A digital health intervention in Canada aimed at changing the diet and physical activity of South Asians did not reduce their MI risk score after 12 months, according to a single-blind, community-based, randomized trial.
In addition, knowledge of a genetic risk status did not reduce the MI risk scores at one year.
Lead researcher Sonia S. Anand, MD, PhD of McMaster University in Canada, and colleagues published their results in JAMA Cardiology on May 18.
The researchers mentioned that previous studies found South Asians had an increased risk of premature MI compared with white individuals.
In this study, known as SAHARA (South Asian Heart Risk Assessment), the researchers examined 178 men and 165 women who were at least 30 years old and were South Asian, which the researchers defined as having their ancestors originating from the Indian subcontinent.
The researchers collected data from June 3, 2012, to Oct. 27, 2013, and calculated an MI risk score based on age, sex, brief dietary and physical activity questions, tobacco exposure, psychosocial stress, blood pressure, waist and hip circumference, and levels of apolipoprotein A and B and hemoglobin A1c.
Participants randomized to the digital health intervention received stages of change-oriented motivational messages every two weeks via email as well as health tips focused on diet and physical activity every week via email or text. They were also encouraged to access a website that had South Asian-specific prevention advice. Participants in the control group were only encouraged to access that same website.
All participants received gift cards for completing visits at six months and one year, during which they underwent clinical assessments.
At baseline, the mean MI risk score of 13.3 was considered moderate. In addition, 72.3 percent of participants had one or two risk alleles for the 9p21 variant, which the researchers said was the most robust single-nucleotide polymorphism for MI.
After a year, the mean MI risk score decreased from 13.3 to 12.3 in the intervention group and from 13.3 to 12.6 in the control group, which did not represent a statistically significant difference. The difference remained nonsignificant in an adjusted model and in a sensitivity analysis of participants with high adherence.
The researchers added there was no association between the baseline genetic risk status on the MI risk score after a year. There was also no interaction between the genetic risk status and the digital health intervention.
Although participants in the intervention group received an average of 80 emails or text messages during the study, the researchers said they may have required more face-to-face contacts to change their behavior. They also said that 64.7 percent of participants were exercising regularly and 71.7 percent were consistently avoiding high-calorie foods at baseline, so the digital health intervention may not have helped them alter their habits.
Further, more than two-thirds of participants could not recall their MI risk score or genetic risk status at the end of the intervention, which was a much higher percentage than the researchers expected.
“Future trials should consider using more frequent text messaging and have bidirectional communication with participants,” the researchers wrote.