Effects of Different Insulin Regimes on Postprandial Myocardial Perfusion Defects in Type 2 Diabetic Patients

OBJECTIVE:--Postprandial glycemia is an independent risk factor for cardiovascular disease that is more powerful than fasting glycemia and determines myocardial perfusion defects in type 2 diabetes. We examined the efficacy of two different insulin regimes (regular insulin and insulin analog) in controlling postprandial hyperglycemia and in preventing myocardial perfusion abnormalities. RESEARCH DESIGN AND METHODS--A total of 20 consecutive type 2 diabetic patients and 20 control subjects were enrolled in this randomized, three-way, cross-over, placebo-controlled study. Myocardial perfusion was assessed by myocardial contrast echocardiography (MCE) in fasting and postprandial (120 min) state. RESULTS:--Insulin analog was associated with lower, but not statistically significant, postprandial glycemia than regular insulin (glucose increase: 116 ± 8 vs. 136 ± 5%, P = NS). However, the area under the curve following insulin analog was significantly lower than regular insulin (18,354 ± 702 vs. 20,757 ± 738 mg per 120 min, P = 0.032). Fasting myocardial flow velocity ({szligbeta}), myocardial blood volume (MBV), and myocardial blood flow (MBF) did not differ between control and type 2 diabetic subjects. Postprandial {szligbeta} (0.67 ± 0.24 vs. 0.92 ± 0.25, P < 0.01), MBV (8.4 ± 2 vs. 10.9 ± 1.2, P < 0.01), and MBF (5.6 ± 2 vs. 9.9 ± 2.8, P < 0.01) increased significantly in control subjects. In type 2 diabetes, during placebo in the postprandial state, {szligbeta} increased (0.65 ± 0.27 vs. 0.89 ± 0.24, P < 0.01), while MBV (8.34 ± 1.2 vs. 4.3 ± 1.3, P < 0.01) and MBF (5.4 ± 1.5 vs. 3.4 ± 0.9, P < 0.01) decreased. Similar changes in MCE variables were observed after regular insulin: {szligbeta} increased (0.65 ± 0.22 vs. 0.92 ± 0.12, P < 0.01) and MBV (8.2 ± 2 vs. 5.2 ± 1.16, P < 0.01) and MBF (5.4 ± 1.9 vs. 4.2 ± 0.86, P < 0.01) were reduced. After insulin analog, postprandial {szligbeta} (0.66 ± 0.18 vs. 0.9 ± 0.18, P < 0.01), MBV (8.2 ± 1.6 vs. 9.6 ± 1.2, P < 0.01), and MBF (5.4 ± 2 vs. 7.2 ± 1.9, P < 0.01) increased. Values of postprandial MBV and MBF were higher after insulin analog than regular insulin treatment. CONCLUSIONS:--Insulin analog partially reversed myocardial perfusion abnormalities observed in postprandial state by improving glucose control.