Characterization of macro-and microvascular function and structure in patients with type 2 diabetes mellitus

Diabetes mellitus (DM) leads to accelerated progression of arteriosclerosis with an increased risk of coronary events in comparison to non-diabetic patients with coronary artery disease (CAD). The precise and early detection of DM-induced vascular alterations is crucial to identify patients with high risk for cardiovascular complications. Thus, we aimed at simultaneously characterizing functional, physicomechanical, and structural vascular alterations in diabetic patients using a non-invasive approach.

In CAD patients with and without type 2 diabetes mellitus (n=50), we non-invasively measured flow-mediated dilation (FMD) of the brachial artery as a marker for endothelial function, fractional diameter changes (FDC) as a marker for physicomechanical properties, intima-media thickness (IMT) as a marker for structural properties, and forearm blood flow (FBF) as a marker for microvascular function.

DM was associated with reduced FMD (2.5±0.2 vs 4.8±0.4%; p≤0.001) indicating impaired macrovascular endothelial function. In parallel, reduced FDC (0.024±0.002 vs 0.034±0.004; p≤0.05) and increased IMT (0.38±0.01 vs 0.31±0.01mm; p≤0.001) indicated increased stiffness and enhanced structural alterations. Furthermore, reduced forearm blood flow during reactive hyperemia (10.7±1.0 vs. 15.3±1.4mL/min*100mL; p≤0.05) was found indicating microvascular dysfunction. Plasma glucose and HbA(1c) correlated with FMD (glucose: r=-0.32; HbA(1c): r=-0.45), IMT (glucose: r=0.54; HbA(1c): r=0.48) and FBF (glucose: r=-0.30) suggesting diabetes-specific effects on vascular properties.

In patients with CAD, DM leads to functional and structural vascular alterations of the peripheral vasculature which are determined by the control of the disease underlining the relevance of a strict control of the DM to prevent accelerated atherosclerosis.