Cardiac Effects of Combined Versus Individual Interventions of Mediterranean Diet and Exercise in Adults with the Hypertriglyceridemic Waist Phenotype: A Randomized Trial

Background: The hypertriglyceridemic waist phenotype, combining abdominal obesity and elevated serum triglycerides, is associated with adverse cardiovascular prognosis. The combination of dietary and exercise programs has the potential to improve outcomes with regard to adverse cardiac remodeling and dysfunction associated with poor metabolic health. We tested the hypothesis that the combination of a Mediterranean Diet (MedDiet) and exercise interventions improves cardiac structure and function more than the sum of each individual intervention. Methods: We performed a randomized 2 × 2 factorial design trial that included adults with the hypertriglyceridemic waist phenotype (triglycerides ≥1.50 mmol/L, waist circumference ≥80 cm in women or ≥94 cm in men). Participants were randomly assigned to one of four 16-week interventions: (1) MedDiet alone, (2) exercise alone, (3) MedDiet + exercise, or (4) control group. The MedDiet groups received education, counseling, and key food items from the MedDiet. The exercise groups participated in a structured exercise program designed to achieve 150 min of moderate-intensity aerobic exercise per week. Data were collected during the screening, baseline, and post-intervention visits. In mixed-effects models, we compared the post-intervention echocardiographic measurements of left ventricular (LV) structure and function per intervention group after adjusting for age, sex, and baseline values. We calculated an interaction ratio between MedDiet and exercise to assess their combined effect. Results: Of the 200 recruited, 185 participants (76% women) had available echocardiographic data. LV measurements were within normal range for most participants. After the intervention, the posterior wall thickness (LV structure) was higher in the MedDiet groups (0.04 [95% CI: 0.01–0.07] cm), and the septal mitral annular tissue Doppler e’ velocity (diastolic function) was higher in the exercise groups (0.4 [95% CI: 0.0–0.8] cm/s). No significant interactions between interventions were identified with respect to LV measurements. Conclusion: No interaction between the MedDiet and exercise interventions on LV structure and function was observed among adults with the hypertriglyceridemic waist phenotype. Further research is needed to ascertain whether the combination of these interventions can prevent the development of adverse LV remodeling over the long term or in participants with more advanced cardiac alterations.