Vitamin D and COPD

January 01, 0001

Vitamin D and COPD

Low vitamin D levels have recently been linked to a number of disease stated, though mechanisms are often lacking. This group of Belgian researchers examined its relationship with chronic obstructive pulmonary disease (COPD). They measured serum 25-hydroxyvitamin D (25-OHD) levels in 414 (ex)-smokers older than 50 years and the link between vitamin D status and presence of COPD was assessed. Additionally, rs7041 and rs4588 variants in the vitamin D-binding gene (GC) were genotyped and compared with the other data.

The researchers report: "In patients with COPD, 25-OHD levels correlated significantly with forced expiratory volume in 1 s (FEV1) (r=0.28). Compared with 31% of the smokers with normal lung function, as many as 60% and 77% of patients with GOLD (Global Initiative for Obstructive Lung Disease) stage 3 and 4 exhibited deficient 25-OHD levels less than 20 ng/ml. Additionally, 25-OHD levels were reduced by 25% in homozygous carriers of the rs7041 at-risk T allele. This correlation was found to be independent of COPD severity, smoking history, age, gender, body mass index, corticosteroid intake, seasonal variation and rs4588. Notably, 76% and 100% of patients with GOLD stage 3 and 4 homozygous for the rs7041 T allele exhibited 25-OHD levels less than 20 ng/ml. Logistic regression corrected for age, gender and smoking history further revealed that homozygous carriers of the rs7041 T allele exhibited an increased risk for COPD (OR 2.11)."

The authors concluded: "Vitamin D deficiency occurs frequently in COPD and correlates with severity of COPD. The data warrant vitamin D supplementation in patients with severe COPD, especially in those carrying at- risk rs7041 variants."

This study finds yet another link between low vitamin D level and disease, this time COPD, but intriguing also finds a link with specific genotypes of a vitamin D binding protein.

For the full abstract, click here.

Thorax 65:215-220, March 2010
© 2010 BMJ Publishing Group Ltd & British Thoracic Society
Vitamin D deficiency is highly prevalent in COPD and correlates with variants in the vitamin D-binding gene. Wim Janssens, Roger Bouillon, Bart Claes, et al. Correspondence to Wim Janssens: [email protected]

Category: R. Respiratory. Keywords: COPD, epidemiology, genetic variant rs7041, vitamin D, vitamin D-binding protein, epidemiologic study, journal watch.
Synopsis edited by Dr Paul Schaefer, Toledo, Ohio. Posted on Global Family Doctor 20 April 2010

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