Digital Health Intervention to Lower Cardiovascular Risk

Study Questions:

Does a digital health intervention to improve diet and physical activity reduce risk for myocardial infarction (MI) among a South Asian population?


The SAHARA (South Asian Heart Risk Assessment) trial was a single-blind, community-based randomized controlled trial among adults of South Asian ancestry, ages ≥30 years, residing in Ontario and British Columbia who were free of cardiovascular disease at baseline. Follow-up was for 12 months. Data were collected between June 3, 2012, and October 27, 2013. The digital intervention included goal setting emails or text messages, which focused on improving diet and physical activity. Messages were tailored to the participant’s self-reported stage of change. The primary outcomes included change in MI risk score from baseline to 1-year follow-up. Secondary outcomes included change in the individual components of the risk score, including blood pressure, waist-to-hip ratio, glycated hemoglobin level, and the ratio of apolipoprotein B to apolipoprotein A. Genetic risk for MI was determined by counting the 9p21 risk alleles; results were provided to each participant at baseline.


A total of 343 men and women (51.9% men, mean age 50.6 years) were randomized to the digital health intervention (n = 169) or the control group (n = 174). The main MI risk score was 13.6 (standard deviation [SD] 6.6) at baseline. No significant differences were observed in the change in MI score after 1 year for the digital health intervention and the control groups (−0.27; 95% confidence interval [CI], −1.12 to 0.58; p = 0.53) after adjusting for baseline scores. No difference was observed between groups for the fully adjusted model (−0.39; 95% CI, −1.24 to 0.45; p = 0.36). No association between knowledge of the genetic risk status at baseline and the change in MI risk score was found (0.19; 95% CI, −0.40 to 0.78; p = 0.53).


The investigators concluded that among South Asian adults, a digital intervention to improve diet and physical activity was not associated with a reduction in MI risk score after 12 months and was not influenced by knowledge of genetic risk status.


Digital health interventions may not promote successful changes in cardiovascular disease risk, when implemented in a manner that does not assess what participants are currently doing and thus build on current lifestyle behaviors and repeat assessments of these behaviors. As the investigators state, many of these participants were already making changes to their diet and physical activity behaviors. Digital health programs may work well in concert with traditional programs (such as in-person counseling).

Clinical Topics: Diabetes and Cardiometabolic Disease, Dyslipidemia, Prevention, Lipid Metabolism, Diet, Exercise

Keywords: Apolipoproteins B, Blood Pressure, Diet, Electronic Mail, Exercise, Health Promotion, Hemoglobin A, Glycosylated, Life Style, Motor Activity, Myocardial Infarction, Primary Prevention, Risk Assessment, Risk Factors, Text Messaging, Waist-Hip Ratio

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