Association between Sleep Duration and Incident Chronic Kidney Disease: A Population-Based Cohort Analysis of the NAGALA Study

Background: The duration of sleep might be a risk factor for chronic kidney disease (CKD). We investigated the relationship between sleep duration and incident CKD. Methods: In this retrospective cohort study of 7,752 men and 6,722 women, we divided the subjects into 4 groups according to sleep duration, i.e., those whose reported regular sleep duration was <6 h (the "<6 h group"), those whose sleep duration was >6 but <7 h (the "6 to <7 h group"), those with a sleep duration of 7 to <8 h (the "7 to <8 h group"), and those with >= 8 h sleep (the ">= 8 h group"). CKD was defined as the presence of proteinuria and/or an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m(2). The HR of the 4 groups for incident CKD were calculated with a Cox proportional hazards model, with the 7 to Results: Incident CKD was detected in 1,513 (19.5%) men and 688 (10.2%) women over the median follow-up period of 7.0 (3.3-11.9) years in the men and 6.7 (3.1-10.8) years in the women. There was no association between sleep duration and incident CKD in the women. In the men, the HR of incident CKD was 0.54 (95% CI 0.45-0.64, p < 0.001) in the <6 h group, 0.73 (95% CI 0.66-0.82, p < 0.001) in the 6 to <7 h group, and 0.93 (95% CI 0.78-1.11, p = 0.433) in the >= 8 h group. Conclusion: The risk of incident CKD is lowest in those who sleep <6 h. We revealed that the risk of incident CKD is lowest in those who sleep <6 h among apparently healthy men.