Association between CRHR1 polymorphism and improved lung function in response to inhaled corticosteroid in patients with COPD

Background and objective: Inhaled corticosteroids are used to treat COPD and asthma. An association between sequence variants in the corticotrophin- releasing hormone receptor 1 (CRHR1) gene and improved lung function in asthmatics treated with inhaled corticosteroids was reported recently. This study investigated the association between the change in lung function in response to inhaled corticosteroids and single-nucleotide CRHR1 polymorphisms in patients with COPD. Methods: COPD patients (n = 87) with a positive smoking history were recruited from the pulmonary clinics of 11 hospitals in Korea. Patients were treated with fluticasone propionate and salmeterol for 12 weeks and lung function was measured at baseline and after the 12-week treatment. Eighty-four of the 87 subjects were successfully genotyped. Results: Seventy-one patients with the wild-type GG genotype and 13 patients with the heterozygous GT genotype in rs242 941 were evaluated. After 12-week treatment, the change in FEV ₁ was significantly higher in patients with wild-type GG genotype (6.0 ± 0.8% of predicted FEV ₁) than in GT heterozygotes (-0.8 ± 1.8, P = 0.003). Conclusions: Improved FEV ₁ following inhaled corticosteroid and a long-acting β2-agonist was associated with CRHR1 genetic polymorphism in patients with COPD.