A culturally-tailored dietary trial for cardiometabolic health in Puerto Rico - ABSTRACT The PREDIMED trial produced strong evidence showing that adhering to a Mediterranean dietary pattern is associated with lower risk of type 2 diabetes (T2D) and cardiovascular disease (CVD). Yet such a diet may not be familiar or accessible to populations of different cultural backgrounds. Few clinical trials have examined the mechanisms that contribute to cardiometabolic improvements, posited to be through changes in the metabolome profile, psychosocial factors, or access to food. Our overall goal is to prevent CVD and T2D among high-risk adults in the United States (US) territory of Puerto Rico (PR), where cardiometabolic burden is excessive, by promoting a healthy, accessible, and culturally appropriate diet. In response, we led PROMED (Puerto Rico-Optimized Mediterranean-like Diet #NCT03975556), a 4-mo, 2-arm, parallel pilot and feasibility randomized trial that tested the efficacy of a culturally tailored intervention vs. standard healthy eating program in improving cardiometabolic risk factors in 44 adults in PR. Participants highly rated PROMED’s cultural acceptability, practicality, and satisfaction. The short-term benefits on blood pressure and HDL-C need to be tested long-term. We therefore propose to test these mechanisms and the intervention’s efficacy by expanding PROMED to a 2-year, 2-arm, parallel randomized clinical trial among 250 free-living adults aged 30-65y in PR with at least one dysregulated risk factor but free of CVD or T2D. The intervention group will receive culturally tailored portion-control advice through monthly individual counseling reinforced with daily text messages, and a monthly supply of legumes, vegetable oils, and locally produced fruit and vegetables. Participants in the control arm will receive standard portion-control non-tailored nutritional counseling in monthly individual sessions reinforced with daily text messages and monthly assistance to purchase healthy foods. Primary outcomes are a cardiometabolic improvement score (CIS) denoting improved cumulative risk factors at a clinically significant value and 10-year atherosclerotic CVD (ASCVD) risk estimated from the pooled cohort equation. We aim to determine the biological mechanisms mediating the efficacy of PROMED vs. control by measuring plasma metabolite signatures that predict changes in CIS and 10-year ASCVD risk; assess change and mediation of psychosocial factors (self-efficacy, self-control, intent) on CIS, and ASCVD; and ascertain changes in food security, access, and expenditure by group, and effects on diet, CIS, and ASCVD. As an exploratory aim, we will assess spillover effect of the intervention by inviting one household member of 70 participants at random for clinical and laboratory assessments. We expect PROMED will improve participants’ cardiometabolic health and elucidate posited mechanisms of action of a healthy diet. This new rigorous evidence will enhance dietary guidelines and shift the paradigm from recommending generalized diets to adapting guidance according to the biological, psychosocial, and social needs of similar populations.
