Study of the relationship between chronic obstructive pulmonary disease with pulmonary hypertension and airflow limitation

Objective To investigate the correlation between chronic obstructive pulmonary disease(COPD) with pulmonary hypertension and airflowlimitation.Methods 82 patients with stable COPD and 26 healthy controls underwent lung function tests,blood gas analysis and echocardiography.According to echocardiography in detecting pulmonary artery systolic pressure(PASP) values,the COPD patients were divided into pulmonary hypertension group(PASP ≥40mmHg) and simple COPD(PASP 40mmHg) group.The correlation of PASP with lung function parameters was analyzed.Results COPD patients with pulmonary hypertension accounted for 22%,further stratified found that light,moderate and severe and very severe COPD patients with pulmonary hypertension rates were 5%,27%,29% and 54%(χ 2 = 9.04,P0.05).Comparison of only very severe COPD group and the mild COPD group,the incidences of pulmonary hypertension were significantly different,other differences between the two groups had no statistical significance.The forced expiratory volume in one second in percentage of predicted(FEV1%),FEV1/forced vital capacity(FVC),and arterial partial pressure of oxygen(PaO)2 of both COPD patients with pulmonary hypertension group and simple COPD group were significantly lower than those in healthy control group(P0.01).FEV1%,FEV1/FVC,carbon monoxide diffusing capacity in percentage of predicted(DLCO%) and arterial partial pressure of carbon dioxide(PaCO)2 of COPD with pulmonary hypertension group and simple COPD group were similar(P all 0.05);but PaO2 differences between the two groups were statistically significant(P0.01).PASP was negatively correlated with the lung function parameters,including FEV1%,FEV1/FVC and DLCO%(respectively:r =-0.42,r =-0.52,r =-0.38,all P0.01).PASP and PaO2 had a strong correlation(r=-0.61,P 0.01).Conclusion As the COPD disease progression,the incidence of pulmonary hypertension increases.Airflow limitation in the formation of pulmonary hypertension is not a single factor.In some COPD patients with airflowlimitation,there isdisproportionatepulmonary hypertension.