The polymorphism -2548G/A in leptin and severity of chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease characterized by airway obstruction that is not fully reversible, and there is evidence of a hereditary component in COPD. We aimed to determine whether the polymorphisms -2548G/A of leptin (LEP) gene were associated with COPD and its severity in Chinese. A total of 456 subjects with COPD and 422 healthy controls from West China Hospital were enrolled in this study. COPD patients had been undergone a spirometry and a physical examination to refer the GOLD I-IV stages. The polymorphisms in the leptin promoter region at position -2548G/A were detected by Polymerase chain reaction-restriction fragment length polymorphism analysis. The genotypes and alleles were scored, and the frequencies of the alleles and genotypes in patients and controls were compared. A significantly higher risk for COPD was observed for carriers of the LEP -2548AA genotype [odds ratio (OR)=7.87, 95% confidence interval (CI) 4.19-14.77, P<0.001] and carriers of the LEP -2548GA genotype (OR=2.98, 95% CI 1.57-5.66, P=0.001). The LEP -2548A allele: frequency was significantly higher in the patient group compared with the control group (OR=2.75, 95% CI: 2.20-3.44, P<0.001). We also found a significant relationship between leptin gene polymorphism and the severity of COPD. In the present case-control study, we found an association between the -2548G/A variant of the leptin gene and pathogenesis, severity of COPD in the Chinese population. It suggests that leptin -2548G/A should be used as a genetic marker of COPD severity.