LOWER RESPIRATORY-TRACT SYMPTOMS IN QUEENSLAND SCHOOLCHILDREN - RISK-FACTORS FOR WHEEZE, COUGH AND DIMINISHED VENTILATORY FUNCTION

Background-The occurrence of respiratory symptoms and abnormal lung fu nction in children is known to be influenced by genetic and many envir onmental factors. The association between specific respiratory symptom s in children of school age and their parents has been examined. Metho ds-Respiratory symptoms and ventilatory function were recorded for 454 9 schoolchildren in Queensland, Australia. Results-The cumulative prev alence of wheezing was 23.1% of 8 year olds and 20.8% of 12 year olds, and the prevalence of wheezing within the previous 12 months was 13.9 % and 10.5% respectively. A parental history of asthma or wheeze and h ayfever was associated with wheeze in the child, but did not affect ei ther the age of onset or frequency of episodes. A history of frequent cough in children who had never wheezed was associated with a parental history of frequent bronchitis, but less strongly with parental wheez e. These familial aggregations were not mediated by common exposure to cigarette smoke. Both a history of parental wheeze and maternal cigar ette use were associated with a decrease in FEF25-75 in the child and these effects were additive. Conclusions-The association of specific s ymptoms (wheeze and cough without wheeze) in parent and offspring is i nterpreted as evidence for different mechanisms of familial transmissi on, which may be genetic.