The Association between Sleep Duration and Non-Alcoholic Fatty Liver Disease among Japanese Men and Women

Abstract

Objective: To examine the relationship between sleep duration and non-alcoholic fatty liver disease (NAFLD). Methods: We evaluated 3,968 subjects who underwent health check-ups from June 2012 to May 2013 at the Watari Hospital Health Center in Fukushima Prefecture in Japan. Fatty liver was detected by ultrasonography. Sleep duration and lifestyle factors were estimated using a questionnaire. Sleep duration was categorized into the following groups: ≤6, 6 to ≤7, >7 to ≤8, and >8 h. The four sleep duration groups were compared using the χ² test and Kruskal-Wallis test. Results: In total, 2,172 subjects were enrolled. The overall prevalence of NAFLD was 29.6% (men, 38.0%; women, 25.3%). The proportion of NAFLD tended to decrease as sleep duration increased in men. The proportion with NAFLD was lowest in the group with a sleep duration of 6 to ≤7 h and highest in the groups with sleep durations of ≤6 and >8 h in women. The distribution showed a U-shaped curve. The age-adjusted odds ratio (OR) (95% confidence interval (CI)) for subjects with NAFLD with a sleep duration ≤6 h compared to the reference (6 to ≤7 h) was 1.44 (1.06-1.96) in women. Conclusion: Sleep shortage tends to be associated with NAFLD in women and may be mediated by body adiposity.

Nighttime sleep duration and risk of nonalcoholic fatty liver disease: the Dongfeng-Tongji prospective study

“…Subsequently, a longitudinal community-based cohort study conducted in Japan demonstrated that, as compared to those who slept 7-8 h, short sleep duration (6 hours) was related to reduce risk of NAFLD in men, while this association was not significant among women (20). The late cross-sectional Japan study found that short sleep duration tends to be associated with NAFLD in women (21). Altogether, the current epidemiologic evidence does not allow for conclusive inferences in favor of a causal link between sleep duration and NAFLD.…”

Sleep Duration and the Risk of Fatty Liver Disease: A Systematic Review and Meta-analysis

“…We also investigated the effect of long sleep duration on FLD risk. By combining three independent datasets from the two studies1213 (including 10,329 subjects), we showed that compared to normal sleep duration (5~7 hours), long sleep duration did not increase or decrease the risk of FLD (the pooled OR = 1.01, 95% CI = 0.72–1.41). The heterogeneity among studies was moderate ( P heterogeneity  = 0.110, I 2  = 54.7%) (Fig.…”

“…ORs and 95% CIs extracted from individual studies were adjusted by age and other covariates. Four studies10111314 reported results separately by sex and one16 reported by obstructive sleep apnea (OSA) status. Thus, we treated them as independent datasets.…”

“…observed an insignificant association between short sleep duration and FLD risk in men12, and Imaizumi et al . observed similar results in men and women13. Long sleep duration was reportedly protective against FLD12, but this result was not supported by subsequent research13.…”

“…observed similar results in men and women13. Long sleep duration was reportedly protective against FLD12, but this result was not supported by subsequent research13.…”