The association of sleep duration and sleep quality with non-alcoholic fatty liver disease in a Taiwanese population

Objective: The association of sleep duration/quality with nonalcoholic fatty liver disease (NAFLD) is inconclusive. Several important covariates were not adjusted concomitantly in some studies, and the severity of NAFLD was not considered. Furthermore, the gender impact of sleep duration or sleep quality on NAFLD remains unclear. We thus aimed to examine the association of sleep duration and quality with NAFLD by gender in a Taiwanese population. Methods: A total of 6663 subjects aged 18 years or more were enrolled. The severity of NAFLD was divided into mild, moderate, and severe degrees based on ultrasound findings. The sleep duration was classified into three groups: short (<6 h), normal (6–8 h), and long (>8 h). Pittsburgh Sleep Quality Index (PSQI) was used to evaluate sleep quality, and poor sleep quality was defined as a global PSQI score greater than 5. Results: After adjustment for potential confounders, multinomial logistic regression showed that poor sleep quality was negatively associated with both mild and moderate-to-severe NAFLD in males, but sleep duration was not independently related to NAFLD. In females, sleep condition was not related to NAFLD. Conclusions: Poor sleep quality but not sleep duration was associated with a lower risk of not only moderate to severe but also mild NAFLD in males. In females, the association of sleep quality and duration with the risk of NAFLD was insignificant.