893-P: A Smartphone App-Based Lifestyle Intervention for Weight Loss, Improvement of Hemoglobin A1c (A1c), and Prediabetes

We previously reported the successful RCT of our smartphone app-based lifestyle intervention in overweight or obese subjects (ClinicalTrials.gov NCT02742662). Our intervention met the prespecified primary outcome of clinically meaningful, statistically significant weight loss at 6 months over standard of care in wait-listed controls (ADA 2018). Here we report effects of the intervention on glycemia and risk of diabetes as assessed by A1c, a prespecified secondary endpoint. The app downloads daily weights from smartscales and physical activity from 3-axis accelerometers. The technology allows peer social networking and remote coaching. Subjects chose diets from a selection of low glycemic index, low fat, low carb or Mediterranean. We performed comparisons using the t test. Intervention group (I) N=13, no dropouts, 84.62% F, age 40.2 ± 3.73 y (means ± SE), initial weight 94.2 ± 3.41 kg, BMI 34.5 ± 1.25 kg/m². Wait-listed Control group (C) n=15, 86.67% F, age 45.9 ± 3.29 y, initial weight 92.3 ± 4.37 kg, BMI 34.4 ± 1.48 kg/m². N=14 began the study and received in-person weight management visits at 0, 3, and 6 months. N=10 completed the 6-12 month phase during which they received the app-based lifestyle intervention. The intervention significantly improved A1c at 6 months -0.251 ± 0.0894 (95% CI -0.4419 to -0.0609) p=0.013 (I over C, per protocol analysis). At 6 months (I) change in A1c (n=9) -0.189 ± 0.0389 (95% CI -0.2786 to -0.0992) p= 0.0013, (C) change in A1c (n=8) +0.0625 ± 0.0844 (95% CI -0.1370 to 0.2620) p=0.48. After receiving the intervention from 6-12 months (C) group (n=10) improved A1c by -0.26 ± 0.0718 (95% -0.4224 to -0.0976) p=0.0056. All (C) subjects with prediabetes (n=4 of 10) who received the intervention resolved prediabetes at 12 months. Thus, the intervention produced clinically and statistically significant improvements in A1c. Our smartphone app-based lifestyle intervention may be a useful tool to treat prediabetes and prevent diabetes.