Vitamin D for the management of asthma

Association between serum 25-hydroxyvitamin D and asthma: Evidence from the National Health and Nutrition Examination Survey (NHANES) 2011-2018

BACKGROUND AND OBJECTIVE

Asthma is a heterogeneous respiratory disease characterized by airway hyper-responsiveness and reversible airflow blockage. There is ongoing debate about the impact of vitamin D on asthma. This research is focused on investigating the correlation between serum levels of 25-hydroxyvitamin D and asthma.

METHODS

This cross-sectional study comprised 22,708 eligible participants. Data on asthma and serum 25-hydroxyvitamin D levels from the National Health and Nutrition Examination Survey (NHANES) 2011-2018 were analyzed. Serum 25-hydroxyvitamin D levels were the main factor, with the presence of asthma as the outcome variable. Weighted logistic regression was utilized to investigate the relationship between serum levels of 25-hydroxyvitamin D and asthma, while accounting for factors such as age, gender, race, length of time in US, annual family income, education level, high-density lipoprotein, low-density lipoprotein, triglycerides, and cholesterol.

RESULTS

Upon adjusting all variables in model III, epi-25-hydroxyvitamin D3 displayed a negative correlation with current asthma at the lower quartile Q1 (0.784, [0.697 to 0.922]), Q2 (0.841, [0.729 to 0.946]), Q3 (0.396, [0.240 to 0.653]) when compared to the highest quartile Q4 level. However, no significant difference was observed between asthma and 25-hydroxyvitamin D2, as well as 25-hydroxyvitamin D3.

CONCLUSIONS

In the U.S. population, elevated levels of epi-25-hydroxyvitamin D3 are correlated with an increased risk of developing existing asthma. However, it is important to interpret this finding carefully given the constraints of cross-sectional studies.

Associations between vitamin D status and biomarkers linked with inflammation in patients with asthma: a systematic review and meta-analysis of interventional and observational studies

BACKGROUND

Numerous studies indicate an association between vitamin D status and inflammatory biomarkers in patients with asthma, but findings are inconsistent. This review aims to summarize the relationship between serum vitamin D status, assessed by 25-hydroxyvitamin D (25(OH)D) level, and inflammatory biomarkers in children and adults with asthma.

METHODS

A literature search of interventional and observational studies on 25(OH)D up to November 2022 was conducted across six electronic databases. Outcomes of interest included a range of inflammatory biomarkers classified in four categories: T helper 2 (Th2) pro-inflammatory, non-Th2 pro-inflammatory, anti-inflammatory, and non-specific biomarkers. Study characteristics were extracted and risk of bias was evaluated using the American Academy of Nutrition and Dietetics tool. Meta-analysis was conducted on studies with a low risk of bias, while narrative reporting was used to present the direction of associations (positive, no association, or negative) for each biomarker, overall and within the low-risk studies.

RESULTS

We included 71 studies (3 interventional, 68 observational) involving asthma patients. These studies investigated the association between serum 25(OH)D and Th2 pro-inflammatory biomarkers (N = 58), non-Th2 pro-inflammatory biomarkers (N = 18), anti-inflammatory biomarkers (N = 16), and non-specific biomarkers (N = 10). Thirteen (18.3%) studies, 50 (70.4%), and 8 (11.3%) were at high, moderate, and low risk of bias, respectively. In all studies, irrespective of risk of bias, the most frequently reported finding was no significant association, followed by a negative association between 25(OH)D and pro-inflammatory biomarkers and a positive association with anti-inflammatory biomarkers. In low-risk studies, one biomarker could be meta-analysed. The pooled estimate for 25(OH)D and serum IgE showed a negative association (β (95% CI)= - 0.33 (-0.65 to - 0.01); I2 = 88%; N = 4 studies). A negative association between 25(OH)D and blood eosinophils was also observed in the largest of three studies, as well as with cathelicidin (LL-37) in the only study reporting it. For other biomarkers, most low-risk studies revealed no significant association with 25(OH)D.

CONCLUSION

Serum 25(OH)D is negatively associated with serum IgE and possibly with blood eosinophils and LL-37, supporting an in vivo immunomodulatory effect of 25(OH)D. Future research should employ rigorous methodologies and standardized reporting for meta-analysis aggregation to further elucidate these associations.

Linkage of serum ITIH4 with Th2 signature cytokine, inflammation, exacerbation risk and severity in childhood asthma

Aim: ITIH4 has anti-inflammatory properties toward eosinophilic/neutrophilic inflammation. This study aimed to explore clinical value of ITIH4 in childhood asthma.Materials & methods: Serum ITIH4 and inflammatory cytokines were determined in 120 childhood asthma patients by enzyme-linked immunosorbent assay.Results: In the entire and acute exacerbation patients, ITIH4 positively associated with IFN-γ, but negatively related to proinflammatory cytokines. ITIH4 was lowest in patients with acute exacerbation, followed by chronic persistent, and highest in clinical remission. By receiver-operating characteristic analysis, ITIH4 potentially estimated acute exacerbation asthma risk. Moreover, ITIH4 negatively related to exacerbation severity in acute exacerbation patients.Conclusion: Serum ITIH4 negatively links with Th2 cell signature cytokine, proinflammatory cytokines, exacerbation risk and severity in childhood asthma.

Comorbidity of patients with noncommunicable diseases in general practice. Eurasian guidelines

Создание руководства поддержано Советом по терапевтическим наукам отделения клинической медицины Российской академии наук.

The effects of vitamin D supplementation on inflammatory biomarkers in patients with asthma: a systematic review and meta-analysis of randomized controlled trials

Background

While the association between vitamin D and several inflammatory biomarkers in asthma patients has been extensively reported, it remains unclear whether supplementation modifies these biomarkers. This review aims to evaluate the impact of vitamin D supplementation on inflammatory biomarkers measured in vivo in individuals with asthma.

Methods

We conducted a systematic review of randomized controlled trials (RCTs) published until November 2022 in six electronic databases evaluating the impact of vitamin D supplementation (any dose, form, administration route, frequency, or duration) compared to placebo in children or adults. The two co-primary outcomes were serum IgE and blood eosinophils reported at the endpoint. Secondary outcomes included other markers of type 2 inflammation (e.g., sputum eosinophils, fractional exhaled nitric oxide, etc.), anti-inflammatory biomarkers (e.g., interleukin (IL)-10, etc.), markers of non-type 2 inflammation (e.g., high-sensitivity C-reactive protein, etc.), and non-specific biomarkers (e.g., macrophages, etc.). Data were aggregated using fixed or random effect models.

Results

Thirteen RCTs (5 in adults, 5 in pediatric patients, and 3 in mixed age groups) testing doses of vitamin D supplementation ranging from 800 to 400,000 IU over periods of 6 weeks to 12 months were included. Eight studies provided data on serum IgE and four on blood eosinophils. As secondary outcomes, three studies reported on sputum eosinophils, four on FeNO, five on serum IL-10, and two on airway IL-10. Compared to placebo, vitamin D supplementation had no significant effect on serum IgE (Mean difference [MD] [95% CI]: 0.06 [-0.13, 0.26] IU/mL), blood eosinophils (MD [95% CI]: - 0.02 [-0.11, 0.07] 103/μL), or FeNO (MD [95% CI]: -4.10 [-10.95, 2.75] ppb) at the endpoint. However, the vitamin D supplementation group showed higher serum IL-10 levels compared to placebo (MD [95% CI]: 18.85 [1.11, 36.59] pg/ml) at the endpoint. Although data could not be aggregated, narrative synthesis suggested no significant effect of supplementation on sputum eosinophils and IL-10 in both sputum and exhaled breath condensate, at the endpoint.

Conclusion

Vitamin D supplementation in individuals with asthma was not associated with lower inflammatory biomarkers related to type 2 inflammation. However, it was significantly associated with higher serum IL-10 compared to placebo.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022365666.

Vitamin D and Respiratory Diseases : Based on 11th Dr. I. C. Verma Excellence in Research Award for Young Pediatricians Delivered as Oration on 15th Oct. 2023

The significance of Vitamin D has been appreciated beyond bone health and calcium metabolism. The importance of Vitamin D in respiratory health has been recognized due to its immunomodulatory and anti-microbial properties. The hypothesis is that Vitamin D could have a significant role in the pathogenesis of respiratory diseases and may represent a novel preventive and therapeutic strategy. Furthermore, enumerable observational studies established the association of Vitamin D deficiency with respiratory diseases such as asthma, bronchiolitis, pneumonia, tuberculosis, etc. However, experimental studies have not shown the encouraging results. This brief review will summarize and discuss the synthesis and metabolism of Vitamin D, the prevalence of Vitamin D deficiency in children, its role in the pathogenesis of various childhood respiratory diseases, and an overview of the therapeutic trials assessing the role of Vitamin D supplementation in childhood respiratory diseases.

Mini-Review on Vitamin D in Pediatric Population and its Role in Respiratory and Atopic Disorders

In recent years, our comprehension of the function of vitamin D has significantly evolved. The ubiquitous presence of the vitamin D receptor (Vitamin D Receptor- VDR) in the body has led to its redefinition from a steroidal hormone primarily involved in skeletal functions to a hormone with pleiotropic effects, exerting its influence on the circulatory, nervous, and immune systems. This has prompted investigations into its potential use in preventing and treating chronic metabolic disorders, cardiovascular diseases, infections, and allergic and autoimmune diseases. This comprehensive review explores the various aspects of vitamin D, including its sources, synthesis, functions, and its impact on different physiological systems. It delves into the epidemiology of vitamin D deficiency, highlighting its occurrence among various age demographics and geographic regions. The impact of vitamin D on the immune system is also explored, elucidating its immunomodulatory and anti-inflammatory properties, particularly in the context of respiratory infections. The review discusses emerging evidence concerning the potential advantages of vitamin D in respiratory diseases, pediatric asthma and atopic dermatitis. It also addresses vitamin D supplementation recommendations for various pediatric populations, including term and preterm infants. The growing concern regarding the global health impacts of insufficient vitamin D levels necessitates further research to bridge gaps in knowledge, particularly in enhancing screening, prevention, and approaches to address vitamin D deficiency from birth onwards. In summary, this comprehensive overview underscores the vital role of vitamin D, highlighting the significance of understanding its multifaceted functions and the need for tailored supplementation strategies, especially in vulnerable populations.

Progress in diagnosis and treatment of difficult-to-treat asthma in children

At present, medications containing inhaled corticosteroids (ICS-containing) are the keystones of asthma treatment. The majority of asthmatic children can significantly improve clinical outcomes with little worsening by standardized inhaled glucocorticoid treatment, but there is still a small proportion of children who are unable to achieve good symptom control even after the maximum standardized treatment, known as 'children with difficult-to-treat asthma (DA)'. The high heterogeneity of DA makes therapy challenging and expensive, which poses a serious risk to children's health and makes it extremely difficult for clinical physicians to accurately identify and treat children with DA. This article reviews the definition, evaluation, and treatment of this asthma in order to provide a reference for optimal clinical decision-making.