Body weight characteristics of subjects on asthma medication

Weight gain is a frequently documented side effect after long-term anti-inflammatory treatment with systemic corticosteroid drugs in patients with asthma. In recent years new types of inhaled corticosteroids have been introduced, which act locally and are more rapidly bio-transformed. Even such corticosteroids may have a detectable, clinically relevant systemic side effect on weight. The aim of this study is to investigate if there is any relationship between body weight and asthma medication.

The relationship between asthma medication and body weight was analysed in two combined randomized samples of the adult Swedish population 16-60 y of age (n = 17,912). Multivariate logistic regression analyses were carried out to obtain estimates for (1) body mass index (BMI) indicating 'obesity' (BMI > 29.9 kg/m2) in men and women controlling for self-reported asthma medication, and (2) self-reported asthma medication controlling for BMI. In both cases we furthermore controlled for interview period, age, Swedish region, smoking habits, physical activities and level of education.

We found no significantly higher odds for obesity in men (OR = 1.21 (0.55-2.64) or women (OR = 1.97 (0.89-4.38) on asthma medication compared to men and women with pharmacologically untreated asthma even after adjustment for smoking habits, physical activities, level of education and other related co-variables. However, we found significant positive associations between obesity and interview period, age and former smoking and inverse significant relationships with the degree of physical activity. We also found significantly higher adjusted odds for asthma, indicated by self-reported asthma medication, in women (OR = 2.74 (1.91-3.91)) but not in men (OR = 1.57 (0.96-2.56)) with BMI indicating 'obesity'.

There is no strong evidence to suggest that modern pharmacological asthma treatment may contribute much to the development of obesity in either men or women on asthma medication. Adjustment for smoking habits, physical activities, level of education and other related co-variables have minor effects on these relationships. Obesity may still be an independent risk factor for asthma since we observed significantly higher odds for self-reported asthma medication in women and an almost significant relationship in men even after control for BMI and other related co-variables.