Differences in airway responsiveness between children and adults living in the same environment: an epidemiological study in two regions of New South Wales

Abstract

D Di if ff fe er re en nc ce es s i in n a ai ir rw wa ay y r re es sp po on ns si iv ve en ne es ss s b be et tw we ee en n c ch hi il ld dr re en n a an nd d a ad du ul lt ts s l li iv vi in ng g i in n t th he e s sa am me e e en nv vi ir ro on nm me en nt t: : a an n e ep pi id de em mi io ol lo og gi ic ca al l s st tu ud dy y i in n t tw wo o r re eg gi io on ns s o of f N Ne ew w S So ou ut th h W Wa al le es s In winter 1991 and 1992, we studied two large random samples of children living in two different regions; and, three months later, we conducted a study of adults who lived with enrolled children. A total of 805 children and 814 adults attended in Lismore, and 850 children and 711 adults in Wagga Wagga. Questionnaires were used to measure symptom history, histamine inhalation challenge to measure airway hyperresponsiveness (AHR) and skin-prick tests to measure allergy.There was a higher prevalence of asthma in children than in adults: recent wheeze was 1.5 times higher; asthma medication use was 1.5 times higher; diagnosed asthma was 1.6 times higher; and AHR was two times higher. Current asthma (AHR and recent wheeze) was 9.5-11.3% in children and 5.4-5.6% in adults. These differences were statistically significant. In both regions, airway responsiveness was more severe in children who were sensitized to common allergens than in similarly sensitized adults.These results suggests that airways can develop protective mechanisms with age, or that recent environmental changes in factors such as allergen levels, diet or treatment practices have led to immunological changes and to incresed airway responsiveness in this generation of children.

Perception of airway narrowing in a general population sample

“…Geometric mean values are reported for population have been reported in detail previously [6]. In July 1992, a large random sample of 8-11 year old children attending schools in the area were recruited for a separate study of asthma prevalence.…”

“…For epidemiological studies in adults and children, we define current asthma as the presence both of airway hyperresponsiveness (AHR) and recent symptoms [3][4][5][6]. In children, this definition distinguishes a group with ongoing, clinically relevant airway disease [4,7].…”

A study of the relative bronchodilator responsiveness in smoker asthmatics

“…The prevalence of asthma is estimated to be around 1.2 to 6.3% in adults in most countries and in India it is reported to be around 2.38%. [1][2][3][4][5][6] In the present scenario we are facing a worldwide epidemic of asthma, which is probably attributed to a number of factors associated with changes in environment and lifestyle. Cigarette smoking is overwhelmingly the most important etiological agent in the development of COPD.…”

Prevention of asthma

“…As many as 25% of children in affluent countries now report that they have wheezed in the last year [7][8][9][10], although only half this number have an asthmatic illness which has clinical importance. Data from studies which have measured the burden and distribution of asthma and which have quantified the aetiological factors can be used to estimate the fraction of illness that is attributable to modifiable risk factors [11], but different types of studies will be needed in the future to estimate the effectiveness and the economic implications of preventive interventions.…”