Uncontrolled asthma is Associated with Increased Visceral Adipose Tissue, Decreased Bone Mineral Content, and Reduced Exercise Capacity

Physical inactivity due to shortness of breath is common among patients with uncontrolled asthma. We evaluated the body mass composition and exercise capacity of patients with poorly controlled asthma, despite maximal inhalation therapy. Methods: We recruited 56 patients from the Asthma Clinic of the University Hospital of Liège between September 2020 and December 2023, and 14 healthy subjects. Patients with asthma underwent detailed investigations, including induced sputum, exercise testing, and Dual-Energy X-ray Absorptiometry (DXA), to determine overall body fat mass and fat-free mass, while healthy subjects only underwent DXA. This study was approved by the Ethics Committee (2019/362). Results: The mean age of patients with asthma was 45 years ± 12; 58% were female, 10% were active smokers, and mean post-BD Forced Expiratory Volume in one second was 85.7% predicted. Compared to healthy subjects, asthmatics had a higher BMI (28.5±5.1 kg/m2 vs 22.5 ±2.8 kg/m2, p<0.0001) and fat mass index (FMI; 10.3 ± 3.7 vs 5.9 ± 2.8 kg/m2, p=0.0005), lower lean and bone mass (62% vs 71%, p=0.0012), and greater android fat distribution (1.00 ± 0.22 vs 0.80 ± 0.13, p<0.0001). Eosinophilic asthma (sputum eosinophil count of ≥3%) was characterized by a better VO 2 max compared to non-eosinophilic asthma (20.7 [17.8-24.3] vs 17.3 [14.0-18.9], p=0.04). Higher lean mass was correlated with better asthma control and lower depression scores. Lean mass and bone mineral content correlated with maximal expiratory, inspiratory, and maximal aerobic power. Conclusion: Our study confirmed that patients with uncontrolled asthma were overweight and had decreased exercise capacity. Plain language summary: Schleich et al conducted a study on a population of 56 patients with asthma and compared their body composition (fat and lean mass proportion, distribution, and bone mineral content) to that of 14 healthy subjects. Patients with uncontrolled asthma have symptoms of dyspnea that may induce a vicious circle in which shortness of breath limits physical activity. Physical inactivity and treatment with corticosteroids may induce changes in body composition. Therefore, the team evaluated the body mass composition and exercise capacity of patients with poorly controlled asthma, despite maximal inhalation therapy. Patients with asthma also underwent detailed investigations, including lung function testing, exhaled nitric oxide, and induced sputum, to establish the inflammatory phenotype. Compared to healthy subjects, asthmatics had higher body mass index and fat mass index levels, lower lean and bone mass, and more android fat distribution. Eosinophilic asthma was characterized by better exercise tolerance than that of non-eosinophilic asthma. Moreover, higher lean mass was associated with better asthma control and lower depression scores. In conclusion, this study confirmed that patients with uncontrolled asthma are overweight and have decreased exercise capacity.