Social network intervention for cardiovascular risk reduction among Hispanic and Somali adults: a cluster randomized trial

Background Immigrants to the United States often face challenges from limited healthcare access and less healthy environments which contribute to rising obesity and cardiovascular risk. Purpose To assess the feasibility and effectiveness of a community-based social network intervention for cardiovascular risk reduction among Hispanic and Somali adults. Methods A social network-informed, community-based participatory research-derived health promotion intervention was delivered by Hispanic and Somali lay health promoters (HPs) to members of their social networks over 1 year (12 biweekly sessions in months 0-6; 12 biweekly check-ins in months 7-12). Using a closed-cohort stepped wedge cluster randomized design, social networks were randomly assigned to receive the intervention immediately or after a delay of 1 year. Measurements at baseline, 6 months, and 12 months were derived from 6 of the American Heart Association’s “Life’s Simple 7”: BMI, blood pressure, fasting glucose, cholesterol, physical activity and dietary quality (range 0-12, with higher values indicating lower cardiovascular risk). Waist circumference and proportion of participants who achieved >5% body weight loss were also assessed. Results Four hundred seventy-five participants were enrolled among 51 HPs (29 Hispanic; 22 Somali). There was a statistically significant improvement in cardiovascular risk in the intervention group (n = 246) compared with controls (n = 229) at 6 months (0.4 [1.8] vs. −0.1 [1.7]; P = .03) that was not sustained at 12 months (0.5 [1.9] vs. 0.3 [1.8]; P = .38). There was a statistically significant higher proportion of participants who lost >5% of body weight in the intervention group compared with controls at 12 months (37% [15] vs. 18% [7.9]; P = .02). Reductions in weight and waist circumference in the intervention group compared with controls did not achieve statistical significance. Conclusion A social network intervention, delivered by lay HPs was feasible and resulted in a modest improvement of cardiovascular risk and clinically significant weight loss. Clinical Trial Identification Number NCT05136339.