The association between vitamin D receptor gene polymorphisms and asthma: a systematic review and meta-analysis

Abstract

Background: Numerous studies have reported on the genetic factors related to asthma. In recent years, the vitamin D receptor (VDR) has been identified as one of the asthma susceptibility genes that is closely associated with the pathogenesis of asthma.Methods: Randomized controlled trials (RCTs) related to asthma and the VDR were identified from the Chinese and English databases. The following keywords were used as search terms: "asthma", "vitamin D receptor", "VDR", "polymorphism", and "mutation". Meta-analysis was performed using RevMan 5.3 and Stata 13 software provided by the Cochrane system.Results: A total of 7 RCTs were included in this meta-analysis, 6 of which described the correct random allocation methods, 6 described the allocation plan in detail, and 4 used the blinding method. The frequency of the CC + CA dominant genotype at the Apa I locus and the GG + GA genotype frequency at the Bsm I locus of the VDR gene were significantly higher in asthmatic patients compared to control healthy patients [odds ratio (OR) =0.81, 95% confidence interval (CI): 0.68 to 0.98, P=0.03<0.05; and OR =2.05, 95% CI:1.23 to 3.41, P=0.006<0.05, respectively]. There were no significant differences between the CC, CT, and TT genotype frequencies at the Fok I site of the VDR gene in the experimental group and the CC, CT, TT genotype frequencies at the Taq I site and the control group (P>0.05). There was no significant difference between the genotype frequencies.Discussion: Meta-analysis confirmed that VDR gene polymorphisms are closely related to the onset of asthma, and the gene expression of the Fok I, Bsm I, Apa I, and Taq I loci directly affects the incidence of asthma.

A relação da vitamina D com a asma brônquica

“…Sua morbidade e mortalidade são notáveis quando relacionadas aos sintomas agudos, principalmente em relação a infecções respiratórias virais, pois esse patógeno acaba por induzir o aumento da produção de citocinas pró-inflamatórias como interleucinas 17A, o que leva a exacerbação das respostas alérgicas das vias respiratórias. (1,2,3,4,6) Devido a alta prevalência da asma, principalmente na população pediátrica, houve diversas especulações dos riscos potenciais. Tem-se como possibilidade a exposição precoce ao ambiente de poluição, as alterações microbianas e metabólicas na infância, a não amamentação exclusiva -por pelo menos durante os 4 primeiros meses de vida, o tipo de parto e os níveis de vitamina D no sangue do cordão umbilical.…”

Vitamin D deficiency and level of asthma control and severity in an adult population in Morocco

“…Vitamin D receptor gene polymorphisms (FF genotype) have been reported to affect bronchial hyperresponsiveness in children, and vitamin D receptor gene polymorphisms may also affect the development of allergic diseases. 6 There are also epigenetic gene expression manner changes with vitamin D. 7 Hypermethylation in the promoter region of various genes was identified in asthmatic patients.…”

Asthma and Vitamin D Deficiency: Occurrence, Immune Mechanisms, and New Perspectives

“…Interestingly, tumor necrosis factor-(TNF-(α can increase MMP-9 activity [39]. VDR mediated the effect of calcitriol on TNFα-induced MMP-9 activity [37], and its gene polymorphism is associated with asthma development [40]. Calcitriol increases the expression of TIMP-1 (tissue inhibitors of matrix metalloproteinases) in the presence of TNF-α and not independently [41].…”