To investigate the effect of recent short-term weight gain on the incidence of nonalcoholic fatty liver disease (NAFLD) in non-obese participants (BMI less than 25 kg/m2), a retrospective cohort study to include nonobese individuals who participated in an annual health checkup between 2008 and 2018 in Tokyo, Japan was carried out.
A multivariable adjusted hazard ratio for the development of NAFLD diagnosis was estimated via ultrasound after a 3-kg unit gain of weight measured at a 2-year landmark time point post baseline. Multivariable adjustments included weight change from the age of 20 and other relevant confounding factors. Sensitivity analyses using additional landmark time points at 1, 3, 4, and 5 years postbaseline and time-dependent Cox proportional hazards regressions were performed.
A total of 27,064 nonobese participants included 142,699 person-years of followup; 2895 were diagnosed with NAFLD. Approximately 90% of the patients with NAFLD maintained their nonobese status before disease diagnosis. The adjusted hazard ratio for the development of NAFLD (for 3-kg unit of weight gain), at the 2-year landmark time post baseline was 1.6 in nonobese men and 1.66 in nonobese women. This association was maintained in the sensitivity analyses.
It was concluded that recent short-term weight gain is an independent risk factor for NAFLD development in nonobese men and women. Clinicians should be mindful of the association between weight gain and NAFLD onset, even in a nonobese population.
Yamada, G., Hagiwara, Y., Kimura, G., et al. “Impact of Body Weight Gain on the Incidence of Nonalcoholic Fatty Liver Disease in Nonobese Japanese Individuals.” American Journal of Gastroenterology 2021; Vol. 116, pp. 735-740.