Exacerbations and lung function decline in COPD: new insights in current and ex-smokers.
OBJECTIVE
To investigate whether there is a significant relationship between an increased frequency of exacerbations and the rate of forced expiratory volume in 1s (FEV(1)) decline in COPD patients. METHODS-MEASUREMENTS: About 102 COPD patients (44 smokers, 58 ex-smokers) participated in a 3-year prospective study. Exacerbations were identified as worsening of patient's respiratory symptoms as recorded on diary cards. Spirometry was performed every 6 months. The effect of frequent exacerbations on lung function was investigated using random effects models.


RESULTS
The median (mean(95% CI)) annual exacerbation rate was 2.85 (3.1 (2.7-3.6)). Patients with an annual exacerbation rate over the median rate had significantly lower baseline post-bronchodilation FEV(1)(%pred), higher MRC dyspnoea score and chronic cough compared to patients who had an annual exacerbation rate less than the median. The average annual rate of FEV(1)(%pred), adjusted for smoking decline (DeltaFEV(1)), was found significantly increased in frequent compared to infrequent exacerbators (P=0.017). The highest DeltaFEV(1) was observed in smokers frequent exacerbators and a significant interaction between exacerbation frequency and DeltaFEV(1) was also observed in ex-smokers.


CONCLUSIONS
Our findings suggest that an increased frequency of exacerbations is significantly associated with FEV(1) decline even in ex-smokers. Thus, smoking and frequent exacerbations may have both negative impact on lung function. Smoking cessation and prevention of exacerbations should be a major target in COPD.
Makris
D
D
Department of Thoracic Medicine, University of Crete, Medical School, 71110 Heraklion, Greece. appollon7@hotmail.com
Moschandreas
J
J
Damianaki
A
A
Ntaoukakis
E
E
Siafakas
N M
NM
Milic Emili
J
J
Tzanakis
N
N
D000368:Aged; D002908:Chronic Disease; D003371:Cough / Q000209:etiology / Q000503:physiopathology; D018450:Disease Progression; D004417:Dyspnea / Q000209:etiology / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000209:etiology / Q000503:physiopathology*; D012720:Severity of Illness Index; D012907:Smoking / Q000009:adverse effects / Q000503:physiopathology*; D016540:Smoking Cessation; D013147:Spirometry