The Role of Vitamin D in Sleep Disorders of Children and Adolescents: A Systematic Review

Serum vitamin D concentrations and sleep disorders: insights from NHANES 2011-2016 and Mendelian Randomization analysis

OBJECTIVE

This investigation seeks to examine the association between serum vitamin D concentrations and the prevalence of sleep disorders, additionally elucidating the causal relationship via Mendelian Randomization (MR) analysis.

MATERIALS AND METHODS

This research employed data from the National Health and Nutrition Examination Survey (NHANES) 2011-2016, focusing on adults aged 20-50 years reporting sleep disorders. The research encompassed 4913 American adults. Weighted multivariable logistic regression models and cubic spline analyses were utilized to evaluate the association between serum vitamin D concentrations and the incidence of sleep disorders. Additionally, a two-sample Mendelian Randomization analysis was performed to evaluate the potential causal link between serum vitamin D concentrations and the risk of sleep disorders.

RESULTS

Within the 2011-2016 NHANES cohort of the U.S. population, a notable inverse association was detected between serum vitamin D concentrations and sleep disorders (β =  - 3.81, 95% CI: - 6.10 to - 1.52, p = 0.003). After multivariate adjustments, a higher incidence of sleep disorders was associated with lower vitamin D Concentrations (OR 1.52, 95% CI 1.10-2.10, trend p = 0.014). Restricted cubic spline regression analysis indicated a linear association between serum vitamin D concentrations and sleep disorders(non-linearity p > 0.05). Lastly, the two-sample MR analysis yielded evidence supporting a potential causal connection between serum vitamin D concentrations and sleep disorders, with each unit increase in genetically predicted serum vitamin D reducing the odds ratio to 0.78 (95% CI 0.61-0.99, p = 0.044).

CONCLUSIONS

These results imply that lower vitamin D concentrations in the population might correlate with a heightened risk of sleep disorders, suggesting the importance of considering vitamin D supplementation when treating sleep disorders.

Association between mean platelet volume and obstructive sleep apnea-hypopnea syndrome: A systemic review and meta-analysis

BACKGROUND

Despite polysomnography (PSG) being acknowledged being considered the gold standard for diagnosing obstructive sleep apnea-hypopnea syndrome (OSAHS), researchers have been seeking a biomarker that is less invasive, more practical in detection, and cost-effective for diagnosing and assessing the severity of the disease. To address this concern, the values of mean platelet volume (MPV) between patients with OSAHS and healthy controls were compared, and the relationship between MPV and multiple sleep monitoring parameters was analyzed in this study.

METHODS

A comprehensive search was conducted across medical databases, including PubMed, Web of Science, EMBASE, CNKI, and Wanfang, up until August 2, 2023, to identify published articles related to OSAHS. This study reviewed the literature regarding the values of MPV in individuals with OSAHS and control groups, the Pearson/Spearman correlation coefficients between MPV and sleep monitoring parameters, and the odds ratios (OR) of MPV concerning the occurrence of cardiovascular diseases (CVDs) in patients with OSAHS. Meta-analyses were performed using standardized mean difference (SMD), Fisher's z values correlation coefficients (ZCOR) and odds ratio (OR) as effect variables. A fixed-effect model was used if the heterogeneity was not significant (I2<50%); otherwise, a random-effect model was applied. We will also combine the treatment effect estimates of individual trials using fixed-effect and random-effects models. Statistical analysis was carried out by employing STATA 11.0 and R 4.1.3.

RESULTS

In total, 31 articles were selected for the final analysis. The study involved 3604 patients and 1165 control individuals. The MPV in the OSAHS group was considerably elevated in comparison to the healthy controls (SMD = 0.37, 95%CI = 0.21-0.53, P < 0.001), particularly among individuals with severe OSAHS (SMD = 0.57, 95%CI = 0.23-0.90, P = 0.001). Subgroup analysis based on ethnicity, mean body mass index (BMI), and study design type also revealed a considerably higher MPV in the OSAHS category in comparison to the healthy controls. Furthermore, MPV showed correlations with various sleep monitoring parameters. The elevation of MPV may be one of the risk factors for CVDs in individuals with OSAHS (adjusted OR = 1.72, 95%CI = 1.08-2.73, P = 0.022).

CONCLUSION

MPV is a relatively simple, cost-effective, and practical indicator of the severity of OSAHS, with its values being linked to the risk of CVDs in individuals with OSAHS.

Potential of Machine Learning for Predicting Sleep Disorders: A Comprehensive Analysis of Regression and Classification Models

Sleep disorder is a disease that can be categorized as both an emotional and physical problem. It imposes several difficulties and problems, such as distress during the day, sleep-wake disorders, anxiety, and several other problems. Hence, the main objective of this research was to utilize the strong capabilities of machine learning in the prediction of sleep disorders. In specific, this research aimed to meet three main objectives. These objectives were to identify the best regression model, the best classification model, and the best learning strategy that highly suited sleep disorder datasets. Considering two related datasets and several evaluation metrics that were related to the tasks of regression and classification, the results revealed the superiority of the MultilayerPerceptron, SMOreg, and KStar regression models compared with the other twenty three regression models. Furthermore, IBK, RandomForest, and RandomizableFilteredClassifier showed superior performance compared with other classification models that belonged to several learning strategies. Finally, the Function learning strategy showed the best predictive performance among the six considered strategies in both datasets and with respect to the most evaluation metrics.

The roles of serum vitamin D and tobacco smoke exposure in insomnia: a cross-sectional study of adults in the United States

Aim

Tobacco smoke exposure and vitamin D (VD) status were both associated with insomnia. However, the combined effect of smoking and VD on insomnia has not been discussed. This study aimed to explore the role of VD in the association between tobacco smoke exposure and insomnia.

Methods

Data on adults were extracted from the National Health and Nutrition Examination Surveys (NHANES) database in 2005-2008 for this cross-sectional study. Weighted univariate and multivariate logistic regression analyses were used to explore the associations between serum cotinine, serum VD, and insomnia. A surface diagram was drawn to reflect the effect of VD on the association between serum cotinine and insomnia. In addition, the potential regulating effect of VD in subgroups of smoking status was also performed. The evaluation index was odds ratios (ORs) with 95% confidence intervals (CIs).

Results

Among the eligible participants, 1,766 had insomnia. After adjusting for covariates, we found that elevated serum cotinine levels were associated with higher odds of insomnia [OR = 1.55, 95% CI: (1.22, 1.97)]. However, the relationship between serum VD level and insomnia was not significant (P = 0.553). Higher serum cotinine levels were also associated with higher odds of insomnia [OR = 1.52, 95% CI: (1.17, 1.98)] when serum VD level was <75 nmol/L; however, this relationship became non-significant when serum VD concentration was elevated (P = 0.088). Additionally, the potential regulating effect of VD was also found in adults who were not smoking.

Conclusion

VD may play a potential regulative role in the association between tobacco smoke exposure and insomnia. Further studies are needed to clarify the causal relationships between VD, tobacco smoke exposure, and insomnia.

Dry eye in mind: Exploring the relationship between sleep and ocular surface diseases

PURPOSE

Dry Eye Disease (DED) is regarded as the most common ocular surface disease worldwide, entailing symptoms that have a major impact on the physical and psychological well-being of DED patients. In this context, the impact of sleep quality on DED has recently attracted attention. Indeed, although little is known about the mechanisms underlying the relationship between sleep and ocular surface diseases, recent evidence suggests that a reciprocal relationship exists between sleep quality and DED. Aim of the study was to investigate such relationship by means of both survey-based and instrumental analysis in a large population.

PATIENTS AND METHODS

The present cross-sectional study included 1182 DED patients who completed the Insomnia Severity Index (ISI) and the Ocular Surface Disease Index (OSDI) questionnaires. Moreover, tear break-up time (TBUT) and ocular surface staining (OSS) data of included patients were collected by physicians.

RESULTS

According to the findings of this study, in DED patients, the severity of dry eye symptoms and signs, assessed by OSDI score, TBUT, and ocular surface staining, is associated with more severe insomnia symptoms. Furthermore, higher severity of DED symptoms seems to be associated with the occurrence of nocturnal awakenings rather than with problems in falling asleep.

CONCLUSIONS

Present work contributes to the understanding of the complex relationship between DED and insomnia by showing that in a large population of DED patients, the more severe the insomnia, the more severe the DED symptoms and signs.

Association between vitamin D and knee osteoarthritis in Indian population: A systematic review and meta-analysis

Background

Vitamin D deficiency (VDD) has been implicated in knee osteoarthritis (KOA) development and progression. Prevalence of hypovitaminosis D and osteoporosis in KOA is widely reported in Indian population. However, there is no attempt to critically evaluate the outcome of these studies. We aimed a systematic review of these studies.

Methods

Pubmed, Google Scholar and Web of Science last updated March 2023, were searched. We reviewed eligible studies on the association between KOA and vitamin D levels in Indian and Asian population for comparison. The mean difference (MD) of vitamin D levels and odds ratio (OR) of vitamin D status were calculated. Data were interpreted by RevMan 5.4 software. The risk of bias was assessed using the Cochrane Risk of Bias tool.

Results

A total of 15 studies that involved 1503 KOA cases and 1609 controls were included. There was significantly reduced level of vitamin D in KOA (MD -8.68 ng/mL, 95%CI -12.21 to -5.15; P = <0.00001, I2 = 82 %) in Indian population. Similarly, in other Asian population significantly reduced vitamin D levels in KOA (MD 18.36 ng/mL, 95%CI -34.72 to -2.00; P = <0.00001, I2 = 100 %) was observed in KOA. VDD was found to be positively correlated with an increased risk of KOA.

Conclusion

Early diagnosis and management of VDD may provide the opportunity to delay the ongoing degenerative process of KOA and this study indicates the importance of screening VDD even in sunlight rich regions.

Association between Serum 25-Hydroxyvitamin D Concentrations and Academic Performance among Adolescent Schoolchildren: A Cross-Sectional Study

The level of association between 25-hydroxyvitamin D (25[OH]D) levels and students' academic performance has not yet been established. The current study aimed to investigate the association between serum 25(OH)D levels and academic performance among schoolchildren in Sudan. A cross-sectional study was conducted among schoolchildren during the 2021/2022 academic year from four randomly selected schools in Almatamah, River Nile State, northern Sudan. Sociodemographic data were collected using a questionnaire. Anthropometric measurements were performed in accordance with standard procedures. Academic performance was obtained from school records. Serum 25(OH)D levels were measured, and regression (multiple linear regression and multivariate logistic) analyses were performed. A total of 241 participants were enrolled in this study, of whom 129 (53.5%) were female. The mean standard deviation (SD) of the participants' ages was 15 ± 1.6 years. In multiple linear regression tests, being female, age, employment, and serum 25(OH)D level were positively associated with academic performance. The average overall academic score was 33.74%. Of the 241 participants, 95 (39.4%) and 149 (61.6%) had good and poor academic performances, respectively. In multivariable logistic regressions, age and 25(OH)D level were inversely associated with poor academic performance and vitamin D deficiency was associated with poor performance. The current study revealed a positive association between 25(OH)D levels and adolescents' academic performance. Effective interventional programs are needed to maintain sufficient vitamin D levels during childhood and adolescence and, as a consequence, to improve academic performance.

Low Sleep Hygiene Is Associated with Less Adherence to the Mediterranean Diet in Chilean Schoolchildren from Rural Public Schools-A Cross-Sectional Study

The Mediterranean diet stands as a widely acknowledged and health-promoting dietary pattern, renowned for its notable linkage to the mitigation of noncommunicable chronic maladies. Nonetheless, the existing body of evidence concerning the potential interrelation between sleep hygiene and this dietary regimen remains circumscribed. The main objective was to determine the association between sleep hygiene and adherence to the Mediterranean diet in Chilean schoolchildren from rural public schools in southern Chile. A non-experimental study was carried out, with an analytical, cross-sectional design. A total of 265 students (56.6% women, mean age 13.5 ± 1.8) from a rural community in southern Chile were recruited. Sleep habits were evaluated using Section 6 of the Life Habits and Adolescence Questionnaire, Sleep and Rest, and adherence to the Mediterranean diet was assessed with the KIDMED Mediterranean Diet Adherence Questionnaire. The main results indicated that 52.8% of schoolchildren need to improve adherence to the Mediterranean diet and 16.6% have a low-quality Mediterranean diet. A high percentage of schoolchildren have behaviors related to poor sleep hygiene (going to bed late (46%), waking up tired and wanting to continue sleeping (63.8%), and having problems falling asleep (42.6%)). Schoolchildren who got up after 8:30 a.m., those who fell asleep after midnight, upon conducting a comparative analysis of the students based on their sleep patterns, those who woke up tired and those who had trouble falling asleep had a lower level of adherence to the Mediterranean diet compared to schoolchildren who got up earlier than 8:30 a.m., fell asleep before midnight, did not wake up tired, and those who did not find it difficult to fall asleep, respectively. In conclusion, having poor sleep patterns including difficulties in both awakening and falling asleep are associated with less adherence to the Mediterranean diet in schoolchildren from rural public schools in southern Chile. Monitoring these variables and promoting healthy lifestyle habits within the educational community are essential measures.

Vitamin D and Bone fragility in Individuals with Osteogenesis Imperfecta: A Scoping Review

Vitamin D affects several body functions, and thus general health, due to its pleiotropic activity. It plays a key role in bone metabolism, and its deficiency impacts bone development, leading to bone fragility. In osteogenesis imperfecta (OI), a group of hereditary connective tissue disorders characterized by bone fragility, additional factors, such as vitamin D deficiency, can affect the expression of the phenotype and aggravate the disorder. The aim of this scoping review was to assess the incidence of vitamin D deficit in OI patients and the association between vitamin D status and supplementation in individuals affected by OI. We searched the PubMed Central and Embase databases and included studies published between January/2000 and October/2022 evaluating vitamin D measurement and status (normal, insufficiency, deficiency) and supplementation for OI. A total of 263 articles were identified, of which 45 were screened by title and abstract, and 10 were included after a full-text review. The review showed that low levels of vitamin D was a frequent finding in OI patients. Vitamin D supplementation was mainly indicated along with drug therapy and calcium intake. Even if widely used in clinical practice, vitamin D supplementation for OI individuals still needs a better characterization and harmonized frame for its use in the clinical setting, as well as further studies focusing on its effect on bone fragility.

Sleep Disturbances in Adolescents With Idiopathic Intracranial Hypertension

BACKGROUND

We aimed to assess the presence of sleep disturbances in adolescents with idiopathic intracranial hypertension (IIH) and to determine whether demographic, anthropometric, and clinical factors are associated with disrupted sleep.

METHODS

Sleep disturbances and patterns were evaluated in a cohort of adolescents (aged 12 to 18 years) with ongoing IIH and compared with a healthy age- and sex-matched control group. All participants responded to three self-rating questionnaires: the School Sleep Habits Survey (SSHS), the Pediatric Sleep Questionnaire (PSQ), and the Depression, Anxiety, and Stress Scale. The study group's demographic, clinical, laboratory, and radiological data were documented, and their association with sleep patterns was examined.

RESULTS

Thirty-three adolescents with ongoing IIH and 71 healthy controls were included. There was a significantly higher prevalence of sleep disturbances in the IIH group compared with the controls (SSHS, P < 0.001 and PSQ, P < 0.001), as well as of their independent subscales: sleep-related breathing disorders (P = 0.006), daytime sleepiness (P = 0.04), sleep/wake disruptions (P < 0.001), and sleep-related depressive tendencies (P < 0.001). According to subgroup analyses, these differences were also present between the normal-weight adolescents but not between the overweight IIH and control adolescents. No differences were found in the demographic, anthropometric, and IIH disease-related clinical measures between individuals with IIH with disrupted and normal sleep patterns.

CONCLUSIONS

Sleep disturbances are common among adolescents with ongoing IIH, irrespective of their weight and disease-related characteristics. Screening adolescents with IIH for sleep disturbances is recommended as part of their multidisciplinary management.

Relationships between 25-Hydroxyvitamin D Levels and Obstructive Sleep Apnea Severity in Children: An Observational Study

The prevalence of hypovitaminosis D is increasing worldwide. Vitamin D deficiency is supposed to play a role in sleep disturbances, but the complex relationships between hypovitaminosis D and pediatric obstructive sleep apnea syndrome (OSAS) are still incompletely understood. This study was aimed to retrospectively investigate the vitamin D status and significant clinical, laboratory, and instrumental variables in a cohort of pediatric patients with OSAS and to assess the possible relationship between serum vitamin D levels and OSAS severity. We consecutively enrolled all children aged 2-14 years admitted to our Pediatric Clinic from 1 July 2018 to 30 November 2020 for sleep-disordered breathing. Each patient underwent standard overnight in-hospital polygraphic evaluation, measurement of serum 25-hydroxyvitamin D (25(OH)D) levels, and clinical and laboratory investigation. A total of 127 children with OSAS were included. The 25(OH)D levels and BMI of OSAS patients were compared with those of an age-matched control group: the serum 25(OH)D levels were significantly lower in OSAS patients than in controls (22.4 vs. 25.5 ng/mL; p-value = 0.009), whereas no differences in the BMI percentile were found between the two groups. The mean value of 25(OH)D was not significantly lower (20.9 ng/mL) in the severe OSAS group compared with the mild (23.0 ng/mL) and moderate (23.3 ng/mL) OSAS groups (p-value = 0.28). Our findings indicate a relationship between vitamin D status and OSAS in children and suggest that severe cases of OSAS have lower vitamin D levels. Future, more extensive prospective studies are needed to confirm such preliminary findings.

Vitamin D Deficit as Inducer of Adenotonsillar Hypertrophy in Children with Obstructive Sleep Apnea-A Prospective Case-Control Study

(1) Objective: This prospective case-control study aimed to assess the level of serum vitamin D comparing pediatric non-allergic patients with obstructive sleep apnea (OSA) and healthy controls. (2) Methods: The period of the enrollment was from November 2021 to February 2022. Children with uncomplicated OSA caused by adenotonsillar hypertrophy (ATH) were recruited. Allergy was excluded by skin prick test (SPT), and the determination of serum IgE level using ELISA test. Plasma concentration of 25-hydroxy vitamin D (25-OHD) was quantitatively determined; then, the vitamin D concentration in patients was compared with healthy controls matched for sex, age, ethnicity, and characteristics. (3) Results: Plasma 25-OHD levels were significantly lower in patients than in healthy subjects (mean 17 ng/mL, 6.27 DS, range 6-30.7 ng/mL, vs. mean 22 ng/mL, 9.45 DS, range 7-41.2 ng/ ml; p < 0.0005). The prevalence of children with vitamin D deficiency was significantly higher in the ATH group than controls. The plasma 25-OHD level did not change following the ATH clinical presentation (III or IV grade according to the Brodsky scale), while the different categories of 25-OHD status (insufficiency, deficiency, and adequacy) in the ATH group were statistically significantly different (p < 0.001) from healthy controls. (4) Conclusions: This study identified statistically significant differences between the ATH group and control regarding the plasma concentration of vitamin D; this data, despite not being directly linkable to the lymphoid tissue hypertrophy (p-value not significant), might suggest a negative effect of vitamin D deficit on the immune system.

Knowledge and Attitudes towards Vitamin D among Health Educators in Public Schools in Jeddah, Saudi Arabia: A Cross-Sectional Study

Health educators in schools are a very important part of the education system. Considering the significant prevalence of vitamin D deficiency in the Kingdom of Saudi Arabia, it is important to investigate the knowledge of and attitude towards vitamin D among health educators. This study aims to examine the knowledge of and attitude towards vitamin D among health educators in public schools in Jeddah as well as to identify the associated sociodemographic factors. A cross-sectional study was conducted between May and December 2021 among 231 health educators. Data were collected via a self-administered online questionnaire. The results revealed that only 45% of health educators had good knowledge of vitamin D, and approximately 43% had a positive attitude towards vitamin D. Additionally, those who had good knowledge of vitamin D were males (58.7%) (p = 0.005) and had a bachelor's degree (74%) (p = 0.01). Moreover, male health educators aged 45-54 years had a positive attitude towards vitamin D (3.8 ± 0.7) (p = 0.007). In addition, female health educators who were divorced (3.8 ± 0.7) and widowed (3.6 ± 0.5) (p = 0.04) and those who were administrators (3.3 ± 0.7) (p = 0.01) had a positive attitude towards vitamin D. The Ministry of Education (MOE) in the Kingdom must educate health educators through educational programmes that aim to increase the knowledge of and develop a positive attitude towards vitamin D intake.

Editorial of Special Issue "The Role of Vitamin D in Human Health and Diseases"

Vitamin D has been described as a differentiative hormone, but this definition is reductive for a molecule targeting every tissue, produced in its active form by many kinds of cells and effective on the whole life of cells by different mechanisms, which lead to nuclear, non-genomic and mitochondrial effects [...].

Association of healthy sleep pattern with the risk of cardiovascular disease and all-cause mortality among people with diabetes: A prospective cohort study

AIMS

This study aimed to assess the association of healthy sleep pattern with the risk of cardiovascular disease and all-cause mortality among people with diabetes.

METHODS

Our study included 12,770 individuals from the UK Biobank at baseline. Sleep patterns were defined by a combination of five sleep behaviors (chronotype, sleep duration, snoring, insomnia, and excessive daytime sleepiness). The competing risk models were used to estimate the relationship between sleep patterns and CVD (including coronary heart disease [CHD] and stroke) in individuals with diabetes. To examine the association between sleep patterns and all-cause mortality risk, we utilized the flexible parametric Royston-Parmar proportion-hazard models.

RESULTS

We recorded 2627 CVD events, which includes 1999 CHD and 903 S events, and 1576 all-cause mortality events. Compared to those with poor sleep pattern, individuals having healthy sleep pattern have a 24% lower CVD risk (p < 0.001), a 26% lower CHD risk (p = 0.001), a 25% lower stroke risk (p = 0.036), and a 21% lower all-cause mortality risk (p = 0.020).

CONCLUSIONS

Adherence to healthy sleep pattern has been significantly related to cardiovascular disease and all-cause mortality risk reduction among people with diabetes.

Understanding patient characteristics and medication prescriptions in children with mental health and neurodevelopmental disorders referred to a sleep clinic-A quality improvement/quality assurance analysis

INTRODUCTION

Motivated by challenges faced in outpatient sleep services for mental health and neurodevelopmental disorders (MHNDD) during the COVID-19 clinical shutdown, a pan-Canadian/international working group of clinicians and social scientists developed a concept for capturing challenging sleep and wake behaviours already at the referral stage in the community setting.

METHODS

In a quality improvement/quality assurance (QIQA) project, a visual logic model was the framework for identifying the multiple causes and possible interventions for sleep disturbances. Intake forms informed clinicians about situational experiences, goals/concerns, in addition to the questions from the Sleep Disturbances Scale for Children (SDSC), the ADHD Rating Scale-IV and medication history. Descriptive statistics were used to describe the sample.

RESULTS

66% of the pilot study patients (n = 41) scored in the SDSC red domains (highest scoring) with highest sub-scores for insomnia (falling asleep 73%; staying asleep: 51%) and daytime somnolence (27%). A total of 90% of patients were taking at least one medication; 59% sleep initiation/sleep medications, 41% in combination with further non-stimulant medications, 9% with stimulants, 27% with antidepressants and 18% with antipsychotics. Polypharmacy was observed in 62% of all patients and in 73% of the ones medicated for sleep disturbances. Qualitative information supported individualisation of assessments.

CONCLUSION

Our intake process enabled a comprehensive understanding of patients' sleep and wake profiles prior to assessment, at the referral stage. The high prevalence of insomnia in patients, combined with polypharmacy, requires special attention in the triaging process at the community level.