NPPB and pulmonary arterial hypertension: Table 1 shows the baseline characteristics of patients with PAH. The mean age of the 116 patients with PAH was 41.53 (13.33) years, and the female proportion was 92.2%. The proportion of WHO functional class III/IV in patients with PAH was 31.9%. Among the total patients with PAH, the mean BMI was 21.60 (3.40) kg/m2, the mean 6MWD was 382.49 (121.58) meters, and the mean BNP level was 359.19 (547.08) pg/mL.