Influence of sunlight on the association between 25-hydroxyvitamin D levels and sleep quality in Brazilian adults: A population-based study

Exploring the interaction between vitamin D pathway gene polymorphisms, vitamin D status, and depression: A population-based study

BACKGROUND

The association between vitamin D and depression is controversial, mainly because of genetic differences and confounding factors.

OBJECTIVE

To evaluate the association between vitamin D and depressive symptoms, considering the influence of genetic variations, skin color, and lifestyle.

METHODS

This population-based cross-sectional study was conducted during the COVID-19 pandemic. Depressive symptoms were assessed using the Patient Health Questionnaire-9. Vitamin D deficiency was defined as levels of <20 ng/mL in healthy individuals or <30 ng/mL in at-risk groups. A genetic risk score for vitamin D deficiency was developed based on gene polymorphisms involved in vitamin D metabolism (DHCR7, GC, and VDR), and this score was categorized into tertiles.

RESULTS

Among 1637 participants, 50.9% were women, with a mean age of 42.9 years (95% CI: 41.62-44.26). No association was found between vitamin D deficiency and depressive symptoms. However, the interaction analysis between vitamin D deficiency and the genetic risk score in the subgroups revealed disparities. Individuals with non-white skin color and vitamin D deficiency in the third tertile, supplement non-users with vitamin D deficiency in the second and third tertiles, and participants with insufficient sun exposure and vitamin D deficiency in the second and third tertiles had a higher prevalence of depressive symptoms.

CONCLUSION

Vitamin D deficiency is linked to a higher prevalence of depressive symptoms in genetically predisposed Brazilians with non-white skin, no vitamin D supplementation, and insufficient sun exposure. Mental health guidelines should aim to promote lifestyle modifications among individuals who are predisposed to depressive symptoms.

Evaluating circadian light hygiene: Methodology and health implications

Background — A growing body of research demonstrates that a substantial daily range of light exposure, characterized by ample daylight followed by darkness during sleep, is essential for human well-being. This encompasses crucial aspects like sleep quality, mood regulation, and cardiovascular and metabolic health. Objective — This study characterizes Circadian Light Hygiene (CLH) as an essential factor in maintaining health, well-being, and longevity in modern society. CLH involves adjusting the 24-hour light exposure dynamic range to support the natural sleep-wake cycle and circadian rhythms. Three major challenges to CLH negatively impacting human health are: 1) light pollution (light at night, or LAN), characterized by excessive evening and nighttime artificial light; 2) insufficient natural daylight; and 3) irregular light exposure patterns. These interacting challenges necessitate a systematic approach to measurement and analysis. Material and Methods — A systematic review of peer-reviewed literature published through October 30, 2024, examined the methodologies and health effects of circadian and seasonal aspects of light exposure. Conclusion — This review elucidates fundamental principles of circadian light hygiene, synthesizing existing literature and our research to assess the benefits of adequate daylight, the risks of light at night, and adverse outcomes stemming from diminished light exposure range, mistimed light exposure, and irregular patterns. Novel indices for quantifying and optimizing circadian light hygiene are introduced.

Prevalence and Mitigation of Cardiovascular Disease Risk Factors Among the Corporate Workforce in Sub-Saharan Africa: A Systematic Review and Meta-Analysis

Cardiovascular disease (CVDs) is the leading cause of mortality worldwide. Corporate workplaces have been identified as important environmental factors that can increase the risk and severity of CVDs. Evidence indicates that the risk and severity of CVDs can be effectively reduced by mitigating modifiable behavioural and intermediate risk factors. Although the prevalence of CVDs and their associated risk factors is increasing in sub-Saharan Africa (SSA), most published data from the region are hospital-based and may not be true estimates. This study investigated the prevalence and distribution of CVD risk factors among the corporate workforce in SSA and the effects of workplace wellness programmes (WWP) on these risk factors. Accordingly, a systematic search was performed using Google Scholar, Cochrane Library, PubMed, MEDLINE, Scopus and Science Direct for articles published between January 2010 and March 2024. A total of 105 studies (n = 76,027) across nine countries met the eligibility criteria and were analysed. The pooled prevalence of the risk factors was unhealthy diet (80%), high salt intake (32%), stress (58%), poor sleep (59%), physical inactivity (PI, 59%), alcohol consumption (29%), harmful alcohol consumption (26%), tobacco smoking (7%), khat chewing (6%), overweight (36%), obesity (23%), central obesity (44%), high blood pressure (29%), high total cholesterol (33%), high low-density lipoprotein cholesterol (LDL-c) (41%), low high-density lipoprotein cholesterol (HDL-c) (45%), hypertriglyceridaemia (17%), dysglycaemia (9%), and metabolic syndrome (MS; 45%). The highest prevalence of unhealthy diet and PI was recorded in East Africa and Central Africa, respectively, whereas West Africa had the highest prevalence of high body mass index (BMI). Ethiopia had the highest prevalence of unhealthy diets, whereas Nigeria had the highest prevalence of stress and poor sleep. The healthcare sector had the highest cluster of risk factors and the highest prevalence of unhealthy diets. Only 5.7% of the studies implemented WWP, which had significant mitigating effects on most risk factors. This study concluded that the prevalence of most modifiable CVD risk factors is high among the corporate workforce in SSA, which is higher than that in the general population in most cases, and a well-designed WWP can significantly mitigate these risk factors.

Association of cardiometabolic index with sleep quality in adults: a population‑based study

The Cardiometabolic Index (CMI) represents an innovative metric that encompasses abdominal obesity and lipid levels, offering a comprehensive assessment of cardiometabolic health. It is derived through the multiplication of the waist-to-height ratio by the triglyceride-to-high-density lipoprotein cholesterol ratio. Although obesity and blood lipid levels are known factors affecting sleep quality, the direct correlation between CMI and sleep quality has yet to be elucidated. This study uses NHANES data to explore the potential correlation between CMI and sleep quality. Our research employed a cross-sectional design, utilizing data from the National Health and Nutrition Examination Survey (NHANES) spanning 2011 to 2014. CMI was used as the exposure variable, with sleep quality assessed through three self-reported measures: trouble sleeping, sleep disorders, and sleep duration. We employed multivariate logistic regression models and linear regression model as well as subgroup analyses to explore the independent relationship between CMI and sleep quality. Additionally, interaction tests were conducted to examine differences across various subgroups. The study included 4298 participants, comprising 2134 males and 2164 females. There was a positive correlation between CMI and trouble sleeping (OR = 1.63, 95% CI 1.28-2.08) and sleep disorders (OR = 1.96, 95% CI 1.43-2.67), while there was a negative correlation between CMI and sleep duration (β = - 0.17, 95% CI - 0.31 to - 0.03), indicating that a higher CMI was associated with shorter sleep duration. Subgroup analyses and interaction tests revealed a consistently positive association between CMI and sleep difficulty across various populations, including gender, age, hypertension, diabetes, and cardiovascular disease history. However, the relationship between CMI and sleep disorders was more prominent among participants aged 50 and above. In American adults, a higher CMI is linked to an increased prevalence of sleep disturbances. In clinical practice, CMI can be considered as a supplementary factor in the assessment and management of sleep problems. Our study also provided new insights for improving sleep quality.

The association of sedentary time with sleep disturbances among the US population, 2005 to 2014

BACKGROUND

Sleep problems increase the risk of premature illness and death. We evaluated the association between sedentary time and sleep disturbances.

METHODS

A cross-sectional analysis of the US nationally representative data of 21,414 adults (aged > = 18 years) from National Health and Nutrition Examination Survey (NHANES) (2005-2014) was performed. The data of sleep disturbances were assessed using NHANES questionnaire results, which included the question, "{Have you/has sp} ever been told by a doctor or other health professional that {you have/s/he has} a sleep disorder?". All participants were stratified by quartiles of sedentary behavior distribution, which was the explanatory variable (sedentary time quartile cut points: Q1, 0 < = Q1 < 3 h; Q2, 3 < = Q2 < 5 h; Q3, 5 < = Q3 < 8 h; Q4, 8 < = Q4 < 20 h). We used multivariable logistic regression and the restricted cubic splines (RCS) model to assess the relationship between sedentary time and sleep disturbances.

RESULTS

In the unadjusted multivariable logistic regression model (crude model), there was a demonstrated tendency for the odds of sleep disturbances to increase with the sedentary time (Q1 as reference, Q2: OR, 1.31 [95% CI 1.09-1.58] P = 0.005; Q3: OR, 1.62 [95% CI 1.39-1.88] P < 0.001; Q4: OR, 1.75 [95% CI 1.48-2.06] P < 0.001; P for trend < 0.001). In the adjusted model 4, adjustment for gender, age, marital type, education type, race, family poverty index ratio, waist circumference, recreational type, smoke status, drink status, diabetes mellitus status, cardiovascular disease status, sleep duration type, body mass index, the OR in Q2 subgroup didn't significantly increase (Q1 as reference. Q2: OR, 1.18 [95% CI 0.96-1.44] P = 0.1). However, the ORs in Q3 and Q4 (Q3: OR, 1.35 [95% CI 1.14-1.59] P < 0.001; Q4: OR, 1.45 [95% CI 1.21-1.75] P < 0.001) both revealed that the risk of sleep disturbances increased with increasing sedentary time, P for trend < 0.001. The unadjusted RCS model revealed that the risk of sleep disturbances increased non-linearly with increasing sedentary time for total participants (P for non-linearity < 0.001). After adjusting for all covariates, the RCS results revealed that the risk of sleep disturbances increased non-linearly with increasing sedentary time for total participants (P for non-linearity = 0.012).

CONCLUSIONS

This study suggested that the longer sedentary time was strongly associated with the sleep disturbances. The protective effect of recreational activities on sleep disturbance, has not been significantly demonstrated.

Vitamin D deficiency: A forgotten aspect in sleep disorders? A critical update

Over the past few years, there has been a surge in interest regarding the connection between sleep duration and quality, sleep disorders, mainly Obstructive sleep apnoea (OSA) and Vitamin D. There is growing evidence to support a new role of Vitamin D in the maintenance and regulation of optimal sleep. Furthermore, a notable link has been identified between OSA and a decrease in serum Vitamin D levels, which appears to intensify as the severity of sleep apnea worsens. Vitamin D status could also potentially serve as a mediator or provide an explanation for the association between OSA and cardiometabolic morbidity, but the current state of research in this area is inadequate. Studies have indicated that the supplementation of Vitamin D can optimize sleep quality, presenting more proof of the connection between insufficient vitamin D levels and sleep disorders. However, it is unclear whether low serum Vitamin D levels are a contributing factor to OSA development or if OSA predisposes individuals to Vitamin D deficiency. As a result, various studies have endeavored to examine the complex relationship between OSA and Vitamin D deficiency. In children and adolescents, while data is limited, there seems also to be a link between sleep disorders and Vitamin D levels. Therefore, the objective of this review is to provide a comprehensive overview of the current evidence on the association between Vitamin D and sleep disorders in both adults and children.

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 of serum 25-hydroxyvitamin D with cardiovascular and all-cause mortality in patients with chronic kidney disease: NHANES 2007‒2018 results

BACKGROUND

Vitamin D insufficiency is a prevalent issue in patients suffering from CKD. The purpose of this study was to determine whether serum 25(OH)D levels are associated with all-cause and cardiovascular mortality in patients with CKD.

METHODS

To examine the associations between 25(OH)D levels and cardiovascular mortality, this retrospective cohort study used the National Health and Nutrition Examination Survey (NHANES) and the National Death Index (NDI) 2007‒2018 database. A total of 2,668 eligible subjects were included in this study, with follow-up conducted until December 31, 2019. The associations were assessed using Cox proportional hazards regression, restricted cubic splines, Kaplan-Meier survival curves, and competing risks survival analysis. Furthermore, subgroup and sensitivity analyses were performed.

RESULTS

During a median follow-up of 72 months in a weighted population of 11,715,452 eligible participants, there were 665 deaths from any cause, including 196 cardiovascular-related deaths. After adjusting for covariates, lower levels of 25(OH)D were significantly associated with increased risks for both all-cause mortality (HR= 0.85, 95 % CI 0.77∼0.94) and cardiovascular mortality (SHR= 0.80, 95 % CI 0.67∼0.94). Consistent results were also observed when analyzing 25(OH)D as a categorical variable (quartile). Compared to group Q1, both group Q3 (HR = 0.71, 95 % CI 0.54‒0.93) and group Q4 (HR = 0.72, 95 % CI 0.55‒0.94) exhibited a significantly reduced mortality risk. Weighted restricted cubic splines revealed an inverse J-shaped linear association between levels of 25(OH) D and all-cause mortality ((PNonliner > 0.05). Subgroup analysis and sensitivity analysis yielded similar findings.

CONCLUSIONS

All-cause mortality and cardiovascular disease-related mortality were significantly increased by lower 25(OH)D levels, both as continuous and categorical variables. 25(OH)D has an inverse J-shaped linear association with all-cause and cardiovascular mortality.

The role of interaction between vitamin D and VDR FokI gene polymorphism (rs2228570) in sleep quality of adults

To evaluate association of vitamin D with sleep quality in adults and the influence of VDR-gene polymorphism FokI (rs2228570;A > G). Cross-sectional population-based study in adults, conducted in Brazil. The outcome was sleep-quality, evaluated by the Pittsburgh Sleep Quality Index. Vitamin D was determined by indirect electrochemiluminescence and classified as deficiency (VDD), 25(OH)D < 20 ng/mL in a healthy population or 25(OH)D < 30 ng/mL for groups at risk for VDD. FokI polymorphism in the VDR-gene was genotyped by qPCR and classified as homozygous wild (FF or AA), heterozygous (Ff or AG), or homozygous mutant (ff or GG). Multivariate logistic analysis was used to estimate the association between vitamin D and FokI polymorphism with sleep-quality. In a total of 1674 individuals evaluated, 53.6% had poor-sleep-quality, 31.5% had VDD, and the genotype frequency of the FokI polymorphism was 9.9% FF, 44.6% Ff, and 45.5% ff. In multivariate analysis, individuals with VDD had 1.51 times the chance of poor-sleep-quality, and individuals with the ff genotype had 1.49 times the chance of poor-sleep-quality (OR:1.49;95%CI:1.05-2.12) when compared to individuals with the FF or Ff genotype. In the combined analysis, individuals with VDD and ff genotype had more chance of poor-sleep-quality than individuals with sufficient vitamin D and genotype Ff or FF (OR:2.19;95%CI:1.27-3.76). Our data suggest that VDD and VDR FokI gene polymorphism are associated with poor-sleep-quality, and combining the two factors increases the chance of poor-sleep-quality compared to separate groups.

Reliability and validity of the Chinese version of the sunlight exposure questionnaire

Objective

This study aimed to translate and validate the reliability and validity of the Chinese version of the Philippines Sunlight Exposure Questionnaire.

Methods

A total of 392 Chinese individuals aged at least 18 years, residing in various cities in Sichuan province for at least 1 year, were recruited. The reliability of the Chinese version of the questionnaire was measured through internal consistency, split-half reliability, and retest reliability, while validity was determined using the content validity index and the structure validity index.

Results

The Chinese version of the Sunlight Exposure Questionnaire, which includes 19 items covering 5 factors, demonstrated McDonald's omega coefficient of 0.788. The split-half reliability of the questionnaire was 0.823, and the retest reliability was 0.940. The content validity index (S-CVI) was 0.952. The five-factor structure, supported by eigenvalues, explained 66.2% of the total variance. Confirmatory factor analysis indicated favorable model fit.

Results

The chi-square value degrees of freedom ratio (χ2/df) = 1.852, the goodness-of-fit index (GFI) = 0.938, the normed fit index (NFI) = 0.922, the incremental fit index (IFI) = 0.962, the comparative fit index (CFI) = 0.962, the Tucker-Lewis index (TLI) = 0.952, and root mean square error of approximation (RMSEA) = 0.047. The indicators of the fit of the model were within reasonable bounds.

Conclusion

The Chinese version of the Sunlight Exposure Questionnaire shows validity and good reliability for assessing sun exposure among adults in a Chinese cultural context.

Organic Synthesis of New Secosteroids from Fucosterol, Its Intestinal Absorption by Caco-2 Cells, and Simulation of the Biological Activities of Vitamin D

We previously examined the cellular uptake of six types of vitamin D in human intestinal Caco-2 cells. Since vitamins D5-D7 were commercially unavailable, we synthesized these compounds organically before studying them. This process led us to understand that new secosteroids could be generated as vitamin D candidates, depending on the sterol used as the starting material. We obtained two new secosteroids-compounds 3 and 4-from fucosterol in the current study. We investigated the intestinal absorption of these compounds using Caco-2 cells cultured in Transwells and compared the results with vitamin D3, a representative secosteroid. The intestinal absorption of compound 4 was comparable to that of vitamin D3. Compound 3 showed similar uptake levels but transported about half as much as vitamin D3. These compounds demonstrated intestinal absorption at the cellular level. Vitamin D is known for its diverse biological activities manifest after intestinal absorption. Using PASS online simulation, we estimated the biological activity of compound 3's activated form. In several items indicated by PASS, compound 3 exhibited stronger biological activity than vitamins D2-D7 and was also predicted to have unique biological activities.

Poor Sleep Quality and Working From Home Influence the Prevalence of Leisure Time Physical Inactivity During the COVID-19 Pandemic: COVID-Inconfidentes Study

OBJECTIVE

The aim of the study is to explore possible associations according to quality of sleep and work from home (WFH) with physical inactivity (PI) during the COVID-19 pandemic.

METHODS

This is a cross-sectional study in two Brazilian cities (>18 years), by probability sampling. Leisure-time physical activity was self-reported and classified according to guidelines. Sleep was by applying the Pittsburgh Sleep Quality Index. Work from home was classified as: total WFH or no WFH.

RESULTS

A total of 1750 adults were analyzed, 69.1% were physically inactive, 51.9% had poor sleep quality, and 79.8% were not in WFH. PI was associated with poor sleep quality and non-WFH. Compared with those who reported WFH and good sleep quality, those who reported non-WFH and poor sleep quality had 4 times the prevalence of PI.

CONCLUSIONS

Poor sleep quality, and not WFH, is associated with leisure PI. These factors combined increase the probability of PI.