Background and objectives Shorter or longer sleep duration and poor sleep quality are risk factors for numerous cardio-metabolic diseases, cardiovascular disease, and mortality in subjects with normal kidney function. The association of sleep duration and sleep quality with health outcomes in patients with CKD remains uncertain.Design, setting, participants, & measurements A 4-year prospective cohort study in 17 nephrology centers in Japan, the CKD Japan Cohort (CKD-JAC) Study, assessed an association of self-reported sleep duration and sleep quality, on the basis of the Pittsburgh Sleep Quality Index (PSQI) questionnaire, with incidence of ESKD in 1601 patients with eGFR 10-59 ml/min per 1.73 m 2 using multivariable-adjusted Cox proportional hazards models.Results Baseline sleep duration and PSQI global score for the 1601 patients were mean6SD 7.061.3 hours and median 4 (interquartile range, 3-7), respectively. Poor sleep quality (PSQI global score $6) was common (n=588 [37%]). During a median of 4.0 (2.6-4.3) years of the follow-up period, 282 (18%) patients progressed to ESKD. After adjusting for age, sex, eGFR, urinary albumin excretion, smoking status, body mass index, history of diabetes and cardiovascular disease, systolic BP, blockade of the renin-angiotensin system, use of hypnotics, and Beck depression inventory score, both shorter (#5 hour) and longer (.8 hour) sleep duration were associated with ESKD (adjusted hazard ratios [95% confidence intervals] for #5.0, 5.1-6.0, 6.1-7.0, 7.1-8.0, and $8.0 hours were 2.05 [1.31 to3.21], 0.98 [0.67 to 1.44], 1.00 [reference], 1.22 [0.89 to 1.66], and 1.48 [1.01 to 2.16]), suggesting a U-shaped relationship between sleep duration and ESKD. PSQI global score $6 was also associated with incidence of ESKD (adjusted hazard ratios [95% confidence intervals] for PSQI global score #5 and $6 were 1.00 [reference] and 1.33 [1.03 to 1.71]).Conclusions Shorter (#5 hour) and longer (.8 hour) sleep duration and poor sleep quality (PSQI global score $6) were associated with ESKD in patients with CKD.

Our investigation suggests that Na-Cl is an independent predictor of CKD progression, especially among patients with CKD stage G4 and those with anemia.

No straightforward correlation was seen between hospital volume and surgical outcome. Hospital volume may not be a suitable single tool to predict the outcome of lung cancer surgery. We should reserve the conclusion that low-volume hospitals offer less effective surgery. We need a risk-adjusted database to study this topic.