Correlation of vitamin D binding protein gene polymorphism and protein levels in chronic obstructive pulmonary disease compared with non-chronic obstructive pulmonary disease subjects.

Aim: The risk of vitamin D binding protein (DBP) variations in chronic obstructive pulmonary disease (COPD) compared with non-COPD Thai males were investigated. Materials & methods: The rs7041 and rs4588 polymorphisms of the DBP gene and protein level were measured in 136 COPD and 68 non-COPD Thai males. Results: In the COPD group, GC1-1 gave increased forced expiratory volume at 1s % predicted compared with GC1-2 but with no significant difference. Significantly lower average DBP serum levels were observed in COPD than non-COPD subjects. Positive correlation between serum DBP and forced expiratory volume at 1 s % predicted was observed in non-COPD subjects. Discussion & conclusion: DBP variations might be associated with risk factors in COPD caused by both inflammatory and vitamin D circulation processes.