Obesity - a risk factor for asthma, but not for atopic dermatitis, allergic rhinitis and sensitization

Objective To analyse the relationship between obesity and overweight and the prevalence of allergic diseases and sensitization, and the impact of gender and place of residence. Design Questionnaire based on those used in ISAAC (International Study of Asthma and Allergies in Childhood) and ECRHS (European Community Respiratory Health Survey). Setting Our study involved populations of the eight largest cities and one rural region in Poland (each with over 150 000 inhabitants). Subjects The study included 18 617 participants (242 % aged 6-7 years, 254 % aged 13-14 years, 504 % adults aged 20-44 years) in eight cities and one rural area. The out-patient study involved 4783 patients (257 %); we performed skin prick testing with fifteen aeroallergens. Results Overweight was found in 1613 % of participants (911 % of 6-7-year-olds, 490 % of 13-14-year-olds and 2561 % of adults), obesity in 641 % (716 %, 245 % and 836 %, respectively). In adults, overweight (OR=134) and obesity (OR=180) increased the prevalence of asthma, especially in women (OR=153, OR=201). Among 13-14-year-olds the prevalence was higher only in the obese (OR=176). Overweight (OR=199) and obesity (OR=217) affected the incidence of doctor-diagnosed asthma in 6-7-year-olds. Overweight (OR=081) and obesity (OR=076) reduced the prevalence of allergic rhinitis in men. There was no relationship between BMI and asthma in people from rural areas. Obesity and overweight did not affect the frequency of sensitization to aeroallergens. Conclusions Overweight and obesity increased the prevalence of symptomatic asthma in adults, especially in women. In 13-14-year-olds, only obesity increased the prevalence of asthma. In children, overweight was associated with increased prevalence of clinically diagnosed and declared asthma and a trend towards atopy. Higher BMI was negatively associated with the prevalence of allergic rhinitis in overweight and obese man. There was no correlation between BMI and sensitization to aeroallergens.