The Impact of Obesity on Asthma as Regards In-hospital Complications and Early Readmission

BACKGROUND: The overlap between asthma and obesity is becoming an increasing health concern, as overweight and obesity are linked to a higher risk of developing asthma and a greater disease burden. OBJECTIVE: To assess the association between obesity and hospital-related complications, as well as early readmission rates, in asthmatic patients. METHODS: This prospective observational cohort study was conducted at the Department of Chest Diseases, Ain Shams University Hospitals, between January 2024 and January 2026. A total of 75 adult patients were included and classified into three BMI groups: normal weight, overweight, and obese (n = 25 each). Clinical characteristics, pulmonary function tests, and in-hospital outcomes were assessed. RESULTS: Asthma severity increased with BMI, with severe asthma present in 96.0% of obese patients compared with 20.0% of overweight patients and none of the normal-weight patients (p < 0.001). Obese patients had lower pre-FEV₁ % predicted (47.5 ± 21.1%) than both overweight (58.5 ± 12.4%) and normal weight patients (65.2 ± 13.5%) (p = 0.003). They also had lower oxygen saturation and longer hospital stay (p < 0.001). ICU admission occurred only in obese patients (40.0%), with 20.0 % requiring mechanical ventilation. BMI correlated with longer hospital stay and lower oxygen saturation (p < 0.001). Predictors of ICU admission included obesity, severe asthma, ventilatory support, lower oxygen saturation, and reduced FEV₁. CONCLUSION: Higher BMI was associated with increased asthma severity, poorer control, impaired lung function, and worse clinical outcomes, including longer hospital stay and greater need for intensive care. These findings highlight the value of weight management and comprehensive care in improving outcomes for obese patients with asthma.