The use of a mobile application to support physical activity and lifestyle changes in persons living with HIV: the smartapp study

INTRODUCTION: Although physical activity has been shown to improve fitness, metabolic and inflammatory parameters in people living with HIV, adherence to exercise programs is usually low when not strictly supervised. Therefore, the aim of this study was to assess if the use of a mobile application will favor engagement to exercise by providing motivational inputs, and therefore adherence to training. We hypothesized, as a consequence an improvement of physical fitness, and therefore of health status. METHODS: This pilot study was a two-armed, parallel group, randomized controlled trials in which HIV-infected subjects were enrolled and assigned to either an experimental group (EG), which trained with a smartphone application, or a control group (CG), which trained with a hard copy training program. Physical activity program included an initial coach-supervised period of 4 weeks, followed by 12 weeks where participants were instructed to train independently. The program consisted of walking or jogging three times/week for 60 minutes. At baseline (BL) and after 16-weeks (W16), patients underwent measurement of CRF by peak oxygen consumption (VO2peak), body composition (body mass, body mass index-BMI, waist, hip circumferences, %fat mass and %fat free mass by bioimpedentiometry), and metabolic parameters (total-, HDL-, LDL-cholesterol). Results are given as number (%) or median (IQR) values. Intention-to-treat analysis regarding an improvement of the 15% of VO2peak was performed with a Chi-Square test. Percentage changes between BL and W16 regarding EG and CG were assessed by Wilcoxon matched-pairs signed rank test. RESULTS: Thirty-seven subjects were screened and 28 were eligible and divided in EG [n=13, age: 52 (36-56) y-o, height: 176 (170-180) cm, BMI: 24.4 (22.1-27.1) kg/m2, CD4+: 648 (439-762)], and CG [n=15, age: 50 (36-56) y-o, height: 172 (170-180) cm, BMI: 24.8 (22.1-27.1) kg/m2, CD4+: 619 (439-762)]. During training we had 1 and 2 drop-outs for EG and CG, respectively. Median training adherence was 100% (IQR 91-100%) during the initial coach supervised period, and 70% (IQR 41-91%) during the independently training period, with 15/28 (54%) who trained for at least 50% of the sessions. Intention-to-treat analysis showed post-intervention improvement in VO2peak (+ 15%, p=0.005), % fat mass (-10%, p=0.014); %fat free mass (+ 8%, p=0.008), total cholesterol (- 6%, p=0.016) between EG and CG were observed. CONCLUSION: Adherence to training is fundamental, but seems to be low when not strictly supervised in HIV infected patients. The preliminary results from this pilot study showed that patients trained using a smartphone application were more adherent and as consequence improved physical fitness, body composition and metabolic parameters.