Sleep, circadian biology and skeletal muscle interactions: Implications for metabolic health

Risk factors for sarcopenia in community setting across the life course: A systematic review and a meta-analysis of longitudinal studies

BACKGROUND

Sarcopenia is generally an age-related condition in older people that impacts adverse health consequences in terms of quality of life, morbidity and mortality. With the increasing interest of clinical and research interest in sarcopenia internationally, the epidemiological evidence reveals sarcopenia risk begins in early adulthood, influenced by gene, lifestyle and a range of chronic conditions across life course.

OBJECTIVES

The purpose of this study was to systematically summarize the risk factors for sarcopenia across the life course, and to identity the high-risk population.

METHODS

Searches were performed in PubMed, Web of Science, Scopus, Embase, MEDLINE, and SPORTDiscus databases from inception to July 2024. Longitudinal studies assessing the risk factors for sarcopenia in community setting were included in the analysis. Fixed- and random-effect models were used to pool effect size. Based on the results of meta-analysis, we developed a risk predictive model for sarcopenia.

RESULTS

Fifty-three studies were included in our systematic review. Risk factors associating with sarcopenia were grouped into eight domains: sociodemographic, anthropometric, health behaviors, health condition, biomarkers, early life factors, psychosocial and living environment factors. Fifteen risk factors derived from the twenty-three included studies were eligible for meta-analysis, and ten variables were identified as statistically significant. A risk predictive model was developed for secondary sarcopenia in community setting.

CONCLUSIONS

This study provides a fully understanding of sarcopenia across the life-course. Our risk predictive model could facilitate the early identification and prevention of secondary sarcopenia in community setting.

REGISTRATION

The systematic review and meta-analysis have been registered in PROSPERO(CRD42024536346).

Minimal Influence of Formulated Nutritional Interventions on Sleep and Next-Morning Physical Performance, Cognitive Function, and Postural Sway in Adult Males: A Randomized, Placebo-Controlled, Crossover Study

Athletes often experience poor sleep quality and quantity which may hinder physical performance and cognitive function. Presleep nutritional strategies may be an alternative to pharmacological interventions to improve sleep. The aim of this study was to examine the effect of two different doses of a nutritional intervention (both containing high Glycemic Index carbohydrate, whey, tryptophan, theanine, and 5'AMP) versus placebo on objective and subjective sleep, next-morning physical performance, cognitive function, and postural sway. Seventeen healthy, trained adult males completed three double-blind trials in a randomized, counterbalanced, crossover design. Participants were allocated to conditions using a Latin Square design. A (a) low-dose, (b) high-dose, or (c) placebo drink was provided 90 min before sleep each night. Polysomnography was used to measure objective sleep parameters. Cognitive function, postural sway, and subjective sleep quality were assessed 30 min after waking. Physical performance was assessed using a 10-min maximal effort cycling time trial each morning. All data were analyzed using linear mixed effects models and effect sizes were calculated using Cohen's d. This study was registered prospectively as a clinical trial with Australian New Zealand Clinical Trials Registry (registration number: NCT05032729). No significant main effects or improvements were observed in objective or subjective sleep parameters, physical performance, cognitive function, or postural sway. The low-dose intervention appeared to reduce N3 sleep duration compared with placebo (-13.6 min). The high-dose intervention appeared to increase N1 sleep duration compared with placebo (+7.4 min). However, the magnitude of changes observed were not likely to cause meaningful reductions in sleep quality and quantity.

The Critical Role of Sleep in Enhancing Pulmonary Rehabilitation Outcomes

Pulmonary rehabilitation is a comprehensive, interdisciplinary intervention that aims to enhance the physical and psychological well-being of individuals with chronic respiratory diseases. This approach entails the implementation of tailored therapies, including exercise training, education, and behavioral modification. Sleep plays a crucial role in numerous physiological processes, including the regulation of inflammation and tissue repair, both of which are fundamental to the efficacy of rehabilitation. A paucity of optimal sleep health has been associated with deleterious effects on pivotal factors that are indispensable for favorable outcomes in pulmonary rehabilitation, including mental and physical health and immune function. This, in turn, may increase susceptibility to impaired pulmonary function. The integration of pulmonary rehabilitation protocols with healthy sleep practices is expected to yield significant improvements in lung function and overall health, which will, in turn, promote long-term adherence to rehabilitative behaviors. This study aims to examine the relationship between sleep health and pulmonary rehabilitation outcomes.

Joint association of daily sitting time and sleep duration with constipation among the US population

Background

This study aimed to investigate the independent and combined effects of prolonged daily sitting time and sleep duration on the risk of constipation, using data from the National Health and Nutrition Examination Survey (NHANES) 2005-2010.

Methods

A total of 6,894 participants were included in the analysis. Daily sitting time and sleep duration were self-reported and categorized as short (<7 h/day) or long (≥7 h/day). Constipation was defined based on stool consistency and frequency using the Bristol Stool Form Scale. Multivariable logistic regression models were used to estimate the odds ratios (ORs) for constipation. A restricted cubic spline analysis was applied to assess the dose-response relationships.

Results

Participants with prolonged daily sitting time and short sleep duration showed a higher risk of constipation compared to those with long sleep duration and short sitting time. In multivariable-adjusted models, long sitting time was positively associated with an increased risk of constipation (OR = 1.424; 95% CI, 1.114-1.821), while long sleep duration was associated with a lower constipation risk (OR = 0.725; 95% CI, 0.553-0.952). The joint analysis revealed that the combination of short sleep duration and long sitting time was associated with the highest constipation prevalence (OR = 1.975; 95% CI, 1.378-2.833).

Conclusion

Both prolonged sitting time and insufficient sleep were associated with an increased risk of constipation, especially when combined. These findings underscore the importance of adopting healthier sleep habits and reducing sedentary behavior to lower constipation risk.

Bone-brain communication mediates the amelioration of Polgonatum cyrtonema Hua polysaccharide on fatigue in chronic sleep-deprived mice

This study aimed to investigate the anti-fatigue efficacy and underlying mechanisms of Polygonatum cyrtonema Hua polysaccharide (PCP) in chronic sleep-deprived mice. Following three weeks of oral administration, PCP demonstrated significant efficacy in alleviating fatigue symptoms. This was evidenced by the prolonged swimming and rotarod time in the high-dose group of PCP, which increased by 73 % and 64 %, respectively. Additionally, serum activities of CAT, GSH-Px, and SOD enzymes rose by 53.56 %, 37.69 % and 53.67 %, respectively, while MDA, lactic acid and BUN levels decreased by 22.90 %, 17.48 % and 24.61 %. The crosstalk between bone and brain is crucial for maintaining energy homeostasis. Molecular docking studies indicated a spontaneous and strong mutual binding between PCP and the bone-promoting target protein BMPR1A. Furthermore, it was observed that PCP enhanced osteogenic differentiation via the BMP-2/Smad1 pathway, leading to an upregulation of osteocalcin expression, which in turn regulated neurotransmitter balance and improved central arousal capacity. Moreover, PCP treatment stimulated neurogenesis by activating the CREB/BDNF/Akt signaling cascade, exhibiting neurotrophic effects. Additionally, PCP increased AMPK phosphorylation and destabilized TXNIP, facilitating astrocyte glucose uptake, glycolysis, and lactate conversion to support neuronal activity. These findings suggested that PCP could effectively respond to energy demands through bone-brain crosstalk, ultimately exerting anti-fatigue properties.

Sleep deprivation alters hepatic UGT1A9 and propofol metabolism in mice

Sleep deprivation (SD) causes circadian misalignment, and circadian clock disruption is associated with metabolic diseases such as obesity, insulin resistance, and diabetes. However, the underlying mechanism for SD-induced circadian clock disruption as well as metabolic enzyme changes is still lacking. Here, we developed SD sensitizes mice with disrupted circadian rhythms to demonstrate the regulation role and mechanism of SD in UDP-glucuronosyltransferases (UGTs) expression and the metabolism of corresponding substrates. We found that UGT Family 1 Member A9 (UGT1A9) expression was significantly decreased in the liver of SD mice, which led to an elevation exposure and prolonged anesthesia effect of propofol, which was attributed to the decreased metabolism. Meanwhile, SD down-regulated basic helix-loop-helix ARNT like 1 (BMAL1) and its target clock genes period circadian clock (Per), cryptochrome circadian regulator (Cry), and nuclear receptor subfamily 1 group D member 1 (Rev-erb) expression in mice. Furthermore, the positive regulation of UGTIA9 mRNA and protein levels by Bmal1 was confirmed in hepatocyte-specific Bmal1-knockout mice (Bmal1-hkO) and Bmal1-overexpressed AML-12 cells. At last, through a combination of promoter analysis, luciferase reporter assay, and chromatin immunoprecipitation (ChIP) assay, it was conducted that Bmal1 regulates Ugtla9 expression by directly binding the -864 bp E-box in Ugtla9 promotor or indirectly acting on the Rev-erbα- differentiated embryo chondrocyte 2 (Dec2) axis. In conclusion, our findings suggested that SD can lead to altered drug disposition and effects in vivo, and Bmal1 plays a crucial role in the crosstalk between SD-induced circadian clock disruption and drug metabolism. It initiates a new direction for the understanding of drug efficacy and toxicity changes in SD conditions and provides a scientific basis for improving the rationality of drug use.

Circadian Rhythms and Lung Cancer in the Context of Aging: A Review of Current Evidence

Circadian rhythm is the internal homeostatic physiological clock that regulates the 24-hour sleep/wake cycle. This biological clock helps to adapt to environmental changes such as light, dark, temperature, and behaviors. Aging, on the other hand, is a process of physiological changes that results in a progressive decline in cells, tissues, and other vital systems of the body. Both aging and the circadian clock are highly interlinked phenomena with a bidirectional relationship. The process of aging leads to circadian disruptions while dysfunctional circadian rhythms promote age-related complications. Both processes involve diverse physiological, molecular, and cellular changes such as modifications in the DNA repair mechanisms, mechanisms, ROS generation, apoptosis, and cell proliferation. This review aims to examine the role of aging and circadian rhythms in the context of lung cancer. This will also review the existing literature on the role of circadian disruptions in the process of aging and vice versa. Various molecular pathways and genes such as BMAL1, SIRT1, HLF, and PER1 and their implications in aging, circadian rhythms, and lung cancer will also be discussed.

Beyond Calories: Individual Metabolic and Hormonal Adaptations Driving Variability in Weight Management-A State-of-the-Art Narrative Review

The global rise in obesity underscores the need for effective weight management strategies that address individual metabolic and hormonal variability, moving beyond the simplistic "calories in, calories out" model. Body types-ectomorph, mesomorph, and endomorph-provide a framework for understanding the differences in fat storage, muscle development, and energy expenditure, as each type responds uniquely to caloric intake and exercise. Variability in weight outcomes is influenced by factors such as genetic polymorphisms and epigenetic changes in hormonal signaling pathways and metabolic processes, as well as lifestyle factors, including nutrition, exercise, sleep, and stress. These factors impact the magnitude of lipogenesis and myofibrillar protein synthesis during overfeeding, as well as the extent of lipolysis and muscle proteolysis during caloric restriction, through complex mechanisms that involve changes in the resting metabolic rate, metabolic pathways, and hormonal profiles. Precision approaches, such as nutrigenomics, indirect calorimetry, and artificial-intelligence-based strategies, can potentially leverage these insights to create individualized weight management strategies aligned with each person's unique metabolic profile. By addressing these personalized factors, precision nutrition offers a promising pathway to sustainable and effective weight management outcomes. The main objective of this review is to examine the metabolic and hormonal adaptations driving variability in weight management outcomes and explore how precision nutrition can address these challenges through individualized strategies.

Associations between meeting 24-h movement guidelines and sarcopenia risk among adults aged ≥ 55 years in five low- and middle-income countries

OBJECTIVE

To diminish the negative influence of sarcopenia on senior adults, the study aimed to investigate the association between adherence to 24-h movement behavior guidelines (physical activity, sedentary behavior, sleep duration) and the risk of sarcopenia among individuals aged ≥55 years in five low- and middle-income countries (LMICs).

METHODS

A total of 16,503 adults aged ≥55 years were included in this cross-sectional study. The study utilized data from Global Aging and Adult Health Survey (SAGE). Participants reported their information about physical activity, sedentary behavior, and sleep duration using the questionnaire. Sarcopenia was identified as low skeletal muscle mass with a diminished gait speed or weakened handgrip strength. Multiple logistic regression models were used to investigate the association between adherence to 24-h movement behavior guidelines and the risk of sarcopenia.

RESULTS

Merely 32.73 % of participants met all three 24-h movement behavior guidelines (physical activity, less sedentary behavior, sleep). Meeting all three guidelines (p < 0.01) was significantly associated with a lower risk of sarcopenia. Meeting physical activity only (p < 0.05), or meeting both physical activity and sedentary behaivor (p < 0.05), or meeting both physical activity and sleep duration (p < 0.01) guidelines were also associated with a reduced risk of sarcopenia. Moreover, adults aged 65+ years who adhered to 24-h movement behavior guidelines exhibited a significantly reduced risk of developing sarcopenia.

CONCLUSION

The findings suggest that the adherence to 24-h movement behavior guidelines for regular physical activity, limited sedentary behavior, and sufficient sleep duration was associated with a reduced risk of sarcopenia in adults aged ≥55 years in five LMICs.

Causal Associations Between Sleep Traits and Low Grip Strength: A Bidirectional Mendelian Randomization Study

Background

Sleep disorders and low grip strength often co-occur clinically and are geriatric symptoms that cause significant socioeconomic burden. Previous observational studies have found an association between sleep behaviors and grip strength, but the causal relationship remains unclear.

Purpose

With the Mendelian randomization (MR) approach, the study aimed to determine the causal association between sleep traits (sleep duration, insomnia, daytime napping, sleep-wake disorders, chronotype) and low grip strength.

Methods

The study used genetic variants from the genome-wide association study (GWAS) archived in UK Biobank and FinnGen. We assessed the potential causal relationship between sleep behaviors and grip strength using inverse variance weighting (IVW), weighted median (WM), and MR-Egger. Additionally, we performed sensitivity analyses using Cochran's Q test, MR Egger Intercept test, funnel plots, and leave-one-out method.

Results

We found that sleep duration is causally negatively associated with low grip strength (OR = 0.618, 95% CI = 0.424-0.900, P = 0.012). Sleep-wake disorders have a positive association with low grip strength (OR = 1.018, 95% CI = 1.002-1.034, P = 0.029). Reversely, high low grip strength risk was causally associated with increased daytime napping (OR = 1.018, 95% CI = 1.004-1.032, P = 0.011).

Conclusion

The study revealed causal associations between sleep duration, sleep-wake disorders, and low grip strength. Understanding their relationship helps in early clinical intervention to improve the life quality of the elderly.

Optimal exercise dose and type for improving sleep quality: a systematic review and network meta-analysis of RCTs

Background

A substantial amount of research has explored the intricate relationship between exercise and sleep quality, consistently confirming that exercise can effectively enhance sleep quality. Nevertheless, previous studies have yet to conclusively determine which specific exercise program is most efficacious in improving sleep quality. To address this gap, the present study systematically evaluated the differential effects of various types of exercise, as well as exercise dosages (including duration, intervention period, frequency, and intensity), on sleep outcomes using a network meta-analysis approach. This endeavor aims to provide evidence-based support for the development of scientifically effective exercise programs tailored to improve sleep quality.

Methods

Through the Web of Science, PubMed, Cochrane Library, Embase, and Scopus databases, we conducted a search for randomized controlled trials investigating the effects of exercise interventions on sleep, with a search cutoff date of April 30, 2024. We rigorously selected the literature according to the PICOS principle, and two independent researchers extracted the data. We would like to change this passage to: Bias risk assessment was conducted using the RevMan 5.4 software, and traditional meta-analysis and network meta-analysis were performed using Stata 17.0 software to generate forest plots, network evidence plots, and funnel plots. Furthermore, we adopted the surface under the cumulative ranking curve (SUCRA) to evaluate and rank the intervention effects of different exercise types and dosages on sleep quality. To verify the robustness of our study results, we performed a sensitivity analysis using the leave-one-out method.

Results

The study strictly adhered to the PRISMA guidelines and included 58 RCT papers with a total of 5,008 participants. The network meta-analysis revealed significant variations in the impact of exercise frequency on sleep outcomes when compared to the control group. Interventions of 1-2 times per week [SMD = -0.85, 95% CI (-1.43, -0.26)], 3 times per week [SMD = -0.45, 95% CI (-0.80, -0.11)], and 4 times per week [SMD = -1.09, 95% CI (-1.92, -0.26)] demonstrated the most notable effects. Interventions lasting ≤30 min and 60-65 min were significantly more effective than the control group, with ≤30 min proving significantly more effective than 40-55 min [SMD = 0.75, 95% CI (0.01, 1.49)]. Interventions lasting 9-10 weeks [SMD = -1.40, 95% CI (-2.37, -0.44)], 12-16 weeks [SMD = -0.55, 95% CI (-0.90, -0.20)], and ≥ 24 weeks [SMD = -0.71, 95% CI (-1.31, -0.10)] were all significantly more effective than the control group. Additionally, the 9-10 weeks intervention period was found to be significantly more effective than the 6-8 weeks period [SMD = -1.21, 95% CI (-2.37, -0.04)]. Furthermore, interventions of moderate intensity [SMD = -1.06, 95% CI (-1.52, -0.61)] and high intensity [SMD = -1.48, 95% CI (-2.55, -0.40)] exercise interventions yielded significantly greater benefits compared to the control group. Specifically, high intensity interventions [SMD = -1.97, 95% CI (-3.37, -0.56)] and moderate intensity [SMD = -1.55, 95% CI (-2.57, -0.54)] exercise interventions were found to be significantly more effective than moderate-high intensity interventions. In terms of exercise types, aerobic exercise [SMD = -0.56, 95% CI (-0.86, -0.27)], traditional Chinese exercises [SMD = -0.57, 95% CI (-0.97, -0.18)], and combined exercise [SMD = -0.99, 95% CI (-1.66, -0.32)] interventions all produced significant improvements compared to the control group. The study determined that the most effective combination of exercise prescription elements for enhancing sleep quality includes a frequency of 4 times per week (SUCRA = 84.7), a duration of ≤30 min (SUCRA = 92.2), a period of 9-10 weeks (SUCRA = 89.9), and high-intensity (SUCRA = 92.9) combined exercise (SUCRA = 82.7).

Conclusion

The current evidence indicates that combined exercise with a frequency of 4 times per week, a duration of ≤30 min, a period of 9-10 weeks, and high intensity is most effective for improving sleep quality. Nevertheless, due to the limited number of studies included, further research is needed to enhance the reliability of the findings.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42024555428.

Unfolding the role of exercise in the management of sleep disorders

Sleep disorders are prevalent among the general population and even more in individuals suffering from chronic diseases. Recent data reveal promising effects of physical exercise as a non-pharmacological approach for improving sleep and managing various sleep disorders. However, more studies with proper design and methodology should be conducted in the future to obtain a clearer understanding of the subject. The role of exercise in preventing and improving sleep disorders is probably much higher than what is currently exploited. To fully exploit the potential benefit of physical activity on sleep disorders in the future, it is necessary to identify the relevant tools to assess sleep-wake disorders and establish specific exercise protocols tailored to different sleep disorders. The present manuscript aims to review the literature on the use of exercise in managing selected sleep disorders. Regular exercise, including short-term aerobic activity, resistance training, and mind-body exercises, can effectively improve sleep quality, particularly in cases of insomnia and sleep-disordered breathing. Additionally, increasing evidence supports the effectiveness of aerobic and strength training, and body-mind exercises such as yoga in managing sleep-related movement disorders. Exercise can be a safe, affordable, and efficient tool in enhancing sleep quality and improving sleep disorders. Per se, regular exercise could play an adjuvant role alongside with established therapies, or a valid alternative when the pharmacological approach is limited by side effects, interactions, or inefficacy. More research is needed to define how exercise affects the physiology of sleep, and consequently how to use exercise in patients with sleep disorders.

Association of habitual sleep duration with abnormal bowel symptoms: a cross-sectional study of the 2005-2010 national health and nutrition examination survey

OBJECTIVES

Nowadays, few studies have examined the relationships between sleep duration and abnormal gut health. In this study, we used data from the National Health and Nutrition Examination Survey (NHANES) to investigate the correlations between habitual sleep duration and abnormal bowel symptoms in adults.

METHODS

This study included 11,533 participants aged ≥ 20 years from the NHANES conducted during 2005-2010. Chronic constipation and chronic diarrhea were defined based on the Bristol Stool Form Scale (BSFS) and frequency of bowel movements. Sleep duration was assessed based on the self-report questionnaire and classified into three groups: short sleep duration (< 7 h), normal sleep duration (7-9 h), and long sleep duration (> 9 h). Weighted data were calculated according to analytical guidelines. Logistic regression models and restricted cubic spline curves (RCS) were used to assess and describe the association between sleep duration and chronic diarrhea and constipation. Univariate and stratified analyses were also performed.

RESULTS

There were 949 (7.27%) adults aged 20 years and older with chronic diarrhea and 1120 (8.94%) adults with constipation among the 11,533 individuals. A positive association was found between short sleep duration and chronic constipation, with a multivariate-adjusted OR of 1.32 (95% CI: 1.05-1.66). Additionally, long sleep duration was significantly associated with an increased risk of chronic diarrhea (OR: 1.75, 95% CI: 1.08-2.84, P = 0.026). The RCS models revealed a statistically significant nonlinear association (P for non-linearity < 0.05) between sleep duration and chronic diarrhea. Furthermore, obesity was found to modify the association between sleep duration and chronic diarrhea and constipation (p for interaction = 0.044).

CONCLUSIONS

This study suggests that both long and short sleep durations are associated with a higher risk of chronic diarrhea and constipation in the general population. Furthermore, a non-linear association between sleep duration and these conditions persists even after adjusting for case complexities.

Combined physical exercise re-synchronizes expression of Bmal1 and REV-ERBα and up-regulates apoptosis and metabolism in the prostate during aging

BACKGROUND

Aging increases the prevalence of prostate cancer. The circadian clock coordinates metabolism, cell cycle, and tumor suppressor p53. Although physical exercise has several effects on preventing prostate diseases, its effect on regulating genes and proteins of the circadian rhythm of the prostate needs to be better evaluated. The present study verified expression of REV-ERBα (Nr1d1), Bmal1, apoptosis, tumor suppressors, energetic metabolism markers, and androgen receptors in the prostatic microenvironment in 18-month-old mice submitted to combined physical training.

METHODS

C57BL/6 J mice were divided into 2 groups: 6 months-old (n = 10) and 18 months-old, (n = 20). The 18-month-old animals were divided into 2 subgroups: sedentary (n = 10, 18 m Sed) and submitted to combined physical training (n = 10, 18 m TR). Combined physical training protocol was performed by running on the treadmill (40-60 % of incremental load test) and climbing strength training (40-50 % of maximum repetition test), consisting of 5×/week (3 days aerobic and 2 days strength) for 3 weeks. The prostate was prepared for Western blot and RT-qPCR analysis, and the plasm was prepared for the biochemistry analysis.

RESULTS

Combined physical exercise during aging led to increased levels of Bmal1 and decreased levels of REV-ERBα in the prostate. These results were accompanied by a reduction in the AMPK/SIRT1/PGC-1α proteins and an increase in the PI3K/AKT and p53/PTEN/caspase 3 pathways, promoting apoptotic potential.

CONCLUSION

These findings suggest that strength and aerobic physical exercise may be preventive in the development of preneoplastic molecular alterations and age-related features by re-synchronizes Bmal1 and REV-ERBα in prostatic tissues.

Association between sleep duration and possible sarcopenia in middle-aged and elderly Chinese individuals: evidence from the China health and retirement longitudinal study

BACKGROUND

Sarcopenia is a common cause of disability in the aging population, and managing sarcopenia is an important step in building intrinsic capacity and promoting healthy aging. A growing body of evidence suggests that sleep deprivation may be a mediator of the development of sarcopenia. The purpose of this study was to explore the longitudinal association between sleep duration and possible sarcopenia using data from a national sample.

METHODS

Two waves of data from the CHARLS database for 2011 and 2015 were used in this study. All possible sarcopenia participants met the Asia Working Group for Sarcopenia 2019 (AWGS 2019) diagnostic criteria. Sleep duration was assessed using a self-report questionnaire, and sleep duration was categorized as short (≤ 6 h), medium (6-8 h), or long (> 8 h) based on previous studies. Longitudinal associations between sleep duration and possible sarcopenia will be calculated by univariate and multifactorial logistic regression analyses and expressed as odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

A total of 5654 individuals participated in the follow-up study, with a prevalence of possible sarcopenia of 53.72% (578) in the short sleep duration group, 38.29% (412) in the medium sleep duration group, and 7.99% (86) in the long sleep duration group. According to the crude model of the second-wave follow-up study, short sleep durations were significantly more strongly associated with possible sarcopenia than were medium and long sleep durations (OR: 1.35, 95% CI: 1.17-1.55, P = 0.000). The association between short sleep duration and possible sarcopenia was maintained even after adjustment for covariates such as age, gender, residence, education level, BMI, smoking status, alcohol consumption and comorbidities (OR: 1.18, 95% CI: 1.02-1.36, P = 0.029). In the subgroup analysis, short sleep duration was associated with low grip strength (OR: 1.20, 95% CI: 1.02-1.41, P = 0.031).

CONCLUSIONS

Sleep deprivation may be closely associated with the development of possible sarcopenia in middle-aged and elderly people, which provides new insights and ideas for sarcopenia intervention, and further studies are needed to reveal the underlying mechanisms involved.

Adapting the athlete sleep behavior questionnaire (ASBQ) for Arabic-speaking populations: Translation, reliability testing, and validation using classical theory and item response theory

Sleep is essential for athletes' physical performance as well as their general health, well-being, and quality of life. To assess athletes' sleep behaviors, the Athlete Sleep Behavior Questionnaire (ASBQ) was developed in the English language. However, a validated Arabic-version of the ASBQ is lacking. This study aimed to translate the ASBQ into Arabic (ASBQ-AR) and evaluate its reliability and validity among Arabic-speaking athletes. A total of 458 participants (254 athletes, 202 non-athletes) from four Arabic countries completed the ASBQ-AR and the Insomnia Severity Index (ISI) questionnaires. The psychometric properties of the ASBQ-AR were examined using unidimensional reliability analysis, confirmatory factor analysis (CFA), Item Response Theory (IRT), and convergent validity. The ASBQ-AR had acceptable internal consistency (Cronbach's α = 0.723, McDonald's ω = 0.725) and a factorial structure, confirming its construct validity. CFA demonstrated improved model fit indices after the removal of two potentially misfitting items (items 4 and 13); however, the model's fit to the data remains suboptimal. IRT results indicated that the majority of items demonstrated a good model fit, suggesting effective measurement of the intended construct without significant interference, except for ASBQ-AR 4. Additionally, ASBQ-AR 4 appears to present the highest level of difficulty for respondents. In terms of convergent validity, the mean ASBQ-AR global score was correlated with the mean ISI global score (r = 0.5, p < 0.0001). The ASBQ-AR is a reliable and valid tool for assessing maladaptive sleep practices among Arabic-speaking athletes. Additional refinements to the ASBQ-AR are warranted to optimize its psychometric properties.

Sleeping more than 8 h: a silent factor contributing to decreased muscle mass in Chinese community-dwelling older adults

BACKGROUND

Muscle mass loss is an age-related process that can be exacerbated by lifestyle, environmental and other factors, but can be mitigated by good sleep. The objective of this study was to investigate the correlation between varying time lags of sleep duration and the decline in muscle mass among individuals aged 60 years or older by using real-world health monitoring data obtained from wearable devices and smart home health monitoring devices.

METHODS

This study included 86,037 observations from 2,869 participants in the Mobile Support System database. Missing data were supplemented by multiple imputation. The investigation utilized generalized estimating equations and restricted cubic spline curve to examine the relationship between sleep duration and low muscle mass. Various lag structures, including 0, 1, 2, 0-1, 0-2, and 1-2 months, were fitted, and the interaction effect of observation time with sleep duration was estimated for each lag structure. Additionally, subgroup analyses were conducted. The models were adjusted for various covariates, including gender, age, body mass index, footsteps, smoking status, drinking status, marital status, number of chronic diseases, number of medications, diabetes mellitus, hyperlipidemia, coronary artery disease, respiratory disease, and musculoskeletal disease and an interaction term between time and sleep duration.

RESULTS

The results of the generalized estimating equation showed a significant correlation (p < 0.001) between sleep duration of 8 h or more and low muscle mass in older adults, using 6-7 h of sleep as a reference. This effect was seen over time and prolonged sleep accumulated over multiple months had a greater effect on muscle mass loss than a single month. The effect of long sleep duration on muscle mass loss was significantly greater in females than in males and greater in the over-75 than in the under-75 age group. Restricted cubic spline plots showed a non-linear relationship between sleep duration and low muscle mass (p < 0.001).

CONCLUSIONS

This study found an association between sustained nighttime sleep of more than eight hours and decreased muscle mass in older adults, especially older women.

Crosstalk between circadian clocks and pathogen niche

Circadian rhythms are intrinsic 24-hour oscillations found in nearly all life forms. They orchestrate key physiological and behavioral processes, allowing anticipation and response to daily environmental changes. These rhythms manifest across entire organisms, in various organs, and through intricate molecular feedback loops that govern cellular oscillations. Recent studies describe circadian regulation of pathogens, including parasites, bacteria, viruses, and fungi, some of which have their own circadian rhythms while others are influenced by the rhythmic environment of hosts. Pathogens target specific tissues and organs within the host to optimize their replication. Diverse cellular compositions and the interplay among various cell types create unique microenvironments in different tissues, and distinctive organs have unique circadian biology. Hence, residing pathogens are exposed to cyclic conditions, which can profoundly impact host-pathogen interactions. This review explores the influence of circadian rhythms and mammalian tissue-specific interactions on the dynamics of pathogen-host relationships. Overall, this demonstrates the intricate interplay between the body's internal timekeeping system and its susceptibility to pathogens, which has implications for the future of infectious disease research and treatment.

Impact of Melatonin Supplementation on Sports Performance and Circulating Biomarkers in Highly Trained Athletes: A Systematic Review of Randomized Controlled Trials

Melatonin (N-acetyl-5 methoxytryptamine) is an indolic neurohormone that modulates a variety of physiological functions due to its antioxidant, anti-inflammatory, and immunoregulatory properties. Therefore, the purpose of this study was to critically review the effects of melatonin supplementation in sports performance and circulating biomarkers related to the health status of highly trained athletes. Data were obtained by performing searches in the following three bibliography databases: Web of Science, PubMed, and Scopus. The terms used were "Highly Trained Athletes", "Melatonin", and "Sports Performance", "Health Biomarkers" using "Humans" as a filter. The search update was carried out in February 2024 from original articles published with a controlled trial design. The PRISMA rules, the modified McMaster critical review form for quantitative studies, the PEDro scale, and the Cochrane risk of bias were applied. According to the inclusion and exclusion criteria, 21 articles were selected out of 294 references. The dose of melatonin supplemented in the trials ranged between 5 mg to 100 mg administered before or after exercise. The outcomes showed improvements in antioxidant status and inflammatory response and reversed liver damage and muscle damage. Moderate effects on modulating glycemia, total cholesterol, triglycerides, and creatinine were reported. Promising data were found regarding the potential benefits of melatonin in hematological biomarkers, hormonal responses, and sports performance. Therefore, the true efficiency of melatonin to directly improve sports performance remains to be assessed. Nevertheless, an indirect effect of melatonin supplementation in sports performance could be evaluated through improvements in health biomarkers.

Learning from circadian rhythm to transform cancer prevention, prognosis, and survivorship care

Circadian timekeeping mechanisms and cell cycle regulation share thematic biological principles in responding to signals, repairing cellular damage, coordinating metabolism, and allocating cellular resources for optimal function. Recent studies show interactions between cell cycle regulators and circadian clock components, offering insights into potential cancer treatment approaches. Understanding circadian control of metabolism informs timing for therapies to reduce adverse effects and enhance treatment efficacy. Circadian adaptability to lifestyle factors, such as activity, sleep, and nutrition sheds light on their impact on cancer. Leveraging circadian regulatory mechanisms for cancer prevention and care is vital, as most risk stems from modifiable lifestyles. Monitoring circadian factors aids risk assessment and targeted interventions across the cancer care continuum.

Circadian Rhythms, Chrononutrition, Physical Training, and Redox Homeostasis-Molecular Mechanisms in Human Health

A multitude of physiological processes, human behavioral patterns, and social interactions are intricately governed by the complex interplay between external circumstances and endogenous circadian rhythms. This multidimensional regulatory framework is susceptible to disruptions, and in contemporary society, there is a prevalent occurrence of misalignments between the circadian system and environmental cues, a phenomenon frequently associated with adverse health consequences. The onset of most prevalent current chronic diseases is intimately connected with alterations in human lifestyle practices under various facets, including the following: reduced physical activity, the exposure to artificial light, also acknowledged as light pollution, sedentary behavior coupled with consuming energy-dense nutriments, irregular eating frameworks, disruptions in sleep patterns (inadequate quality and duration), engagement in shift work, and the phenomenon known as social jetlag. The rapid evolution of contemporary life and domestic routines has significantly outpaced the rate of genetic adaptation. Consequently, the underlying circadian rhythms are exposed to multiple shifts, thereby elevating the susceptibility to disease predisposition. This comprehensive review endeavors to synthesize existing empirical evidence that substantiates the conceptual integration of the circadian clock, biochemical molecular homeostasis, oxidative stress, and the stimuli imparted by physical exercise, sleep, and nutrition.

Association between nocturnal sleep duration and midday napping and the incidence of sarcopenia in middle-aged and older adults: a 4-year longitudinal study

BACKGROUND

Identifying treatment targets for sarcopenia is a public health concern. This study aimed to examine the association of nocturnal sleep duration and midday napping with the presence of sarcopenia in middle-aged and older adults, utilizing data from the China Health and Retirement Longitudinal Study in 2011 and 2015.

METHODS

A sum of 7,926 individuals (≥40 years) took part in this study. Sarcopenia was diagnosed according to the Asian Working Group for Sarcopenia. A self-reported questionnaire was used to collect data on nocturnal sleep duration and midday napping. Nocturnal sleep duration was categorized into three groups: short sleepers (<6 h), normal sleepers (6-8 h), and long sleepers (>8 h). Midday napping was coded as a dichotomous outcome (yes/no).

RESULTS

The incidence of sarcopenia was 5.3% during the 4-year follow-up. Short sleep duration (<6 h) was substantially linked to an increased incidence of sarcopenia (OR: 1.50, 95% CI: 1.21-1.87) as compared to nocturnal sleep length (6-8 h). Adults with midday napping had a lower risk of developing sarcopenia than non-nappers (OR: 0.78, 95% CI: 0.63-0.95). We further found that short sleepers with midday napping did not have a significantly higher risk of subsequent diagnosis of sarcopenia compared to normal sleepers without midday napping.

CONCLUSION

These findings imply that short sleep duration in middle-aged and older persons is related to an increased incidence of sarcopenia. However, the adverse effect of short sleep duration on sarcopenia can be compensated by midday napping.

The relationship between sleep- and circadian rhythm-related parameters with dietary practices and food intake of sedentary adults: a cross-sectional study

We aimed to explore the link between sleep-related parameters and dietary practices. This cross-sectional exploratory study includes sedentary individuals between 20 and 59 years of age. We applied exigent inclusion and exclusion criteria, such as weight stability and without humor- or sleep-related diseases. Also, shift workers were not included. We evaluated sleep quality (by Pittsburg Sleep Quality Index; PSQI), sleepiness (by Epworth Sleepiness Scale), chronotype (by Morningness Eveningness Questionnaire; MEQ), and social jetlag from sleep dairy. Moreover, Food Practices Measurement Scale was used to assess dietary practices. Food intake estimates (i. e., energy, eating window, and late-night dinner eating) were derived from two 24-h food recalls (R24h). For analysis, dietary practices and energy intake from R24h were considered dependent variables, while PSQI, ESS, MEQ, STJ, EW, and LNDE were considered independent variables. Our sample comprises 42 adults (21 women and 21 men; 35.4 (12.5) y; 25.6 (5.21) kg/m2 BMI; 26.5 (7.97) % body fat). We verified that persons with poor sleep quality showed lower dietary practice scores (MD - 6.68; p = 0.021). Besides, in regression analysis, chronotype (β = 0.266; p = 0.039) was positively associated with dietary practices, and eating window was positively associated with energy intake (β = 267 kcal; p = 0.023). In contrast to our hypothesis, other sleep- and circadian-related variables were not associated with dietary practices or energy intake. In summary, we conclude that morning chronotype appears to be related to better dietary practices from the Food Guide for the Brazilian Population guide and that higher eating window was positively associated with energy intake.

Exercise leads to better sleep in children with inflammatory bowel disease

BACKGROUND

The aim of our study was to investigate the effect of an exercise program on health-related quality of life (HRQoL) and sleep quality in children with inflammatory bowel disease (IBD) in remission.

METHODS

A total of 42 pediatric IBD patients in remission were recruited to participate in a 6-month-long home-based exercise program. Their mean age was 15.3 years (with a range of ± 2.08 years) and there were 25 boys. With regard to disease type, 22 had Crohn's disease (CD), 18 had ulcerative colitis (UC), and two had unclassified inflammatory bowel disease (IBD-U). Prior to starting the program, and after its completion, HRQoL was assessed using the IMPACT III questionnaire, and sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) questionnaire. Patients also wore a triaxial accelerometer for 5 consecutive days before and after the completion of the exercise program to assess physical activity (PA) objectively.

RESULTS

Study participants experienced no significant increase in their IMPACT III score (from 147.6 ± 2.7 to 149.6 ± 2.7, p = 0.106) following the completion of the exercise program. The prevalence of impaired sleep quality (PSQI > 5) decreased significantly from 30.9 to 23.8% (p = 0.027). At the baseline, participants' time spent in light PA (LPA) correlated positively with their IMPACT III score (coefficient (coef.) 0.398, p = 0.013). Following the completion of the resistance training program, the changes in the IMPACT III score correlated positively with time spent in moderate-to-vigorous PA (MVPA) (coef. 0.329, p = 0.047) and negatively with changes in PSQI score (coef. -0.493, p = 0.001).

CONCLUSION

The number of children with impaired sleep quality decreased significantly following the completion of a 6-month-long home-based resistance training program but improvements in HRQoL scores did not reach statistical significance.

Sleep, Nutrition, and Injury Risk in Adolescent Athletes: A Narrative Review

This narrative review explores the impact of sleep and nutrition on injury risk in adolescent athletes. Sleep is viewed as essential to the recuperation process and is distinguished as an active participant in recovery through its involvement in growth, repair, regeneration, and immunity. Furthermore, the literature has shown that the sleep of athletes impacts elements of athletic performance including both physical and cognitive performance, recovery, injury risk, and mental well-being. For sleep to have a restorative effect on the body, it must meet an individual's sleep needs whilst also lasting for an adequate duration and being of adequate quality, which is age-dependent. The literature has suggested that athletes have increased sleep needs compared to those of the general population and thus the standard recommendations may not be sufficient for athletic populations. Therefore, a more individualised approach accounting for overall sleep health may be more appropriate for addressing sleep needs in individuals including athletes. The literature has demonstrated that adolescent athletes achieve, on average, ~6.3 h of sleep, demonstrating a discrepancy between sleep recommendations (8-10 h) and actual sleep achieved. Sleep-wake cycles undergo development during adolescence whereby adaptation occurs in sleep regulation during this phase. These adaptations increase sleep pressure tolerance and are driven by the maturation of physiological, psychological, and cognitive functioning along with delays in circadian rhythmicity, thus creating an environment for inadequate sleep during adolescence. As such, the adolescent period is a phase of rapid growth and maturation that presents multiple challenges to both sleep and nutrition; consequently, this places a significant burden on an adolescent athletes' ability to recover, thus increasing the likelihood of injury. Therefore, this article aims to provide a comprehensive review of the available literature on the importance of sleep and nutrition interactions in injury risk in adolescent athletes. Furthermore, it provides foundations for informing further investigations exploring the relation of sleep and nutrition interactions to recovery during adolescence.

Intraindividual variability in sleep among athletes: A systematic review of definitions, operationalizations, and key correlates

Via systematic review with narrative synthesis of findings, we aimed to document the ways by which researchers have defined, operationalized, and examined sleep variability among athletes. We identified studies in which scholars examined intraperson variability in sleep among athletes via a search of six databases (Web of Science, Embase, Medline, PsycINFO, CINHAL Plus, and ProQuest Dissertations and Theses Global) using a protocol that included keywords for the target outcome (sleep*), population (athlet* OR sport*), and outcome operationalization (variability OR variation OR "standard deviation" OR fluctuate OR fluctuation OR stability OR instability OR reactivity OR IIV OR intraindividual). We complemented this primary search with citation searching of eligible articles. Assessments of study quality captured eight core elements, namely aims/hypotheses, sample size justification, sample representativeness, number of days sleep assessed, measures of sleep and its correlates, missing data, and inferences and conclusions. From a total of 1209 potentially relevant papers, we identified 16 studies as meeting our eligibility criteria. Concept definitions of variability were notably absent from this work and where available were vague. Quantitative deviations from one's typical level of target sleep metrics reflected the essence by which all but one of the research teams operationalized sleep variability. We assessed the overall quality of empirical work as moderate in nature. We propose a working definition of sleep variability that can inform knowledge generation on the temporal, day-to-day dynamics of sleep functioning that is required for personalized interventions for optimizing sleep health.

Metabolic diseases and healthy aging: identifying environmental and behavioral risk factors and promoting public health

Aging is a progressive and irreversible pathophysiological process that manifests as the decline in tissue and cellular functions, along with a significant increase in the risk of various aging-related diseases, including metabolic diseases. While advances in modern medicine have significantly promoted human health and extended human lifespan, metabolic diseases such as obesity and type 2 diabetes among the older adults pose a major challenge to global public health as societies age. Therefore, understanding the complex interaction between risk factors and metabolic diseases is crucial for promoting well-being and healthy aging. This review article explores the environmental and behavioral risk factors associated with metabolic diseases and their impact on healthy aging. The environment, including an obesogenic environment and exposure to environmental toxins, is strongly correlated with the rising prevalence of obesity and its comorbidities. Behavioral factors, such as diet, physical activity, smoking, alcohol consumption, and sleep patterns, significantly influence the risk of metabolic diseases throughout aging. Public health interventions targeting modifiable risk factors can effectively promote healthier lifestyles and prevent metabolic diseases. Collaboration between government agencies, healthcare providers and community organizations is essential for implementing these interventions and creating supportive environments that foster healthy aging.

Effects of exercise on circadian rhythms in humans

The biological clock system is an intrinsic timekeeping device that integrates internal physiology and external cues. Maintaining a healthy biological clock system is crucial for life. Disruptions to the body's internal clock can lead to disturbances in the sleep-wake cycle and abnormalities in hormone regulation, blood pressure, heart rate, and other vital processes. Long-term disturbances have been linked to the development of various common major diseases, including cardiovascular diseases, metabolic disorders, tumors, neuropsychiatric conditions, and so on. External factors, such as the diurnal rhythm of light, have a significant impact on the body's internal clock. Additionally, as an important non-photic zeitgeber, exercise can regulate the body's internal rhythms to a certain extent, making it possible to become a non-drug intervention for preventing and treating circadian rhythm disorders. This comprehensive review encompasses behavioral, physiological, and molecular perspectives to provide a deeper understanding of how exercise influences circadian rhythms and its association with related diseases.

Molecular targets and mechanisms involved in the action of Banxia Shumi decoction in insomnia treatment

Insomnia is a common sleep-wake rhythm disorder, which is closely associated with the occurrence of many serious diseases. Recent researches suggest that circadian rhythms play an important role in regulating sleep duration and sleep quality. Banxia Shumi decoction (BSXM) is a well-known Chinese formula used to treat insomnia in China. However, the overall molecular mechanism behind this therapeutic effect has not yet been fully elucidated. This study aimed to identify the molecular targets and mechanisms involved in the action of BSXM during the treatment of insomnia. Using network pharmacology and molecular docking methods, we investigated the molecular targets and underlying mechanisms of action of BSXM in insomnia therapy. We identified 8 active compounds from Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform and the traditional Chinese medicine integrative database that corresponded to 26 target genes involved in insomnia treatment. The compound-differentially expressed genes of the BXSM network indicated that cavidine and gondoic acid could potentially become key components of drugs used for insomnia treatment. Further analysis revealed that GSK3B, MAPK14, IGF1R, CCL5, and BCL2L11 were core targets significantly associated with the circadian clock. Pathway enrichment analysis of Kyoto Encyclopedia of Genes and Genomes revealed that epidermal growth factor receptor tyrosine kinase inhibitor resistance was the most prominently enriched pathway for BSXM in the insomnia treatment. The forkhead box O signaling pathway was also found to be significantly enriched. These targets were validated using the Gene Expression Omnibus dataset. Molecular docking studies were performed to confirm the binding of cavidine and gondoic acid to the identified core targets. To our knowledge, our study confirmed for the first time that the multi-component, multi-target, and multi-pathway characteristics of BXSM may be the potential mechanism for treating insomnia with respect to the circadian clock gene. The results of this study provided theoretical guidance for researchers to further explore its mechanism of action.

The effect of caffeine on subsequent sleep: A systematic review and meta-analysis

The consumption of caffeine in response to insufficient sleep may impair the onset and maintenance of subsequent sleep. This systematic review and meta-analysis investigated the effect of caffeine on the characteristics of night-time sleep, with the intent to identify the time after which caffeine should not be consumed prior to bedtime. A systematic search of the literature was undertaken with 24 studies included in the analysis. Caffeine consumption reduced total sleep time by 45 min and sleep efficiency by 7%, with an increase in sleep onset latency of 9 min and wake after sleep onset of 12 min. Duration (+6.1 min) and proportion (+1.7%) of light sleep (N1) increased with caffeine intake and the duration (-11.4 min) and proportion (-1.4%) of deep sleep (N3 and N4) decreased with caffeine intake. To avoid reductions in total sleep time, coffee (107 mg per 250 mL) should be consumed at least 8.8 h prior to bedtime and a standard serve of pre-workout supplement (217.5 mg) should be consumed at least 13.2 h prior to bedtime. The results of the present study provide evidence-based guidance for the appropriate consumption of caffeine to mitigate the deleterious effects on sleep.

Effect of Circadian Rhythm Disturbance on the Human Musculoskeletal System and the Importance of Nutritional Strategies

The circadian system in the human body responds to daily environmental changes to optimise behaviour according to the biological clock and also influences various physiological processes. The suprachiasmatic nuclei are located in the anterior hypothalamus of the brain, and they synchronise to the 24 h light/dark cycle. Human physiological functions are highly dependent on the regulation of the internal circadian clock. Skeletal muscles comprise the largest collection of peripheral clocks in the human body. Both central and peripheral clocks regulate the interaction between the musculoskeletal system and energy metabolism. The skeletal muscle circadian clock plays a vital role in lipid and glucose metabolism. The pathogenesis of osteoporosis is related to an alteration in the circadian rhythm. In the present review, we discuss the disturbance of the circadian rhythm and its resultant effect on the musculoskeletal system. We also discuss the nutritional strategies that are potentially effective in maintaining the system's homeostasis. Active collaborations between nutritionists and physiologists in the field of chronobiological and chrononutrition will further clarify these interactions. This review may be necessary for successful interventions in reducing morbidity and mortality resulting from musculoskeletal disturbances.

Pyjamas, Polysomnography and Professional Athletes: The Role of Sleep Tracking Technology in Sport

Technological advances in sleep monitoring have seen an explosion of devices used to gather important sleep metrics. These devices range from instrumented 'smart pyjamas' through to at-home polysomnography devices. Alongside these developments in sleep technologies, there have been concomitant increases in sleep monitoring in athletic populations, both in the research and in practical settings. The increase in sleep monitoring in sport is likely due to the increased knowledge of the importance of sleep in the recovery process and performance of an athlete, as well as the well-reported challenges that athletes can face with their sleep. This narrative review will discuss: (1) the importance of sleep to athletes; (2) the various wearable tools and technologies being used to monitor sleep in the sport setting; (3) the role that sleep tracking devices may play in gathering information about sleep; (4) the reliability and validity of sleep tracking devices; (5) the limitations and cautions associated with sleep trackers; and, (6) the use of sleep trackers to guide behaviour change in athletes. We also provide some practical recommendations for practitioners working with athletes to ensure that the selection of such devices and technology will meet the goals and requirements of the athlete.