Similarity and differences in elderly patients with fixed airflow obstruction by asthma and by chronic obstructive pulmonary disease.

摘要

BACKGROUND: Epidemiologic studies have demonstrated that elderly patients with fixed airflow obstruction can be affected by asthma or chronic obstructive pulmonary disease (COPD). METHODS: We studied 49 consecutive elderly outpatients, presenting fixed airflow obstruction, by clinical history (smoking), pulmonary function tests, blood gas analysis, and induced sputum. RESULTS: The age was not different in patients with COPD (n=28) and asthma (n=21) (70.2+/-3.9 years vs. 69.6+/-3.7 years), also the degree of fixed airflow obstruction was similar (FEV(1): 58.3+/-1.5% vs. 59.0+/-1.4% of predicted). Patients with asthma had significantly more eosinophils in peripheral blood (0.43+/-0.05x10(-3)muL vs. 0.27+/-0.1x10(-3)muL, P<0.0001), and in induced sputum (5.0% [(p25th and p75th) 5.0-6.0%] vs. 1.0% [(p25th and p75th) 0.01-1.0%]; P<0.0001), as well as serum ECP (18.6+/-4.9ng/mL vs. 7.7+/-4.7ng/mL, P<0.0001) and ECP in the induced sputum (31.6+/-2.9ng/mL vs. 5.6+/-4.9ng/mL, P<0.0001). Finally, in induced sputum the eosinophils EG(2)(+) were higher in patients with asthma than in patients with COPD (40.5 [(p25th and p75th) 39.3-44.3] MFI vs. 3.9 [(p25th and p75th) 0-11.4] MFI, P<0.0001). They also had significantly higher diffusing capacity, and a greater reversibility to steroids, after 14-day course of therapy, whereas the reversibility to 400mug of salbutamol was similar. CONCLUSION: Despite similar fixed airflow obstruction, elderly patients with asthma have distinct characteristics compared with patients with COPD.