Non-alcoholic fatty liver disease (NAFLD) is associated with low level of physical activity: a population-based study

High intensity exercise improves metabolic status and may potentially mobilise hepatic fat.

To assess the level of physical activity (PA) of subjects with non-alcoholic fatty liver disease (NAFLD).

Data were obtained from NHANES (2003-2006). Activity counts obtained from accelerometer readings (ActiGraph, Fort Walton Beach, FL), from 7 consecutive days quantified total PA and time spent engaged in different levels of activity. All measures were counts/minutes/day: (sedentary <100; light 100-0027; moderate, 2020-5999 and vigorous, 6000+). NAFLD was defined as a fatty liver index >60 (FLI) in the absence of other chronic liver disease. Subjects with NAFLD were compared to controls using stratum-specific Chi-squared and t-tests. Simple linear regression analyses (with Taylor series linearised variance estimation and weighting) were used to determine the association between PA levels and NAFLD. P-values <0.05 were considered significant. Statistical analyses were conducted using sudaan version 10.1 and sas version 9.1.

We included 3056 participants. NAFLD patients were older, had higher BMI, larger waist circumference, higher sum of skinfolds, more likely to have insulin resistance (HOMA > 3.0) and type-2 diabetes (all P-values <0.01). Average PA for NAFLD subjects was about 28.7 counts/minute/day less than controls (P < 0.01). Furthermore, NAFLD subjects spent less time participating in activity at any level (P < 0.01). Subjects with NAFLD and DM were in the lowest quartile of average PA as well as moderate-vigorous PA (P < 0.01).

Data from this study show that non-alcoholic fatty liver disease patients have low level of physical activity and, when they have diabetes mellitus, they perform at the lowest quartile of physical activity and moderate-vigorous physical activity.