Abstract
Evidence for the influence of lifestyle factors on nonalcoholic fatty liver disease (NAFLD) onset is limited because the association between lifestyle factors and NAFLD has been reported mostly in cross-sectional studies. Our purpose was to elucidate which lifestyle factors are associated with NAFLD onset by performing a longitudinal study. This was a longitudinal study of 1,713 Japanese participants who underwent multiple health checkups from June 2013 to the end of March 2018 and were not diagnosed with NAFLD at the first health checkup at Watari Hospital in Fukushima, Japan. Baseline characteristics, including lifestyle factors, were compared among participants with and without NAFLD. Cox proportional hazards models were used to identify the association between lifestyle factors and NAFLD onset. Among the 1,713 participants, 420 (24.5 %) developed NAFLD during the observation period (median 47 months). There were significant differences in body mass index and hepatobiliary enzyme levels between participants with and without NAFLD. In Cox proportional hazards models, eating between meals (hazard ratio (HR): 2.08, 95 % confidence interval (CI): 1.25-3.45, p < 0.01) and eating fast (HR: 1.59, 95 % CI: 1.26-2.00, p < 0.01) were risk factors for NAFLD onset in men and women, respectively. Moreover, fast walking was a protective factor against NAFLD onset in women (HR: 0.76, 95 % CI: 0.60-0.96, p = 0.02). These findings could help to identify patients at risk and prevent future NAFLD onset.