Interaction between Mediterranean diet and statins on mortality risk in patients with cardiovascular disease: Findings from the Moli-sani Study

BACKGROUND: Statins are prescribed for patients with cardiovascular disease (CVD), along with the recommendation of adopting healthy diets. We evaluated the independent and the combined effect of statins and Mediterranean diet (MD) towards mortality risk in patients with previous CVD by using real-life data from a population-based prospective cohort.

METHODS: Longitudinal analysis on 1180 subjects (mean age 67.7 ± 10) with prior CVD at enrollment in the Moli-sani Study and followed up for 7.9 y (median). Adherence to MD was appraised by a Mediterranean diet score. Hazard ratios (HR) with 95% confidence intervals (95% CI) were calculated by multivariable Cox regression and competing risk models.

RESULTS: Multivariable risk estimates associated with a 2-point increase in MD score were 0.84 (95% CI 0.70-1.00), 0.77 (0.61-0.97) and 0.70 (0.52-0.93) for overall, cardiovascular and coronary artery disease (CAD)/cerebrovascular deaths, respectively. Statins were not associated with death risk. Subjects combining statins and average-high adherence to MD had much lower than expected risk of cardiovascular and CAD/cerebrovascular mortality (p for interaction = 0.045 and 0.0015, respectively) as compared to those neither using statins nor having average-high MD. The combination of average-high MD and statins was associated in a likely synergistic way with reduced low-grade inflammation, but not with blood cholesterol.

CONCLUSIONS: MD lowered the risk of all-cause, cardiovascular and CAD/cerebrovascular mortality CVD patients, net of statins. In the same population, statins reduced CVD death risk only in combination with MD. Low-grade inflammation, rather than lipids, is likely to be on the pathway of the interaction between MD and statins towards mortality risk.