The Effect of Trandolapril on Insulin Resistance is Determined by the Degree of Baseline Resistance Level

Insulin resistance (IR) is the core problem in type 2 diabetes mellitus that may lead to cardiovascular morbidity and mortality. Hypertension commonly accompanies type 2 diabetes. Antihypertensive agents improving IR may reduce the risk of cardiovascular diseases. This study was conducted to assess the effect of trandolapril on IR, glucose and lipid metabolisms in hypertensive subjects with different degrees of IR and investigate the importance of IR level in angiotensin converting enzyme inhibitor response. The subjects were nondiabetic and type 2 diabetic hypertensive patients treated with trandolapril for 12 weeks. Blood pressures (BP) and metabolic parameters were measured in all patients at baseline and after 12 weeks of trandolapril treatment and compared. Trandolapril reduced BP similarly in nondiabetic and diabetic patients. Homeostasis model assessment insulin resistance (HOMA-IR), serum glucose and hemoglobin A1C (A1C) in diabetic patients were higher than nondiabetics. HOMAsignificantly after trandolapril in diabetics, while serum glucose, insulin and A1C remained unchanged. The posttreatment HOMA-IR values were comparable in both groups. Pretreatment HOMA-IR value was found to be associated with HOMA-IR response to trandolapril while changes in BMI, A1C and BPs were unrelated. The patients with a pretreatment HOMA-IR of >4.67 responded better. In conclusion, trandolapril improved insulin sensitivity better in type 2 diabetic hypertensive patients with higher degree of IR compared with the ones with low grade IR, being independent of its hemodynamic action.