Full-scale Intervention Study: Genetic Risk Communication and Wearables

Background: Communication of information about risk of type 2 diabetes (T2D) alone has not been associated with changes in habitual behaviors among individuals of European ancestry. In contrast, the use of wearable devices that monitor physical activity (PA) has been associated with changes in behavior in some studies. It is uncertain whether risk communication might enhance the effects of wearable devices. We aim to assess the effects on wearable-device-measured PA of communicating genetic risk for T2D alone or in combination with goal setting and activity prompts from a wearable device among overweight or obese East Asians. Methods: In a parallel group, randomized controlled trial, a total of 355 overweight or obese East Asian individuals aged 40-60 years will be allocated into one of three groups: 1 control and 2 intervention groups. Blood samples will be used for estimation of T2D genetic risk and analysis of metabolic risk markers. Genetic risk of T2D will be estimated based on 113 SNPs associated with T2D among East Asians using an established method. All three groups will receive a Fitbit device. Both intervention groups will be given T2D genetic risk estimates along with lifestyle advice, but one of the intervention groups will additionally use Fitbit's step-goal setting and prompt functions. Questionnaires and physical measurements will be administered at baseline, immediately after intervention delivery, and 6 and 12-month post-intervention following standard operating procedures. The primary outcome is time spent in moderate-to-vigorous PA measured through the Fitbit. Secondary outcomes include other parameters of wearable-device-measured PA, sedentary time, and sleep, body mass index, systolic and diastolic blood pressure, five intermediate metabolic risk markers, hand grip strength, self-reported PA, self-reported fruit and vegetable consumption and smoking status, and a list of psychological variables. Discussion: This study will be the first randomi