Cardiovascular structure and function in baboons with Type 1 diabetes - a transvenous ultrasound study

Diabetes mellitus is an important risk factor for both macrovascular and ca rdiac disease in humans. The availability of a novel intravenous ultrasound probe allows detailed interrogation of a large proportion of the vasculatu re, as well as the heart, during the same examination. Six male baboons (Pa pio hamadryas) with Type I diabetes and known microangiopathy, and six cont rol animals were studied. Vascular structure in the major large arteries an d cardiac function were studied using transvenous ultrasound introduced via the right femoral vein and positioned under fluoroscopy. All arteries were examined for atherosclerotic plaque and for presence of increased intima-m edia thickness (IMT). Left ventricular function was assessed at rest and fo llowing infusions of dobutamine (positive inotrope) and esmolol (negative i notrope). The procedure was performed safely and successfully in all cases. No atherosclerotic plaque was seen in either diabetic or normal baboons. T here was no difference in the aortic IMT (0.38 +/-0.04 vs 0.37 +/- 0.05 mm, normal vs. diabetic, P = NS) or in doppler flow in the renal or iliac arte ries between diabetic and normal baboons. Left ventricular wall thickness a nd systolic tissue velocity were similar in the two groups at rest (6.9 +/- 2.5 vs. 6.2 +/- 1.4 cm/s, normal vs. diabetic, P = NS), after dobutamine ( 15.5 +/- 2.2 vs. 12.7 +/- 3.9 cm/s, normal vs. diabetic, P = NS), and after esmolol (4.3 +/- 1.0 vs. 5.6 +/- 1.0 cm/s. normal vs, diabetic, P = NS). I n a high primate model of diabetes with microangiopathy, the presence of hy perglycemia for 7 years per se does not product abnormalities of macrovascu lar or cardiac structure. (C) 2001 Elsevier Science Inc. All rights reserve d.