Sleep debt and prevalence of proteinuria in subjects with short sleep duration on weekdays: a cross-sectional study

Sleep Duration and Kidney Function - Does Weekend Sleep Matter?

Objective

Weekend sleep duration is linked to health issues, including mortality. However, how weekend sleep duration can impact chronic kidney disease (CKD) still needs to be understood. Therefore, we aimed to analyze how weekend sleep duration is associated with kidney function.

Methods

This is a cross-sectional study. Data were obtained from the 2017-2018 National Health and Nutrition Examination Survey. We included 5362 study participants and categorized them into nine subgroups by sleep duration (short: ≤6 hours, normal: 6-9 hours, and long: ≥9 hours) on weekdays and weekends and analyzed for the respective association with renal function using stratified multivariable linear regression.

Results

Weekend sleep duration for 9 hours or more was associated with decreasing estimated glomerular filtration rate (eGFR) levels by 2.8 to 6.4 mL/min/1.73 m2 among people with long to short weekday sleep duration compared with short weekday and weekend sleep durations (control group) after adjusting for demographic characteristics, body measurement, sleep quality, smoking, and comorbidities. The study population with short weekday sleep duration (sWK) and long weekend sleep duration (lWD) had the most significant decline in eGFR. For the study population with sWK, eGFR level significantly decreased by 1.1 mL/min/1.73 m2 as sleep duration on weekends increased by one hour.

Conclusion

The underlying mediators of lWD and CKD could be the dysregulation of human behaviors, metabolism, or biological functions. Longer weekend sleep duration was linked to a decrease in eGFR levels. It warrants further study to clarify the mediators.

Short sleep duration associated with the incidence of cardio-cerebral vascular disease: a prospective cohort study in Shanghai, China

IMPORTANCE

Sleep duration plays an important role in predicting CCVD incidence, and have implications for reducing the burden of CCVD. However, the association between sleep duration and predicted cardio-cerebral vascular diseases (CCVD) risk remains to be fully understood.

OBJECTIVE

To investigate the effects of sleep duration on the development of CCVD among Chinese community residents.

DESIGN

A prospective cohort study. The baseline survey was conducted from January 2013 to July 2013. The cohort has been followed until December 31, 2016 using a combination of in-person interviews and record linkages with the vital registry of Pudong New Area, Shanghai, China.

SUBJECTS

A total of 8245 Chinese community residents were initially enrolled in the cohort. Of those, 6298 underwent the follow-up examination.

EXPOSURE

Self-reported sleep duration and sleep quality were obtained via the questionnaire. Sleep duration was divided into five categories: ≤5, 6, 7, 8, or ≥ 9 h per day.

MAIN OUTCOME(S) AND MEASURE(S)

CCVD, Coronary heart disease (CHD) and Stroke occurrence, Hazard ratios (HRs) and 95% confidence intervals (95% CIs) were calculated using Fine-Gray proportional subdistribution hazards models.

RESULTS

During a median follow-up of 3.00 years (IQR 2.92-3.08), we observed 370 participants have had incident CCVD events, of whom 230 had CHDs, 169 had strokes, and 29 had both. After adjustment for relevant confounders, short sleepers (≤ 5 h) had 83% higher risk of total CCVD incidence (HR: 1.83; 95% CI: 1.32-2.54), 82% higher risk of CHD incidence (HR: 1.82; 95% CI: 1.21-2.75), and 82% higher risk of stroke incidence (HR: 1.82; 95% CI: 1.12-2.98) in contrast to the reference group (7 h). Some of these U-shaped relationships varied by age, and were more pronounced in individuals aged < 65 years. Individuals who slept ≤ 5 h per day with baseline hypertension had the highest risk of CCVD incidence (HR: 3.38, 95% CI 2.08-5.48), CHD incidence (HR: 3.11, 95% CI 1.75-5.53), and stroke incidence (HR: 4.33, 95% CI 1.90-9.86), compared with those sleep 7 h and without baseline hypertension.

CONCLUSIONS

Short sleep duration is independently associated with greater incidence of CCVD, CHD and stroke.

Effect of Seat Angle when Sleeping in a Car on Quality of Sleep and Its Impact on Calculation Performance the Following Day

The number of occasions to stay in a car overnight is increasing during disasters; however, the effects on sleep and the impact on daytime functioning are not well understood. We investigated the effect of seat angle when sleeping in a car and its impact on calculation performance the following day. Fifteen healthy males participated in three trials (sleeping in a car with the front seat angled at 45° and 60° in a laboratory and sleeping at home); sleep and calculation performance the following day were compared. Increased wake after sleep onset and decreased slow-wave sleep were observed in the 60° trial, that is, near-vertical, compared with the others. Subjective sleep quality and calculation performance in the 45° and 60° trials were poorer than those in the home trial. The effect of seat angle on sleep was confirmed objectively, but not subjectively, suggesting that a large seat angle might cause sleep impairment.

Frequency of Breakfast, Lunch, and Dinner and Incidence of Proteinuria: A Retrospective Cohort Study

Although multiple studies have revealed a close association of skipping breakfast with cardiometabolic diseases, few studies have reported its association with chronic kidney disease (CKD). Furthermore, there is scant reporting on the clinical impacts that skipping lunch and dinner has on cardiometabolic diseases and CKD. This retrospective cohort study, including 5439 female and 4674 male workers of a national university in Japan who underwent annual health checkups between January 2005 and March 2013, aimed to assess an association of frequencies of breakfast, lunch, and dinner with incidence of proteinuria (dipstick urinary protein ≥1+). The incidence of proteinuria was observed in 763 (14.0%) females and 617 (13.2%) males during the median 4.3 and 5.9 years of the observational period, respectively. In females, skipping breakfast as well as skipping dinner, but not lunch, were associated with the incidence of proteinuria (adjusted hazard ratios of breakfast frequency of "every day", "sometimes", and "rarely": 1.00 (reference), 1.35 (1.09-1.66), and 1.54 (1.22-1.94), respectively; those of dinner frequency of "every day" and "≤sometimes": 1.00 (reference) and 1.31 (1.00-1.72), respectively). However, no association was observed in male workers. Skipping breakfast and skipping dinner were identified as risk factors of proteinuria in females, but not in males.