Significant Dose-Response Association of Physical Activity and Diet Quality With Mortality in Adults With Suspected NAFLD in a Population Study.

INTRODUCTION

We aimed to determine whether higher levels (volume and intensity) of physical activity (PA) and diet quality (DQ) are associated with better survival rates in nonalcoholic fatty liver disease (NAFLD).

METHODS

Using data from the 2011-2014 National Health and Nutrition Examination Survey, 3,548 participants with a Fatty Liver Index ≥60 were included. PA was collected using a wrist-worn triaxial accelerometer and expressed as 2 metrics using Monitor-Independent Movement Summary (MIMS) units: the average of daily MIMS, which represents volume, and peak 30-minute MIMS, which is the average of the highest 30 MIMS min/d and represents intensity. DQ was assessed by the Healthy Eating Index-2015. Mortality follow-up was recorded using the National Death Index linkage through December 31, 2019.

RESULTS

Our analyses revealed a dose-dependent, nonlinear association of PA (volume and intensity) with all-cause mortality and a dose-dependent, linear association of DQ with all-cause mortality. The maximum protective dose of PA volume was observed at 14,300 MIMS/min (adj. HR: 0.20, 95% CI: 0.11-0.38). The maximum protective dose of PA intensity was observed at 54.25 MIMS/min (adj. HR: 0.10, 95% CI: 0.05-0.23), beyond which mortality risks flattened. The Healthy Eating Index-2015 showed its maximum protective effect at 66.17 (adj. HR: 0.54, 95% CI: 0.40-0.74). Higher PA (volume and intensity) levels were associated with a lower risk of cardiovascular-related but not cancer-related mortality. A healthier diet was linked to a reduced risk of cardiovascular-specific and cancer-specific mortality. Sensitivity analyses showed that the beneficial effects of PA and DQ on survival rates remained significant across sex, racial/ethnic, and age groups as well as in participants without NAFLD.

DISCUSSION

Our findings suggest that higher daily accumulated and peak effort PA and DQ are associated with lower all-cause and cardiovascular mortality in US adults with NAFLD.