Insulin resistance by clamp analysis tied to LV dysfunction in diabetics

Using the hyperinsulinaemic-euglycaemic clamp as the gold-standard for assessment, recent research has shown that insulin resistance (IR) may be causally linked to left ventricular (LV) diastolic and systolic dysfunction in patients with type 2 diabetes mellitus (T2DM).

Researchers retrospectively evaluated 34 T2DM patients in whom LV function had been assessed through echocardiography. The hyperinsulinaemic-euglycaemic clamp was used to evaluate IR, as was the homeostasis model assessment (HOMA). Diastolic function was measured as the ratio of the peak early- to late-diastolic mitral inflow velocities (E/A), while systolic function as the LV ejection fraction (LVEF).

Simple correlation analysis found a significant link between the insulin sensitivity index (ISI) and both EA (r, 0.480; p=0.004) and LVEF (r, 0.360; p=0.037). HOMA-IR, in comparison, was not associated with either cardiac parameter.

ISI showed no interaction with other echocardiographic parameters, such as LV end-diastolic and end-systolic diameters, intraventricular septum thickness, LV posterior wall thickness, or E-wave deceleration time.

Multivariate linear regression analysis, controlled for age, hypertension, and ISI, confirmed that ISI was indeed an independent and significant predictor of LVEF (β, 4,414.1±2,112.6 p=0.045) and of the log of E/A (β, 387.9±171.2; p=0.031).

“We have here shown that insulin resistance as evaluated by the hyperinsulinaemic-euglycaemic clamp, but not by HOMA-IR, was inversely correlated with both LV diastolic and systolic function in individuals with T2DM,” the researchers said.