Factors associated to lifestyle and risk of adult onset asthma

Abstract

Background: Asthma prevalence has been increasing especially in developed countries. The change seems to be associated with changes in lifestyle. We have made a prospective study to assess the effect of lifestyle factors, including smoking, educational level, physical activity and obesity, on adult onset asthma. Methods: A population of 10 597 adult twins, initially free of asthma was followed for 9 years. The main outcome measure was questionnaire-based report of physician diagnosed asthma. Logistic regression was used to estimate the risk of asthma predicted by lifestyle factors, with adjustment for atopy and respiratory symptoms. Results: Obesity at baseline increased asthma risk (multivariable adjusted OR=3.00, 95% CI: 1.64–5.50 for those with BMI≥30 compared to those with normal weight BMI: 20–24.99). Taller height was associated to lower asthma incidence. Leisure time physical activity had a slightly protective effect on asthma risk among men ( P for trend=0.037), while smoking and education did not have significant effects on the risk of adult onset asthma. Conclusions: Obesity was associated to the risk of adult onset asthma, while short height and low leisure time physical activity can be considered as other potential risk factors.