ABSTRACT
Given the continued rise in the average body mass index (BMI) among the general population, it is not surprising that a considerable number of subjects with asthma are also overweight or obese. Many studies have shown being overweight or obese is a risk factor for increased asthma severity, poor asthma control, and lower asthma-related quality of life. As adiposity increases, several well-known physiological changes occur. Restrictive lung physiology is induced by excess adipose deposition around the upper abdomen and chest wall and by diaphragmatic displacement due to increased abdominal fat. Being overweight or obese has been shown in several studies to be a risk factor for increased asthma severity. Compared with lean asthmatics, obese and overweight asthmatics have more frequent respiratory symptoms, use rescue therapies more often, and have poorer asthma-related quality of life and asthma control. Increasing BMI in asthmatics has either not been associated or, somewhat paradoxically, has been inversely related to airway biomarkers of eosinophilic inflammation.
