Prevalence and Risk Factors of Elevated Alanine Aminotransferase among Korean Adolescents: 2001-2014

Abstract

Introduction: An elevated alanine aminotransferase (ALT) level is a surrogate marker of non-alcoholic fatty liver disease (NAFLD), the most common liver disorder in adolescents. The majority of previous NAFLD studies in adolescents were performed in selected obese populations or had a cross-sectional design without a time-trend analysis. The purpose of this study was to estimate the prevalence and time trends of elevated ALT levels in a general adolescent population and to identify factors associated with ALT elevation. Methods: We analysed data on adolescent participants (aged 10–18 years) in the Korean National Health and Nutrition Examination Survey 2001–2014, a representative sample of the general population in South Korea. Suspected NAFLD was defined by ALT elevation (>30 U/L) without hepatitis B surface antigen. In all the statistical analyses, sampling weight- and design-based data were used. Results: ALT was elevated in 5.3% (standard error: 0.3%) of the study population of adolescent participants (N=8455). No significant trends were found from 2001-2014 in the prevalence of elevated ALT among male and female adolescents. In the multiple logistic regression analysis, elevated ALT was independently associated with sex (odds ratio [OR] male versus female 4.5

95% CI, 3.3-6.2), obesity (OR 7.6

95% CI, 5.3-11.0), and truncal obesity (OR 2.5

95% CI, 1.8-3.5). Furthermore, male sex, obesity, truncal obesity and high household income level were associated with log transformed ALT levels in multiple regression analysis. Conclusions: In Korean adolescents, the prevalence of elevated ALT levels was stable from 2001 to 2014 in adolescents of both genders. This study revealed that sex, obesity, truncal obesity and household income level are associated with paediatric NAFLD.