Abstract P226: Aerobic and Muscle Strengthening Physical Activity and Television Viewing Are Independently Associated With Odds of Nonalcoholic Fatty Liver Disease: The Cardia Study

Abstract

Introduction: The prevalence of nonalcoholic fatty liver disease (NAFLD) in US adults is over 25%, yet the etiology of lifestyle factors in the development of NAFLD remains understudied. We examined the independent and joint associations among aerobic physical activity (PA) intensity (moderate, vigorous) and PA type (aerobic, muscle strengthening), television viewing (TV), and odds of NAFLD. Hypothesis: Higher levels of aerobic and muscle strengthening PA are associated with lower odds of NAFLD, and higher levels of TV are associated with higher odds of NAFLD. Methods: We analyzed data from Year 25 of the CARDIA cohort study. Our exposures (moderate and vigorous aerobic and muscle strengthening PA, TV; hr/wk) were assessed using validated questionnaires. Our outcome (NAFLD) was measured using non-contrast computed tomography. We constructed multivariable logistic regression models to examine the independent and joint associations between PA (moderate or vigorous aerobic and strength), TV, and odds of NAFLD. Covariates were sex, age, race, study center, education, diet, smoking status, alcohol consumption, and waist circumference. Results: 2726 participants (648 with NAFLD) were analyzed (mean (SD) age, 50.1 (3.6) years; 49% Black; 43% male). Fully adjusted odds ratios per IQR-standardized continuous PA and TV were: moderate aerobic PA (IQR = 4.3), 0.93 (95% CI, 0.81-1.07); vigorous aerobic PA (IQR = 1.9), 0.63 (95% CI, 0.55-0.73); muscle strengthening PA (IQR = 3.3), 0.80 (95% CI, 0.07-0.92); and TV (IQR = 14.0), 1.20 (95% CI, 1.10-1.32). Only vigorous aerobic PA remained statistically significant after waist circumference adjustment, 0.83 (95% CI, 0.70-0.98). A PA-TV index model (Figure) indicated the combination of higher vigorous aerobic and muscle strengthening PA and lower TV resulted in an odds ratio of 0.23 (95% CI, 0.15-0.37). Conclusion: Concurrent higher levels of vigorous aerobic PA (≥2 hr/wk), muscle strengthening PA (≥2 hr/wk), and lower levels of TV (<7 hr/wk) were associated with 77% lower odds of NAFLD.