Correlation Study Of Serum NT-proBNP Level In Patients Of The Acute Exacerbation Of Chronic Obstructive Pulmonary Disease

Objective: To investigate the correlation and clinical significance of serum amino-terminal pro-brain natriuretic peptide(NT-proBNP) level in different severity patients of the acute exacerbation of chronic obstructive pulmonary disease. Methods: A total of 40 patients diagnosed as AECOPD in department of Respiratory of Medicine in the First Affiliated Hospital of Wannan Medical College during October 2013 to September 2014 were analyzed as our research group, meanwhile other 40 COPD patients with stabled condition considered as controls were obtained. According to their pulmonary function(FEV1) and pulmonary artery systolic pressure(PASP), all the 40 AECOPD patients were classified as I to IV grade and three groups including normal PASP(<40mmHg) group, slight PH(40-59mmHg) group and moderate to severe PH(≥60mmHg) group. Serum NT-proBNP were measured through ELISA. The pulmonary function of patients and PASP were also monitored before and after treatment. Results:(1)serum NT-proBNP(research group) of AECOPD patients(738.90±558.19 ng/L) are obviously higher than the stabled condition of physical examination COPD patients( 477.91±178.47ng/L),and differences are statistically significant( P <0.01).The NT-proBNP also apparently decreased during the clinical treatment with 738.90±558.19ng/L level before treatment and 477.91±178.47ng/L level after treatment. The differences was also statistically significant(P<0.05).(2)the research group were classified as three groups according to PASP, and the higher serum NT-proBNP was observed in the group with higher PASP(patients with normal were PASP 212.14±37.84ng/L, slightly PH group were 606.93±138.22ng/L, Moderate to severe PH group were 1608.54±259.30ng/L), and differences are statistically significant(P<0.05).(3)The research group was classified as I to IV grade on the basis of pulmonary function(FEV1). The higher serum NT-proBNP was found in the higher pulmonary function grade,(grade I 182.77±19.11ng/L, grade II 293.28±81.81ng/L, grade III 725.52±238.86ng/L, grade IV 1685.73±228.51ng/L). The difference between class I and class II had no statistical significance(P>0.05),and the difference between class I、II and class IV was statistically significant(P<0.05. Meanwhile, the difference between class III and class IV was statistically significant(P<0.05), and the difference between class I、II and class IV was statistically significant(P<0.05).(4)After clinical treatment, the patients in the research group showed great improvement of their pulmonary function. The pulmonary function was 51.63±22.18% before therapy and 63.23±15.82% after therapy. PASP was 51.69±12.76 mmHg before therapy and 44.25±11.17 mmHg after therapy. The difference are statistically significant(P<0.05).(5)There was a high positive correlation between the NT-proBNP level and the PASP before treatment(r=0.868), and a negative correlation between the NT-proBNP level and pulmonary function( r=-0.756), and the differences are statistically significant(P<0.01).(6)The changes of serum NT-proBNP level was correlated with the PASP changes( r=0.484), and negatively correlated with the pulmonary function(r=-0.837).Moreover, the differences was statistically significant(P<0.01). Conclusion:Serum NT-proBNP level are closely related with the pulmonary function and PASP of the AECOPD patients, thus could be considered as a reliable indicator of the severity of the patients pulmonary function and PH.