 overweight adolescents aged 10 to 16 yr and their parents were included. Measurements included anthropometry, ultrasonography to diagnose NAFLD, fasting glucose, aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lipids for adolescents and parents, and additional parameters of blood pressure, body fat percentage (BF%), fasting insulin, apolipoprotein C3, tumour necrosis factor-alpha and adiponectin for adolescents. The variables were compared between adolescents with and without NAFLD, and logistic regression analysis was performed. Results: Mean age and body mass index (BMI)SD score (SDS) were 11.9 +/- 1.6 yr and 2.3 +/- 1.1, respectively. NAFLD was seen in 62.5 per cent of the adolescents. The prevalence of NAFLD in the parents was similar among the adolescents with and without NAFLD, while BMI and waist circumference SDS, BF per cent, blood pressure (BP), ALT, AST, insulin and homeostatic model assessment of insulin resistance (HOMA-IR) were significantly higher in the adolescents with NAFLD. On multiple logistic regression, abdominal obesity, HOMA-IR and BF per cent were independently associated with NAFLD with odds ratios (95% confidence interval) of 2.77 (1.40-5.47), 2.21 (1.16-4.21) and 2.17 (1.12-4.22), respectively. Interpretation & conclusions: NAFLD was noted among nearly two-thirds of the overweight adolescents. An independent association was observed between abdominal obesity, HOMA-IR and body fat percentage and NAFLD in overweight adolescents.