Role of -2549 Insertion/Deletion Polymorphism in the Promoter Region of VEGF Gene and Its Association with Chronic Obstructive Pulmonary Disease (COPD) Susceptibility and Clinical Parameters.

Abstract

Chronic Obstructive Pulmonary Disease (COPD) is a progressive lung disease that is characterized by inflammation, airway remodelling, and long-term airflow limitation. Vascular Endothelial Growth Factor (VEGF) is a key regulator of angiogenesis and has an antiapoptotic effect on endothelial cells. The −2549 insertion/deletion (I/D) polymorphism found in the promoter region of VEGF gene is known to affect gene expression Objectives: The aim of this study was to determine the role of -2549 insertion/deletion polymorphism in the promoter region of VEGF in modulating susceptibility to COPD and its associated clinical parameters. Methods: A case-control study was conducted with 100 COPD patients and 100 age- and sex matched healthy controls. Genomic DNA was extracted from peripheral blood, and VEGF −2549 I/D genotyping was performed using PCR. Chi-square test assessed allelic and genotypic distributions, with ORs and 95% CIs estimating disease risk. Logistic regression analyzed age, gender, and smoking status, and Bonferroni correction was applied for multiple comparisons. Results: In COPD patients DD genotype of the VEGF −2549 I/D polymorphism was more frequent as compared to controls. The DD genotype was linked to worse lung function indices (lower FEV₁), higher CAT scores, and advanced GOLD stages; however, after adjustment the association was not statistically significant. Upon subgroup analysis, it has been found that men and smoker were having greater genotype effects. Conclusions: From this study VEGF −2549 I/D polymorphism seems to affect a person's vulnerability to COPD and could contribute to different clinical symptoms observed among individuals. The results from study support the idea of using VEGF genetic variations as predictive biomarkers for the commence and progression of COPD, especially among the genetically diverse groups.