Abstract: 〗［Abstract］ Objective〖HTSS〗〓To explore the relationship between circulating red cell distribution width(RDW) and the pulmonary arterial hypertension in patients with chronic obstructive pulmonary disease.
〖HTH〗〖WTHZ〗Methods〖HTSS〗〓According to the degree of pulmonary artery pressure, patients are divided into normal pulmon artery pressure group(<35 mmHg, n=56),mild pulmon artery pressure group(35-50 mmHg, n=47), moderate pulmon artery pressure group(＞50-70 mmHg, n=50) and severe pulmon artery pressure group(>70 mmHg, n=45)．Fifty healthy persons served as control group, The RDW and pulmonary function and arterial blood gas analysis were measured and compared.
〖HTH〗〖WTHZ〗Results〖HTSS〗〓The RDW and PaCO2 were increased with the increase of pulmon aryarterial systolic pressure(PASP)(P＜0.05), but PaCO2 had no difference between control group and normal pulmon artery pressure group. The PaO2, forced expiratory volume in one second to pred(FEV1/pred) and forced vital capacity rate of one second(FEV1/FVC) were decreased of with the increase of PASP(P＜0.05). The RDW was significantly positive correlated with pulmonary hypertension(r=0.745， P=0.000). The FEV1％pred, FEV1/FVC, pH, PaO2were negatively correlated with RDW(r=-0.678,-0.696， -0.306， -0.629， P=0.000).
〖HTH〗〖WTHZ〗Conclusion〖HTSS〗〓RDW can be used as one of the evaluation indicators of decline in lung function in patients with chronic obstructive pulmonary disease, and acidosis and hypoxemia are also the main reasons for the RDW.

Key words: pulmonary disease, chronic obstructive, hypertension, pulmonary, red cell distribution width