Is there a link between asthma and obesity?

Abstract

The association between obesity and several diseases is well known, but an association with asthma hasbeen much less described. Epidemiological studies have shown that obesity is an independent risk factorfor asthma in children and adults. Fundamental is the influence of the definition of the type of asthma onthe link between those two diseases. Several reports have shown a stronger association between obesityand clinical asthma phenotypes than with physiological and inflammatory asthma phenotypes. Amongthe mechanisms that have been proposed to explain the obesity-asthma relationship, the immunological,hormonal and environmental are the most important; however, the impact of genetic factors should alsobe considered. Environmental factors such as high-calorie and low antioxidant diet, low maternal vitaminconsumption and in particular low vitamin D have been recently discussed. Serum concentration of 25(OH)Dhas been found to be insufficient in children with asthma. Low 25-hydroxyvitamin D concentration leadsto increasing asthma severity and requires more intensive glucocorticoids treatment. 25(OH)D may havea protective effect against asthma exacerbations as it enhances steroid responsiveness. The nature ofthe asthma-obesity relationship is very complex and involves several mechanisms. Among these, bronchialsmooth muscle cells dysfunction, inflammatory mediators and oxidative stress, dietary and geneticfactors play major roles.