Behavioral Weight Loss and Physical Activity Intervention in Obese Adultswith Asthma. A Randomized Trial

摘要

>Rationale: The effect of weight loss on asthma in obese adults warrants rigorous investigation.>Objectives: To examine an evidence-based, practical, and comprehensive lifestyle intervention targeting modest weight loss and increased physical activity for asthma control.>Methods: The trial randomized 330 obese adults with uncontrolled asthma to receive usual care enhanced with a pedometer, a weight scale, information about existing weight management services at the participating clinics, and an asthma education DVD, or with these tools plus the 12-month intervention.>Measurements and Main Results: The primary outcome was change in Asthma Control Questionnaire (ACQ) scores from baseline to 12 months. Participants (mean [SD] age, 47.6 [12.4] yr) were 70.6% women, 20.0% non-Hispanic black, 20.3% Hispanic/Latino, and 8.2% Asian/Pacific Islander. At baseline, they were obese (mean [SD] body mass index, 37.5 [5.9] kg/m²) and had uncontrolled asthma (Asthma Control Test score, 15.1 [3.8]). Compared with control subjects, intervention participants achieved significantly greater mean weight loss (±SE) (intervention, −4.0 ± 0.8 kg vs. control, −2.1 ± 0.8 kg; P = 0.01) and increased leisure-time activity (intervention, 418.2 ± 110.6 metabolic equivalenttask–min/wk vs. control, 178.8 ± 109.1 metabolic equivalenttask–min/wk; P = 0.05) at 12 months. Butbetween-treatment mean (±SE) differences were not significant for ACQ changes(intervention, –0.3 ± 0.1 vs. control,–0.2 ± 0.1; P = 0.92) from baseline(mean [SD], 1.4 [0.8]), nor for any other clinical asthma outcomes (e.g., spirometricresults and asthma exacerbations). Among all participants regardless of treatmentassignment, weight loss of 10% or greater was associated with a Cohend effect of 0.76 and with 3.78 (95% confidence interval,1.72–8.31) times the odds of achieving clinically significant reductions(i.e., ≥0.5) on ACQ as stable weight (<3% loss or gain from baseline).The effects of other weight change categories were small.>Conclusions: Moderately and severely obese adults with uncontrolledasthma can safely participate in evidence-based lifestyle intervention for weightloss and active living. The modest average weight and activity improvements arecomparable to those shown to reduce cardiometabolic risk factors in studies ofsimilar interventions in other populations but are not associated with significantnet benefits for asthma control or other clinical asthma outcomes in the currentpopulation. Instead, weight loss of 10% or greater may be required to produceclinically meaningful improvement in asthma.Clinical trial registered with ().