Joint effect of alcohol and usual sleep duration on the risk of dysglycemia.

STUDY OBJECTIVES Sleep duration and alcohol use influence metabolic function. However, limited information exists regarding a combined effect of alcohol and sleep duration on glucose metabolism. The aim of this study was to assess the potential interaction effect of alcohol and inappropriate sleep duration on dysglycemia epidemiologically. DESIGN Cross-sectional and observational retrospective study. SETTING A medical health checkup program in a general hospital. PARTICIPANTS 2933 apparently healthy Japanese individuals, aged 46 to 60 years. INTERVENTION N/A. MEASUREMENTS AND RESULTS We examined the relationships between usual sleep duration and dysglycemia, and furthermore assessed the combined effects of alcohol consumption and sleep time on glucose dysmetabolism. A U-shaped relationship between sleep duration and the prevalence of hyperglycemia (fasting plasma glucose level > or =110 mg/dL) was observed when sleep duration was treated as a continuous variables and centered at 7.0 h (quadratic term P = 0.024). In a multivariate quadratic regression model, there was a significant interaction effect between sleep duration and alcohol consumption category (nondrinkers, light-moderate drinkers [ethanol comsumption < or =210 g/wk], and heavy drinkers [ethanol consumption of >210 g/wk]) on fasting plasma glucose levels, with shorter or longer sleep duration being more diabetogenic in individuals who consumed more alcohol (P interaction = 0.018). Furthermore, we found a similar interaction effect of sleep duration and alcohol consumption on the incidence of hyperglycemia during the past 5 years (P interaction = 0.039). CONCLUSION Alcohol interacts with reduced sleep duration to increase the risk of dysglycemia.