Prevalence and Predictors of Suspected Metabolic Dysfunction-Associated Steatotic Liver Disease in Adolescents in the United States.

Background: Nomenclature for steatotic liver disease has been updated to include metabolic dysfunction-associated steatotic liver disease (MASLD), which requires the presence of hepatic steatosis and at least one cardiometabolic risk factor. The prevalence of MASLD in adolescents is understudied.

Aim: To determine the prevalence of suspected MASLD among adolescents in the United States and to examine the relationships between elevated alanine aminotransferase (ALT) and cardiometabolic risk factors.

Methods: A cross-sectional analysis of the National Health and Nutrition Examination Survey from 2011 to 2020 was conducted for adolescents aged 12-19 years. Elevated ALT was defined using sex-specific biological upper limits: > 26 U/L for males and > 22 U/L for females. Suspected MASLD was identified by elevated ALT and at least one cardiometabolic risk factor. Adolescents with elevated ALT were categorised as having suspected MASLD, elevated ALT due to other causes or cryptogenic ALT elevation.

Results: Overall, 14.6% of adolescents had elevated ALT. Of these, 77.2% had suspected MASLD, 20.2% had cryptogenic ALT elevation, 1.9% took hepatotoxic medications and 0.7% had viral hepatitis. Body mass index had the strongest association with elevated ALT (OR 3.55), followed by high triglycerides (OR 2.09), low HDL cholesterol (OR 2.05) and high blood pressure (OR 1.93).

Conclusions: Most adolescents with elevated ALT met MASLD criteria, yet a portion lacked cardiometabolic risk factors or other identifiable causes. These results support the adoption of MASLD criteria in adolescents while indicating a need for further research into cryptogenic ALT elevation in paediatric populations.