Asthma attacks with eosinophilia predict mortality from chronic obstructive pulmonary disease in a general population sample

We studied the association between allergy defined as eosinophilia (greater than or equal to 275 cells/mm(3)) and/or positive skin tests (sum score gr eater than or equal to 3) and mortality from chronic obstructive pulmonary disease (COPD) after adjustment for major risk factors. In addition, we inv estigated this association in subgroups of respiratory symptoms and lung fu nction. We used data from 7,556 participants of the respiratory surveys in 1964-1972 in the general populations of Vlagtwedde, Vlaardingen, and Meppel (The Netherlands; mean age +/- SD: 39.3 yr +/- 14 in the 1960s). In 1995, the vital status was available (5,135 alive, 106 lost to follow-up, 121 pri mary deaths from COPD, and 2,194 other primary causes of which 137 had a se condary death cause from COPD. Positive skin tests were not associated with increased COPD mortality. The association between eosinophilia and COPD mo rtality was restricted to those who had reported asthma attacks and was pre sent for both COPD as a primary cause (relative risk [RR] = 4.80; 95% confi dence interval [CI] 1.9 to 11.9) and combined primary and secondary causes of death (RR = 3.90; 95% CI 2.05 to 7.40). We conclude that eosinophilia wi th asthma attacks is a risk factor for COPD mortality in addition to known risk factors also found in our study such as male gender, older age, curren t smoking, low lung function, underweight, and dyspnea.