High risk of adult asthma following severe wheezing in early life.

BACKGROUND: Severe wheezing in early life is associated with an increased risk of asthma during childhood and adolescence. The aim of the present follow-up was to investigate the asthma prevalence and risk factors for asthma in adulthood. METHODS: We have prospectively studied asthma development in 101 children hospitalized due to severe wheezing before the age of 24 months. The cohort was re-investigated at a mean age of 27 years and tested for bronchial hyper-responsiveness and allergic sensitization. The response rate in adulthood was 81% (82/101). The results were compared with a population-based, age-matched control group (n = 1,210) recruited from the West Sweden Asthma Study. RESULTS: Current doctor-diagnosed asthma was found in 37% (30/82) compared with 7% (82/1,210) in the control group. The risk of adult asthma in the cohort compared with the control group was increased 10-fold (adjusted OR 10.0, 95% CI 5.3-18.7), independently of allergic rhinitis, gender, smoking and heredity. Within the cohort, current allergy (aOR 9.6, 95% CI 3.0-31.2) and female gender (aOR 3.2, 95% CI 1.1-9.3) independently increased the risk of adult asthma. Females with current allergy had the highest risk of adult asthma (OR 29.4, 95% CI 5.0-173.3), compared with males without allergy. When separately adjusting for factors present at admission in early life within the cohort, a family history of asthma was a significant risk factor for asthma in adulthood (aOR 4.0, 95% CI 1.3-12.5). CONCLUSION: Subjects with severe early wheezing have a 10-fold increase in the risk of adult asthma compared to an age-matched control group, adjusted for allergic rhinitis, gender, smoking and heredity.

Reduced airway function in early adulthood among subjects with wheezing disorder before two years of age.

AIM: To compare airway function in early adulthood in subjects with wheezing in infancy with age-matched controls and to analyze what accounts for a possible difference. METHODS: Asthma development has been prospectively studied in 101 children hospitalized due to wheezing before the age of two. The cohort was re-investigated at age 17-20 years and tested with spirometry and for bronchial hyper-responsiveness and allergic sensitization. An age-matched population (n = 294) was used for comparison. RESULTS: The cohort had a significantly lower FEV(1)/FVC ratio and MEF(50), both pre- and post-bronchodilation, compared with the controls, P < 0.01. The reduction in airway function was most evident in current asthmatic female subjects, but a reduced pre-bronchodilation FEV(1)/FVC ratio was also seen in symptom-free cohort subjects, P = 0.03. In the multivariate analysis, female gender was the most prominent independent risk factor for reduced airway function in early adulthood, pre-bronchodilation OR 4.0 (1.4-11.3) and post-bronchodilation OR 8.8 (1.8-42.0). In addition, a history of early wheezing, that is, belonging to the cohort, was an independent risk factor for reduced airway function pre-bronchodilation, OR 3.3 (1.3-8.7). Furthermore, there was an association between current bronchial hyper-responsiveness and an increased risk of reduced airway function post-bronchodilation, OR 7.3 (2.0-26.6). CONCLUSION: Reduced airway function in early adulthood was found in subjects with wheezing early in life, compared with age-matched controls. The reduction was most prominent in females with current asthma.

The impact of pre- and post-natal smoke exposure on future asthma and bronchial hyper-responsiveness.

AIM: To analyse the impact of pre- and post-natal smoke exposure on asthma presence, bronchial hyper-responsiveness, airway function and active smoking in early adulthood. METHODS: We have prospectively studied 101 children hospitalized due to wheezing before the age of 2 years. The cohort was re-investigated at age 17-20 years and tested for airway function and bronchial hyper-responsiveness. Data on maternal smoking during pregnancy were obtained from the Swedish Medical Birth Register. RESULTS: There was a significant, independent correlation between both pre- and post-natal smoke exposure and asthma at age 17-20 years, OR 3.5 (1.1-11.3) and 3.4 (1.2-10.1), respectively. Maternal smoking during pregnancy was an independent risk factor for current bronchial hyper-responsiveness, OR 6.6 (1.2-35.5). Pre-natal smoke exposure seemed to negatively affect small airway function in early adulthood due to structural changes. Post-natal smoke exposure was independently associated with an increased risk of current smoking, OR 7.4 (1.6-35.2). CONCLUSION: In subjects hospitalized due to early wheezing, pre- and post-natal smoke exposure increase the risk of asthma in early adulthood. The connection between pre-natal smoke exposure and asthma appears to be mediated via the development of bronchial hyper-responsiveness. Smoke exposure in infancy is associated with an increased risk of active smoking in early adult age, which is in turn linked to current asthma.

Asthma symptoms in early childhood--what happens then?

AIM: To study the outcome in early adulthood for children with early asthma symptoms and to analyse the factors associated with current asthma. METHODS: In a prospective study, we have re-investigated 89/101 children who were hospitalized before the age of two years due to wheezing. The children were investigated using a questionnaire and allergy and bronchial hyper-responsiveness tests at the age of 17-20 years and compared with age-matched controls. RESULTS: In the cohort, 43% had had asthma symptoms in the preceding 12 months compared with 15% in the control group. The strongest risk factors for asthma were current allergy, bronchial hyper-responsiveness and female gender. Female gender and passive smoking in infancy were independent infantile risk factors. In addition to female gender, two pathways led to current asthma: an allergic pathway from family atopy via the development of allergy and another pathway from early passive smoking via hyper-responsiveness and active smoking. CONCLUSION: In children with early wheezing disorder, current allergy, bronchial hyper-responsiveness and female gender were the strongest risk factors for asthma in early adulthood, while female gender and passive smoking in infancy were independent infantile risk factors. The effects of early passive smoking persist longer than previously reported.