IGHE and allergic respiratory disease: In seven Danish population-based studies of adults from different time periods, we investigated the association between several potential lifestyle-related factors of atopy, i.e. serum total cholesterol, systolic blood pressure, smoking habits, alcohol intake, leisure time physical activity, body mass index, age, gender and education, and atopy, defined as specific IgE or skin prick test positivity against inhalant allergens that are both well-accepted objective biomarkers of allergic respiratory disease.