Short sleep duration increases the risk of chronic kidney disease in shift workers

The association of sleep duration with the risk of chronic kidney disease: a systematic review and meta-analysis

Background and hypothesis

Published literature suggests that sleep duration and quality may be affected in adults with chronic kidney disease. However, the relationship between these two entities remains a matter of debate. The objective of this systematic review and meta-analysis is to assess the effect of sleep duration and quality on chronic kidney disease.

Methods

A systematic review of the Medline/PubMed, Embase, Cochrane Library, and CINAHL databases was conducted for articles pertaining to the association between sleep duration and quality on chronic kidney disease. The main outcome was the hazard/risk ratio of chronic kidney disease in patients of varying sleep durations and quality.

Results

In total, 42 studies (2 613 971 patients) with a mean age of 43.55 ± 14.01 years were included in the meta-analysis. Compared with a reference range of 7 to 8 hours of sleep, short sleep durations of ≤4 hours (RR 1.41, 95% CI: 1.16 to 1.71, P < 0.01), ≤5 hours (RR 1.46, 95% CI: 1.22 to 1.76, P < 0.01), ≤6 hours (RR 1.18, 95% CI: 1.09 to 1.29, P < 0.01), and ≤7 hours (RR 1.19, 95% CI: 1.12 to 1.28, P < 0.01) were significantly associated with an increased risk of incident chronic kidney disease. Long sleep durations of ≥8 hours (RR 1.15, 95% CI: 1.03 to 1.28, P < 0.01) and ≥9 hours (RR 1.46, 95% CI: 1.28 to 1.68, P < 0.01) were also significantly associated with an increased risk of incident chronic kidney disease. Meta-regression did not find any significant effect of age, gender, geographical region, and BMI and an association with sleep duration and risk of incident chronic kidney disease.

Conclusion

Both short and long sleep durations were significantly associated with a higher risk of chronic kidney disease. Interventions targeted toward achieving an optimal duration of sleep may reduce the risk of incident chronic kidney disease.

Short or long sleep duration was associated with chronic kidney disease in a Chinese nationwide cohort study

OBJECTIVE

Sleep duration is an important factor influencing health outcomes. The association between sleep duration and kidney function remains elusive. This study aimed to explore the association between sleep duration and chronic kidney disease (CKD) amongst Chinese adults.

METHODS

We conducted a cross-sectional study based on the China Health and Nutrition Survey (CHNS) in the wave of 2009. Participants were divided into three groups: ≤ 6 h/day (short sleepers), 7-8 h/day (regular sleepers) and ≥ 9 h/day (long sleepers) according to self-reported sleep duration. CKD was defined as estimated glomerular filtration rate < 60 mL/min/1.73 m2.

RESULTS

A total of 8096 Chinese adults (45.9% men) with a mean age of 50.6 years were included in the study. Compared with regular sleepers, both short and long regular sleepers had a higher prevalence of CKD. A U-shaped relationship between sleep duration and CKD was displayed by restricted cubic spline curve (P-overall < 0.001, P-nonlinear < 0.001). Multivariate logistic regression models revealed that both short and long sleep duration were clinically associated with higher odds of CKD, after adjustments for covariates [adjusted odds ratio (OR) 1.25 and 1.30; 95% confidence interval (CI) 1.00-1.56 and 1.08-1.54, for short and long sleep duration, respectively]. In subgroup analyses, we found the association was still observed in participants without hypertension or diabetes mellitus.

CONCLUSION

Short or long sleep duration was associated with CKD in the general population.

Circadian Regulation of Endocrine Fibroblast Growth Factors on Systemic Energy Metabolism

The circadian clock is an endogenous biochemical timing system that coordinates the physiology and behavior of organisms to earth's ∼24-hour circadian day/night cycle. The central circadian clock synchronized by environmental cues hierarchically entrains peripheral clocks throughout the body. The circadian system modulates a wide variety of metabolic signaling pathways to maintain whole-body metabolic homeostasis in mammals under changing environmental conditions. Endocrine fibroblast growth factors (FGFs), namely FGF15/19, FGF21, and FGF23, play an important role in regulating systemic metabolism of bile acids, lipids, glucose, proteins, and minerals. Recent evidence indicates that endocrine FGFs function as nutrient sensors that mediate multifactorial interactions between peripheral clocks and energy homeostasis by regulating the expression of metabolic enzymes and hormones. Circadian disruption induced by environmental stressors or genetic ablation is associated with metabolic dysfunction and diurnal disturbances in FGF signaling pathways that contribute to the pathogenesis of metabolic diseases. Time-restricted feeding strengthens the circadian pattern of metabolic signals to improve metabolic health and prevent against metabolic diseases. Chronotherapy, the strategic timing of medication administration to maximize beneficial effects and minimize toxic effects, can provide novel insights into linking biologic rhythms to drug metabolism and toxicity within the therapeutical regimens of diseases. Here we review the circadian regulation of endocrine FGF signaling in whole-body metabolism and the potential effect of circadian dysfunction on the pathogenesis and development of metabolic diseases. We also discuss the potential of chrononutrition and chronotherapy for informing the development of timing interventions with endocrine FGFs to optimize whole-body metabolism in humans. SIGNIFICANCE STATEMENT: The circadian timing system governs physiological, metabolic, and behavioral functions in living organisms. The endocrine fibroblast growth factor (FGF) family (FGF15/19, FGF21, and FGF23) plays an important role in regulating energy and mineral metabolism. Endocrine FGFs function as nutrient sensors that mediate multifactorial interactions between circadian clocks and metabolic homeostasis. Chronic disruption of circadian rhythms increases the risk of metabolic diseases. Chronological interventions such as chrononutrition and chronotherapy provide insights into linking biological rhythms to disease prevention and treatment.

Chronic Kidney Disease Among Agricultural Workers in Taiwan: A Nationwide Population-Based Study

Introduction

Chronic kidney disease (CKD) in agricultural communities is a significant public health issue. We aimed to investigate the epidemiology of CKD among Taiwanese farmers and its association with outdoor heat exposure.

Methods

A nested case-control study was conducted on participants in the National Adult Health Examination (NAHE) from 2012 to 2018. The farming occupation was identified through National Health Insurance data. The primary outcomes of interest were the development of CKD, defined as a decreased estimated glomerular filtration rate (eGFR) with diagnosis by physicians, and CKD of undetermined etiology (CKDu), defined as CKD excluding common traditional etiologies. We calculated the county-wide average ambient temperature from a climate reanalysis dataset (ERA5-Land). All CKD cases were matched 1:2 to non-CKD participants by age and biological sex. We estimated the odds ratios (ORs) of CKD and CKDu for farmers and changes in mean ambient temperature (°C) before the examination.

Results

We identified 844,412 farmers and 3,750,273 nonfarmers. Among 24.9% of farmers and 7.4% of nonfarmers with reduced kidney function, only 1 in 7 received a diagnosis of CKD. The farming occupation was independently predictive of CKDu (OR = 1.09, 95% confidence interval [CI] = 1.001-1.18) but not CKD. Increased ambient temperature (°C) was associated with a higher risk of CKD (OR = 1.023, 95% CI = 1.017-1.029), with particularly strong associations observed among middle-aged participants and diabetics.

Conclusions

Taiwanese farmers might have a higher risk of developing CKDu. Outdoor heat exposure is associated with the development of CKD, and middle-aged participants and those with diabetes are more vulnerable than the general population.

Depressive symptoms and sleep duration in relation to chronic kidney disease: Evidence from the China health and retirement longitudinal study

OBJECTIVE

Nowadays, the joint effects of depressive symptoms and sleep duration on the risk of chronic kidney disease (CKD) are still unclear. We aimed to prospectively assess the combined effect of depressive symptoms and sleep duration on the incidence of CKD in middle-aged and elderly Chinese population.

METHODS

A total of 10,953 participants from the China Health and Retirement Longitudinal Study (CHARLS) were included. Depressive symptoms were measured using the 10-item Center for Epidemiological Studies Depression scale (CESD-10). Sleep duration was evaluated by self-reported. CKD events were based on self-reported physicians' diagnosis or personal estimate glomerular filtration rate level (eGFR <60 mL/min/1.73 m2). Cox regression models were established to analyze the correlation between depressive symptoms, sleep duration and the risk of CKD.

RESULTS

Over a mean follow-up time was 6.76 ± 0.98 years, 851 (7.8%) participants had reported CKD events during the follow-up. Elevated depressive symptoms (HR = 1.65, 95% CI = 1.43-1.90) and short sleep duration (HR = 1.48, 95% CI = 1.27-1.72) were independently associated with an increased CKD risk after adjusting for potential confounding factors. Participants with short sleep duration (< 6 h)/elevated depressive symptoms (HR = 2.24, 95% CI = 1.89-2.65) were associated with the highest risk of CKD than those with normal sleep duration/low depressive symptoms.

CONCLUSIONS

Elevated depressive symptoms and short sleep duration were independent risk factors for CKD. There was a combined effect between depressive symptoms and sleep duration in increasing the risk of CKD.

Effect of night shift work on the reduction of glomerular filtration rate using data from Korea Medical Institute (2016-2020)

Background

Shift work increases the risk of chronic diseases, including metabolic diseases. However, studies on the relationship between shift work and renal function are limited. The aim of this study was to investigate the association between shift work and a decreased glomerular filtration rate (GFR).

Methods

Data were evaluated for 1,324,930 workers who visited the Korean Medical Institute from January 1, 2016 to December 31, 2020 and underwent a health checkup. Daytime workers were randomly extracted at a ratio of 1:4 after matching for age and sex. In total, 18,190 workers aged over 40 years were included in the analyses; these included 3,638 shift workers and 14,552 daytime workers. Participants were categorized into the shift work group when they underwent a specific health checkup for night shift work or indicated that they were shift workers in the questionnaire. The odds ratio was calculated using a conditional logistic regression to investigate the relevance of shift work for changes in GFR.

Results

35 workers in the shift group and 54 in the daytime group exhibited an estimated GFR (eGFR) value of < 60 mL/min/1.73m2 (p < 0.01). The difference in eGFR values between two checkups differed significantly depending on the type of work (p < 0.01); the difference in the shift work group (-9.64 mL/min/1.73 m2) was larger than that in the daytime work group (-7.45 mL/min/1.73 m2). The odds ratio for eGFR reduction to < 60 mL/min/1.73 m2 in the shift group versus the daytime group was 4.07 (95% confidence interval: 2.54-6.52), which was statistically significant.

Conclusions

The results of this study suggest that eGFR decreases by a significantly larger value in shift workers than in daytime workers; thus, shift work could be a contributing factor for chronic kidney disease (CKD). Further prospective studies are necessary to validate this finding and identify measures to prevent CKD in shift workers.

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

INTRODUCTION

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Association between sleep parameters and chronic kidney disease: findings from iranian ravansar cohort study

INTRODUCTION

The relationship between sleep duration and chronic kidney disease (CKD) has received relatively little attention in the Kurdish community. Considering the ethnic diversity of Iran and the importance of the Kurdish community, the present study investigated the association between sleep parameters and CKD among a large sample of Iranian-Kurds.

METHODS

This cross-sectional study was conducted among 9,766 participants (M_age: 47.33, SD = 8.27, 51% female) from the Ravansar Non Communicable Disease (RaNCD) cohort study database. Logistic regression analyses were applied to examine the association between sleep parameters and CKD.

RESULTS

Results showed that prevalence of CKD was detected in 1,058 (10.83%) individuals. Time to fall asleep (p = 0.012) and dozing off during the day (p = 0.041) were significantly higher in the non-CKD group compared to the CKD group. Daytime napping and dozing off during the day in females with CKD were significantly more than males with CKD. A long sleep duration (> 8 h/day) was associated with 28% (95% CI: 1.05, 1.57) higher odds of CKD compared to normal sleep duration (7 h/d), after adjusting for confounding factors. Participants who experienced leg restlessness had a 32% higher probability of developing CKD than those who did not experience leg restlessness (95% CI: 1.03, 1.69).

CONCLUSION

Results suggest that sleep duration and leg restlessness may be associated with an increased likelihood of CKD. Consequently, regulating sleep parameters may play a role in improving sleep and preventing CKD.

Association between social jetlag and chronic kidney disease among the Korean working population

Social jetlag refers to the discrepancy between social time and the body's internal rhythm, which can lead to unfavorable health outcomes. However, no study has directly explored the relation between social jetlag and chronic kidney disease (CKD). This study aims to investigate the relationship between social jetlag and CKD in a representative population of South Korea. This study included 8259 currently economically active Korean population in the Korea National Health and Nutrition Examination Survey. Social jetlag was calculated as the difference between the midpoint of sleep time on weekdays and free days. The estimated glomerular filtration rate (eGFR) was calculated the by using the serum creatinine value according to the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Participants with an eGFR less than 60 ml/min/1.73 m² were defined as CKD cases. The estimated glomerular filtration rate decreased as social jetlag increased. Multiple logistic regression analysis showed that the adjusted odds ratio (95% confidence interval) of CKD for 1-2 h of social jetlag was 0.926 (0.660-1.299), while the odds ratio for more than 2 h was 2.042 (1.328-3.139) when less than 1 h was used as reference. This study found that social jetlag and risk of CKD were significantly related in the Korean working population.

Association between sleep duration and quality with rapid kidney function decline and development of chronic kidney diseases in adults with normal kidney function: The China health and retirement longitudinal study

Research have shown that sleep is associated with renal function. However, the potential effects of sleep duration or quality on kidney function in middle-aged and older Chinese adults with normal kidney function has rarely been studied. Our study aimed to investigate the association of sleep and kidney function in middle-aged and older Chinese adults. Four thousand and eighty six participants with an eGFR ≥60 ml/min/1.73 m² at baseline were enrolled between 2011 and 2015 from the China Health and Retirement Longitudinal Study. Survey questionnaire data were collected from conducted interviews in the 2011. The eGFR was estimated from serum creatinine and/or cystatin C using the Chronic Kidney Disease Epidemiology Collaboration equations (CKD-EPI). The primary outcome was defined as rapid kidney function decline. Secondary outcome was defined as rapid kidney function decline with clinical eGFR of <60 ml/min/1.73 m² at the exit visit. The associations between sleep duration, sleep quality and renal function decline or chronic kidney disease (CKD) were assessed based with logistic regression model. Our results showed that 244 (6.0%) participants developed rapid decline in kidney function, while 102 (2.5%) developed CKD. In addition, participants who had 3-7 days of poor sleep quality per week had higher risks of CKD development (OR 1.86, 95% CI 1.24-2.80). However, compared with those who had 6-8 h of night-time sleep, no significantly higher risks of rapid decline in kidney function was found among those who had <6 h or >8 h of night time sleep after adjustments for demographic, clinical, or psychosocial covariates. Furthermore, daytime nap did not present significant risk in both rapid eGFR decline or CKD development. In conclusion, sleep quality was significantly associated with the development of CKD in middle-aged and older Chinese adults with normal kidney function.

The association between long-term night shift work and metabolic syndrome: a cross-sectional study of male railway workers in southwest China

OBJECTIVES

Metabolic syndrome (MetS) increases the risk of new diabetes and cardiovascular disease. Night shift work (NSW) may influence metabolic disturbance and lead to MetS. This study aims to investigate the association between long-term NSW (≥ 10 years) and MetS combined with its components in male railway workers in southwest China.

METHODS

11,023 male railway workers with long-term NSW of more than 10 years in the Physical Examination Center of the Affiliated Hospital of Chengdu University were enrolled. The basic data were collected by investigators and blood test results were collected. The primary outcome was the prevalence of metabolic syndrome. The results were analyzed using statistical software SPSS 22.0.

RESULTS

In total, 11,023 people over the age of 40 with more than 10 years of working experience were enrolled, and 4759 (43.2%) participants had a diagnosis of MetS. The basic data indicated that night shift workers tended to be younger, shorter working years, but with higher body mass index and longer hip circumference (p < 0.05). The adjusted analysis revealed that there was no significant association between NSW and metabolic syndrome (OR 1.03, 95% CI 0.94-1.12, p = 0.543). NSW was associated with SBP ≥ 130 mmHg (OR 1.11, 95% CI 1.02-1.21, p < 0.001) and waist circumference ≥ 90 cm (OR 1.11, 95% CI 1.02-1.21, p < 0.001).

CONCLUSIONS

Long-term night shift workers had a higher prevalence of MetS. However, long-term NSW is not associated with a significantly increased risk of metabolic syndrome in male railway workers in southwest China. Long-term NSW is associated with elevated SBP, and waist circumference increase.

Association Between Long Working Hours and Chronic Kidney Disease According to Diabetic Status: A Nationwide Study (Korean National Health and Nutrition Examination Survey 2010-2017)

OBJECTIVE

This study aimed to investigate the relationship between long working hours and chronic kidney disease (CKD) according to diabetic status.

METHODS

Twelve thousand seven hundred three full-time employees without diabetes and 2136 with diabetes were included in this study. Participants were grouped according to working hours: ≤40, 41 to 52, and >52 h/week. Multiple logistic regression was used to evaluate the association between working hours and CKD prevalence.

RESULTS

Participants with diabetes who worked 41 to 52 h/week showed 1.85 times higher odds of CKD (95% CI 1.15-2.96; P = 0.0112) compared with those who worked ≤40 h/week after adjusting for covariates. An interaction between diabetes and long working hours was observed (P for interaction = 0.0212) in the model.

CONCLUSION

Long working hours are associated with CKD in participants with diabetes. An interaction between long working hours and diabetes leading to CKD development may exist.

The association of nighttime sleep duration and quality with chronic kidney disease in middle-aged and older Chinese: a cohort study

OBJECTIVE

This cohort study aimed to assess the associations between sleep duration and quality with the risk of incident chronic kidney disease (CKD) in middle-aged and older Chinese.

METHODS

We used the 2011 and 2015 surveys of the China Health and Retirement Longitudinal Study (CHARLS). Nighttime sleep duration was categorized into five groups: ≤4, (4-6], (6-8], (8-10], and >10 h/night. Sleep quality was assessed by restless days in the past week (<1, 1-2, 3-4, and 5-7 days/week). Multivariate logistic regression was used to assess the association between sleep duration and quality with incident CKD.

RESULTS

A total of 11,339 participants free of CKD at baseline were included in this study. After four years follow-up, the incidence of CKD was 7.8%. There was a "U-shaped" association between sleep duration and risk of CKD. Compared to 6-8 h of nighttime sleep duration, those who slept ≤4 h/night (RR: 1.639, 95% CI: 1.287-2.087) or >10 h/night (RR: 2.342, 95% CI: 1.007-5.451) had increased risk of developing CKD after adjustment for confounders. Participants with 5-7 restless days per week had significantly increased risk of CKD (adjusted RR: 1.686, 95% CI: 1.352-2.102), compared to those who rarely or never had a restless sleep.

CONCLUSIONS

Extreme nighttime sleep duration and poor sleep quality were associated with increased risk of CKD in middle-aged and older Chinese. Obtaining an optimal nighttime sleep duration and better sleep quality might reduce the risk of CKD.

Association and pathways between shift work and cardiovascular disease: a prospective cohort study of 238 661 participants from UK Biobank

BACKGROUND

This study aimed to study the association between shift work and incident and fatal cardiovascular disease (CVD), and to explore modifying and mediating factors.

METHODS

This is a population-based, prospective cohort study with a median follow-up of 11 years; 238 661 UK Biobank participants who were in paid employment or self-employed at baseline assessment were included.

RESULTS

Shift workers had higher risk of incident [hazard ratio (HR) 1.11, 95% confidence interval (CI) 1.06-1.19] and fatal (HR 1.25, 95% CI 1.08-1.44) CVD compared with non-shift workers, after adjusting for socio-economic and work-related factors. The risk was higher with longer duration of shift work, in women and in jobs with little heavy manual labour. Current smoking, short sleep duration, poor sleep quality, adiposity, higher glycated haemoglobin and higher cystatin C were identified as the main potentially modifiable mediators. Mediators collectively explained 52.3% of the associations between shift work and incident CVDs.

CONCLUSIONS

Shift workers have higher risk of incident and fatal CVD, partly mediated through modifiable risk factors such as smoking, sleep duration and quality, adiposity and metabolic status. Workplace interventions targeting these mediators have the potential to alleviate shift workers' CVD risk.

Effects of sleep apnea and kidney dysfunction on objective sleep quality in nondialyzed patients with chronic kidney disease: an ESADA study

STUDY OBJECTIVES

Patients with chronic kidney disease (CKD) often report poor sleep quality, but they commonly exhibit OSA. The aim of this study was to evaluate the influence of OSA severity and of estimated glomerular filtration rate impairment on objective sleep quality in nondialyzed patients with CKD, defined as an estimated glomerular filtration rate <60 mL/min/1.73m².

METHODS

Polysomnographic sleep characteristics were compared between patients with (n = 430) and without CKD (n = 6,639) in the European Sleep Apnea Database cohort. Comparisons were repeated in 375 patients with CKD and 375 control patients without CKD matched for sleep center, age, sex, and AHI, and in 310 matched CKD and non-CKD patients without psychiatric disturbances.

RESULTS

Among all patients with and without CKD, total sleep time was similar but sleep stage N1 (median 8.7% [IQR 4.8-18.0] vs 6.7% [3.6-12.7], respectively) and sleep stage R (12.6% [6.8-17.7] vs 14.2% [8.8-19.8], respectively) significantly differed (P < .0001). No difference in sleep characteristics was observed between matched patients either with or without psychiatric disturbances. After subdividing the matched patients according to AHI tertile (<25, ≥25 to <49, and ≥49 events/h) and estimated glomerular filtration rate (≥60, 45 to <60, <45 mL/min/1.73m²), we found a significant effect of AHI on sleep stages N2, N3, and R (P < .001), but there was no effect of CKD.

CONCLUSIONS

In nondialyzed patients with CKD, objective sleep quality is influenced similarly by AHI as in patients without CKD but is not affected by CKD severity. Previously reported poor sleep quality in CKD may partly result from the high prevalence of OSA in CKD.

Long work hours and decreased glomerular filtration rate in the Korean working population

OBJECTIVES

We studied the association between long working hours and decreased kidney function, which was determined using estimated glomerular filtration rate (eGFR), among the working population in South Korea.

METHODS

We analysed nationally representative cross-sectional data for 20 851 Korean workers ≥20 years of age. A negative binomial regression model was used to test differences in the prevalence of chronic kidney disease (eGFR <60 mL/min/1.73 m²) among workers divided into groups according to weekly working hours (<30, 30-40, 41-51 and ≥52 hours/week). Multivariate linear regression analysis was performed to investigate the association between weekly working hours and eGFR, with adjustments made for age, sex/gender, income, education, shift work, occupation, smoking, alcohol use, hypertension, diabetes mellitus, body mass index, systolic blood pressure, fasting blood glucose and total serum cholesterol.

RESULTS

A 1-hour increase in weekly working hours was associated with 0.057 mL/min/1.73 m² (95% CI 0.005 to 0.109) decrease in eGFR among participants who worked ≥52 hours/week. Among participants without hypertension or diabetes, a 1-hour increase in weekly working hours was significantly associated with 0.248 and 0.209 mL/min/1.73 m² decrease in eGFR among participants who worked 30-40 hours/week and 41-51 hours/week, respectively.

CONCLUSION

Long working hours are associated with decreased kidney function. We expect that our findings could call for more research regarding this association and provide policy-oriented perspectives.

Association of sleep duration with chronic kidney disease and proteinuria in adults: a systematic review and dose-response meta-analysis

BACKGROUND AND OBJECTIVES

Previous studies have found that sleep duration may be associated with chronic kidney disease (CKD) and proteinuria in adults. However, the correlation remains controversial. In this study, we aimed to assess the effects of sleep duration on CKD and proteinuria.

METHODS

PubMed, EMBASE, and Cochrane Library were searched from their inception up to April 5, 2019 for observational study. The outcomes were CKD and/or proteinuria and the exposure was sleep duration assessed by self-reported questionnaire or interview. Studies were included if they provided risk estimates of effects of sleep duration on patients with CKD or proteinuria. The overall effects were measured by odds ratios (OR) and 95% confidence intervals (CI). Heterogeneity was quantified using Q statistics and the I² statistics. The potential causes of heterogeneity were investigated using sensitivity analysis.

RESULTS

Eleven observational studies with 521,242 individuals were included. The adjusted ORs of CKD in individuals who slept ≤ 6 h/night and ≥ 8 h/night were 1.13 (95% CI, 1.02-1.25; I² = 29%) and 1.14 (95% CI, 1.07-1.22; I²= 0%), respectively. Meanwhile, the adjusted ORs of proteinuria in those who slept ≤ 6 h/night and ≥ 8 h/night were 1.24 (95% CI, 1.06-1.44; I² = 61%) and 1.15 (95% CI, 1.04-1.29; I² = 0%), respectively. Furthermore, a U-shaped relationship was observed between sleep duration and CKD or proteinuria, with the lowest risk at 7 h/night of sleep.

CONCLUSIONS

Both short and long sleep durations are significantly associated with CKD and proteinuria. Our findings suggest curvilinear dose-response associations of sleep duration with CKD and proteinuria.

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 m2. The HR of the 4 groups for incident CKD were calculated with a Cox proportional hazards model, with the 7 to <8 h group set as the reference.

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.

Self-reported sleep duration and daytime napping are associated with renal hyperfiltration and microalbuminuria in an apparently healthy Chinese population

Background

Sleep duration affects health in various ways. The objective of the present study was to investigate the relationships among sleep duration, daytime napping and kidney function in a middle-aged apparently healthy Chinese population.

Methods

According to self-reported total sleep and daytime napping durations, 33,850 participants who were 38–90 years old and recruited from eight regional centers were divided into subgroups. Height, weight, waist circumference, hip circumference, blood pressure, biochemical indexes, fasting blood glucose (FBG), postprandial blood glucose (PBG), HbA1c, creatinine and urinary albumin-creatinine ratio (UACR) were measured and recorded for each subject. Microalbuminuria was defined as UACR ≥30 mg/g, chronic kidney disease (CKD) was defined as eGFR <60 ml/min, and hyperfiltration was defined as eGFR ≥135 ml/min. Multiple logistic regression was applied to investigate the association between sleep and kidney function.

Results

Compared to sleeping for 7–8 h/day, the ORs for microalbuminuria for sleeping for >9 h/day, 8–9 h/day 6–7 h/day and <6 h/day were 1.343 (1.228–1.470, P<0.001), 1.223 (1.134–1.320, P<0.001), 1.130 (1.003–1.273, P = 0.045) and 1.140 (0.908–1.431, P = 0.259), respectively. The eGFR levels exhibited a U-shaped association with sleep duration among subjects with an eGFR ≥90 ml/min and an N-shaped association with sleep duration among subjects with an eGFR <90 ml/min. The OR for hyperfiltration for >9 h/day of sleep was 1.400 (1.123–1.745, P = 0.003) among participants with an eGFR ≥90 ml/min. Daytime napping had a negative effect on renal health. Compared to the absence of a napping habit, the ORs for microalbuminuria for 0–1 h/day, 1–1.5 h/day and >1.5 h/day of daytime napping were 1.552 (1.444–1.668, P<0.001), 1.301 (1.135–1.491, P<0.001) and 1.567 (1.353–1.814, P<0.001), respectively.

Conclusion

The association of total sleep duration with renal health outcomes is U-shaped. Daytime napping has a negative effect on renal health.

Sleep and the Risk of Chronic Kidney Disease: A Cohort Study

STUDY OBJECTIVES

Little information is available regarding the effect of sleep on the development of chronic kidney disease (CKD). This large-cohort study aimed to investigate the association between sleep and the incidence of CKD.

METHODS

We recruited 194,039 participants without CKD aged 20 years or older between 1996 and 2014. Incident CKD was defined as an estimated glomerular filtration rate of < 60 mL/min/1.73 m². Information about sleep duration and quality was obtained from a questionnaire and used to generate a score reflecting the sleep profile. Cox proportional hazards regression models were used to calculate the hazard ratio (HR) and 95% confidence interval (CI) for CKD associations with sleep duration, quality, and score categories.

RESULTS

Regarding sleep duration, participants who slept for fewer than 4 hours (HR 1.45, 95% CI 1.22-1.71), 4 to 6 hours (1.07, 1.02-1.14), or more than 8 hours (1.12, 1.04-1.21) had an increased risk of incident CKD, compared to those who slept 6 to 8 hours. Regarding sleep quality, participants who fell asleep but awoke easily (1.13, 1.07-1.19), had difficulty falling asleep (1.14, 1.06-1.22), or used sleeping pills or sedatives (1.14, 1.20-1.66) had a higher risk of incident CKD, compared to those who slept well. Furthermore, participants with sleep scores of 4 to 6 (1.07, 1.02-1.13) and less than 4 (1.61, 1.37-1.89) had an increased risk of incident CKD, compared to those with a sleep score higher than 6.

CONCLUSIONS

A poor sleep profile is associated with increased risk of CKD development. Therefore, sleep duration and quality should be considered when developing strategies to improve sleep and thus prevent CKD.

COMMENTARY

A commentary on this article appears in this issue on page 371.

Daytime napping and diabetes-associated kidney disease

BACKGROUND

Diabetes-associated Kidney Disease (DKD) is a common comorbidity in patients with type 2 diabetes. The present study investigates whether daytime sleeping duration in patients, ill with type 2 diabetes, is associated with DKD.

METHODS

A total of 733 outpatients of the cross-sectional baseline survey of the DIACORE study were analyzed with respect to their self-reported daytime sleeping duration, assessed by a standardized questionnaire. DKD was defined as eGFR <60 ml/min/1.73 m² and/or urinary albumin-to-creatinine-ratio (UACR) > 30 mg/g.

RESULTS

Mean daytime sleeping duration was 17 ± 27 min. With increasing daytime sleeping duration a statistically significant decrease in eGFR (p = 0.002) and increase in UACR (p < 0.001) were found, respectively. Prevalence of DKD was significantly higher in patients with longer daytime sleeping duration (31% in patients not napping, 40% in patients napping less than 30 min, 47% in patients napping 30-60 min, 56% in patients napping 60 min or more; p = 0.001). After accounting for known modulators (Age, sex, BMI, waist-hip-ratio, systolic and diastolic blood pressure, physical activity, diabetes duration, HbA1c, homeostasis model assessment (HOMA-Index), nighttime sleeping duration, apnea-hypopnea-index (AHI), Epworth Sleepiness Scale (ESS)), longer daytime sleeping duration was significantly associated with impaired eGFR [B (95% CI) = -0.05 (-0.09; 0.00), p = 0.044] and increased UACR [B (95% CI) = 0.01 (0.01; 0.02), p < 0.001], respectively.

CONCLUSION

Increased daytime sleeping duration is significantly associated with reduced eGFR and higher UACR, independent of known modulators of DKD. The direction of this relationship remains unclear.

Association of Chronic Insomnia With Mortality and Adverse Renal Outcomes

OBJECTIVE

To examine whether chronic insomnia is associated with an increased risk of adverse renal outcomes and all-cause mortality.

PATIENTS AND METHODS

We examined associations of chronic insomnia (defined as the presence of both International Classification of Diseases, Ninth Revision codes 307.42, 307.49, and 780.52 and long-term use of insomnia medications) with adverse renal outcomes (end-stage renal disease, incidence of estimated glomerular filtration rate [eGFR] ≤45 mL/min per 1.73 m², and eGFR slopes <-3.0 mL/min per 1.73 m² per year) and all-cause mortality in a national cohort of 1,639,090 US veterans by using Cox proportional hazards and logistic regression models with multivariable adjustments.

RESULTS

A total of 36,741 patients (2.24%) had chronic insomnia; 32,985 (89.8%) were male and 28,090 (76.5%) were white, with a mean baseline eGFR of 84.1±16.4 mL/min per 1.73 m². Chronic insomnia was associated with a significantly higher risk of eGFR 45 mL/min per 1.73 m² or less (multivariable-adjusted hazard ratio [HR], 1.39; 95% CI, 1.34-1.44; P<.001), and rapid loss of kidney function (odds ratio, 1.07; 95% CI, 1.03-1.12; P=.002), but not end-stage renal disease (HR, 1.25; 95% CI, 0.81-1.93; P=.32). Chronic insomnia was not associated with a higher risk of all-cause mortality (HR, 1.00; 95% CI, 0.97-1.03; P=.99).

CONCLUSION

Chronic insomnia is associated with a higher risk of development and progression of chronic kidney disease, but not ESRD. Further studies are needed to establish the underlying mechanisms of action and to determine whether treatment of insomnia could be beneficial to prevent deteriorating kidney function.

Separation of circadian- and behavior-driven metabolite rhythms in humans provides a window on peripheral oscillators and metabolism

Shift workers, whose schedules are misaligned relative to their suprachiasmatic nuclei (SCN) circadian pacemaker, are at elevated risk of metabolic disorders. In a study of simulated day- versus night-shift work followed by a constant routine, we separated plasma-circulating metabolites according to whether their 24-h rhythms aligned with the central SCN pacemaker or instead reflected externally imposed behavioral schedules. We found that rhythms in many metabolites implicated in food metabolism dissociated from the SCN pacemaker rhythm, with the vast majority aligning with the preceding sleep/wake and feeding/fasting cycles. Our metabolomics study yields insight into the link between prolonged exposure to shift work and the spectrum of associated metabolic disorders by providing a window into peripheral oscillators and the biobehavioral factors that orchestrate them.

Misalignment between internal circadian rhythmicity and externally imposed behavioral schedules, such as occurs in shift workers, has been implicated in elevated risk of metabolic disorders. To determine underlying mechanisms, it is essential to assess whether and how peripheral clocks are disturbed during shift work and to what extent this is linked to the central suprachiasmatic nuclei (SCN) pacemaker and/or misaligned behavioral time cues. Investigating rhythms in circulating metabolites as biomarkers of peripheral clock disturbances may offer new insights. We evaluated the impact of misaligned sleep/wake and feeding/fasting cycles on circulating metabolites using a targeted metabolomics approach. Sequential plasma samples obtained during a 24-h constant routine that followed a 3-d simulated night-shift schedule, compared with a simulated day-shift schedule, were analyzed for 132 circulating metabolites. Nearly half of these metabolites showed a 24-h rhythmicity under constant routine following either or both simulated shift schedules. However, while traditional markers of the circadian clock in the SCN—melatonin, cortisol, and PER3 expression—maintained a stable phase alignment after both schedules, only a few metabolites did the same. Many showed reversed rhythms, lost their rhythms, or showed rhythmicity only under constant routine following the night-shift schedule. Here, 95% of the metabolites with a 24-h rhythmicity showed rhythms that were driven by behavioral time cues externally imposed during the preceding simulated shift schedule rather than being driven by the central SCN circadian clock. Characterization of these metabolite rhythms will provide insight into the underlying mechanisms linking shift work and metabolic disorders.

The effects of short sleep duration on proteinuria and chronic kidney disease: a systematic review and meta-analysis

Background

The risks of proteinuria and chronic kidney disease (CKD) in adults who regularly have short sleep duration (short sleepers) are controversial. The aim of this meta-analysis was to assess the effects of short sleep duration on proteinuria and CKD.

Methods

A literature search was conducted using MEDLINE, EMBASE and the Cochrane Database of Systematic Reviews from the inception of the databases through November 2015. Studies that reported relative risks, odd ratios or hazard ratios comparing the risks of proteinuria and CKD in short sleepers were included. Pooled risk ratios (RR) and 95% confidence intervals (CI) were computed utilizing a random-effect, generic inverse variance method.

Results

Six observational studies with 252 075 individuals and three observational studies with 37 197 individuals were included in the analyses to assess the risks of CKD and proteinuria in short sleepers, respectively. The pooled RR of CKD in short sleepers was 1.51 (95% CI, 0.99-2.55). When meta-analysis was restricted only to studies with adjusted analysis for confounders assessing the risk of CKD in short sleepers, the pooled RR of CKD was 1.54 (95% CI, 0.80-2.95). The pooled RR of proteinuria in short sleepers was 1.47 (95% CI, 1.26-1.72).

Conclusions

Despite the lack of significant association between short sleep duration and CKD, our meta-analysis suggests a potential association between short sleep duration and proteinuria, a surrogate marker for kidney disease progression. Future study is required to investigate if reversal of short sleep helps reduce proteinuria.

Sleep Duration and Diabetic Kidney Disease

Aims: Abnormally short or long durations of sleep have been proposed as a risk factors for diabetes and its micro- and macro-vascular complications. However, the relationship between sleep duration and diabetic kidney disease (DKD) has not been well-characterized. Thus, we aimed to examine the association of sleep duration with DKD in two Asian populations. Methods: We included 1,258 persons (Malay, n = 403; Indian, n = 855) aged 40-80 years with diabetes from a population-based cross-sectional sample from Singapore. DKD was defined by low estimated glomerular filtration rate (eGFR <60 mL/min/1.73 m²) and albuminuria (urinary albumin-to-creatinine ratio ≥30 mg/g, only measured in Indian participants). Self-reported habitual sleep duration was categorized into 4 categories: very short (<5 h), short (5-6.9 h), normal (7-8 h) and long (>8 h). The associations of sleep duration with low eGFR and albuminuria were analyzed using multivariable logistic regression models adjusted for multiple potential confounders (including classic risk factors such as HbA1c and hypertension). Results: In total, 268 (21.3%) participants had low eGFR, and 271 (34.7% in Indians) had albuminuria. The number (%) of individuals with very short, short, normal, and long durations of sleep were 117 (9.3%), 629 (50.0%), 429 (34.1%), and 83 (6.6%), respectively. Long sleep duration was associated with a higher odds of renal insufficiency compared to normal sleep duration (OR [95% CI]: 2.31 [1.27-4.19]) on multivariable analysis. Similarly, both long and very short durations of sleep were associated with higher odds of albuminuria (OR [95%]: 2.44 [1.36, 4.38] and 2.37 [1.25, 4.50], respectively) in Indian participants (where data on albuminuria were available). Conclusions: Our study suggests that abnormally short or long durations of sleep were associated with DKD, manifesting as either a reduced eGFR or increased albuminuria. However, further longitudinal data would be required for confirmation.

Understanding the direction of the relationship between white matter hyperintensities of vascular origin, sleep quality, and chronic kidney disease-Results from the Atahualpa Project

OBJECTIVE

The burden of cerebral small vessel disease, sleep disorders, and chronic kidney disease is on the rise in remote rural settings. However, information on potential links between these conditions is limited. We aimed to assess the relationships between these conditions in community-dwelling older adults living in rural Ecuador.

PATIENTS AND METHODS

Atahualpa residents aged ≥60 years were offered a brain MRI. A venous blood sample was obtained for serum creatinine determination. Baseline interviews and procedures were directed to assess demographics, cardiovascular risk factors, and sleep quality. Using generalized structural equation modeling (GSEM), we assessed the associations between white matter hyperintensities (WMH) of vascular origin, sleep quality and kidney function, as well as the directions of the relationships between these variables.

RESULTS

Of 423 candidates, 314 (74%) were enrolled. Moderate-to-severe WMH were noticed in 74 (24%) individuals, poor sleep quality in 101 (31%), and moderate-to-severe chronic kidney disease in 28 (9%). GSEM showed that the direction of the effect was from kidney function to WMH and from the latter to sleep quality. Of independent variables investigated, worse kidney function was associated with age, high glucose levels and male sex. WMH was associated with cholesterol blood levels, blood pressure, level of education and severe edentulism. Poor sleep quality was associated with poor physical activity.

CONCLUSION

This population based study shows that chronic kidney disease is associated with increased severity of WMH, which, in turn, is associated with a poor sleep quality.

Sleep duration and quality in relation to chronic kidney disease and glomerular hyperfiltration in healthy men and women

Background

It is unclear whether sleep duration and quality are associated with chronic kidney disease (CKD) and glomerular hyperfiltration. The aim of this study was to examine the association of sleep duration and quality with CKD and glomerular hyperfiltration in young and middle-aged adults.

Methods

We conducted a cross-sectional study of men and women who underwent a health checkup examination, including assessment of sleep duration and quality (n = 241,607). Chronic kidney disease (CKD) was defined as an estimated glomerular filtration rate (eGFR) less than 60 ml/min/1.73 m², and glomerular hyperfiltration was defined as eGFR above the age-/sex-specific 95^th percentile.

Results

In a multinomial logistic regression analysis adjusting for relevant confounders, the adjusted prevalence ratios for CKD (95% confidence interval) comparing sleep durations of ≤ 5, 6, 8, and 9 hours with 7 hours were 1.22 (0.95–1.55), 0.93 (0.75–1.14), 0.97 (0.75–1.26), and 1.56 (1.06–2.30) in men and 0.98 (0.68–1.43), 1.03 (0.72–1.46), 1.39 (0.97–2.00), and 1.31 (0.78–2.22) in women, respectively. The corresponding prevalence ratios (95% confidence interval) for glomerular hyperfiltration were 1.00 (0.93–1.08), 0.97 (0.91–1.03), 1.03 (0.94–1.13), and 1.39 (1.13–1.72) in men and 1.04 (0.95–1.14), 0.96 (0.90–1.04), 1.11 (1.02–1.20), and 1.28 (1.14–1.45) in women, respectively. Poor subjective sleep quality was associated with glomerular hyperfiltration in men and women.

Conclusion

In this large study of young and middle-aged adults, we found that long sleep duration was associated with CKD and glomerular hyperfiltration. Additionally, poor subjective sleep quality was associated with increased prevalence of glomerular hyperfiltration, suggesting the importance of adequate quantity and quality of sleep for kidney function.

Sleep duration and chronic kidney disease: The Korean Genome and Epidemiology Study (KoGES)-Kangwha study

BACKGROUND/AIMS

Sleep duration affects health in various ways. The objective of this study was to investigate the associations of sleep duration with chronic kidney disease (CKD) in a Korean adult population.

METHODS

This cross-sectional analysis was conducted for total of 1,360 participants who completed baseline health examinations for the Korean Genome and Epidemiology Study-Kangwha study in 2010 to 2011. Sleep habits were measured by an interviewer-assisted questionnaire. Sleep duration was calculated based on the number of hours per day participants had slept over the past 1 year. CKD was defined as either proteinuria or estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m². Multiple logistic regression models were applied to examine associations between sleep duration and CKD.

RESULTS

Women with very long sleep duration (≥ 9 hours/day) were at significantly increased odds for having high serum creatinine (odds ratio [OR], 2.936; 95% confidence interval [CI], 1.176 to 7.326), low eGFR (OR, 3.320; 95% CI, 1.372 to 8.034), and CKD (OR, 3.112; 95% CI, 1.315 to 7.363), compared those with a typical sleep duration (7 to < 8 hours/day), after adjusting for sociodemographic status, socioeconomic status, health behaviors, comorbidities, and sleep quality. Among women, for every 1 hour increase in sleep duration per day, there was a 24.6% increase in the presence of CKD (OR, 1.246; 95% CI, 1.019 to 1.523). However, among men, sleep duration was not significantly associated with CKD.

CONCLUSIONS

Very long sleep duration was independently associated with a higher prevalence of CKD among Korean women. Gender may influence this association.

Nonapnea Sleep Disorders and the Risk of Acute Kidney Injury: A Nationwide Population-Based Study

Nonapnea sleep disorders (NASDs) and associated problems, which are highly prevalent in patients with kidney diseases, are associated with unfavorable medical sequelae. Nonetheless, whether NASDs are associated with acute kidney injury (AKI) development has not been thoroughly analyzed. We examined the association between NASD and AKI. We conducted a population-based study by using 1,000,000 representative data from the Taiwan National Health Insurance Research Database for the period from January 1, 2000, to December 31, 2010. We studied the incidence and risk of AKI in 9178 newly diagnosed NASD patients compared with 27,534 people without NASD matched according to age, sex, index year, urbanization level, region of residence, and monthly income at a 1:3 ratio. The NASD cohort had an adjusted hazard ratio (hazard ratio [HR]; 95% confidence interval [CI] = 1.15-2.63) of subsequent AKI 1.74-fold higher than that of the control cohort. Older age and type 2 diabetes mellitus were significantly associated with an increased risk of AKI (P < 0.05). Among different types of NASDs, patients with insomnia had a 120% increased risk of developing AKI (95% CI = 1.38-3.51; P = 0.001), whereas patients with other sleep disorders had a 127% increased risk of subsequent AKI (95% CI = 1.07-4.80; P = 0.033). Men with NASDs were at a high risk of AKI (P < 0.05). This nationwide population-based cohort study provides evidence that patients with NASDs are at higher risk of developing AKI than people without NASDs.