NPPB and pulmonary emphysema: Similarly, Wang et al. reported that, in multivariable logistic regression, the RDW was independently associated with pulmonary hypertension (OR = 1.054, 95% CI 1.008 to 1.103, p = 0.02) after adjusting for GOLD stage, emphysema, PaCO2, NT-pro-BNP, and neutrophil-to-lymphocyte ratio.