The impact of adolescent nonalcoholic fatty liver disease (NAFLD) on health, independent of fat mass, is unclear.
The objective of the study was to determine the independent (of total body fat) association of ultrasound scan (USS)-determined NAFLD with liver fibrosis, insulin resistance, and dyslipidemia among healthy adolescents.
One thousand eight hundred seventy-four (1059 female) individuals of a mean age of 17.9 years participated in the study.
USS assessed liver stiffness (shear velocity, an indicator of fibrosis) and volume, fasting glucose, insulin, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, alanine amino transferase, aspartate amino transferase, γ-glutamyltransferase, and haptoglobin.
The prevalence of NAFLD was 2.5% [95% confidence interval (CI) 1.8–3.3] and was the same in females and males. Dual-energy X-ray absorptiometry determined total body fat mass was strongly associated with USS NAFLD: odds ratio 3.15 (95% CI 2.44–4.07) per 1 SD (∼10 kg) fat mass. Those with NAFLD had larger liver volumes and greater shear velocity. They also had higher fasting glucose, insulin, triglycerides, low-density lipoprotein cholesterol, alanine amino transferase, aspartate amino transferase, γ-glutamyltransferase, and haptoglobin and lower high-density lipoprotein cholesterol. Most associations were independent of total body fat. For example, after adjustment for fat mass and other confounders, hepatic shear velocity [mean difference 22.8% (95% CI 15.6–30.5)], triglyceride levels [23.6% (95% CI 6.0–44.2)], and insulin [39.4% (95% CI 10.7–75.5)] were greater in those with NAFLD compared with those without NAFLD.