A J-shaped Relationship between Sleep Duration and the Risk of Insulin Resistance in a General Japanese Population

OBJECTIVE: Data on the role of sleep in the risk of insulin resistance (IR) are lacking. We therefore examined the association between sleep duration and IR in a general Japanese population. METHODS: Data of 1,344 individuals 34 to 89 years old from the Tanushimaru Study were analysed. IR was calculated using the fasting plasma glucose level×fasting insulin level/405, i.e. the homeostasis model assessment of IR (HOMA-IR). IR was defined as a HOMA-IR ≥1.73 based on the diagnostic criteria used in Japan. Information regarding sleep duration was collected via questionnaire. RESULTS: The frequencies of IR and metabolic syndrome (MetS) were 36.7% and 26.9%, respectively. A J-shaped relationship between sleep duration and IR was observed, and the same relationship was also shown between sleep duration and MetS; however, the relationship with MetS disappeared after adjusting for age, sex, and other confounding factors. CONCLUSION: A J-shaped relationship was observed between sleep duration and the risks of IR in a general Japanese population.