JMIR Publications

ABSTRACT

Background:

Walking therapy improves functional outcomes in peripheral artery disease (PAD). Less is known about the additive benefit of a dietary intervention.

Objective:

Our objectives were to develop a smartphone application (App) and, as a pilot, explore its potential efficacy as compared to motivational interviewing (MI) to increase walking distance and promote weight loss in overweight/obese adults with PAD.

Methods:

We conducted a 3-month, 2-arm randomized pilot study at the University of Kansas. Inclusion criteria were a body mass index (BMI) > 27 kg/m2 and symptomatic PAD, defined by an ankle-brachial index (ABI) < 0.9. Patients were randomized into two groups: 1) MI, delivered through in-person and telephone counseling, or 2) App, a mobile smartphone application. Both interventions encouraged walking for exercise and healthy dietary habits (increasing fruits and vegetables as well as whole grains while reducing fat and sugary drinks). We assessed medical history at baseline. At baseline and 3 months, participants completed an assessment of 6-minute walking distance, weight, quality of life, exercise behaviors, and dietary habits. The primary outcome was 3-month change in walking distance. Secondary outcomes were changes in weight, quality of life, exercise behaviors, and dietary habits. We used Wilcoxon rank-sum test to analyze the primary and secondary outcomes at three months within the MI and App groups, and to compare the changes between the groups with adjustment for baseline.

Results:

We randomized 29 participants with a mean age of 66.03 (SD 8.12) years. Twenty five participants completed the trial. At baseline, mean walking distance among completers was 260.40 meters (SD 94.32) and 326.15 meters (SD 69.28) for MI and App participants, respectively. At three months, the mean walking distance was 298.67meters (SD 101.20) and 331.19 meters (SD 58.63) for MI and App participants, respectively (group difference p-value = 0.033, adjusting for baseline). Increase in walking distance at three-month was 40.5 meters (95%CI: 6.77-61.34; p-value=0.02) in MI group. At baseline, mean body weight was 253.10 lbs. (SD 59.45) and 225.13 lbs. (SD 58.93) for MI and App participants, respectively. At three months, mean body weight was 242.14 (SD 58.54) and 223.44 (SD 59.54) for MI and App, respectively (group difference p =0.006, adjusting for baseline). Pre-post study decrease in weight was 10.1lb (95%CI: -17.9, -3.0) and 2.3lb (95%CI -3.4, -0.7) in MI and APP group, respectively. Comparing baseline to three months, there were no statistically significant differences in quality of life, exercise behaviors, or dietary habits.

Conclusions:

Our study demonstrates that MI can promote walking and weight loss in overweight/obese adults with PAD. The smartphone APP showed a small weight loss, but no statistically significant increase in walking distance. As this was a pilot study, future large-scale studies are needed to replicate the efficacy of MI to promote weight loss in overweight or obese adults with PAD. Clinical Trial: The clinical trial registration for this study is NCT03694652 (https://clinicaltrials.gov/).