Longer sleep duration and the incidence and progression of diabetic nephropathy: a prospective cohort study

Abstract

Abstract Background Sleep duration has been linked to adverse health outcomes, but its association with diabetic nephropathy remains unclear. Objective This study aimed to assess the association between sleep duration and a composite endpoint of incidence and progression of diabetic nephropathy. Methods The study participants were 678 Japanese outpatients with type 2 diabetes. Lifestyle habits were assessed at baseline and at years 2 and/or 5. Mean values of lifestyle factors were calculated by averaging measurements from baseline to the date of endpoint onset or the end of follow-up. A multivariable Cox proportional hazards model was used. Results During a follow-up of 6.0 ± 2.7 years, 215 participants experienced the endpoint. Among lifestyle factors, mean sleep duration was the only factor associated with the endpoint. Compared with participants sleeping <6 hours, the multivariable-adjusted hazard ratios for mean sleep duration of 6 to <7, 7 to <8, and ≥8 hours were 1.08 (95% CI, 0.74-1.57), 1.56 (95% CI, 1.05-2.31), and 1.92 (95% CI, 1.15-3.19), respectively (P for trend = .003). This association remained significant after adjustment for key lifestyle and diabetes-related factors. The association was stronger in older participants and those with microalbuminuria or reduced kidney function. Conclusion Longer, but not shorter, sleep duration is associated with an increased risk of incidence and progression of diabetic nephropathy.