OBJECTIVETo assess the risk factors correlating to the likelihood for airflow obstruction among first-degree children of chronic obstructive pulmonary disease (COPD) patients and whether familial aggregation of pulmonary function abnormality exists.

METHODSFifty-nine smokers with COPD and 28 smokers without COPD as control and all their children available were recruited into the study. Their history was recorded and a binary logistic regression analysis was carried out to ascertain the effects of their relationship to a proband with COPD, when other potential risk factors were controlled.

RESULTSChildren with COPD probands showed increased risk of FEV1 below the 70% predicted (OR = 1.987) after accounting for the effects of smoking, sex and clinical symptoms. The lower the pulmonary function of the COPD proband, the higher the risk to their children for FEV1 below the 70% predicted.

CONCLUSIONSOur finding demonstrates the presence of a household aggregation inclination of COPD and pulmonary function impairment. Genetic factors might act as the basis of the familial aggregation.