NPPB and chronic obstructive pulmonary disease: After the follow-up, for both of the actual variation value and variation rate, the increase of NT-pro BNP (P<0.001; P = 0.03) and CAT score (P = 0.001; 0.002), as well as the decrease of PaO2 (P = 0.03; 0.086) and Peak VO2 (P = 0.021; 0.009) in COPD-PH-anemia group were highest among four groups.