Relationship between Vitamin D, Inflammation and Lung Function In Patients with Severe Uncontrolled Asthma

Liu

et al. 2019

Respiratory Medicine

Background: There is a controversy in terms of the efficacy of vitamin D supplementation in improving asthma symptom control. Moreover, whether there is a difference in the treatment effect with respect to baseline vitamin D status remains unknown. This meta-analysis was to assess the correlations of vitamin D status with asthmarelated respiratory outcomes. Methods: PubMed, EMBASE, and Cochrane Library were searched for randomized controlled trials of vitamin D supplementation in patients with asthma. Primary outcomes were the rate of asthma exacerbation and predicted percentage of forced expiratory volume in first second (FEV 1 %). Secondary outcomes were asthma control test (ACT) scores, fractional exhaled nitric oxide (FeNO), interleukin-10 (IL-10) and adverse events. Results: A total of 14 randomized controlled trials (1421 participants) fulfilled the inclusion. Vitamin D supplementation was associated with a significant reduction in the rate of asthma exacerbation by 27% (RR: 0.73 95%Cl (0.58-0.92)). In subgroup analysis, the protective effect of exacerbation was restricted in patients with vitamin D insufficiency (vitamin D < 30 ng/ml) (RR: 0.76 95%Cl (0.61-0.95)). An improvement of FEV 1 % was demonstrated in patients with vitamin D insufficiency and air limitation (FEV 1 % < 80%) (MD: 8.3 95%Cl (5.95-10.64). No significant difference was observed in ACT scores, FeNO, IL-10 and adverse events. Conclusions: Vitamin D supplementation reduced the rate of asthma exacerbation, especially in patients with vitamin D insufficiency. Additionally, the benefit of vitamin D had a positive effect on pulmonary function in patients with air limitation and vitamin D insufficiency.

Section: Discussionsupporting

confidence: 68%

Association between vitamin D status and asthma control: A meta-analysis of randomized trials

Liu

et al. 2019

Respiratory Medicine

The Journal of Allergy and Clinical Immunology: In Practice

“…Vitamin D has been described in several studies to have independent effects upon inflammatory processes responsible for asthma morbidity, 24,28,50,51 however, an immune-modulatory role in response to air pollution has been underexplored. Inflammatory responses to ambient particulate air pollution exposure alone have been shown to generate a systemic reaction through mechanisms that enhance bone-marrow release of polymorphonuclear leukocytes into the peripheral circulation.…”

Section: Discussionmentioning

confidence: 99%

Vitamin D Status Modifies the Response to Indoor Particulate Matter in Obese Urban Children with Asthma

Bose¹,

Diette

Woo³

et al. 2019

Background: Indoor fine particulate air pollution (PM2.5) is linked to asthma morbidity; however, whether vitamin D status influences individual susceptibility to airborne exposures is unclear. Objective: We aimed to determine if vitamin D modifies effects of indoor PM2.5 upon asthma symptoms in urban children. Methods: 120 children aged 5–12 years with physician-diagnosed asthma were evaluated at baseline and every 3 months for 9 months. Indoor PM2.5, serum 25-hydroxy vitamin D (25-OH D) levels and asthma symptoms were simultaneously assessed at each time point. Adjusting for confounders, generalized estimating equations assessed 3-way interaction effects of 25-OH D, obesity and PM upon asthma symptoms. Results: Children were of mean (SD) age 9.7 (2.2) years, 36% were obese, and 95% self-reported black race. Mean (SD) PM2.5 indoor exposure was 38.2 (42.9) μg/m3 and 25-OH D was 19.1 (7.5) ng/ml. Three-way interaction models demonstrated significantly greater PM2.5-associated effects on daytime asthma symptoms only among obese children with low 25-OH D levels (ORPM2.5=1.26,p =0.049 at vitamin D=15.5 ng/ml, increasingly stronger PM effects at levels<15.5 ng/ml). In homes with increased PM2.5, higher 25-OH D was associated with decreased symptom odds (e.g., ORVitamin D = 0.87; p=0.049 at PM2.5 = 52.5 μg/m3, increasingly protective effects >52.5 μg/m3) among obese children. Conclusion: Among obese urban children with asthma, low individual 25-OH vitamin D enhanced adverse respiratory effects associated with indoor PM2.5. In high PM2.5 environments, 25-OH D was protective against asthma symptoms. Optimizing vitamin D status in children may help reduce asthma morbidity driven by indoor air pollution.

“…Moreover, in addition to its effects on bone, vitamin D also exerts important functions in skin homeostasis and its deficiency is linked with Pso development ( 48 , 59 ). Vitamin D is therefore no longer considered to just be an essential factor for the maintenance of a normal skeletal structure, but its extraskeletal effects, including cell cycle regulation and immune modulation, are becoming increasingly known ( 60 – 62 ).…”

Section: The Role Of Vitamin Dmentioning

confidence: 99%

“…Moreover, vitamin D activity is determined through vitamin D receptors, which are present not only in the skeleton but also in different types of cells, including antigen-presenting-cells, immune cells, and keratinocytes. In particular, DCs, lymphocytes, monocytes/macrophages, neutrophils, and epithelial cells can produce IL-33 and other cytokines involved in both bone remodeling and Pso inflammation, including IL-31, IL-17, and TNF-alpha ( 29 , 62 , 107 ). IL-33 therefore orchestrates the immune cascade of Pso.…”

Section: The Relationship Between Vitamin D and The Il-33/st2 Axis Inmentioning

confidence: 99%

“…Moreover, in addition to its effects on bone, vitamin D also exerts important functions in skin homeostasis and its deficiency is linked with Pso development (48,59). Vitamin D is therefore no longer considered to just be an essential factor for the maintenance of a normal skeletal structure, but its extraskeletal effects, including cell cycle regulation and immune modulation, are becoming increasingly known (60)(61)(62). The epidermis is the natural source of vitamin D synthesis through the action of ultraviolet light (53), and in turn, vitamin D functions as a key regulator of cutaneous barrier homeostasis.…”

Section: The Role Of Vitamin Dmentioning

confidence: 99%

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IL-33/Vitamin D Crosstalk in Psoriasis-Associated Osteoporosis

et al. 2021

Patients with psoriasis (Pso) and, in particular, psoriatic arthritis (PsoA) have an increased risk of developing osteoporosis (OP). It has been shown that OP is among the more common pathologies associated with Pso, mainly due to the well-known osteopenizing conditions coexisting in these patients. Pso and OP share common risk factors, such as vitamin D deficiency and chronic inflammation. Interestingly, the interleukin (IL)-33/ST2 axis, together with vitamin D, is closely related to both Pso and OP. Vitamin D and the IL-33/ST2 signaling pathways are closely involved in bone remodeling, as well as in skin barrier pathophysiology. The production of anti-osteoclastogenic cytokines, e.g., IL-4 and IL-10, is promoted by IL-33 and vitamin D, which are stimulators of both regulatory and Th2 cells. IL-33, together with other Th2 cytokines, shifts osteoclast precursor differentiation towards macrophage and dendritic cells and inhibits receptor activator of nuclear factor kappa-B ligand (RANKL)-induced osteoclastogenesis by regulating the expression of anti-osteoclastic genes. However, while the vitamin D protective functions in OP and Pso have been definitively ascertained, the overall effect of IL-33 on bone and skin homeostasis, because of its pleiotropic action, is still controversial. Emerging evidence suggests a functional link between vitamin D and the IL-33/ST2 axis, which acts through hormonal influences and immune-mediated effects, as well as cellular and metabolic functions. Based on the actions of vitamin D and IL-33 in Pso and OP, here, we hypothesize the role of their crosstalk in the pathogenesis of both these pathologies.