Determinants of Respiratory Symptom Development in Patients with Chronic Airflow Obstruction

Abstract

To know which is determinant of respiratory symptom development in chronic airflow obstruction(CAO), we used data obtained as part of the KNHANES. Categories of symptomatic and asymptomatic CAO were defined using questionnaire responses and spirometric results. Among 187 patients with CAO, 69 had no respiratory symptoms. CAO patients with symptoms were significantly older than CAO patients without symptom(p<0.05). Hypertension was more common among symptomatic CAO patients than among asymptomatic CAO patients(p<0.01). Symptomatic CAO patients had higher fasting blood glucose levels than symptomatic CAO patients(p<005). In questionnaire responses, symptomatic CAO patients had more difficulty in walking or lifting(p<0.0010, more needing help with personal care(p<0.05), and worse general health than asymptomatic CAO patients(p<0.01). Symptomatic CAO patients had significantly lower forced expiratory volume in 1 second(FEV1)(P<0.01), forced vital capacity(FVC)(p<0.01), FEV1/FVC than asymptomatic CAO patients(p<0.001). Statistically significant predictors of symptom development were as follow: age(odds ratio, 1.04;p<0.05), hypertension(OR,4.41;p<0.01),fasting blood glucose(OR, 1.02;p<0.05), FEV1/FVC(OR, 0.00;p<0.01),FEV1(OR, 0.07;p<0.01), FVC(OR, 0.08;p<0.01). Multiple regression analyses revealed two independent factors associated with symptom development:FEV1/FVC(OR, 0.001;p<0.01) and hypertension(OR, 5.95;p<0.01). In CAO, respiratory symptom development was significantly associated with low FEV1/FVC and the presence of hypertension.