FEV₁ decline and clinical predictors in asthma after 10 Years of follow-up: BMI as a modifiable risk factor

Lung function declines with age and may be more pronounced in asthma. This study assessed FEV₁ decline over 10 years and identified associated risk factors.

A retrospective cohort study was conducted in 200 asthma patients with spirometric, inflammatory, and clinical data. Bivariate and multivariate analyses were performed. Patients were evaluated at baseline (T1), 2 years (T2), 5 years (T5), and 10 years (T10).

At 5 years, the mean FEV₁ loss was 46.49 mL/year, decreasing to 31.92 mL/year at 10 years. Greater decline at T5 was associated with older age, higher body mass index (BMI), and increased inhaled corticosteroid (ICS) use, while better baseline lung function was protective. At T10, higher eosinophils, age, ICS dose, and FeNO were linked to greater decline, whereas higher baseline FEV₁ was protective. Multivariate models identified BMI as a significant predictor of decline at T5 (p < 0.05). At 5 years, BMI >25 kg/m² showed 75 % sensitivity and 60 % specificity, while BMI <18.5 kg/m² had 100 % sensitivity and 98 % specificity (AUC = 0.60). At 10 years, BMI >25 kg/m² had 79 % sensitivity and 65 % specificity; BMI <18.5 kg/m² retained 100 % sensitivity and 98 % specificity (AUC = 0.65).

Predictors of FEV₁ decline were identified in both the medium and long term. Most patients did not exhibit accelerated decline. BMI emerged as a significant and modifiable marker, underscoring the relevance of monitoring nutritional status in asthma management and long-term lung function trajectories.