PURPOSE: Indentifying the prevalence and risk factors of overlapping lung obstructive diseases (overlap syndrome) among airway obstructive symptomatic patients admitted in 2005 in a clinical pneumology setting from south-eastern part of Romania, Constantza.
METHODS: 278 adult patients, 54.6% males, performed respiratory questionnaires, lung function measurements, induced sputum and clinical respiratory evaluation. Statistics performed by SPSS.10, EpiInfo 3.5.1 and MedCalc 22.214.171.124/2008.
RESULTS: The prevalence rate of overlap syndrome was 38.4% (n=107/278). 41.6% (n=40/96) of asthmatics (AA) were identified as COPD-like patients (AC); 38.1% (n=29/76) COPD patients (CC) were more asthmatics (CA); 35.8% (n=38/106) of chronic bronchitis patients (BB) were finally considered as COPD patients (BC). Variability of airflow measured by FEV1 revealed differences in AA (70.26) vs AC (53.33) with an incomplete reversible airway obstruction (F=10.49; p< 0.002). The risk factors for COPD overlapping were increased age (63.59 yrs.), tobacco smoke exposure (nAC=11/40; 27.5% vs nAA=4/56; 0.7%; OR=3.84; RR=3.24; CI 75%; p< 0.03), exacerbations (nAC= 21/40 vs nAA= 8/56; OR=3.67; RR=2.75; CI 75%; p< 0.004),recurrent lower respiratory infection (nBC= 16/38; 42.1% vs nBB= 9/68; 13.2%; OR=3.18; RR=2.53; CI 75%; p< 0.02). The effect of severe exacerbations on the progression of airway obstruction was observed in nonsmoking asthmatics with moderate-to-severe disease. CA patients had significantly more eosinophils in peripheral blood (%mean+SD: 6.85 + 4.18 vs 1.59 + 1.48; F= 53.2485; p< 0.0001) and in induced sputum (%mean+SD: 18.26 + 20.91 vs 1.47 + 1.84; F= 18.5171; p< 0.0001).
CONCLUSION: Overlap syndrome was mainly diagnosed among elderly patients, asthmatics tobacco-users, being associated with exacerbated asthma and recurrent lower respiratory infections in bronchitic group. Induced sputum is useful in asthma misdiagnosed cases. The effect of severe exacerbations on the progression of airway obstruction and loss of lung function was observed in nonsmoking asthmatics with moderate-to-severe disease.
CLINICAL IMPLICATIONS: The onset of the overlap syndrome remains unclear and open to discussion. Exacerbation rate in patients with asthma and recurrent respiratory infections in chronic bronchitis could predict an excess decline in FEV1 and overlapped into COPD.
DISCLOSURE: Oana Arghir, No Financial Disclosure Information; No Product/Research Disclosure Information