Sleep duration and chronic kidney disease: analysis of the national health interview survey

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.

Age-dependent interaction between Life's Essential 8 and chronic kidney disease: A national cross-sectional analysis

OBJECTIVE

Chronic kidney disease (CKD), an age-related condition, is closely associated with cardiovascular disease. We aimed to examine the age-dependent interaction between Life's Essential 8 (LE8), the updated measurement of cardiovascular health (CVH), and CKD in the United States.

METHODS

The cross-sectional study involved 25,529 participants from National Health and Nutrition Examination Survey in 2007-2018. Multivariate logistic regressions were used to estimate the age-dependent interaction between LE8 and CKD, and restricted cubic spline regressions were used to analyze the dose-response relationships between LE8 and CKD among adults and all age subgroups.

RESULTS

Overall, 2934 (9.3%), 17,278 (66.2%), and 5317 (24.5%) participants had low, moderate, and high CVH, separately. After adjusting for the potential covariates, LE8 was negatively associated with CKD [odds ratio (OR) for per 1 standard deviation (SD) increase and 95%CI, 0.71 (0.67, 0.75)], with a nonlinear dose-response relationship (P for nonlinearity = 0.001). The inversed association was stronger among participants aged 65 and older (0.65 (0.59, 0.71)) compared to youngers [20-39 years, 0.63 (0.59, 0.58), 40-64 years, 0.63 (0.59, 0.58)] (P for interaction = 0.002).

CONCLUSIONS

CVH, as measured by the LE8 score, was negatively associated with the presence of CKD in non-linear fashions, more pronounced in participants aged 65 and older compared to younger age groups.

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.

Sleep duration and cognitive function among older adults with chronic kidney disease: results from the National Health and Nutrition Examination Survey (2011-2014)

BACKGROUND

Short and long sleep durations are associated with cognitive dysfunction. Given the increased prevalence of sleep abnormalities in the chronic kidney disease (CKD) population, we tested whether the association between sleep duration and cognitive function differed between older adults with and without CKD.

METHODS

This was a study of 3215 older adults (age ≥60 years) enrolled in the National Health and Nutrition Examination Survey (2011-14) evaluating sleep duration, cognitive function (immediate recall, delayed recall, verbal fluency, executive function and processing speed and global cognition) and kidney function. We quantified the association between sleep duration and cognitive function using linear regression and tested whether the associations differed among those with CKD and without using a Wald test for interaction.

RESULTS

Among 3215 participants, 13.3% reported 2-5 hours of sleep/day, 75.2% reported 6-8 hours, and 11.5% reported ≥9 hours. Persons with CKD were more likely to sleep ≥9 hours [odds ratio 1.73 (95% confidence interval 1.22-2.46)]. Among participants with CKD, those with a sleep duration ≥9 hours demonstrated worse global cognitive function (P for interaction = .01), immediate recall (P for interaction = .01) and verbal fluency (P for interaction = .004) than those with a sleep duration of 6-8 h; no differences were observed for participants with CKD who slept 2-5 hours. Among participants without CKD, sleep was not associated with any measures of cognitive function.

CONCLUSIONS

Longer sleep duration is associated with worse cognitive function only among persons with CKD, and global cognition, delayed recall and verbal fluency are particularly affected. Studies should identify interventions to improve sleep patterns and quality in this population.

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.

Duração do sono autorrelatada e objetiva em pacientes com DRC: contam a mesma história?

Resumo Introdução: Há discordância entre os dados sobre duração do sono obtidos a partir de questionários e medições objetivas. Não se sabe se isto também é verdade para indivíduos com DRC. Aqui comparamos a duração do sono autorrelatada com a duração do sono obtida por meio de actigrafia. Métodos: Este estudo prospectivo incluiu indivíduos adultos com DRC estadio 3 recrutados entre Setembro/2016 e Fevereiro/2019. Avaliamos a duração subjetiva do sono, fazendo a seguinte questão: “Quantas horas de sono real você teve à noite?” Resultados: Os pacientes (N=34) eram relativamente jovens (51 ± 13 anos). A duração do sono autorrelatada e mensurada foi de 7,1 ± 1,7 e 6,9 ± 1,6 horas, respectivamente, sem correlação entre elas (p=0,165). Embora a diferença média entre as medições tenha sido de 0,21 h, os limites de concordância variaram de -3,7 a 4,1 h. Conclusão: Pacientes com DRC que não estão em diálise apresentam uma percepção equivocada do sono. Dados sobre a duração do sono devem ser obtidos preferencialmente a partir de medições objetivas em pacientes com DRC.

Self-reported and objective sleep duration in patients with CKD: are they telling the same story?

Abstract Introduction: There is disagreement between data on sleep duration obtained from questionnaires and objective measurements. Whether this is also true for individuals with CKD is unknown. Here we compared self-reported sleep duration with sleep duration obtained by actigraphy. Methods: This prospective study included adult individuals with stage 3 CKD recruited between September/2016 and February/2019. We evaluated subjective sleep duration by asking the following question: “How many hours of actual sleep did you get at night?” Results: Patients (N=34) were relatively young (51 ± 13 years). Self-reported and measured sleep duration were 7.1 ± 1.7 and 6.9 ± 1.6 hours, respectively, with no correlation between them (p=0.165). Although the mean difference between measurements was 0.21 h, the limits of agreement ranged from -3.7 to 4.1 h. Conclusion: Patients with CKD who are not on dialysis have an erroneous sleep perception. Data on sleep duration should be preferentially obtained from objective measurements in patients with CKD.

Understanding the patient experience of chronic kidney disease stages 2-3b: a qualitative interview study with Kidney Disease Quality of Life (KDQOL-36) debrief

Background

Qualitative patient interviews and patient-reported outcome instruments are important tools to understand the patient experience of disease. The aim of this study was to use patient interviews to identify concepts relevant and important to patients living with chronic kidney disease (CKD) stages 2–3b, develop a comprehensive conceptual model of the patient experience and debrief the Kidney Disease Quality of Life 36-item instrument (KDQOL-36) for patients with CKD stages 2–3b.

Methods

Concept elicitation interviews were conducted with patients with CKD stages 2–3b to identify signs/symptoms and impacts most relevant and important to patients (i.e., ‘salient’ concepts) and develop a conceptual model for the disease. Based on the salient concepts identified in the interviews, new items were proposed to supplement the KDQOL-36. Cognitive debriefing was performed to evaluate the KDQOL-36 and the additional items.

Results

A total of 31 patients were interviewed in this study (22 for concept elicitation and 15 for cognitive debriefing). The interviews identified 56 concepts (33 signs/symptoms and 23 impacts), 17 of which had not been identified in a previous literature review. Four signs/symptoms (‘fatigue/lack of energy/tiredness’, ‘sleep problems’, ‘increased urination [including nocturia]’ and ‘swelling in legs/ankles/feet’) and two impacts (‘anxiety/worry’ and ‘general negative emotional/mental impact’) were identified as salient. Of the salient signs/symptoms, three were not covered by the KDQOL-36 (sleep problems, increased urination and swelling in legs/ankles/feet) and were represented during cognitive debriefing interviews through four additional items (trouble falling asleep, trouble staying asleep, increased urination [including nocturia] and swelling in legs/ankles/feet) generated in the style of the KDQOL-36. All patients found the KDQOL-36 plus the four additional items relevant, and the majority found them clear.

Conclusions

By identifying previously unknown concepts and augmenting the understanding of which are most important to patients, a comprehensive conceptual model was developed for patients who have CKD stages 2–3b. This study also demonstrates the suitability of the KDQOL-36 for patients who have CKD stages 2–3b and provides suggestions for how the instrument could be further developed to more comprehensively capture patient experience.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02826-3.

Short sleep duration and physical and psychological health outcomes among adult survivors of childhood cancer

BACKGROUND

To examine associations between phenotypes of short sleep duration and clinically assessed health conditions in long-term survivors of childhood cancer.

METHODS

Survivors recruited from the St. Jude Lifetime Cohort (n = 911; 52% female; mean age 34 years; 26 years postdiagnosis) completed behavioral health surveys and underwent comprehensive physical examinations. Sleep was assessed with the Pittsburgh Sleep Quality Index. Short sleep was defined as ≤6 h per night with phenotypes of short sleep including poor sleep efficiency (<85%), prolonged sleep onset latency (SOL; ≥30 min), and wake after sleep onset (≥3 times per week). Covariates included childhood cancer treatment exposures, demographics, body mass index, and physical inactivity. Separate modified Poisson regression models were computed for each health category to estimate relative risks (RR) and 95% confidence intervals (CI). Multinomial logistic regression models examined associations between sleep and an aggregated burden of chronic health conditions.

RESULTS

Short sleep duration was reported among 44% (95% CI 41%-47%) of survivors. In multivariable models, short sleep duration alone was associated with pulmonary (RR = 1.35, 95% CI 1.08-1.69), endocrine (RR = 1.22, 95% CI 1.06-1.39) and gastrointestinal/hepatic conditions (RR = 1.46, 95% CI 1.18-1.79), and anxiety (RR 3.24, 95% CI 1.64-6.41) and depression (RR = 2.33, 95% CI 1.27-4.27). Short sleep with prolonged SOL was associated with a high/severe burden of health conditions (OR = 2.35, 95% CI 1.12-4.94).

CONCLUSIONS

Short sleep duration was associated with multiple clinically ascertained adverse health conditions. Although the temporality of these associations cannot be determined in this cross-sectional study, sleep is modifiable and improving sleep may improve long-term health in survivors.

Financial Hardship Among Nonelderly Adults With CKD in the United States

RATIONALE & OBJECTIVE

The burden of financial hardship among individuals with chronic kidney disease (CKD) has not been extensively studied. Therefore, we describe the scope and determinants of financial hardship among a nationally representative sample of adults with CKD.

STUDY DESIGN

Cross-sectional.

SETTING & PARTICIPANTS

Nonelderly adults with CKD from the 2014-2018 National Health Interview Survey.

EXPOSURE

Sociodemographic and clinical characteristics.

OUTCOME

Financial hardship based on medical bills and consequences of financial hardship (high financial distress, food insecurity, cost-related medication nonadherence, delayed/forgone care due to cost). Financial hardship was categorized into 3 levels: no financial hardship, financial hardship but able to pay bills, and unable to pay bills at all. Financial hardship was then modeled in 2 different ways: (1) any financial hardship (regardless of ability to pay) versus no financial hardship and (2) inability to pay bills versus no financial hardship and financial hardship but able to pay bills.

ANALYTICAL APPROACH

Nationally representative estimates of financial hardship from medical bills were computed. Multivariable logistic regression models were used to examine the associations of sociodemographic and clinical factors with the outcomes of financial hardship based on medical bills.

RESULTS

A total 1,425 individuals, representing approximately 2.1 million Americans, reported a diagnosis of CKD within the past year, of whom 46.9% (95% CI, 43.7%-50.2%) reported experiencing financial hardship from medical bills; 20.9% (95% CI, 18.5%-23.6%) reported inability to pay medical bills at all. Lack of insurance was the strongest determinant of financial hardship in this population (odds ratio, 4.06 [95% CI, 2.18-7.56]).

LIMITATIONS

Self-reported nature of CKD diagnosis.

CONCLUSIONS

Approximately half the nonelderly US population with CKD experiences financial hardship from medical bills that is associated strongly with lack of insurance. Evidence-based clinical and policy interventions are needed to address these hardships.

Obstructive sleep apnea, sleep duration and chronic kidney disease in patients with coronary artery disease

BACKGROUND

Limited evidence is available addressing the potential role of sleep disorders on renal function. Here, we aimed to explore the associations of obstructive sleep apnea (OSA) and sleep duration (SD) with renal function in subjects with high cardiovascular risk.

METHODS

Consecutive subjects with coronary artery disease (CAD) underwent clinical evaluation, sleep study to define OSA and one-week wrist actigraphy to objectively measure SD. OSA was defined by an apnea-hypopnea index (AHI) of ≥15 events/hour. The estimated glomerular filtration rate (eGFR) was calculated using the CKD-EPI equation. We analyzed the associations of OSA and SD with continuous eGFR values and according to the presence of CKD (eGFR<60 mL/min/1.73 m²) after adjusting for multiple confounding factors.

RESULTS

We studied 242 subjects (62.8% men). The frequency of OSA was 55.4% and the median SD was 412.8 (363.4-457.25) min. There was no difference in the eGFRs between participants with and without OSA (69.3 ± 19.1 vs. 74.6 ± 19.3 mL/min/1.73 m², p = 0.72) and the rate of eGFR <60 mL/min/1.73 m² (34.3% vs. 25.9%; p = 0.21). Similarly, we did not find differences in patients in eGFR for those with SD ≥ 6 h versus SD < 6 h (72.5 ± 20.3 vs. 71.4 ± 19.1 mL/min/1.73 m², p = 0.72). In the linear regression analysis, AHI was independently associated with an eGFR<60 mL/min/1.73 m² in the unadjusted model [-0.15 (-0.27 to -0.04)], (P = 0.01), but not in the adjusted models. Analyses of continuous SD or the stratification in SD ≥ 6 h or <6 h also revealed neutral results on eGFR.

CONCLUSION

OSA severity and SD were not independently associated with CKD in subjects with CAD.

Kidney cancer mortality disparities among Hispanics in the US

INTRODUCTION

Kidney cancer incidence is increasing among Hispanics but rate differences by distinct group, such as Cuban, Puerto Rican, and Mexican have not been studied. To fill this knowledge gap, we use mortality data, reflecting fatal kidney cancers, to examine patterns by race-ethnicity, including detailed Hispanic groups, and correlate the mortality rates with each group's prevalence of known kidney cancer risk factors: smoking, obesity, hypertension, diabetes, and chronic kidney disease.

METHODS

We used individual-level death data for California, Florida, and New York (2008-2018), and population prevalence data from the National Health Interview Surveys (2008-2018). Age-adjusted mortality rates (AAMRs) and regression-derived mortality rate ratios (MRRs) were computed. Pearson correlation analyses assessed the extent to which group-specific risk factor prevalence explained variability in observed AAMRs.

RESULTS

US-born Mexican Americans and American Indians had the highest rates and MRRs compared to Whites: 1.44 (95 %CI: 1.35-1.53) and 1.51 (1.38-1.64) for Mexican American men and women, respectively, and 1.54 (95 %CI: 1.25-1.89) and 1.53 (95 %CI: 1.15-2.04) for American Indians. In contrast, non-Mexican Hispanics had lower rates than Whites. Among males, positive correlations between AAMRs and smoking, obesity, and chronic kidney disease prevalence by race-ethnicity were found.

CONCLUSION

Mexican Americans and American Indians are high-risk for fatal kidney cancer. Disparities are only partially attributable to higher smoking and obesity prevalence, and more so among men than women. A shared risk factor profile, as well as possible genetic similarities, may explain their disproportionately higher kidney cancer mortality, but further research is warranted.

Multiple, objectively measured sleep dimensions including hypoxic burden and chronic kidney disease: findings from the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Poor sleep may contribute to chronic kidney disease (CKD) through several pathways, including hypoxia-induced systemic and intraglomerular pressure, inflammation, oxidative stress and endothelial dysfunction. However, few studies have investigated the association between multiple objectively measured sleep dimensions and CKD.

METHODS

We investigated the cross-sectional association between sleep dimensions and CKD among 1895 Multi-Ethnic Study of Atherosclerosis Sleep Ancillary Study participants who completed in-home polysomnography, wrist actigraphy and a sleep questionnaire. Using Poisson regression models with robust variance, we estimated separate prevalence ratios (PR) and 95% CIs for moderate-to-severe CKD (glomerular filtration rate <60 mL/min/1.73 m² or albuminuria >30 mg/g) among participants according to multiple sleep dimensions, including very short (≤5 hours) sleep, Apnoea-Hypopnoea Index and sleep apnoea-specific hypoxic burden (SASHB) (total area under the respiratory event-related desaturation curve divided by total sleep duration, %min/hour)). Regression models were adjusted for sociodemographic characteristics, health behaviours and clinical characteristics.

RESULTS

Of the 1895 participants, mean age was 68.2±9.1 years, 54% were women, 37% were white, 28% black, 24% Hispanic/Latino and 11% Asian. Several sleep metrics were associated with higher adjusted PR of moderate-to-severe CKD: very short versus recommended sleep duration (PR=1.40, 95% CI 1.06 to 1.83); SASHB (Box-Cox transformed SASHB: PR=1.06, 95% CI 1.02 to 1.12); and for participants in the highest quintile of SASHB plus sleep apnoea: PR=1.28, 95% CI 1.01 to 1.63.

CONCLUSIONS

Sleep apnoea associated hypoxia and very short sleep, likely representing independent biological mechanisms, were associated with a higher moderate-to-severe CKD prevalence, which highlights the potential role for novel interventions.

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.

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.

Habitual sleep and kidney function in chronic kidney disease: the Chronic Renal Insufficiency Cohort study

Physiological evidence suggests that sleep modulates kidney function. Our objective was to examine the cross-sectional association between kidney function and objectively-estimated habitual sleep duration, quality and timing in a cohort of patients with mild to moderate chronic kidney disease. This study involved two US clinical centers of the Chronic Renal Insufficiency Cohort (CRIC) study, including 432 participants in a CRIC ancillary sleep study. Habitual sleep duration, quality and timing were measured using wrist actigraphy for 5-7 days. Validated sleep questionnaires assessed subjective sleep quality, daytime sleepiness and risk of sleep apnea. Kidney function was assessed with the estimated glomerular filtration rate using the Chronic Kidney Disease Epidemiology Collaboration equation, and the urinary protein to creatinine ratio. Lower estimated glomerular filtration rate was associated with shorter sleep duration (-1.1 mL min^-1  1.73 m^-2 per hour less sleep, P = 0.03), greater sleep fragmentation (-2.6 mL min^-1  1.73 m^-2 per 10% higher fragmentation, P < 0.001) and later timing of sleep (-0.9 mL min^-1  1.73 m^-2 per hour later, P = 0.05). Higher protein to creatinine ratio was also associated with greater sleep fragmentation (approximately 28% higher per 10% higher fragmentation, P < 0.001). Subjective sleep quality, sleepiness and persistent snoring were not associated with estimated glomerular filtration rate or protein to creatinine ratio. Thus, worse objective sleep quality was associated with lower estimated glomerular filtration rate and higher protein to creatinine ratio. Shorter sleep duration and later sleep timing were also associated with lower estimated glomerular filtration rate. Physicians treating patients with chronic kidney disease should consider inquiring about sleep and possibly sending for clinical sleep assessment. Longitudinal and interventional trials are needed to understand causal direction.

Sleep Disorders and Cardio-Renal Disease: Implications for Minority Populations

Obesity is a major public health problem that is reaching pandemic proportion. Currently two thirds of the American population is either overweight or obese and worldwide, 39% of the population is overweight and 13% are considered obese [1,2]. This rapid rise in obesity is associated with increased in diabetes mellitus type 2 (DM2), hypertension (HTN), chronic kidney disease (CKD) and cardiovascular diseases (CVD), the major killer of adults in the USA. Parallel to this epidemic is the rapid rise of sleep disorders such as Obstructive Sleep Apnea (OSA). These disorders lead to increased morbidity and mortality and generally go undiagnosed and undertreated, particularly among minority groups. Accumulating evidence indicates common pathophysiologic background underlying all of these related disorders. Among these include: increased inflammation, increased oxidative stress, endothelial dysfunction, dyslipidemia and hypercoagulability. We discuss the rising epidemic of sleep disorders and its interrelationship with DM2, HTN, CVD and renal disease highlighting the racial disparity in diagnosis and treatment of these disorders that disproportionately affects minority populations. We also discuss the various treatment modalities and the cutting edge developments in this field.

Association of sleep duration with kidney function and albuminuria: NHANES 2009-2012

OBJECTIVE

The purpose of this study was to examine the association between self-reported sleep duration and markers of kidney function.

DESIGN

A cross-sectional survey from the 2009-2012 National Health and Nutrition Examination Survey.

SETTING AND PARTICIPANTS

The participants were 8690 adults (e20years) without a previous sleep disorder diagnosis, end-stage kidney failure, or other kidney or liver problems. Subsamples with pre-diabetes and pre-hypertension were examined.

MEASUREMENTS

Participants reported habitual sleep duration, coded as d5, 6, 7, 8, and e9hours per night. Biomarkers of kidney function were determined, including glomerular filtration rate (eGFR) estimated from the Chronic Kidney Disease Epidemiology Collaboration equation, urine albumin-to-creatinine ratio (ACR), microalbuminuria status, and glomerular hyperfiltration status. Weighted and adjusted general linear models assessed associations between sleep duration with eGFR and ACR. Logistic regression analyses evaluated the associations of microalbuminuria and glomerular hyperfiltration status with sleep duration.

RESULTS

Greater eGFR was related to short sleep duration in the total sample and among participants with pre-diabetes. Greater ACR was associated with short and long sleep duration. Short sleep duration (d5hours) was associated with an increased odds for glomerular hyperfiltration (OR, 1.41; 95% CI, 0.97-2.06) and microalbuminuria (OR, 1.31; 95% CI, 0.96-1.79).

CONCLUSIONS

In a US representative sample of adults, self-reported short and long sleep duration were related to higher ACR. Short sleep duration was associated with higher eGFR and microalbuminuria. Research is needed to understand whether these associations indicate increased risk for kidney damage and cardiovascular risk.