Increasing trend in atopy markers prevalence in a Croatian adult population between 1985 and 1999.

Background: Reports about the increasing prevalence of atopy and atopic diseases are common, but recently they have been critically reviewed and the need for relevant research methods has been established.

Objectives: This study evaluated a 15-year trend in the prevalence of atopy markers [elevated total IgE, positive skin prick test (SPT) to common aeroallergens and positive atopic symptoms] in Croatian adults, separately for women and men.

Methods: The study included 721 subjects (445 men and 276 women), 18-45 years old, examined for allergies within a pre-employment preventive examination. All subjects underwent medical history, SPT with common inhalatory allergens and total serum IgE measurement. The trend analysis of atopy prevalence was performed after stratification of subjects into three consecutive 5-year periods from 1985 to 1999.

Results: The prevalence of concurrently elevated total IgE and positive atopic symptoms significantly increased during the studied period in men [odds ratio (OR) 2.44, 95% confidence interval (CI) 1.39-4.29, P=0.002]. Women showed an increased prevalence of positive SPT only, with borderline significance (OR 1.65, 95% CI 1.00-2.71, P=0.050). In women, rural residence was found to be a predictor of elevated total IgE (OR 5.36, 95% CI 2.41-11.93, P=0.000) and smoking to be a predictor of concurrently elevated total IgE and positive SPT (OR 6.20, 95% CI 1.67-23.07, P=0.006).

Conclusions: An increasing trend in the prevalence of concurrently elevated total IgE and positive atopic symptoms was found in the Croatian adult male population between 1985 and 1999, but not in the female population. Sex differences responsible for the production and regulation of IgE were suggested.