Abstract MP71: Associations Between Physical Activity Trajectories and Nonalcoholic Fatty Liver Disease: The Cardia Study

Abstract

Introduction: Non-alcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease in the US. Weight loss and lifestyle modifications, including increases in physical activity (PA), are the primary therapeutic recommendations for managing NAFLD. However, little is known about longitudinal physical activity patterns and NAFLD prevalence among a racially diverse population of adults. This study aimed to (1) identify distinct physical activity trajectories from young to middle adulthood and (2) examine the associations between physical activity trajectories and NAFLD prevalence in middle-aged adults. Methods: The analytic sample included 2833 participants of the Coronary Artery Risk Development in Young Adults (CARDIA) study. Physical activity was self-reported at eight examinations over 25 years (1985/1986 to 2010/2011), and separately scored for moderate- (MPA) and vigorous-intensity (VPA) physical activity. NAFLD was defined as liver attenuation values ≤51 Hounsfield units after exclusion of other causes of liver fat, measured using computed tomography in year 25 (2010/2011). Group-based trajectory modeling was used to identify MPA and VPA trajectories over 25 years. Modified Poisson regression models were used to estimate the risk ratios (RR) of NAFLD across the PA trajectories, adjusted for year 25 sex, age, CARDIA study center, race, education, smoking status, dietary pattern, and alcohol consumption. Results: We identified three distinct MPA and VPA trajectories. MPA: ‘very low stable’ (53%), ‘low stable’ (39%), and ‘moderate increasing’ (8%). VPA: ‘low stable’ (57%), ‘moderate stable’ (36%), and ‘high decreasing’ (7%). Year 25 NAFLD prevalence was 24%. Relative to participants with ‘moderate increasing’ MPA over time, those with lower levels of MPA had adjusted risk ratios of 1.11 (95% CI 0.87-1.43) for ‘low stable’ and 1.11 (95% CI 0.86-1.42) for ‘very low stable.’ Relative to participants with ‘high decreasing’ VPA over time, those with lower levels of VPA had adjusted risk ratios of 1.26 (95% CI 0.95-1.69) for ‘moderate stable’ and 1.62 (95% CI 1.21-2.16) for ‘low stable.’ Conclusions: Our results suggest a higher risk of NAFLD in middle age for those with low levels of VPA from young to middle adulthood relative to those with the highest levels of VPA over time, with evidence of dose-response. Sustaining VPA throughout adulthood may be efficacious in the prevention of NAFLD, highlighting the importance of targeted delivery of prevention and management programs aimed at modifying lifestyle risk factors to reduce NAFLD risk.