Effects and differences of sleep duration on the risk of new-onset chronic disease conditions in middle-aged and elderly populations

Association Between Internet Use and Sleep Health Among Middle-Aged and Older Chinese Individuals: Nationwide Longitudinal Study

BACKGROUND

Sleep disorders are common among older adults and have a bidirectional impact on their emotional well-being. While some studies suggest that internet use may offer mental health benefits to this population, the relationship between internet use and sleep outcomes remains underexplored.

OBJECTIVE

This study investigates the association between internet use (including use frequency) and sleep quality and duration in middle-aged and older Chinese adults.

METHODS

A longitudinal analysis was conducted using the China Health and Retirement Longitudinal Study data from 2015 to 2018. Sleep quality was assessed using the sleep item from the Centre for Epidemiologic Studies Depression Scale, categorized as "good" (<1 day; reference), "fair" (1-4 days), or "poor" (5-7 days). Sleep duration was classified as short (<6 hours), medium (6-9 hours; reference), or long (>9 hours). Adjusted multinomial logistic regressions were used to examine the associations between internet use or frequency in 2015 and sleep quality or duration in 2018, controlling for age, sex, residence, diseases, smoking, drinking, and napping time and further exploring sex and age group variations.

RESULTS

The baseline analysis included 18,460 participants aged 45 years and older, with 1272 (6.9%) internet users, 8825 (48.1%) participants had fair or poor sleep, and 6750 (37.2%) participants had abnormal sleep duration. Internet users, particularly those who used it almost daily, were less likely to report poor sleep quality (relative risk [RR] 0.71, 95% CI 0.54-0.94) and longer sleep duration (RR 0.22, 95% CI 0.11-0.44) than nonusers. In the longitudinal analysis, baseline internet users had a significantly reduced risk of fair (RR 0.66, 95% CI 0.51-0.86) and poor sleep quality (RR 0.60, 95% CI 0.44-0.81), as well as short (RR 0.73, 95% CI 0.53-1.00) and long sleep duration (RR 0.39, 95% CI 0.21-0.72) during the follow-up period than nonusers. These associations remained significant for almost daily internet use (RR 0.32, 95% CI 0.15-0.69). Subgroup analyses by sex revealed a positive relationship between internet use and sleep quality, with a stronger effect in female (poor sleep: RR 0.57, 95% CI 0.36-0.89) than male (poor sleep: RR 0.61, 95% CI 0.40-0.92) participants. The effect on sleep duration was significant only in daily male users, showing a reduced risk of long sleep duration (RR 0.30, 95% CI 0.11-0.78). In the age subgroup analysis, most internet users were in the 45- to 59-year age group, with results consistent with the overall findings.

CONCLUSIONS

This study suggests that internet use is associated with a reduced risk of sleep problems in middle-aged and older adults. The findings indicate that moderate, regular internet engagement-such as daily use-may promote better sleep health in this population.

Interaction effect between sleep duration and dynapenic abdominal obesity for predicting functional disability: A longitudinal study

OBJECTIVE

To assess the interaction of dynapenic abdominal obesity (DAO) and sleep duration on the risk of functional disability among middle-aged and older Chinese individuals.

METHODS

Data were extracted from the China Health and Retirement Longitudinal Study conducted in 2011, 2013, 2015, 2018, and 2020. A total of 6,343 participants were enrolled in this retrospective cohort study. Sleep duration was obtained through face-to-face interviews. Dynapenia (D) and abdominal obesity (AO) were defined by handgrip strength and waist circumference, respectively. Functional disability was assessed according to activities of daily living scales. Cox proportional hazard models analyzed the interactions of DAO and sleep duration on functional disability.

RESULTS

Over a mean follow-up of 10 years, 3,879 (61.2%) participants reported functional disability. Individuals with short sleep duration and D/AO (appropriate but short: RR = 1.42, 95% CI = 1.10-1.82, too short sleep: RR = 1.54, 95% CI = 1.16-2.06), long sleep duration and D/AO (appropriate but long: RR = 1.61, 95% CI = 1.11-2.33; too long: RR = 1.63, 95% CI = 1.15-2.32), were more likely to develop functional disability than those with normal sleep duration and ND/NAO in the fully adjusted model. The multiplicative interaction between the short sleep group and D/NAO or ND/AO were both significant. Middle-aged individuals and females were more susceptible to the effects of short sleep and DAO, while elderly individuals and males were more susceptible to the effects of long sleep and DAO.

CONCLUSIONS

Short and long sleep durations combined with DAO increase the risk of functional disability. Managing waist circumference and improving grip strength in middle-aged and older adults with abnormal sleep durations may help prevent functional disability.

Association between nap time, nighttime sleep, and multimorbidity in Chinese older adults: a cross-sectional study

OBJECTIVE

This study aims to explore the relationship between sleep duration and multimorbidity among elderly Chinese and to determine the optimal sleep duration for preventing multimorbidity.

METHODS

This study is based on data from the 2020 China Health and Elderly Care Longitudinal Survey (CHARLS), which collected detailed information from 5,761elderly individuals, including demographic characteristics, sleep duration, health status, and lifestyle information. Logistic regression models were used to investigate the relationship between sleep duration and multimorbidity, and restricted cubic spline analysis was employed to analyze the dose-response relationship between sleep duration and multimorbidity.

RESULTS

After adjusting for potential confounders, a U-shaped association was found between nighttime sleep duration and the likelihood of multimorbidity among the elderly. Specifically, elderly individuals with a nighttime sleep duration of 7 h had the lowest incidence of multimorbidity. Compared to those with 6-8 h of nighttime sleep, elderly individuals with less than 6 h (OR = 1.24, 95% CI: 1.05-1.48) or more than 8 h (OR = 1.79, 95% CI: 1.37-2.34) of nighttime sleep had a 24% and 79% increased likelihood of multimorbidity, respectively. The restricted cubic spline analysis further confirmed this U-shaped relationship, showing that the likelihood of multimorbidity gradually decreased as sleep duration increased from 6 to 7 h, but gradually increased as sleep duration exceeded 7 h. Additionally, a positive correlation was found between napping habits and the likelihood of multimorbidity, with elderly individuals without napping habits having a lower likelihood of multimorbidity compared to those with napping habits. Subgroup analysis indicated no significant differences in the impact of 6-8 h of nighttime sleep on multimorbidity among male and female elderly individuals and different age groups.

CONCLUSION

Appropriate nighttime sleep duration may be an important factor in preventing multimorbidity among the elderly, while increased napping duration may increase the likelihood of multimorbidity. These findings provide scientific evidence for sleep health management among the elderly, suggesting the promotion of appropriate sleep duration to reduce the likelihood of multimorbidity in this population.

Associations Between Sleep Duration and Activity of Daily Living Disability Among Older Adults in China: Cross-Sectional Study

Background

China has the largest elderly population globally; the growth rate of the aged tendency of the population was higher than that of Western countries. Given the distinctions in historical, ethnic, and economic status as well as socio-cultural background, Chinese adults had different sleep patterns compared with adults in other countries. Considering the heavy disease burden caused by activities of daily living (ADL) disability, we conducted a cross-sectional analysis using data from the China Health and Retirement Longitudinal Study (CHARLS) to test the hypothesis that individuals with short and longer sleep duration are more likely to have ADL disability.

Objective

ADL disability is a common condition affecting the quality of life among older people. This study aimed to explore the associations between sleep duration and ADL disability among middle-aged and older adults in China.

Methods

This cross-sectional study used data from 17,607 participants from the 2018 CHARLS (from 2018 to 2020), an ongoing representative survey of adults aged 45 years or older and their spouses. Self-reported sleep duration per night was obtained from face-to-face interviews. The ADL was measured using a 6-item summary assessed with an ADL scale that included eating, dressing, getting into or out of bed, bathing, using the toilet, and continence. Multiple generalized linear regression models-adjusted for age, sex, education, marital status, tobacco and alcohol use, depression, place of residence, sensory impairment, self-reported health status, life satisfaction, daytime napping, chronic disease condition, and sample weights-were used.

Results

Data were analyzed from 17,607 participants, of whom 8375 (47.6%) were men. The mean (SD) age was 62.7 (10.0) years. Individuals with 4 hours or less (odds ratio [OR] 1.91, 95% CI 1.60-2.27; P<.001), 5 hours (OR 1.33, 95% CI 1.09-1.62; P=.006), 9 hours (OR 1.48, 95% CI 1.13-1.93; P<.001), and 10 hours or more (OR 1.88, 95% CI 1.47-2.14; P<.001) of sleep per night had a higher risk of ADL disability than those in the reference group (7 hours per night) after adjusting for several covariates. Restricted cubic splines analysis suggested a U-shaped association between sleep duration and ADL disability. When sleep duration fell below 7 hours, an increased sleep duration was associated with a significantly low risk of ADL disability, which was negatively correlated with sleep duration until it fell below 7 hours (OR 0.83, 95% CI 0.79-0.87; P<.001). When sleep duration exceeded 7 hours, the risk of ADL disability would increase facing prolonged sleep duration (OR 1.19, 95% CI 1.12-1.27; P<.001). ADL disability should be monitored in individuals with insufficient (≤4 or 5 hours per night) or excessive (9 or ≥10 hours per night) sleep duration.

Unlabelled

In this study, a U-shaped association between sleep duration and ADL disability was found. Future longitudinal studies are needed to establish temporality and examine the mechanisms of the associations between sleep duration and ADL disability.

Mapping the 9-year sleep trajectory and its implications for chronic disease risks among middle-aged and older adults

OBJECTIVE

To identify the 9-year trajectories of sleep duration and to assess the relationship between time-dependent sleep duration and sleep trajectories with 14 chronic diseases in adults.

METHODS

This study used five waves of data of the China Health and Retirement Longitudinal Survey. Participants with complete sleep duration data and at least one record of 14 chronic diseases were included. The group-based trajectory model was used to identify sleep trajectories from 2011 to 2020. Time-dependent survival analysis and logistic regression were used to examine the relationship between time-dependent sleep duration and sleep trajectories with chronic diseases.

RESULTS

A total of 9063 participants were included, with a mean (standard deviation, SD) sleep duration of 6.37 (1.83) h/d. Sleeping <7 h/d predicted higher risks of 11 chronic diseases at follow-up, with hazard ratios (HR) and 95 % confidence intervals (CI) ranging from 1.71 (1.26-2.33) for psychiatric disease to 1.15 (1.04-1.27) for dyslipidemia. Five sleep trajectories were identified and labeled as group 1-5 based on ascending order of sleep duration. Consistently sleeping <4 h/d (group 1) and 4-6 h/d predicted higher risks of most chronic diseases, with the highest HR (95 %CI) of 3.50 (1.73-6.92) and 2.94 (1.82-4.49) for psychiatric diseases, respectively. Consistently sleeping 6-7 h/d (group 3) predicted higher risks of digestive diseases and arthritis. Decreasing sleep (group 4) predicted higher risks of psychiatric diseases and memory-related diseases.

CONCLUSIONS

Consistently sleeping <6 h/d predicted higher risks of most chronic diseases, especially psychiatric diseases. Digestive disease and arthritis were more sensitive to consistently inadequate sleep.

The Interplay between nighttime/midday sleep duration and the number of new-onset chronic diseases: A decade-long prospective study in China

OBJECTIVE

To investigate the interplay between individual nighttime and midday sleep duration and the number of new-onset chronic diseases and determine the optimal sleep duration associated with lowest number of new-onset chronic diseases.

METHODS

We used data from the China Health and Retirement Longitudinal Study (CHARLS) covering a decade and involving 10,828 participants. A random intercept cross-lagged model was used to explore the interplay between nighttime/midday sleep durations and new-onset chronic diseases at both the within-individual and between-individual levels, followed by a dose-response analysis at the between-individual level to determine the optimal sleep duration. New-onset chronic diseases include 14 types of self-reported diseases diagnosed by doctors.

RESULTS

Within-individual analysis revealed that increased nighttime/midday sleep duration led to a higher number of new-onset chronic diseases, and an increased number of new-onset chronic diseases resulted in decreased nighttime sleep duration. Between nighttime and midday sleep, one type of sleep duration increase was likely to lead to an increase in another type. Between-individual analysis found a nonlinear relationship between the number of new-onset chronic diseases and nighttime sleep duration, identifying the optimal nighttime sleep duration as 7.46 h.

CONCLUSIONS

These findings elucidate the interplay between sleep duration and number of new-onset chronic diseases and underscore the need for public awareness and comprehensive interventions. Future studies should focus on refining sleep monitoring and exploring the sleep-chronic diseases nexus in greater depth.

Cognitive benefits of sleep: a narrative review to explore the relevance of glucose regulation

Sleep is essential for maintaining optimal health. Both sleep duration and quality have been linked to various physiological functions and physical and mental health outcomes. Nutrition has been shown to impact sleep parameters, from the nutrient composition of foods, such as tryptophan levels, to the physiological response to foods, such as the glucose response. However, the relationship between glycemic control and sleep, and its impact on next-day benefits, particularly on cognitive performance, remains complex and is not fully understood. This narrative review aims to explore the relationship between glycemia and sleep, and how it may affect cognitive performance the following day. The review includes data from observational and interventional studies, discussing mechanisms of action that may explain the modulating effect of glycemia on sleep and cognition. The evidence suggests that lower postprandial glucose and low variation of nocturnal glucose are associated with better sleep quality and shorter sleep onset latency. Good sleep quality, in turn, is positively associated with cognitive processes such as sustained attention and memory consolidation measured the next day after sleep. Future research opportunities lie in investigating the effects of modulating the glycemic and insulinemic responses through evening meals on sleep quality and next-day cognitive performance. Well-designed clinical trials involving healthy individuals are necessary to establish the effects of these interventions. Controlling glycemic and insulinemic profiles through the evening meal may have significant implications for improving sleep quality and cognitive performance, with potential impact on individual mental health, productivity, and overall well-being.

Gender-based differences in the association of self-reported sleep duration with cardiovascular disease and diabetes

OBJECTIVE

Insufficient or prolonged sleep each day may contribute to the onset of cardiovascular disease and diabetes, and there may be some variability between genders; however, current research evidence is limited. We aimed to investigate the effects of gender on self-reported sleep duration and the prevalence of cardiovascular disease and diabetes.

RESEARCH DESIGN AND METHODS

This study is a population-based, cross-sectional analysis. Data from a nationally representative sample of US adults obtained from the National Health and Nutrition Examination Survey (NHANES) (2005-2020), and 13,002 participants, including 6,774men and 6,228women, were obtained by excluding the missing values for each variable self-reported sleep duration data obtained by using a habitual baseline questionnaire. Logistic regression models investigated the associations between gender-specific self-reported sleep duration, CVDs, and diabetes events.

RESULT

In all participants, respectively, compared with sleep 7-8 h/day, the multivariable-adjusted odds ratios significantly associated with < 7 h /day and > 8 h /day were (1.43[1.15, 1.78]) and (1.34[1.01, 1.76]) for CHF, (1.62[1.28, 2.06]) for Angina, (1.42[1.17, 1.71]) for heart attack, (1.38[1.13, 1.70]) and (1.54[1.20, 1.97]) for Stroke, (1.21[1.09, 1.35]) and (1.28[1.11, 1.48]) for diabetes. In men, CHF (1.67[1.21, 2.14]), Angina (1.66[1.18, 2.15]), Stroke (1.55[1.13,1.97]), and diabetes (1.15[1.00, 1.32]) were significantly associated with < 7 h /day, and stroke (1.73[1.16, 2.32]) and diabetes (1.32[1.06, 1.52]) were significantly associated with > 8 h /day. In women, angina(1.83[1.16, 2.50]), heart attack(1.63[1.11, 2.15]), and diabetes (1.32[1.11, 1.54]) were significantly associated with < 7 h /day, while diabetes (1.31[1.03, 1.59]) was significantly associated with > 8 h /day.

CONCLUSION

Self-reported long and short sleep duration was independently associated with partial CVDs and diabetes risk. However, sleep duration and gender did not have multiplicative or additive interactions with the onset of diabetes and CVDs.

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.

The Impact of Sleep on Haematological Parameters in Firefighters

Sleep is a vital process that impacts biological functions such as cell renewal, bone regeneration, and immune system support. Disrupted sleep can interrupt erythropoiesis, leading to fewer red blood cells, reduced haemoglobin concentration, and decreased haematocrit levels, potentially contributing to haematological disorders. This is particularly concerning for shift workers for example firefighters. While previous studies have explored sleep's adverse effects on various professions, research specific to firefighters is limited. This study investigates the relationship between sleep quality and haematological parameters among firefighters in Northeast Portugal. From a sample of 201 firefighters, variations in red blood cells, haemoglobin, and haematocrit values were linked to sleep quality. The study utilised non-parametric tests (Wilcoxon-Mann-Whitney, Spearman's correlation) to explore the connection between sleep quality and haematological profile. The impact of covariates on haematological parameters was assessed using non-parametric ANCOVA (Quade's). A multiple regression analysis was employed to further understand how sleep quality and various confounding variables impact haematological levels. Findings suggest a negative link between sleep quality and haematological levels, meaning that as sleep quality deteriorates, there is a tendency for haematological levels to decrease, as indicated by Spearman's correlation (rRBC = -0.157, pRBC = 0.026; rHb = -0.158, pHb = 0.025; rHCT = -0.175, pHCT = 0.013). As observed in scientific literature, the correlation found suggests a possible inhibition of erythropoiesis, the process responsible for red blood cell production. Despite firefighters presenting a haematological profile within the reference range (RBC: 5.1 × 106/mm3 (SD ± 0.4), Hb: 15.6 g/dL (SD ± 1.3), 47% (SD ± 1.0), there is already an observable trend towards lower levels. The analysis of co-variables did not reveal a significant impact of sleep quality on haematological levels. In conclusion, this study underscores the importance of sleep quality in determining haematological parameters among firefighters. Future research should investigate the underlying mechanisms and long-term implications of poor sleep quality on firefighter health. Exploring interventions to enhance sleep quality is vital for evidence-based strategies promoting firefighter well-being.

Associations between sarcopenic obesity and risk of cardiovascular disease: A population-based cohort study among middle-aged and older adults using the CHARLS

BACKGROUND

Previous studies have demonstrated that sarcopenia was associated with a high risk of cardiovascular disease (CVD). Nevertheless, little is known about the associations between sarcopenic obesity/possibly sarcopenic obesity and the risk of CVD among senior and middle-aged adults.

METHODS

Utilizing the nationally representative data from the China Health and Retirement Longitudinal Study (CHARLS), a sum of 7703 individuals aged at least 45 years were divided into four groups. The effects of sarcopenic obesity and possibly sarcopenic obesity on CVD were calculated using Cox proportional hazards regression models. Non-sarcopenic participants with optimal body mass index (BMI) or waist circumference (WC) served as a control group.

RESULTS

Sarcopenic obesity were related to increased risks of CVD (HR = 1.39; 95% CI = 1.16-1.67), heart disease (HR = 1.36; 95% CI = 1.10-1.67) and stroke (HR = 1.40; 95% CI = 1.02-1.92) compared with the optimal reference group. Similarly, the risk of CVD, heart disease and stroke increased by 0.34, 0.28 and 0.39 times in obese people with possible sarcopenia compared to the control group. Sensitivity analysis identified similar results to those described above. Patients with sarcopenia and a BMI ≥28.0 kg/m2 had a 1.47- and 1.48-fold risk of developing CVD and heart disease than controls.

CONCLUSION

Sarcopenic obesity and possibly sarcopenic obesity are positively associated with the development of CVD. The middle-aged and elderly population should prevent obesity and maintain muscle mass through some interventions such as weight control and moderate exercise, which may reduce the CVD risk.

Relationship between daytime napping with the occurrence and development of diabetes: a systematic review and meta-analysis

OBJECTIVE

To determine the relationship of napping with incident diabetes risk and glycaemic control in people with diabetes.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE (PubMed), EMBASE, Web of Science and the Cochrane Library were searched for studies published from database inception to 9 May 2023.

ELIGIBILITY CRITERIA

Observational studies reporting the relationship of napping with diabetes or glycaemic control in patients with diabetes in adult populations were included.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently screened the literature, extracted data and assessed the quality of the included studies. The results were reported as ORs and 95% CIs, which were pooled by using fixed and random effects models, and subgroup analyses were performed. The Grading of Recommendations Assessment, Development and Evaluation method was used to assess the quality of the evidence.

RESULTS

Forty studies were included in our review. Habitual napping was associated with an increased diabetes risk (OR 1.20, 95% CI 1.14 to 1.27) and poor glycaemic control in patients with diabetes (OR 2.05, 95% CI 1.55 to 2.73). Nap durations less than 30 min were unrelated to diabetes (OR 1.05, 95% CI 0.97 to 1.14). Nap durations of 30-60 min were associated with diabetes risk (OR 1.09, 95% CI 1.02 to 1.17), but there were differences in the subgroup analysis results. Nap durations of more than 60 min significantly increased the risk of diabetes (OR 1.31, 95% CI 1.20 to 1.44).

CONCLUSIONS

Napping is associated with increased diabetes risk and poor glycaemic control, and future research will need to confirm whether there are sex and regional differences. Nap durations of more than 60 min significantly increases the risk of diabetes, and the relationship between nap duration and glycaemic control in patients with diabetes needs to be further explored in the future.

PROSPERO REGISTRATION NUMBER

CRD42021292103.

The relationship between sleep health and multimorbidity in community dwelling populations: Systematic review and global perspectives

Previous research has identified a relationship between sleep problems and multimorbidity, defined as the co-occurrence of two or more chronic health conditions in the same individual. This systematic review sought to summarize the literature on the association between sleep duration and quality and multimorbidity in adult community-dwelling populations. A comprehensive search of the PubMed, Embase and CINAHL databases identified studies published between January 1990 and January 2023. Studies were included if they focused on community-dwelling populations, used an observational design, measured sleep quality or duration, used multimorbidity as the main study outcome, and explored the relationship between sleep and multimorbidity. Two reviewers independently conducted study screening, data extraction, and bias assessments. Twenty-four cross-sectional and five prospective cohort studies met the inclusion criteria, with studies from 16 countries and two with cross-country comparisons, and a total participant number of 481,862. Overall, poorer sleep quality and sleep duration outside current recommendations were consistently associated with multimorbidity, though with varying strength. This association was present regardless of specific multimorbidity definitions from different studies. Definitions of sleep duration and quality were inconsistent across studies, possibly contributing to mixed evidence on the observed association. Most studies were cross-sectional, limiting the assessment of the temporal direction of association. Our results corroborate relationships between poor sleep and risk of multimorbidity in adult community-dwelling populations around the world. Examining this relationship may help increase public health awareness of sleep as a modifiable risk factor for the prevention of chronic disease and healthy aging.