Results
Current atopic sensitization (OR: 5.04) and current allergy (OR: 6.25) were associated with an increased risk of current asthma (Table 1). Other current potential current risk factors (i.e. sex and current daily smoking), were not significantly associated with asthma (Table 1). Both current atopic sensitization (adjusted OR: 4.91, 95% CI: 1.25-19.36) and current allergy (6.08, 1.70-21.74) remained statistically significant risk factors for asthma in the multivariate analyses, adjusted for sex and current tobacco smoking.
Asthma in parents (OR: 5.56) was a significant risk factor for current asthma, whereas asthma in mothers alone was not, although the OR was high (5.24) (Table 2). Atopic dermatitis in early childhood (4.07) was a significant asthma-predictive factor. Other potential risk factors, including allergies in parents, age at the time of index hospital admission in early childhood, passive smoke exposure or the presence of household pets in infancy, did not show significant associations with asthma at a mean age of 18.8 years (Table 2).
Neither the serum level of total IgE nor the serum level of specific IgE to inhalants or food allergens at the time of index hospital admission in early childhood was associated with asthma in young adulthood (Table 3). Elevated eosinophil counts (≥ 0.45 x 109/L) at the time of index hospital admission in early childhood were significant predictor (OR: 4.52) of asthma in young adulthood (Table 3). ECP concentrations in serum or mucus samples taken at the time of index hospital admission were not associated with asthma risk in young adulthood (Table 3).
Wheezing episodes (OR: 5.14) and asthma diagnoses (OR: 5.54) at the 1-year follow-up after the index hospital admission and at subsequent follow-ups at mean ages of 4.0 years (OR: 6.00), 7.2 years (OR: 6.22) and 12.3 years (OR: 8.00) increased the current asthma risk (Table 4).
Multivariate analyses were adjusted for sex, current daily smoking and age at the time of index hospital admission, in addition to passive smoke exposure during infancy, and the presence of household pets or pets in day care during infancy and. As shown by the results, atopic dermatitis in infancy (adjusted OR: 4.20) and blood eosinophilia at the time of index hospital admission (adjusted OR: 5.18) remained statistically significant risk factors for asthma in young adulthood (Table 5). However, parental asthma marginally lost its statistical significance, although the adjusted OR was high (4.18). Asthma diagnoses at the follow-up one year after index hospital admission (adjusted OR: 7.13) and at the follow-ups when the participants were aged 4.0 years (adjusted OR: 8.86), 7.2 years (adjusted OR: 8.05) and 12.3 years (adjusted OR: 21.16) remained significant predictors of current asthma.