Sleep Disruption and Bone Health

ED-71 Ameliorates Bone Loss in Type 2 Diabetes Mellitus by Enhancing Osteogenesis Through Upregulation of the Circadian Rhythm Coregulator BMAL1

Purpose

Bone loss is a common complication of type 2 diabetes mellitus (T2DM). Circadian rhythms play a significant role in T2DM and bone remodeling. Eldecalcitol (ED-71), a novel active vitamin D analog, has shown promise in ameliorating T2DM. We aimed to investigate whether the circadian rhythm coregulator BMAL1 mediates the anti-osteoporotic effect of ED-71 in T2DM and its associated mechanisms.

Methods

A T2DM mouse model was established using high-fat diet (HDF) and streptozotocin (STZ) injection, and blood glucose levels were monitored weekly. HE staining, Masson staining, and Micro-CT were performed to assess the changes in bone mass. IHC staining and IF staining were used to detect osteoblast status and BMAL1 expression and RT-qPCR was applied to detect the change of oxidative stress factors. In vitro, high glucose (HG) stimulation was used to simulate the cell environment in T2DM. RT-qPCR, Western blot, IF, ALP staining and AR staining were used to detect osteogenic differentiation and SIRT1/GSK3β signaling pathway. DCFH-DA staining was used to detect reactive oxygen species (ROS) levels.

Results

ED-71 increased bone mass and promoted osteogenesis in T2DM mice. Moreover, ED-71 inhibited oxidative stress and promoted BMAL1 expression in osteoblasts The addition of STL1267, an agonist of the BMAL1 transcriptional repressor protein REV-ERB, reversed the inhibitory effect of ED-71 on oxidative stress and the promotional effect on osteogenic differentiation. In addition, ED-71 facilitated SIRT1 expression and reduced GSK3β activity. The inhibition of SIRT1 with EX527 partially attenuated ED-71's effects, whereas the GSK3β inhibitor LiCl further enhanced ED-71's positive effects on BMAL1 expression.

Conclusion

ED-71 ameliorates bone loss in T2DM by upregulating the circadian rhythm coregulator BMAL1 and promoting osteogenesis through inhibition of oxidative stress. The SIRT1/GSK3β signaling pathway is involved in the regulation of BMAL1.

Association Between Changes in Sleep, Nap Duration and Bone Mineral Density in Mexican Adults

Studies have found associations between sleep, nap duration, and bone mineral density (BMD). However, the longitudinal relationship between sleep, nap duration, and BMD has not been explored. We evaluated the association between the change in sleep and nap duration and BMD in Mexican adults. Data come from 1,337 adult participants of the Health Workers Cohort Study (341 were men and 996 were women, including 450 women < 45 years old and 546 ≥ 45 years old), with two study waves. At each wave, sleep and nap duration was assessed using self-administered questionnaires and BMD in g/cm2 was determined by dual X-ray absorptiometry. We used fixed-effect regression models stratified by sex and adjusted for BMI, diet, physical activity, vitamin supplements, and hormone replacement therapy. Women who changed from < 7 to ≥ 7 h/day of sleep from baseline to follow-up were associated with increases in the total hip (β = 0.012 g/cm2; 95% CI: 0.002, 0.022) and lumbar spine BMD (β = 0.024 g/cm2; 95% CI: 0.009, 0.039). Furthermore, most of these associations were observed in women ≥ 45 years. For women, a changing from 0 to > 60 min/day of napping was associated with a significant increase in total hip BMD of 0.012 g/cm2 (95% CI: 0.004, 0.024) and lumbar spine BMD of 0.027 g/cm2 (95% CI: 0.009, 0.045). No significant associations were observed for men. Our results suggest that increased sleep and nap duration are associated with gains in BMD in Mexican women, emphasizing sleep's role in promoting bone health and supporting established recommendations.

Multiplex influences on vigilance and biochemical variables induced by sleep deprivation

Introduction

Sleep loss and sleep deprivation (SD) cause deleterious influences on health, cognition, mood and behaviour. Nevertheless, insufficient sleep and SD are prevalent across many industries and occur in various emergencies. The deleterious consequences of SD have yet to be fully elucidated. This study aimed to assess the extensive influences of SD on physiology, vigilance, and plasma biochemical variables.

Methods

Seventeen volunteers were recruited to participate in a 32.5-h SD experiment. Multiple physiological and cognitive variables, including tympanic temperature, blood oxygen saturation (SaO2), and vigilance were recorded. Urinal/salivary samples were collected and subjected to cortisol or cortisone analysis, and plasma samples were subjected to transcriptomic analysis of circular RNA (circRNA) expression using microarray. Plasma neurotransmitters were measured by targeted metabolic analysis, and the levels of inflammatory factors were assessed by antibody microarray.

Results

The volunteers showed significantly increased sleepiness and decreased vigilance during SD, and the changes in circadian rhythm and plasma biochemistry were observed. The plasma calcium (p = 0.0007) was induced by SD, while ischaemia-modified albumin (IMA, p = 0.0030) and total bile acid (TBA, p = 0.0157) decreased. Differentially expressed circRNAs in plasma were identified, which are involved in multiple signaling pathways including neuronal regulation and immunity. Accordingly, SD induced a decrease in 3-hydroxybutyric acid (3OBH, p = 0.0002) and an increase in thyroxine (T4, p < 0.0001) in plasma. The plasma anti-inflammatory cytokine IL-10 was downregulated while other ten inflammatory factors were upregulated.

Conclusion

This study demonstrates that SD influences biochemical, physiological, cognitive variables, and the significantly changed variables may serve as candidates of SD markers. These findings may further our understanding of the detrimental consequence of sleep disturbance at multiple levels.

Effects of Testosterone in Mediating the Relationship Between Daytime Napping and Osteoporosis in European Populations: A Mendelian Randomization Study

We aimed to explore the causal effect of daytime napping on the risk of osteoporosis and the mediation role of testosterone in explaining this relationship. Summary data for Mendelian randomization (MR) analysis were obtained from the IEU OpenGWAS database. Univariable MR(UVMR) analysis and multiple sensitivity analyses were applied to explore the casual relationship between daytime napping and bone mineral density (BMD)/osteoporosis. We also conducted multivariable Mendelian randomization (MVMR) analysis to evaluate the correlation between testosterone-associated single-nucleotide variations and BMD/osteoporosis. Then, mediation analysis was performed to explore whether the association between daytime napping and BMD/osteoporosis was mediated via testosterone. Genetically predicted daytime napping was significantly associated with femoral neck BMD (β [95% CI]: 0.2573 [0.0487, 0.4660]; P = 0.0156), lumbar spine BMD (β [95% CI]: 0.2526 [0.0211, 0.4840]; P = 0.0324), and osteoporosis (OR [95% CI]: 0.5063 [0.2578, 0.9942]; P = 0.0481). β and 95%CIs indicate the standard deviation (SD) unit of BMD increase per category increase in daytime napping. OR and 95%CIs represent the change in the odds ratio of osteoporosis per category increase in daytime napping. We observed a potentially causal effect of more frequent daytime napping on higher BMD and a lower risk of osteoporosis. Daytime napping was causally associated with a higher level of bioavailable testosterone (β [95% CI]: 0.1397 [0.0619, 0.2175]; P = 0.0004). β and 95%CIs represent the change in the SD of testosterone per category increase in daytime napping. Furthermore, the causal effects of daytime napping on BMD/osteoporosis were partly mediated by bioavailable testosterone. Daytime napping can efficiently increase BMD and reduce the risk of osteoporosis, and testosterone plays a key mediating role in this process.

Problematic video gaming is negatively associated with bone mineral density in adolescents

Adolescent bone health may be negatively impacted by problematic video gaming (PVG) due to factors such as prolonged screen time, poor sleep quality, and increased depression. Although sedentary behaviors have been linked to decreased bone mass, there is limited research on how PVG impacts bone health. We aimed to evaluate the association between PVG and bone mineral density (BMD) in adolescents by comparing the BMD z-scores of adolescents with and without PVG and by identifying PVG-related risk factors that may affect low BMD scores. This cross-sectional study took place between May 2019 and August 2021 with 110 adolescents who played video games for at least two hours per day. Data on screen time, game genre, tobacco, alcohol, caffeine consumption, and vigorous physical activity status were recorded. PVG was assessed using the Internet Gaming Disorder-Short Form (IGDS9-SF), with scores ≤ 16 comprising the control group and > 16 the PVG group. Sleep quality was assessed by Pittsburgh Sleep Quality Index, and depression was evaluated by Children's Depression Inventory. Dual-energy X-ray absorptiometry measurements of femoral neck and lumbar spine BMD were compared between the two groups. The mean age of the participants was 14.2 ± 1.8 years, and 86.4% were males. The PVG group exhibited lower femoral neck z-scores (p = 0.013) and a higher proportion of adolescents with low femoral neck BMD risk (27.8% vs 9.7%, p = 0.041). Lumber spine z-scores did not differ (p = 0.271). Despite poorer depressive symptoms and sleep quality in the PVG group, they were not associated with low BMD risk (OR 1.02, 95% CI 0.97-1.08, p = 0.398 and OR 1.00, 95% CI 0.87-1.18, p = 0.972, respectively). Among all PVG-related risk factors, video game time (aOR = 1.22, 95% CI = 1.06-1.41, p = 0.006) and vigorous physical activity amount (aOR = 2.86, 95% CI = 0.93-8.76, p = 0.080) showed the strongest associations with femoral neck z-scores.  Conclusion: The results of this study, showing a negative association between PVG and femoral neck BMD in adolescents, underscore the importance evaluating, monitoring, and supporting lower extremity bone health in adolescents with PVG. What is Known: • Adolescents with problematic video gaming are at risk for depression, impaired sleep; sedentary lifestyle; consumption of tobacco, alcohol, and drugs; and high caffeine intake. • These risk factors might lead to compromised bone health. What is New: • Problematic video gaming is associated with the low femoral neck bone mineral density risk in adolescents. • Extended video game time and reduced physical activity are found to be the primary risk factors.

The Association between Sleep and Bone Mineral Density: Cross-Sectional Study Using Health Check-up Data in a Local Hospital in Japan

This study aimed to investigate the association between daily sleep duration of <7 hours and lower bone mineral density (BMD) using data from annual health check-ups conducted in Japan between 2020 and 2022. Multivariate regression models were used, where BMD was the objective variable and daily sleep duration (<5 hours, 5 to <7 hours, 7 to <9 hours [reference], ≥9 hours) was the exposure variable adjusted for age, body mass index, physical activity, smoking status, and alcohol intake for men and women and further adjusted for menopausal status for women. The association between insomnia and BMD was also investigated. BMD was determined using calcaneal quantitative ultrasound and expressed as a percentage of the young adult mean (%YAM). In total, 896 men and 821 women were included. Median age was 54 years (interquartile range [IQR]: 46 to 64) for men and 55 years (IQR: 46 to 64) for women). Median BMD for men and women was 79%YAM (IQR: 71 to 89) and 75%YAM (IQR: 68 to 84), respectively. Approximately 80% of men and women slept <7 hours daily. Multivariate regression showed no association between sleep duration and BMD in men. However, women who slept 5 to <7 hours daily had significantly higher BMD by 3.9% compared with those who slept 7 to<9 hours (p = 0.004). No association between insomnia and BMD was found. Overall, a daily sleep duration of <7 hours was not independently associated with lower BMD compared to those who slept 7 to <9 hours in men and women. However, as there is evidence of both shorter and longer sleep durations being associated with an increased risk of adverse events, including cardiovascular events, our result needs to be interpreted with caution. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Night shift work and serum markers of bone turnover in male shift workers

Night shift work is related to sleep disorders, disruption of circadian rhythm and low serum levels of vitamin D. It is known that all these conditions can adversely affect bone mass. The rate of bone turnover can be assessed through the measurement of molecules called bone turnover markers, including C-terminal telopeptide fragment of type I collagen (CTX) and procollagen type I N-terminal propeptide (P1NP). In this study, we evaluated the serum levels of CTX, P1NP and 25-Hydroxy Vitamin D in 82 male subjects (42 daytime workers and 40 night shift workers) to assess the possible risk of osteoporosis in male shift workers. Serum levels of CTX and P1NP were found to be higher in night shift workers than in daytime workers. No significant difference was found in vitamin D levels between night shift and daytime workers. The increased CTX and P1NP levels reveal a higher rate of bone turnover in night shift workers and thus a possible increased risk of osteoporosis in this category of workers compared with daytime workers. In view of this, our results highlight the importance of further studies investigating the bone health in male night shift workers.