Insights into wheeze and asthma across the life course

Wheeze and asthma are major health problems worldwide, affecting all age groups. Severe asthma and asthma exacerbations represent particular problems because they are associated with high morbidity and healthcare costs. This thesis used data collected as part of the EuroPrevall and UBIOPRED studies to provide new insights into wheeze and asthma across the life course. Areas explored included risk factors for preschool wheeze, the relationship between atopy and disease severity and risk factors for exacerbations in patients with severe asthma/preschool wheeze. The EuroPrevall birth cohort consisted of 12,049 infants from nine European countries. Data on wheeze in the second year of life was available in 8775 (72.8%). The prevalence of wheeze varied considerably across Europe, ranging from 1.7% in Lodz (Poland) to 17.2% in Reykjavik (Iceland). Risk factors for wheeze in the second year of life included lower respiratory tract infections, postnatal maternal smoking, day care attendance and male gender. However, their importance varied between centres suggesting that unique risk factors operate in different countries. In the UBIOPRED study, participants with mild to moderate and severe asthma/preschool wheeze were recruited into adult, school and preschool age cohorts. At baseline, a detailed asthma and allergic disease history was taken. Skin prick testing, specific IgE measurement and component resolved allergen diagnostics (ISAC Chip®) were performed. The severe cohorts were followed up after 12-18 months. Clinical clusters and allergic sensitisation clusters were generated. The prevalences of allergic disease and allergic sensitisation did not differ significantly according to asthma/wheeze severity in any age group. A history of previous exacerbations and poor asthma control were risk factors for future exacerbations across the life course. Rates of prospective exacerbations did not differ between clinical or allergic sensitisation clusters. Further research is needed to determine whether novel biomarkers can more accurately predict asthma outcomes than clinical parameters.