Serum Biomarkers and Gene Polymorphisms in COPD and COPD with T2DM Patients

Inflammation plays an important role in chronic obstructive pulmonary disease (COPD). Increasing evidence points to the role of inflammation in the pathogenesis of type 2 diabetes mellitus (T2DM). We investigated the adiponectin: leptin and IL-8 genes in COPD-induced T2DM patients, along with the effect of polymorphism on the levels of these cytokines. We enrolled COPD, COPD plus T2DM, and healthy subjects from the institution according to standard criteria. Further, we drew a blood sample and performed genotypic analysis and an enzyme-linked immunosorbent assay (ELISA). We enrolled a total of 500 subjects in this study, including 250 controls, 191 COPD patients, and 59 COPD patients with T2DM. Genotyping of leptin (C/T), adiponectin (C/G), and IL-8 (C/T) polymorphisms was performed. Serum levels of leptin, adiponectin, and IL-8 were significantly higher (P < 0.001) in COPD with diabetes when compared with COPD in healthy individuals. The genotype frequency of the "CT" leptin gene variant was significantly associated with the risk of developing COPD by 3.7 folds, although it was not associated with the development of T2DM in COPD. Whereas genotype 'TT' was significantly associated with the risk of developing T2DM in COPD patients by 2.4 folds. It indicates that individuals with genotype 'TT' are at higher risk of developing COPD, and moreover, they are at higher risk of developing T2DM. We conclude that genotypes 'TT' of leptin, 'GG' diponectin, and 'TT' of IL-8 may be exploited as biomarkers for the prognosis and diagnosis of T2DM in COPD and COPD, respectively. While 'CT' of IL-8 was a protective biomarker against COPD.