Association of Vitamin D Receptor Gene Polymorphism (FokI) with Asthma - COPD Overlap: A Cross Sectional Study

Abstract

Background: Asthma- COPD) overlap ACO is a new phenotype in the world of respiratory ailments. Though it has been shown that this group of morbid patients might possess vitamin D3 deficiency, but its association with vitamin D receptor (VDR) gene polymorphism has not been investigated yet. Objective: To assess the association of VDR gene polymorphism (FokI) with ACO. Methods: This cross-sectional study was carried out in the Department of Physiology of Bangabandhu Sheikh Mujib Medical University, Dhaka, from January 2018 to July 2018 on 23 (twenty three) patients (aged ≥40 years) with ACO. For comparison, 24 (twenty four) age, smoking duration and BMI matched apparently healthy subjects were selected. For all participants single nucleotide polymorphism (SNP) of VDR gene FokI (rs10735810) was done by DNA extraction, polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). Results were expressed as frequency distribution in percentage and data were statistically analyzed by Graphpad prism (Version 7) using Chi-square test. In the interpretation of results, ≤0.05 level of probability (p) was accepted as significant. Results: The frequency distribution of FokI genotype was 86.95% (FF), 8.69% (Ff), 4.35% (ff) and 91.66% (FF), 4.17% (Ff), 4.17% (ff) in ACO patients and healthy subjects, respectively. However, difference between groups in regard to the frequencies in both VDR genotypes were statistically non-significant. Furthermore, the association of FokI [FF, OR 1·65 (95% Cl 0·25–10.91], p=0·6; Ff, OR 0·46 (95% Cl 0·04–5.41], p=0·53; ff, OR 0·96 (95% Cl 0·06–16.26], p=0·98;] VDR SNP with ACO was statistically non-significant. Conclusion: Results of the present study reveals that, FokI VDR SNP is not associated with ACO.