Effect of a Mediterranean diet on endothelial progenitor cells and carotid intima-media thickness in type 2 diabetes: Follow-up of a randomized trial

Background We assessed the long-term effects of a Mediterranean diet on circulating levels of endothelial progenitor cells (EPCs) and the carotid intima-media thickness (CIMT) in patients with type 2 diabetes. Design This was a parallel, two-arm, single-centre trial. Methods Two hundred and fifteen men and women with newly diagnosed type 2 diabetes were randomized to a Mediterranean diet (n = 108) or a low-fat diet (n = 107). The primary outcome measures were changes in the EPC count and the CIMT of the common carotid artery after the treatment period defined as the end of trial (EOT). Results At the EOT, both the CD34+KDR+ and CD34+KDR+CD133+ counts had increased with the Mediterranean diet compared with the low-fat diet (p < 0.05 for both). At the EOT evaluation, there was a significant (p = 0.024) difference of -0.025 mm in the CIMT favouring the Mediterranean diet. Compared with the low-fat diet, the rate of regression in the CIMT was higher in the Mediterranean diet group (51 vs. 26%), whereas the rate of progression was lower (25 vs. 50%) (p = 0.032 for both). Changes in the CIMT were inversely correlated with the changes in EPC levels (CD34+KDR+, r = -0.24, p = 0.020; CD34+KDR+CD133+, r = -0.28, p = 0.014). At the EOT, changes in levels of HbA1c, HOMA, total cholesterol, high-density lipoprotein cholesterol and systolic blood pressure were significantly greater with the Mediterranean diet than with the low-fat diet. Conclusion Compared with a low-fat diet, a long-term trial with Mediterranean diet was associated with an increase in circulating EPCs levels and prevention of the progression of subclinical atherosclerosis in patients with newly diagnosed type 2 diabetes.