An Online Weight Loss Intervention for People With Obesity and Poorly Controlled Asthma

Background: Weight loss might improve asthma control in people with obesity. However, people with asthma might have particular challenges losing weight and the amount of weight loss needed to improve asthma control is not clear. Objectives: To pilot-test an online weight loss intervention and to estimate the impact of weight loss on asthma control. Methods: We performed a 6-month, single-arm, futility trial of an online weight loss intervention at 2 centers. To reject the assumption of futility, 9 or more participants had to lose at least 5% of their body weight. We also assessed the association between weight loss (≥5%) and asthma outcomes. Results: Forty-three participants (85% women) started the weight loss intervention. The median and interquartile range for the body mass index was 40.3 kg/m² (range 34.7–46.8 kg/m²), and 14 (range 12–17 kg/m²) for the Asthma Control Test score. At 6 months, 10 participants (23%; 95% CI 12%–39%) lost at least 5% of their initial weight. Weight loss of at least 5% was associated with a clinically and statistically significant improvements in their Asthma Control Test (median [interquartile range] increase of 3 [1 to 7]; P < .05), Marks Asthma Quality of Life Score (–9.5 [–18 to –3]; P = .008), and their general health-related quality of life score (RAND-36; improved by 9.4 [2.8 to 22.5]; P =.014). Conclusions: An online weight loss intervention has the potential to meet U.S. Food and Drug Administration guidance for product evaluation (at least a 5% weight loss in 35% of people) for treating obesity, and is associated with a clinically significant improvement in asthma control, quality of life, and overall health-related quality of life.