Home-Based Multicomponent Intervention Increases Exercise Activity and Improves Body Mass Index: Results of a 5-Year Randomized Trial among Individuals with Alpha-1 Antitrypsin Deficiency-Associated Lung Disease

Background: The Step Forward Study (SFS) was designed to increase exercise activity and improve body mass index (BMI) among individuals with alpha-1 antitrypsin deficiency (AATD)-associated lung disease. Methods: The SFS is a randomized trial of an intensive distance intervention that was delivered via a series of mailings and teleconferences versus no additional intervention. All participants (n=500) were also enrolled in a disease management program designed for individuals with AATD-associated lung disease who have been prescribed augmentation therapy. The primary outcome was self-reported number of exercise minutes per week. The secondary outcome was body mass index (BMI). Linear mixed model analyses were used to assess the difference in average weekly exercise minutes between the intervention arms over time. T-tests, Signed Rank and Wilcoxon rank-sum tests were used to evaluate changes in BMI between the intervention arms and within each BMI category. Results: The study included 429 individuals with evaluable primary outcome data. There was a significant effect of intervention on exercise minutes over time (p=0.018). Participants in the intervention group reported an average of 167.14 minutes (SD=10.68) of weekly exercise and those in the standard care group reported 148.31 minutes (SD=10.96). There was a significant difference in BMI change between the intervention (mean BMI decrease 0.74, SD=2.16) and the standard care group (mean BMI decrease 0.27, SD=1.63); p=0.0122. Conclusions: Individuals who were randomly assigned to the intervention group reported more exercise activity and improvements in BMI over the course of this multicomponent intervention compared to individuals assigned to standard care.