Cardiac hypertrophy in diabetes patients with and without hypertension: effects of troglitazone, a novel antidiabetic drug, on diastolic function.

Abstract

Patients with non-insulin-dependent- (type 2) diabetes mellitus (NIDDM) have excessive cardiovascular morbidity and mortality even in the absence of albminuria and hypertension1. Left ventricular hypertrophy (LVH), which is an ominous prognostic sign and an independent risk factor for cardiac events, is often present in NIDDM patients2,3. It is also demonstrated that reversal of LVH reduced the increased cardiovascular risk in patients with essential hypertension and LVH4,5. Possible contributions of hyperinsulinemia and insulin resistance to LV mass have also been suggested in normotensive NIDDM patients but the results reported are not consistent6,7. Thus, LVH in diabetes patients is associated with hyperinsulinemia in the regardless of the presence or absence of albminuria and hypertension. Those patients also show the early diastolic dysfunction of the left ventricle rather than systolic dysfunction8. There are several literatures in which calcium antagonists or angiotensin converting enzyme (ACE) inhibitors could reduce left ventricular mass in hypertensive NIDDM patients9,10but ACE inhibitors seemed to offer a reduction beyond that explained by their blood pressure-lowering properties as reviewed by Schmieder et al». Troglitazone, a novel member of the insulin-sensitizing thiazolidinediones, has been widely used to treat patients with NIDDM. The treatment with Troglitazone reduced hyperglycemia, plasma trigycerides, and blood pressure12–15In addition, recent studies show that Troglitazone attenuate high glucose-induced abnormalities in relaxation and intracellular calcium in rat ventricular myocytes16 and may improve cardiac function in diabetic patients17. Thus, the beneficial effects of Troglitazone on heart have described but not been clearly established in the diastolic function of NIDDM patients.