The relationship between endothelial-dependent flow-mediated dilation and diastolic function in type 2 diabetes

Diastolic dysfunction represents the earliest and most common manifestation of diabetic cardiomyopathy. Nitric oxide (NO), a potent vasodilator and anti-inflammatory mediator released from the subendocardial and coronary endothelium, favors left ventricular distensibility and relaxation. In type 2 diabetes (T2D), the NO bioavailability is reduced due to the oxidative stress and inflammatory state of the endothelium, because of chronic hyperglycemia. The aim of the present research is to evaluate the relationship between endothelial function and diastolic function in subjects with T2D.

Subjects with T2D and age and sex-matched healthy controls were consecutively recruited. All participants underwent flow-mediated dilation (FMD) to assess endothelial function, and echocardiography to evaluate diastolic function.

Thirty-five patients (6 women, 29 men) and 35 healthy controls were included in the final analysis. FMD was significantly lower in T2D than controls (4.4 ± 3.4 vs. 8.5 ± 4.3%, p = 0.001). T2D presented different abnormalities in diastolic function compared to controls: lower E/A (early to late diastolic transmitral flow velocity), lower septal and lateral e' (early diastolic myocardial tissue velocity at septum and lateral wall), and higher E/e' (surrogate of filling pressure). In subjects with T2D, we observed a significant correlation between FMD and E/e' (r = -0.63, p = 0.001), lateral e' (r = 0.44, p = 0.03), and septal e' (r = 0.39, p = 0.05).

Our observational study demonstrated a link between FMD and diastolic dysfunction in subjects with type 2 diabetes.