Impact of Overweight and Obesity in Severe Asthma Patients and Its Influence on Achieving Clinical Remission.

BACKGROUND AND OBJECTIVES: Obesity exacerbates asthma, resulting in more severe symptoms, poor disease control, and a reduced quality of life. With the increasing use of biologic therapies, achieving clinical remission (CR) has become an important treatment goal. This study evaluated the prevalence and impact of obesity on biologic response and CR in severe asthma patients.

METHODS: This prospective observational study included 525 patients enrolled in the Kuwait Severe Asthma Registry (KSAR). This prospective observational study included 525 patients enrolled in the Kuwait Severe Asthma Registry (KSAR). Patients were categorized according to body mass index (BMI) into normal weight, overweight, mild-to-moderate obesity, and morbid obesity groups. Demographic, clinical, and biomarker data, including blood eosinophil count (BEC), total immunoglobulin E (IgE), fractional exhaled nitric oxide (FeNO), and IL4 and IL6 gene polymorphisms, were collected. Patients treated with biologics for at least 12 months were followed. CR was defined as absence of exacerbations, no oral corticosteroid (OCS) use, Asthma Control Test (ACT) score ≥20, Asthma Control Questionnaire (ACQ-6) score ≤0.75, and predicted forced expiratory volume in one second (FEV1) ≥80%.

RESULTS: Overweight and obesity were highly prevalent, with only 15.4% of patients having normal weight. Morbidly obese patients were older, had longer disease duration, worse asthma control, lower lung function, and higher rates of diabetes and allergic rhinitis. Biologic therapy significantly improved ACT, ACQ-6, exacerbation frequency, OCS use, and lung function across all BMI groups (p<0.001). However, morbidly obese patients continued to demonstrate poorer asthma control, lower FEV1 and FVC, and higher exacerbation and OCS rates. No significant changes were observed in BEC, total IgE, or FeNO. CR was achieved in 17.3% of patients overall, with higher rates in normal-weight individuals (25%) and lower rates in morbid obesity (11%). Younger age and the IL4 CC genotype were associated with greater likelihood of CR.

CONCLUSION: Obesity was highly prevalent among severe asthma patients and was associated with poorer disease outcomes and lower CR rates despite biologic therapy. These findings highlight the importance of weight management and personalized treatment strategies in severe asthma.