NPPB and chronic obstructive pulmonary disease: The results of the logistic regression analysis showed that the G allele at the rs198389 locus, the A allele at the rs6668352 locus, and the T allele at the rs198388 locus of BNP were high risk factors for the COPD patients complicated with PH (adjusted OR = 2.426, 95% CI = 1.992–2.955, P<0.001; adjusted OR = 2.257, 95% CI = 1.853–2.747, P<0.001; and adjusted OR = 1.842, 95% CI = 1.524–2.219, P<0.001, respectively).