Background: Patients with type 2 diabetes mellitus (T2DM) have a high rate of cardiovascular disease (CVD). The Mediterranean diet is preferred for CVD prevention. Endothelial dysfunction is demonstrated early in T2DM.

Objectives: To study the effects of dietary intervention of T2DM patients without known CVD on endothelial function and vascular inflammation.

Methods: A prospective study enrolled 22 patients with T2DM. Patients were divided randomly into two groups: an intervention group with 12 patients (55 ± 7 years old, 6 women) and a control group with 10 patients (59 ± 10 years old, 5 women). Clinical evaluation included body mass index (BMI) and endothelial function measured by the flow mediated percent change (FMD%). Fasting blood was drawn on entry to the study and 3 months later, measuring C-reactive protein (CRP), intercellular adhesion molecule-1 (ICAM-1), total cholesterol, triglycerides, and glycosylated hemoglobin (HbA1C%). The intervention was based on weekly telephone calls by a clinical dietitian for 3 months.

Results: In the intervention group CRP and ICAM-1 were reduced (from 4.2 ± 3.3 mg/dl to 0.4 ± 0.5 mg/dl, P = 0.01 and from 258.6 ± 98.3 ng/ml to 171.6 ± 47.7 ng/ml, P = 0.004). Endothelial function (FMD%) was improved (from 0.5 ± 8.0% to 9.5 ± 11.5%, P = 0.014). No change was observed in BMI, HbA1C%, total cholesterol, and triglycerides levels in either group.

Conclusions: Patients with T2DM on the Mediterranean diet who received a weekly telephone call for 3 months improved their endothelial function with reduction of markers of inflammation.