Homocysteine Levels are Associated with Endothelial Function in Newly Diagnosed Type 2 Diabetes Mellitus Patients

Background: Endothelial dysfunction is the earliest indicator of atherosclerosis. Both type 2 diabetes mellitus (T2DM) and hyperhomocysteinemia (HHCY) are the risk factors of endothelial dysfunction. However, the combined effect of T2DM and HHCY on endothelial dysfunction is not clear. We investigated the endothelial function in T2DM patients with HHCY in this study. Material and Methods: Fifty newly diagnosed T2DM patients and 54 healthy subjects were recruited from Beijing Chaoyang hospital. T2DM patients were divided into two subgroups as T2DM + NHCY (n = 30) and T2DM + HHCY (n = 20) according to plasma homocysteine (HCY). HHCY was defined as plasma HCY level higher than 15 μmol/L. Endothelial function was measured by the reactive hyperemia index (RHI) with Endo PAT-2000. Results: Sex and age were matched between T2DM group and healthy controls. T2DM group had significantly higher HCY level (14.44 ± 4.30 vs. 12.09 ± 2.48 mmol/L, P < 0.05) and lower RHI (1.73 ± 0.50 vs. 2.05 ± 0.49, P < 0.01) than controls. In the subgroup analysis, T2DM with HHCY had significantly lower RHI than T2DM patients without HHCY (1.53 ± 0.20 vs. 1.86 ± 0.59, P < 0.05). RHI was negatively correlated with HCY (r = -0.325, P < 0.01), low-density lipoprotein cholesterol (LDL-C) (r = -0.268, P < 0.01), HbA1c (r = -0.219, P < 0.05), and HOMA-IR (r = -0.226, P < 0.05). Multiple linear regressions analysis was performed and HCY, LDL-C, HbA1c, and HOMA-IR were entered in the model. Analysis showed that HCY levels were independent negatively associated with RHI (β = -0.032, P < 0.05). Conclusions: T2DM patients with HHCY had poor endothelial function. Serum HCY levels were negatively associated with RHI.