AIRWAYS RESPONSIVENESS IN A POPULATION-SAMPLE OF ADULTS AND CHILDREN

Abstract

Nonspecific bronchial responsiveness was assessed with eucapneic hyperpnea to subfreezing air in a population-based sample of 134 adults and 213 children in East Boston, Massachusetts [USA]. Increased responsiveness was considered to be present if the decrease in forced expiratory vol in 1 s with cold air divided by the initial vital capacity was > 9%. Men and women had similar bronchial responsiveness, but children and young adults (24 yr of age and younger) were significantly more likely to be responders than were older subjects (P < 0.001). Children with a doctor''s diagnosis of asthma at any time in the past were twice as likely (42.9%) to be responders as were nonasthmatic children (19%) (P = 0.004). Of currently active asthmatics, 92% (11/12) were responders. A large percentage of asymptomatic children had increased levels of bronchial responsiveness (18.9%). This cross-sectional study demonstrates the feasibility of measurement of nonspecific bronchial responsiveness in epidemiologic studies and its relationship to age and wheeze symptoms in children.