Background: Nonalcoholic fatty liver disease (NAFLD) is increasing at alarming rates in obese children. The study aim was to describe body composition/somatotype and its interrelationships to biomarkers of liver disease, insulin resistance, and lipid and cytokine expression in youth with NAFLD.
Methods: Somatotype and body composition of children (7-18 years) diagnosed with NAFLD (n= 18) were compared with obese (n = 11) and lean children (n = 17). Anthropometric variables assessed included weight, height, body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHTR), and multiple skinfold thicknesses. Fat mass (FM) and somatotype analysis were measured using validated methodologies. Fasting liver biochemistries (aspartate aminotransferase [AST], alanine aminotransferase [ALT], γ-glutamyltransferase [GGT]), insulin, glucose, leptin, C-reactive protein (CRP), tumor necrosis factor-α, interleukin (IL) factors 6/10, apolipoproteins B-100/B-48 and C-III, triglycerides, and high-density lipoprotein (HDL)/low-density lipoprotein (LDL) cholesterol were measured. Insulin resistance was assessed by the homeostasis model of insulin resistance (HOMA-IR).
Results: BMI z score, WC, FM, and somatotype did not differ between NAFLD and obese groups; however, lean children were lighter/leaner across all anthropometric measures (P < .001). Children with NAFLD had a higher sum-of-trunk to sum-of-extremity ratio (1.6 ± 0.4) than did obese (1.3 ± 0.2) and lean (1.1 ± 0.5) children (P < .001). Markers of central visceral (WC/WHTR) and subcutaneous fat (subscapular, abdominal, suprailiac skinfolds) were associated with elevated plasma concentrations of insulin, HOMA-IR, ALT, GGT, and AST and lower HDL cholesterol and IL-10 (P < .001).
Conclusion: Comprehensive assessment of body composition, including measurement of surrogate markers of subcutaneous and visceral fat, provides information regarding metabolic dysregulation and liver disease risk in obese children with NAFLD.