Background: While the importance of vascular endothelial growth factor (VEGF) in the pathogenesis of several diseases (eg, neoplasms) has been proven, its role in asthma, especially in terms of the potential associations between genetic variants of VEGF and airway remodeling, has received relatively little attention.
Objectives: This study aimed to evaluate the possible connection between a genetic factor, ie, the polymorphism del/ins in the VEGF promoter region, and airway remodeling potential in asthmatics with and without irreversible bronchoconstriction.
Materials and Methods: The study population comprised 82 patients with asthma (of whom 42 had irreversible bronchoconstriction) and a group of 40 controls. DNA was isolated from peripheral blood leukocytes. Polymerase chain reaction was used to type the VEGF (18-bp deletion/insertion) gene polymorphism at loci –2549 –2567. Other factors (ie, smoking, disease duration) were also taken into consideration.
Results: The del/del genotype was found in 74.39% of patients with asthma (P=.031; OR=2.38), 80.95% of patients with irreversible bronchoconstriction (P=.012; OR=3.48), and 67.5% patients with reversible bronchoconstriction (P=.251; OR=1.70). The proportion of smokers to nonsmokers was higher (P=.032) and disease duration was longer (P=.041) in patients with irreversible bronchoconstriction than in those with reversible bronchoconstriction.
Conclusions: Our results showed that the risk of irreversible bronchoconstriction in asthmatics was associated with the presence of the del18 genotype at the –2549 –2567 position in the promoter region of the VEGF gene, as were disease duration and other factors such as smoking.

Key words: Vascular endothelial growth factor (VEGF), Gene polymorphisms, Asthma, Airway remodeling, Irreversible bronchoconstriction