Prevalence of Suspected Nonalcoholic Fatty Liver Disease in Lean Adolescents in the United States

Objectives: Nonalcoholic fatty liver disease (NAFLD) can develop in lean subjects referred to as lean NAFLD. We aim to evaluate the prevalence and risk factors of NAFLD in lean adolescents in the United States (US). Methods: Cross sectional data from 1482 lean subjects (body mass index <85th percentile) ages between 12 and 18 years, who were enrolled in the National Health and Examination Survey during the 2005 to 2014 cycles were included. We defined suspected NAFLD as alanine aminotransferase >25.8 U/L for boys and >22.1 U/L for girls; hypertriglyceridemia as triglycerides ≥150 mg/dL; low HDL as HDL <40 mg/dL and insulin resistance (IR) as homeostatic model assessment of IR ≥3. Results: The mean weighted prevalence of suspected NAFLD among lean adolescents during 2005 to 2014 cycles was 8% (95% CI 6.2-9.9). Lean subjects with suspected NAFLD were significantly older compared with lean non-NAFLD subjects (15.5 vs 15 years, P value <0.05). Low HDL (15.5% vs 6.8%; P value 0.016) and hypertriglyceridemia (10% vs 3.9%; P value 0.028) were also found to be more common among lean NAFLD subjects compared with their non-NAFLD counterparts. Presence of IR increased the risk of having suspected NAFLD by 4-fold among lean adolescents. Non-Hispanic black lean adolescents were less likely to have suspected NAFLD compared with non-Hispanic white lean adolescents. Conclusions: The estimated prevalence of suspected NAFLD among lean adolescents in the US was found to be 8% with evidence of metabolic derangements such as low HDL, hypertriglyceridemia, and IR.