Increasing prevalence of nonalcoholic fatty liver disease among United States adolescents, 1988-1994 to 2007-2010

Abstract

Objective: To assess recent trends in nonalcoholic fatty liver disease (NAFLD) prevalence among US adolescents.

Study design: Cross-sectional data from 12 714 12-19 year olds (exclusions: chronic hepatitis, hepatotoxic medications) in the National Health and Examination Survey between 1988-1994 and 2007-2010 were used to estimate trends in suspected NAFLD, defined as overweight (body mass index ≥85th percentile) plus elevated alanine aminotransferase levels (boys >25.8 U/L; girls >22.1 U/L). Linear trends in prevalence and the independent effect of demographic indicators and adiposity on NAFLD risk were tested using regression models. Complex sampling methods and P values of <.05 were used to assess statistical significance.

Results: Suspected NAFLD prevalence (SE) rose from 3.9% (0.5) in 1988-1994 to 10.7% (0.9) in 2007-2010 (P < .0001), with increases among all race/ethnic subgroups, males and females, and those obese (P trend ≤.0006 for all). Among those obese, the multivariate adjusted odds of suspected NAFLD were higher with increased age, body mass index, Mexican American race, and male sex; the adjusted odds in 2007-2010 were 2.0 times those in 1988-1994. In 2007-2010, 48.1% (3.7) of all obese males and 56.0% (3.5) of obese Mexican American males had suspected NAFLD.

Conclusion: Prevalence of suspected NAFLD has more than doubled over the past 20 years and currently affects nearly 11% of adolescents and one-half of obese males. The rapid increase among those obese, independent of body mass index, suggests that other modifiable risk factors have influenced this trend.

Conflict of interest statement

The authors declare no conflicts of interest.

Copyright © 2013 Mosby, Inc. All rights reserved.

Figures

Figure 1

Trends in the unadjusted prevalence of suspected NAFLD among US adolescents 12–19 years old (N = 12 714) defined using overweight plus various cutpoints for elevated ALT, including sex-specific (>25.8 U/L for boys and >22.1 U/L for girls) as well as alternative cutpoints of >40 U/L and >30 U/ L. P for linear trend <.0001 for all.

Figure 2

Trends in the adjusted prevalence of suspected NAFLD (overweight plus ALT >25.8 U/L for boys and >22.1 U/ L for girls), the prevalence of high waist circumference (>90th sex and age percentile), and mean BMI z-score among A, obese female and B, obese male adolescents in the NHANES III through NHANES 2007–2010. Estimates were adjusted for age and race/ethnicity. P for linear trend was <.0001 for the prevalence of NAFLD in both males and female and for the prevalence of high waist circumference among females. Trends in BMI z-score were not significant for either males or females.