Postprandial myocardial perfusion in healthy subjects and in type 2 diabetic patients

Article

关键词: BLOOD-FLOW RESERVE;    ENDOTHELIUM-DEPENDENT VASODILATION;    IDIOPATHIC DILATED CARDIOMYOPATHY;    MUSCLE GLUCOSE-UPTAKE;    CONTRAST ECHOCARDIOGRAPHY;    MICROVASCULAR RECRUITMENT;    ACUTE HYPERGLYCEMIA;    METABOLIC CONTROL;    OXIDATIVE STRESS;    ELDERLY SUBJECTS;   

DOI  :  10.1161/CIRCULATIONAHA.104.495127

来源: SCIE

【 摘 要 】

Background - In diabetic patients, postprandial hyperglycemia is a more powerful risk factor for cardiovascular disease than fasting hyperglycemia itself. A negative influence of acute hyperglycemia on systemic endothelial function (brachial artery) has been shown. However, myocardial perfusion during postprandial hyperglycemia has not been investigated. Methods and Results - We evaluated the effects of a standardized mixed meal on myocardial perfusion in 20 healthy subjects and 20 consecutive patients with type 2 diabetes mellitus without macrovascular or microvascular complications. Myocardial perfusion was assessed in fasting and postprandial states by myocardial contrast echocardiography. Fasting myocardial flow velocity (beta, 0.65 +/- 0.27 versus 0.67 +/- 0.24; P=NS), myocardial blood volume (MBV; 8.3 +/- 1.2 versus 8.4 +/- 2; P=NS), and myocardial blood flow (5.4 +/- 1.5 versus 5.6 +/- 2; P=NS) did not differ between control subjects and diabetic patients. In the postprandial state, beta(0.67 +/- 0.24 versus 0.92 +/- 0.35; P < 0.01), MBV (8.4 +/- 2 versus 10.9 +/- 2.7; P < 0.01), and myocardial blood flow (5.6 +/- 2 versus 9.9 +/- 2.8; P < 0.01) increased significantly in control subjects. In diabetic patients, beta increased (0.65 +/- 0.27 versus 0.8 +/- 0.24; P < 0.01) but MBV (8.3 +/- 1.2 versus 4.3 +/- 1.3; P < 0.01) and myocardial blood flow (5.4 +/- 1.5 versus 3.4 +/- 0.9; P < 0.01) decreased significantly. Changes in MBV (expressed as [(MBVpostprandial-MBVfasting)/MBVfasting]x100) were significantly correlated with postprandial glycemia levels in diabetic patients. Conclusions - Postprandial hyperglycemia determines myocardial perfusion defects in type 2 diabetic patients. They are secondary to deterioration in microvascular function causing a decrease in MBV. In diabetic patients without microvascular or macrovascular complications, postprandial myocardial perfusion defects may represent an early marker of the atherogenic process in the coronary circulation; hence, its reversal constitutes a potential goal of treatment.

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