Vitamin D Deficiency Is Associated with Decreased Lung Function in Chinese Adults with Asthma

Harvard University, Cambridge, Massachusetts, United States
Respiration (Impact Factor: 2.59). 12/2010; 81(6):469-75. DOI: 10.1159/000322008
Source: PubMed


Vitamin D deficiency has been associated with markers for allergy and asthma severity in children with asthma. However, its association with Chinese adult asthmatics has not been studied.
To examine whether vitamin D status is associated with lung function and total serum IgE in Chinese adults with newly diagnosed asthma.
We conducted a cross-sectional study including 435 Chinese patients aged >18 years with newly diagnosed asthma. Vitamin D status was assessed by measuring serum 25 hydroxyvitamin D (25OHD) concentrations. The primary outcomes included airflow limitation, as measured by the forced expiratory volume in 1 s (FEV(1)), FEV(1) % predicted, and FEV(1)/forced vital capacity (FVC), and serum total IgE concentration.
Vitamin D deficiency was prevalent in Chinese adults with asthma, with 88.9% of the subjects having 25OHD <50 nmol/l. Serum 25OHD concentration was positively correlated with FEV(1) % predicted (p = 0.02, r = 0.12). After adjusting for age, sex, body mass index, smoking, month of blood collection, and symptom duration, we found significant positive associations between 25OHD concentrations and FEV(1) (in liters), FEV(1) % predicted, and FEV(1)/FVC (p for trend < 0.05 for all). The adjusted odds ratios for the highest versus the lowest 25OHD quartile were 0.50 (0.26-0.96) for FEV(1) <75% predicted and 0.44 (0.20-0.95) for FEV(1)/FVC% <0.75. There was no significant association between 25OHD concentrations and total IgE.
Vitamin D deficiency was highly prevalent in Chinese asthma patients, and vitamin D status was associated with lung function.

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Available from: Fuzhi Lian, Oct 07, 2015
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    • "The findings of a cross-sectional study including Chinese patients with newly diagnosed asthma concluded that vitamin D deficiency was highly prevalent and was associated with decreased lung function in this population.101 Also, in asthmatic adult patients, reduced vitamin D levels were associated with impaired lung function, increased airway hyperresponsiveness, and reduced glucocorticoid response, suggesting that supplementation of vitamin D levels in these patients might improve multiple parameters of asthma severity and treatment response.9 "
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    ABSTRACT: Humans have the ability to synthesize vitamin D during the action of ultraviolet (UV) radiation upon the skin. Apart from the regulation of calcium and phosphate metabolism, another critical role for vitamin D in immunity and respiratory health has been revealed, since vitamin D receptors have also been found in other body cells. The term "vitamin D insufficiency" has been used to describe low levels of serum 25-hydroxyvitamin D that may be associated with a wide range of pulmonary diseases, including viral and bacterial respiratory infection, asthma, chronic obstructive pulmonary disease, and cancer. This review focuses on the controversial relationship between vitamin D and asthma. Also, it has been found that different gene polymorphisms of the vitamin D receptor have variable associations with asthma. Other studies investigated the vitamin D receptor signaling pathway in vitro or in experimental animal models and showed either a beneficial or a negative effect of vitamin D in asthma. Furthermore, a range of epidemiological studies has also suggested that vitamin D insufficiency is associated with low lung function. In the future, clinical trials in different asthmatic groups, such as infants, children of school age, and ethnic minorities are needed to establish the role of vitamin D supplementation to prevent and/or treat asthma.
    Drug Design, Development and Therapy 09/2013; 7:1003-1013. DOI:10.2147/DDDT.S50599 · 3.03 Impact Factor
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    • "This percentage (90%) is higher than that reported in another study of Costa Rican asthmatic children, in which 28% had vitamin D insufficiency,7 and much higher than the 20% reported by Alyasin et al.15 in Iranian children. However, this high percentage is similar to that reported by Li et al.16 in asthmatic adults from China and is consistent with the epidemics of hypovitaminosis D in developing countries reported by Arabi et al.17 "
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    ABSTRACT: Non-classical actions of vitamin D as a cytokine are related to the immunopathology of asthma. Few studies have examined vitamin D levels and asthma severity in adults. The aim of this research was to assess the relationship between vitamin D levels, atopy markers, pulmonary function, and asthma severity. We analyzed 25-hydroxyvitamin D levels in serum collected from 121 asthmatic adults from Costa Rica to investigate the association between vitamin D levels (categorized as sufficient, ≥30 ng/mL, or insufficient, <30 ng/mL), allergic rhinitis, total IgE and peripheral blood eosinophils (as markers of atopy), asthma severity, baseline forced expiratory volume in 1 second (FEV1), and forced vital capacity (FVC). Univariate and multivariate analyses were performed to assess these relationships. When the population was stratified by vitamin D status, 91% of asthmatic patients with vitamin D levels below 20 ng/mL (n=36) and 74% of patients with vitamin D levels between 20 and 30 ng/mL (n=73) had severe asthma versus 50% of those with vitamin D sufficiency (n=12; P=0.02). Vitamin D insufficiency was associated with a higher risk of severe asthma (odds ratio [OR], 5.04; 95% Confidence interval [CI], 1.23-20.72; P=0.02). High vitamin D levels were associated with a lower risk of hospitalization or emergency department visit during the last year (OR, 0.90; 95% CI, 0.84-0.98; P=0.04). Although there appeared to be a direct relationship between vitamin D levels and FEV1 (regression coefficient=0.48; r(2)=0.03), it did not reach statistical significance (P=0.07). Our findings suggest that vitamin D insufficiency is common among our cohort of asthmatic adults. Lower vitamin D levels are associated with asthma severity.
    Allergy, asthma & immunology research 09/2013; 5(5):283-8. DOI:10.4168/aair.2013.5.5.283 · 2.43 Impact Factor
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    • "In adult patients several clinical studies then analysed vitamin D levels and the severity of allergies such as asthma and chronic rhinoconjunctivitis (CRS). While in one study no difference in serum vitamin D levels of adult asthma patients and healthy controls was observed, Li and coworkers56 found that vitamin D deficiency was highly prevalent in allergy patients and vitamin D status strongly correlated with pulmonary function (FEV1) in asthmatics. Also other observations showed that higher vitamin D serum levels improve pulmonary function in adults while insufficient serum levels are associated with severe pulmonary dysfunction.57 "
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    ABSTRACT: Atopic diseases such as atopic dermatitis (AD) are very common in industrialized countries. Up to 15%-30% of all children and 2%-10% of all adults suffer from AD. Already in early disease stages, a defective epidermal barrier is known to contribute to the pathogenesis of AD. Central elements in the epidermal barrier are antimicrobial peptides (AMPs), which are secreted by keratinocytes, sweat gland cells but also infiltrating immune cells. AMPs function as endogenous antibiotics and are able to kill bacteria, viruses, and fungi. Furthermore AMPs act as immune modulators with effects on the innate and adaptive immune system. The probably best studied AMPs in human skin are the defensins and cathelicidin. In atopic diseases the functions of AMPs such as cathelicidin might be impaired and microbial superinfections could serve as cofactors for allergic sensitization. Hence, induction of AMPs could be beneficial in these patients. Cathelicidin which is often referred to its peptide form hCAP18 or LL-37 can be induced by ultraviolet light B (UVB) irradiation and is upregulated in infected and injured skin. The cathelicidin gene carries a vitamin D response element and the vitamin D pathway could therefore be targeted for cathelicidin regulation. As the development and course of atopic diseases might be influenced by vitamin D signaling these pathomechanisms could explain the growing evidence connecting vitamin D to allergic diseases, including AD, allergic rhinitis, food allergies and asthma. In this review the role of vitamin D and the AMP cathelicidin in the pathogenesis of atopic diseases with impaired barrier function will be discussed.
    Allergy, asthma & immunology research 05/2013; 5(3):119-28. DOI:10.4168/aair.2013.5.3.119 · 2.43 Impact Factor
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