Association of Self-Reported Nighttime Sleep Duration with Chronic Kidney Disease: China Health and Retirement Longitudinal Study

Abstract

<b><i>Introduction:</i></b> The cohort study aimed to assess the association of nighttime sleep duration and the change in nighttime sleep duration with chronic kidney disease (CKD) and whether the association between nighttime sleep duration and CKD differed by daytime napping. <b><i>Methods:</i></b> This study included 11,677 individuals from the China Health and Retirement Longitudinal Study (CHARLS) and used data from the 2011 baseline survey and four follow-up waves. Nighttime sleep duration was divided into three groups: short (<7 h per night), optimal (7–9 h), and long nighttime sleep duration (>9 h). Daytime napping was divided into two groups: no nap and with a nap. We used Cox proportional hazards model to examine the effect of nighttime sleep duration at baseline and change in nighttime sleep duration on incident CKD and a joint effect of nighttime sleep duration and nap time on onset CKD. <b><i>Results:</i></b> With a follow-up of 7 years, the incidence of CKD among those with short, optimal, and long nighttime sleep duration was 9.89, 6.75, and 9.05 per 1,000 person-years, respectively. Compared to individuals with optimal nighttime sleep duration, short nighttime sleepers had a 44% higher risk of onset CKD (hazard ratio [HR]: 1.44, 95% confidence interval [CI]: 1.21–1.72). Compared to participants with persistent optimal nighttime sleep duration, those with persistent short or long nighttime sleep duration had an increased risk of incident CKD (HR: 1.44, 95% CI: 1.15–1.80). We found a lower incidence of CKD in participants with short nighttime sleep duration and a nap (HR: 0.74, 95% CI: 0.60–0.93), compared to those with short nighttime sleep duration and no nap. <b><i>Conclusion:</i></b> Short nighttime sleep duration and persistent long or short nighttime sleep duration were associated with a higher risk of onset CKD. Keeping persistent optimal nighttime sleep duration may help reduce CKD risk later in life. Daytime napping may be protective against CKD incidence.

Hitting the Snooze Button on Chronic Kidney Disease

“…On the other hand, biological mechanisms linking long sleep duration to CKD are unknown and even remain elusive in CVD, warranting more attention. Unique to Jiang et al [14], daytime napping was found to offset the excess risk of CKD portended by short sleep duration. This parallels experimental work, which demonstrates that extreme nocturnal sleep restriction, when supplemented with daytime nap opportunity, does not increase urinary norepinephrine excretion compared to normal sleep opportunity [17].…”

“…In this issue of the American Journal of Nephrology , Jiang et al [14] report an association between sleep duration and CKD in a large sample of mid-life and older Chinese adults from the China Health and Retirement Longitudinal Study (CHARLS; n = 11,677). Unique to the present study, a novel assessment of temporal sleep pattern stability was obtained through repeated surveys over a 7-year follow-up period.…”

“…Jiang et al [14] acknowledged several limitations, which justify the need for follow-up epidemiological and mechanistic studies to investigate the nexus between sleep duration and CKD. First, only subjective sleep characteristics were collected in the present study.…”

“…Another important consideration pertains to the sample studied by Jiang et al [14]. Because their cohort included only Chinese participants, it is unknown whether their findings are applicable to other populations.…”

“…In summary, Jiang et al [14] provide robust epidemiological evidence suggesting a link between inadequate sleep duration and risk of CKD, adding the observation that consistent 7–9 h sleep time and daytime napping supplementation of insufficient nocturnal sleep are novel factors, which may reduce incident CKD risk. Importantly, short sleep duration may be implicated in the known kidney health disparities afflicting both Asian and Black/African-American populations, and more work is needed to determine the mechanistic link between sleep and CKD.…”