The Relationship between Screen Time, Weight Status, and Fatty Liver Disease in U.S. Adolescents, a Cross-Sectional Study Using NHANES, 2017-2018

Objective: The purpose of this study was to assess if screen time in U.S. adolescents is positively associated with evidence of fatty liver disease (steatosis and/or fibrosis) on FibroScan technology and to test the hypothesis that being overweight or obese mediates this relationship. Methods: The analysis used cross-sectional data from 12–17-year-old participants (n = 612) in the 2017-2018 National Health and Nutrition Examination Survey (NHANES) to evaluate the association between self-reported average daily screen time and the presence of liver steatosis and/or fibrosis using FibroScan. Adjusted logistic regression analysis was performed to describe the independent association between screen time and the presence of liver disease. Additionally, mediation analysis was conducted by sequentially regressing obesity on screen time and regressing liver disease on screen time and obesity. Results: Overall, 38.2% of adolescents had evidence of liver disease on FibroScan. A significant effect of daily screen time was seen on liver disease status, t (610) = 2.74, p =.006. Adolescents with evidence of liver steatosis and/or fibrosis spent an average of 38.4 minutes (95% CI, 11.0 - 65.8) per day longer on screens than those who did not have liver disease. Sobel’s test (ab = .128, Z=2.053, p=.040) confirmed that overweight/obesity significantly mediates the relationship between screen time and liver disease. After accounting for the mediating effect of overweight/obese status, screen time has a small, but not statistically significant direct effect on fatty liver disease. Discussion: Average daily screen time in adolescents affects liver steatosis and/or fibrosis indirectly through obesity