Nighttime sleep duration, restlessness and risk of multimorbidity - A longitudinal study among middle-aged and older adults in China

Determinants of Multimorbidity in a Low-Resource Setting: A Population-Based Cross-Sectional Study in Bangladesh

Multimorbidity is a complex and highly prevalent health condition characterised by the coexistence of two or more chronic diseases within an individual. It is a growing public health issue worldwide, predominantly in low-resource countries like Bangladesh. Therefore, this study aimed to determine the prevalence and associated factors of multimorbidity among the adult population in Bangladesh. A cross-sectional study was carried out among 504 respondents who were 18 years or older. The generalised linear mixed model was used to identify the risk factors. Among the respondents, 65.3% (95% confidence interval [CI]: 61.0 to 69.3) had multimorbidity. The most common chronic conditions were allergic disorder (34%, 95% CI: 30 to 39), gastritis (31%, 95% CI: 27 to 35), low back pain (28.4%, 95% CI: 24.6 to 32.5), oral diseases (27%, 95% CI: 23 to 29) and arthritis (21%, 95% CI: 18 to 25). Middle-aged adults (adjusted odds ratio [AOR] = 7.97; 95% CI: 3.35 to 18.92) and older adults (AOR = 8.44; 95% CI: 1.90 to 36.64) had significantly higher odds of multimorbidity than young adults. Employed respondents had an 86% (AOR = 0.14; 95% CI: 0.07 to 0.36) lower odds of multimorbidity than non-working individuals. Higher sleeping duration (6 to 8 h: AOR = 0.44; 95% CI: 0.25 to 0.80; 8 to 10 h: AOR = 0.26; 95% CI: 0.11 to 0.60), regular vegetable consumption (AOR = 0.42; 95% CI: 0.22 to 0.80) and adequate water intake (AOR = 0.48; 95% CI: 0.29 to 0.79) were protective factors against multimorbidity, whereas obesity increased the odds (AOR = 3.32; 95% CI: 1.06 to 10.43). These findings emphasise the need to promote healthy lifestyle habits, such as maintaining a balanced diet, staying hydrated and engaging in regular physical exercise, to reduce the burden of multimorbidity in low-resource settings.

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.

Insights into the complex relationship between triglyceride glucose-waist height ratio index, mean arterial pressure, and cardiovascular disease: a nationwide prospective cohort study

BACKGROUND

Both the triglyceride glucose-waist height ratio (TyG-WHtR) index and elevated arterial blood pressure are risk factors for cardiovascular disease (CVD). However, it is uncertain whether the TyG-WHtR index can increase the risk of CVD by influencing arterial blood pressure, and the extent to which the TyG-WHtR index may mediate the association between arterial blood pressure and CVD. The purpose of this study is to evaluate complex association of the TyG-WHtR index and mean arterial pressure (MAP) with CVD.

METHODS

All data in this study were obtained from the China Health and Retirement Longitudinal Study (CHARLS) free of CVD at baseline. CVD was defined as self-reporting heart disease and stroke. Cox proportional hazards model and restricted cubic spline (RCS) were used to analyze the association of the TyG-WHtR index and MAP with the risk of CVD. Time-dependent receiver operating characteristic (ROC) analysis was used to assess the predictive performance of TyG-WHtR, MAP for CVD. Four-way decomposition method explored the mediating effects of the TyG-WHtR index and MAP in CVD.

RESULTS

A total of 7976 participants were included in this study. The mean age of the participants was 58.68 ± 9.60 years, and 4263 (53.45%) were females. During a maximum follow-up of 7.0 years, 1326 (16.62%) people developed CVD. Both the TyG-WHtR index and MAP were signifcantly associated with CVD. The RCS regression analyses demonstrated a positive linear association of the TyG-WHtR index and MAP with the incidence of CVD. Compared with participants with TyG-WHtR < median and MAP < median, those with TyG-WHtR ≥ median and MAP ≥ median had the highest risk of CVD (HR 1.961; 95%CI 1.660-2.317). The combination of TyG-WHtR and MAP demonstrated incremental predictive utility over either biomarker alone, as evidenced by improvements in integrated discrimination improvement (IDI) and net reclassification improvement (NRI). While absolute predictive performance remained moderate. Increased MAP signifcantly mediated 52.43% of the associations between TyG-WHtR index and CVD, and increased TyG-WHtR index signifcantly mediated 83.40% of the associations between MAP and CVD.

CONCLUSION

The combination of a higher TyG-WHtR index and a higher MAP was associated with the highest risk of CVD. The combined model of the TyG-WHtR index and MAP showed improved predictive ability, as indicated by IDI and NRI, although its overall predictive performance was still moderate. The MAP could partially mediate the association between TyG-WHtR index and CVD, as well as TyG-WHtR index could also partially mediate the association between MAP and CVD. These findings suggested that the combination of TyG-WHtR index and MAP helps identify populations at early risk of CVD and improve risk stratifcation.

Cross-sectional and prospective associations between sleep health and multimorbidity in middle to older-aged adults: Results from the Canadian Longitudinal Study on Aging (CLSA)

OBJECTIVE

Middle-aged to older adults often exhibit the co-existence of poor sleep health and multimorbidity. We examined cross-sectional and prospective associations of pooled index of sleep health with prevalent and incident multimorbidity in the framework of an ongoing cohort study in Canada.

METHODS

Data were from approximately 24,000 individuals from the Canadian Longitudinal Study on Aging (CLSA), an ongoing national study of community-dwelling adults aged 45-85 years at baseline. Multimorbidity was defined as two or more chronic conditions out of five major condition categories. Sleep variables included sleep duration, quality, initiation, maintenance, and excessive daytime sleepiness, which were combined into an index using pooled approaches. Weighted logistic regression models were computed for each index with additional age- and sex-stratified analyses.

RESULTS

Higher sleep index scores, indicating poorer sleep health, were observed in females and younger age groups (ages 45-54 and 55-64). In cross-sectional analysis, the fully adjusted model showed that a 1-unit increase in pooled scores was significantly associated with 1.48 higher odds (95 % CI = 1.38, 1.58; p < 0.001) of prevalent multimorbidity at baseline. Similarly, the prospective analysis indicated significant changes in incident multimorbidity with pooled index scores in the fully adjusted model (OR = 1.33; 95 % CI = 1.20, 1.48; p < 0.001).

CONCLUSION

The pooled sleep index introduced in this study may offer a novel, concise, and comprehensive approach to assessing sleep health among middle-aged and older adults. Those in these age groups experiencing poorer sleep health are at a greater risk of prevalent multimorbidity, as well as of developing multimorbidity over time.

Association between the triglyceride glucose-body mass index and future cardiovascular disease risk in a population with Cardiovascular-Kidney-Metabolic syndrome stage 0-3: a nationwide prospective cohort study

BACKGROUND

The American Heart Association (AHA) has recently introduced the concept of Cardiovascular-Kidney-Metabolic (CKM) syndrome, which is the result of an increasing emphasis on the interplay of metabolic, renal and cardiovascular diseases (CVD). Furthermore, there is substantial evidence of a correlation between the triglyceride glucose-body mass index (TyG-BMI ) and CVD as an assessment of insulin resistance (IR). However, it remains unknown whether this correlation exists in population with CKM syndrome.

METHODS

All data for this study were obtained from the China Health and Retirement Longitudinal Study (CHARLS). The exposure was the participants' TyG-BMI at baseline, which was calculated using a combination of triglycerides (TG), fasting blood glucose (FBG) and body mass index (BMI). The primary outcome was CVD, which were determined by the use of a standardised questionnaire during follow-up. To examine the relationship between TyG-BMI and CVD incidence in population with CKM syndrome, both Cox regression analyses and restricted cubic spline (RCS) regression analyses were performed.

RESULTS

A total of 7376 participants were included in the final analysis. Of these, 1139, 1515, 1839, and 2883 were in CKM syndrome stages 0, 1, 2, and 3, respectively, at baseline. The gender distribution was 52.62% female, and the mean age was 59.17 ± 9.28 (years). The results of the fully adjusted COX regression analyses indicated that there was a 6.5% increase in the risk of developing CVD for each 10-unit increase in TyG-BMI,95% confidence interval (CI):1.041-1.090. The RCS regression analyses demonstrated a positive linear association between TyG-BMI and the incidence of CVD in the CKM syndrome population (P for overall < 0.001, P for nonlinear = 0.355).

CONCLUSIONS

This cohort study demonstrated a positive linear association between TyG-BMI index and increased CVD incidence in a population with CKM syndrome stage 0-3. This finding suggests that enhanced assessment of TyG-BMI index may provide a more convenient and effective tool for individuals at risk for CVD in CKM syndrome stage 0-3.

Bidirectional associations between sleep quality/duration and multimorbidity in middle-aged and older people Chinese adults: a longitudinal study

BACKGROUND

Multimorbidity and sleep disorder possess high incidence rates in the middle-aged and older people populations, posing a significant threat to quality of life and physical and mental health. However, investigators have previously only analysed the unidirectional association between sleep status and multimorbidity. We aimed to investigate bidirectional associations between sleep quality or duration and multimorbidity in middle-aged and older Chinese adults from a longitudinal perspective.

METHOD

We enrolled a total of 9823 participants 45 years and older from the China Health and Retirement Longitudinal Study from 2015 to 2018 in our study. Multimorbidity was defined as two or more coexisting chronic diseases in the same individual based on 14 self-reported disease questions. Sleep quality was classified as "good" (restless < 1 day per week) and "poor" (restless ≥ 1 days per week); and sleep duration was divided into short (< 6 h), medium (6-9 h), and long (> 9 h). The bidirectional association between multimorbidity and sleep condition was examined using multivariate logistic regression models with adjustments for covariates.

RESULTS

Individuals with poor sleep quality showed a significantly higher prevalence of multimorbidity in the future. The adjusted OR (95% CI) values of individuals with poor sleep quality with respect to developing two diseases, three diseases, and ≥ 4 diseases were 1.39 (1.19, 1.63), 1.56 (1.23, 2.03), and 2.36 (1.68, 3.33), respectively. In addition, individuals with multimorbidity exhibited a significantly higher risk of poor sleep quality in the future. Short sleep duration led to multimorbidity in the future (OR = 1.49; 95 CI%, 1.37-1.63), while multimorbidity contributed to short sleep duration (< 6 h) in the future (OR = 1.39; 95% CI, 1.27-1.51) after full adjustment.

CONCLUSIONS

There was a bidirectional association between sleep quality or short sleep duration and multimorbidity in middle-aged and older Chinese adults. We recommend that greater attention be given to clinical management among adults with sleep disorders or physical multimorbidities.

Risk factors for multimorbidity in adulthood: A systematic review

BACKGROUND

Multimorbidity, the coexistence of multiple chronic diseases in an individual, is highly prevalent and challenging for healthcare systems. However, its risk factors remain poorly understood.

OBJECTIVE

To systematically review studies reporting multimorbidity risk factors.

METHODS

A PRISMA-compliant systematic review was conducted, searching electronic databases (MEDLINE, EMBASE, Web of Science, Scopus). Inclusion criteria were studies addressing multimorbidity transitions, trajectories, continuous disease counts, and specific patterns. Non-human studies and participants under 18 were excluded. Associations between risk factors and multimorbidity onset were reported.

RESULTS

Of 20,806 identified studies, 68 were included, with participants aged 18-105 from 23 countries. Nine risk factor categories were identified, including demographic, socioeconomic, and behavioral factors. Older age, low education, obesity, hypertension, depression, low pysical function were generally positively associated with multimorbidity. Results for factors like smoking, alcohol consumption, and dietary patterns were inconsistent. Study quality was moderate, with 16.2% having low risk of bias.

CONCLUSIONS

Several risk factors seem to be consistently associated with an increased risk of accumulating chronic diseases over time. However, heterogeneity in settings, exposure and outcome, and baseline health of participants hampers robust conclusions.

Adverse childhood experiences and depressive symptoms among middle-aged or older adults in China and the mediating role of short sleep duration

BACKGROUND

Limited research has simultaneously examined the link between adverse childhood experiences (ACEs), short sleep duration, and depressive symptoms among middle-aged or older Chinese adults. This study aims to investigate the association between ACEs and later-life depressive symptoms, and to examine the mediating role of short sleep duration (<6 h/night) in this association.

METHODS

Data of 11,452 participants aged ≥45 years were obtained from the China Health and Retirement Longitudinal Study. Information on ACEs, depressive symptoms, and sleep duration were reported via questionnaires. The mediating effect of short sleep duration in the association between ACEs and depressive symptoms was examined by Baron and Kenny's causal steps method and Karlson/Holm/Breen (KHB) method.

RESULTS

Compared to non-exposed group, exposure to ACEs was significantly associated with increased odds of depressive symptoms in a dose-response pattern. The odds ratio of depressive symptoms increased from 1.27 (95 % CI: 1.11-1.46) for one ACE to 3.38 (95 % CI: 2.92-3.90) for ≥4 ACEs. The KHB method identified significant mediating role of short sleep duration in the association between experiencing three or more ACEs and depressive symptoms, with the proportional mediation estimated at 8.96 % and 8.85 % for the groups with 3 ACEs and ≥4 ACEs, respectively. The results were consistent across genders and gender did not moderate these associations.

LIMITATIONS

The cross-sectional design limited the ability to make causal inference.

CONCLUSIONS

ACEs were positively associated with depressive symptoms, and short sleep duration partially mediated this association. Promoting optimal sleep duration among ACE-exposed individuals might improve their mental health.

Sleep Behaviors and Progression of Multimorbidity in Middle-Aged and Older Adults: A Prospective Cohort Study From China

BACKGROUND

Sleep behavior (eg, sleep duration, sleep quality, and nap) is closely related to many chronic conditions. However, less is known about its association with multiple chronic conditions (multimorbidity), particularly evidence from cohort studies.

METHODS

Data were collected from a cohort of 8 937 individuals aged 45 and older from the China Health and Retirement Longitudinal Study (2011-2018). Sleep duration, sleep quality, and nap duration were collected in 2011 and 2013. Progression of multimorbidity was defined as the first report of 2 or more chronic conditions for participants without multimorbidity or the new report of 1 or more conditions for those with multimorbidity. Cox regression models were performed to calculate the hazard ratios and 95% confidence intervals (CIs) of the associations between sleep behaviors and the progression of multimorbidity.

RESULTS

Short sleep duration and poor sleep quality were associated with the progression of multimorbidity independently and jointly, especially in those less than 65 years and females. The U-shaped dose-response relationships were observed between nighttime and total sleep duration and the progression of multimorbidity. Persistent short and unsteadily changed sleep behaviors increased the risk of multimorbidity progression. Individuals sleeping ≤5 h/night with 5-7 restless days/week had 1.53 times higher risk of multimorbidity progression (95% CI: 1.37-1.71), compared to those sleeping 7-8 h/night with <1 restless day/week.

CONCLUSIONS

Short sleep duration and poor sleep quality were independently and jointly associated with a higher risk of multimorbidity progression in a mid-to-older population. Optimal sleep duration and sleep quality should be emphasized in multimorbidity prevention and control.

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.

Large muscle group movements during sleep in healthy people: normative values and correlation to sleep features

STUDY OBJECTIVES

To investigate the frequency and characteristics of large muscle group movements (LMMs) during sleep in healthy adults.

METHODS

LMMs were scored following the International Restless Legs Syndrome Study Group criteria in 100 healthy participants aged 19-77 years. A LMM was defined as a temporally overlapping increase in EMG activity and/or the occurrence of movement artifacts in at least two channels. LMM indices and durations in total sleep time (TST), NREM and REM sleep, and association with arousals, awakenings, and/or respiratory events were calculated. Correlations of LMMs indices and durations with sleep architecture, respiratory and motor events, and subjective sleep quality were investigated.

RESULTS

Median LMMs index in TST was 6.8/h (interquartile range (IQR), 4.5-10.8/h), median mean duration 12.4 s (IQR 10.7-14.4 s). Mean LMMs duration was longer in NREM (median 12.7 s, IQR 11.1-15.2 s) versus REM sleep (median 10.3 s, IQR 8.0-13.5s), p < 0.001. LMMs associated with awakening increased with age (p = 0.029). LMMs indices in TST were higher in men than women (p = 0.018). LMMs indices correlated positively with N1 sleep percentage (ρ = 0.49, p < 0.001), arousal index (ρ = 0.40, p = 0.002), sleep stages shift index (ρ = 0.43, p < 0.001, apnea index (ρ = 0.36, p = 0.017), and video-visible movements indices (ρ = 0.45, p < 0.001), and negatively with N3 sleep (ρ = -0.38, p= 0.004) percentage.

CONCLUSIONS

This is the first study providing normative data on LMMs frequency in healthy adults. LMMs are a ubiquitous phenomenon often associated with other events. Correlation with arousals and respiratory events suggests a potential clinical significance of LMMs in adults that awaits further investigation.

Association between sleep problems and multimorbidity patterns in older adults

BACKGROUND

Sleep problems are frequent in older adults and are associated with chronic diseases. However, the association with multimorbidity patterns is still unknown. Considering the negative impacts that multimorbidity patterns can have on older adults' life, knowledge of this association can help in the screening and early identification of older adults with sleep problems. The objective was to verify the association between sleep problems and multimorbidity patterns in older Brazilian adults.

METHODS

This was a cross-sectional study conducted with data from 22,728 community-dwelling older adults from the 2019 National Health Survey. The exposure variable was self-reported sleep problems (yes/no). The study outcomes were: multimorbidity patterns, analyzed by self-report of the coexistence of two or more chronic diseases with similar clinical characteristics: (1) cardiopulmonary; (2) vascular-metabolic; (3) musculoskeletal; (4) coexisting patterns.

RESULTS

Older adults with sleep problems had 1.34 (95%CI: 1.21; 1.48), 1.62 (95%CI: 1.15; 2.28), 1.64 (95%CI: 1.39; 1.93), and 1.88 (95%CI: 1.52; 2.33) greater odds of presenting vascular-metabolic, cardiopulmonary, musculoskeletal, and coexisting patterns, respectively.

CONCLUSIONS

These results suggest that public health programs aimed at preventing sleep problems in older adults are essential to reduce possible adverse health outcomes, including multimorbidity patterns and their negative consequences for older adults' health.

Association of comorbid depression and obesity with cardiometabolic multimorbidity among middle-aged and older Chinese adults: A cohort study

PURPOSE

To evaluate the association of comorbid depression and obesity with the risk of incident cardiometabolic multimorbidity among middle-aged and older Chinese adults.

METHODS

This cohort study extracted data from the 2011 and 2015 waves of the China Health and Retirement Longitudinal Study (CHARLS). Depression was confirmed by the 10-item Center for Epidemiologic Studies Depression Scale (CESD-10) with a cut-off score ≥10. Obesity was defined as a body mass index ≥28 kg/m². Participants were categorized into four groups based on depression and obesity status at baseline, i.e., with neither condition, depression only, obesity only, and with both conditions. Cardiometabolic multimorbidity was defined as the coexistence of two or more of heart diseases, stroke, and diabetes mellitus. Logistic regression models were established to estimate the associations.

RESULTS

A total of 9,308 participants without cardiometabolic multimorbidity at baseline were included (mean [SD] age, 58.8 [9.0] years; 4,449 [47.8%] were males). During four-year of follow-up, 349 (3.8%) participants developed cardiometabolic multimorbidity. Compared to participants without depression or obesity, comorbid depression and obesity was associated with greater risk of cardiometabolic multimorbidity (adjusted OR: 4.79, 95% CI: 3.09-7.43) than that in participants with depression alone (adjusted OR: 1.84, 95% CI: 1.37-2.46) or obesity alone (adjusted OR: 2.26, 95% CI: 1.48-3.45). The findings were consistent in different gender and age groups.

CONCLUSIONS

Comorbid depression and obesity was associated with excessive risk of cardiometabolic multimorbidity. Intervention targeting at individuals with both depression and obesity might have substantial benefit in minimizing the risk of cardiometabolic multimorbidity.

Efficacy of brief behavioural therapy for insomnia in older adults with chronic insomnia: a systematic review and meta-analysis from randomised trials

BACKGROUND

chronic insomnia is a highly prevalent and persistent health concern among older adults, and it has significant adverse effects on cognitive function and physical health.

OBJECTIVES

the study aimed to evaluate the efficacy of a brief 4-week behavioural therapy for insomnia (BBTi) on insomnia remission in older adults with chronic insomnia.

DESIGN

a systematic review and meta-analysis were conducted.

SUBJECTS

adults aged 60 years or older.

METHODS

eight electronic databases were systematically searched through the end of March 2022. Studies followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Statement.

RESULTS

four randomised controlled trials (190 subjects) were included. The mean age of the participants was 69.06 (65.10-71.65), and 29.9% (27.3-32.3%) were male. Older adults who received the BBTi showed a significant insomnia remission (standardised mean differences, -1.07; 95% confidence interval, -1.43 to -0.71; I2, 0%). Sleep parameters measured by actigraphy revealed that in older adults, the BBTi program significantly improved total sleep time, wake after sleep onset (WASO), sleep onset latency (SOL) and sleep efficacy (SE) compared to the controls. For the subjective sleep parameters measured the by sleep diary, older adults who received BBTi obtained a more effective improvement in WASO, SE and SOL. The overall risk of bias was mostly low or of some concern due to the difficulty of blinding participants and assessors.

CONCLUSIONS

a 4-week BBTi program can be considered an effective and nonselective intervention for insomnia remission among older adults with chronic insomnia and thereby has the potential to ameliorate WASO, SE and SOL.

Linear and non-linear Mendelian randomization analyses of sex-specific associations between sleep duration and hyperuricemia

Background

Observational studies have suggested a potential non-linear association between sleep duration and hyperuricemia. However, the causal nature and sex-specific differences are poorly understood. We aimed to determine the shape of sex-specific causal associations between sleep duration and hyperuricemia in the UK Biobank.

Methods

Logistic regression was used to investigate the observational association between self-reported sleep duration and hyperuricemia among 387,980 white British participants (mean age: 56.9 years and 46.0% males). Linear and non-linear Mendelian Randomization (MR) analyses were performed to assess the causal association between continuous sleep duration and hyperuricemia. The causal effects of genetically predicted short (<7 h) and long (>8 h) sleep durations on hyperuricemia were further estimated, respectively.

Results

Traditional observational analysis suggested U- and J-shaped associations between sleep duration and hyperuricemia in females and males, respectively. Linear MR did not support the causal effect of sleep duration on hyperuricemia. Non-linear MR demonstrated an approximately U-shaped causal association between continuous sleep duration and hyperuricemia in overall participants and females, but not in males. Genetically predicted short sleep duration was significantly associated with hyperuricemia in females (OR [95% CI]: 1.21 [1.08–1.36]; P = 0.001), but not in males (1.08 [0.98–1.18]; P = 0.137). By contrast, genetically predicted long sleep duration was not significantly associated with the risk of hyperuricemia in either females or males.

Conclusion

Genetically predicted short sleep duration is a potential causal risk factor for hyperuricemia for females but has little effect on males. Long sleep duration does not appear to be causally associated with hyperuricemia.

Association between sleep and multimorbidity in Chinese elderly: Results from the Chinese Longitudinal Healthy Longevity Survey (CLHLS)

OBJECTIVE

Abnormal sleep duration and poor sleep quality were associated with multiple diseases. However, the association between sleep behavior (including sleep duration and quality) and multimorbidity among the elderly remains unclear. Thus, our study aimed to explore this association in the Chinese elderly.

METHODS

We conducted a cross-sectional study using data from the Chinese Longitudinal Healthy Longevity Survey (2014 wave). Nineteen chronic diseases were used to measure multimorbidity. Self-reported nighttime sleep duration and sleep quality were used as exposures. Multivariate logistic regression analysis and stratification were used to explore the association between sleep behavior and multimorbidity in different groups. Restrictive cubic splines were used to examine the exposure-response relationship.

RESULTS

Compared with those with nighttime sleep duration between 7 and 9 h, participants with shorter (<7 h) and longer (>9 h) sleep duration had a higher prevalence of multimorbidity (odds ratio [OR], 95% confidence interval [CI] were 1.38, 1.18-1.61 and 1.30, 1.09-1.56 respectively). Besides, poor sleep quality (OR = 2.25, 95% CI:1.82-2.72) and moderate sleep quality (OR = 1.35, 95% CI:1.16-1.58) were positively associated with multimorbidity.

CONCLUSIONS

Although the role of sleep behavior in multimorbidity has not been fully understood, this study highlighted the importance of normal nighttime sleep duration and good sleep quality in preventing multimorbidity.

Comorbid depression and obesity, and its transition on the risk of functional disability among middle-aged and older Chinese: a cohort study

Background

Evidence has indicated that depression and obesity were associated with functional disability, independently. However, little is known about the detrimental impact of comorbid depression and obesity, as well as its transition on functional disability. This study investigated the association of baseline depression-obesity status and its dynamic change with incident functional disability among middle-aged and older Chinese.

Methods

This cohort study included 5507 participants aged ≥45 years from the 2011 and 2015 waves of China Health and Retirement Longitudinal Study. Depression was defined with a score ≥ 10 using the 10-item Centre for Epidemiologic Studies Depression Scale. Obesity was defined as body mass index ≥28 kg/m². Participants were cross-classified by depression and obesity status at baseline, and its change during follow-up. Logistic regression models were constructed to evaluate the association of baseline depression-obesity status and its transition with incident functional disability defined by the Katz index of activities of daily living scale.

Results

Over four-year follow-up, 510 (9.3%) participants developed functional disability. Individuals with baseline comorbid depression and obesity had the highest risk of functional disability (OR = 2.84, 95% CI: 1.95–4.15) than non-depressive participants without obesity, or those with depression or obesity alone. When investigating the dynamic changes of depression-obesity status on functional disability incidence, those with stable comorbidity throughout two surveys had the greatest risk of functional disability (OR = 4.06, 95% CI: 2.11–7.80). Progression of depression-obesity status was associated with increased risk of functional disability, while regression from baseline to follow-up was linked to attenuated risk estimates.

Conclusions

Among middle-aged and older Chinese adults, the risk of functional disability was exaggerated with comorbid depression and obesity. Our data further suggest that transitions of depression and obesity over time are associated with the risk of developing functional disability.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-02972-1.

Sleep-Wake and Circadian Disorders after Tick-Borne Encephalitis

Tick-borne encephalitis (TBE) is an infectious disease affecting the central nervous system. Recently, the occurrence of TBEV infections has steadily increased, reaching all-time high incidence rates in European countries. Up to 50% of patients with TBE present neurological sequelae, among them sleep–wake and circadian disorders (SWCD), which are poorly characterized. The aim of this review is to investigate the prevalence, clinical characteristics, and prognosis of SWCD after TBE. The literature review was performed in accordance with PRISMA guidelines. The quality of the paper was assessed using a standardized quality assessment. The analysis of SWCD was categorized into four different time intervals and two age groups. The literature search identified 15 studies, five including children and 10 including adults. In children, fatigue was most frequently observed with a prevalence of 73.9%, followed by somnolence/sleepiness, restlessness, and sleep-wake inversion. In adults, tiredness/fatigue was the most reported sequela with a prevalence of 27.4%, followed by extensive daytime sleepiness/somnolence, and insomnia (3.3%). Two studies showed impaired social outcomes in patients after TBE infections. SWCD after TBE in children and adults is a newly recognized sequela. Additional clinical and experimental research is needed to gain more precise insight into the clinical burden of SWCD after TBE and the underlying mechanisms.