Effects of Mediterranean diet on lipid levels and cardiovascular risk in renal transplant recipients

Background: Renal transplant recipients have an increased incidence of cardiovascular disease. These patients present abnormalities of lipoprotein profile which are persistent and involve an increasing number of individuals, suggesting the opportunity of an early therapeutic intervention. Methods: We evaluated the effects of a 10- to 12-week diet based on the American Heart Association step-one diet criteria, modified with an increased intake of monounsaturated fats and alimentary fibers, on lipid profile and lipid-related cardiovascular risk in 78 normolipidemic and hyperlipidemic renal transplant recipients. Results: Diet led to a significant reduction in total cholesterol levels by 10%, triglycerides by 6.5%, low-density lipoprotein (LDL)-cholesterol by 10.4% and LDL-cholesterol/high-density lipoprotein (HDL)-cholesterol ratio by 10%, whereas HDL-cholesterol levels remained unchanged. Dividing renal transplant recipients into risk classes according to the National Cholesterol Expert Program guidelines and LDL-cholesterol levels, we observed a progressively increasing reduction in total cholesterol and LDL-cholesterol levels among 'desirable LDL-cholesterol', 'borderline high-risk LDL-cholesterol' and 'high-risk LDL-cholesterol' patients, while HDL-cholesterol levels did not change in any group and the LDL-cholesterol/HDL-cholesterol ratio significantly decreased in 'borderline high-risk LDL-cholesterol' and in 'high-risk LDL-cholesterol' patients (respectively by 6.8%, p < 0.05, and by 21.1%, p < 0.0001). Reduction in triglyceride levels was statistically significant only in subjects with 'desirable LDL-cholesterol' (by 12.3%, p < 0.01). Patients in the 'desirable LDL-cholesterol' class increased from 28 (35.9% of total patients) before diet to 45 (57.7% of total patients, p < 0.01), while subjects in the 'high-risk LDL-cholesterol' class reduced from 24 (30.8% of total patients) to 8 (10.2% of total patients, p < 0.005). Conclusion: These data suggest the possibility of a nutritional hypolipidemic approach in renal transplant recipients, even if normolipidemic. Dietetic treatment determined an inversion in the typical trend of renal transplant recipients, reducing instead of increasing the number of subjects with hypercholesterolemia, permitting the selection of individual candidates for further pharmacological treatment by carefully evaluating risk/benefit costs.