Body Mass Index and Bronchodilator Responsiveness in Adults: Analysis of 2 Population-Based Studies in 4 South...

In South America, the rise in chronic respiratory diseases and weight-related issues due to the ongoing epidemiological transition has prompted research into their interrelationship.

We sought to assess the association between body mass index (BMI) and bronchodilator responsiveness (BDR) among adults in Peru, Chile, Uruguay, and Argentina, using population-based data from 2 cohort studies. We defined BDR as a ≥12% and ≥200mL increase in either forced expiratory volume in 1 second (FEV₁) or forced vital capacity (FVC) after administration of a short-acting bronchodilator. The analysis also distinguished between FEV₁- and FVC-specific BDR. We used logistic regression adjusted for confounders to evaluate associations with BMI.

Among 7160 participants (55.2% men, mean age 57.3 years), 23.7% had a BMI <25kg/m² and 35.5% had a BMI ≥30 kg/m². Overall, 9.5% met the criteria for BDR; with 7.8% showing FEV₁-specific and 4.9% FVC-specific responses. Compared to a BMI of 20-24.9kg/m², a BMI ≥30kg/m² was associated with higher odds of FVC-specific BDR (adjusted odds ratio = 1.47, 95% confidence interval 1.08-2.03), whereas a BMI <20kg/m² was associated with FEV₁-specific BDR among participants with asthma (6.61, 1.23-35.6) and chronic bronchitis (4.71, 1.28-15.9), and with higher odds of any BDR in those with chronic bronchitis (3.90, 1.19-11.9).

There was a differential relationship between BMI and types of BDR: higher BMI was associated with FVC-specific responsiveness, whereas lower BMI was linked to FEV₁-specific BDR in individuals with asthma and chronic bronchitis and to overall BDR in those with chronic bronchitis.