ABSTRACT
Arterial elastic properties are altered with increasing age and in various disease states, including non-insulin-dependent diabetes mellitus [NIDDM]. Whether young patients with insulin-dependent diabetes mellitus [IDDM] have reduced arterial compliance before developing endothelial dysfunction or overt micro-and macrovacular disease is unclear. A total of 30 young patients with IDDM and 20 healthy subjects underwent [1] systemic arterial compliance determination by vessel wall movement detector system [complior], [2] common carotid artery-intimal medial thickness [IMT] by B-mode ultrasound, [3] echocardiographic assessment of systolic and diastolic left ventricular function, [4] brachial artery responses to reactive hyperemia [with increased flow causing endothelium-dependent dilatation] and sublingual isosorbide dinitrate [causing endothelium-independent dilatation], [5] lipid profile and hemoglobin A1c, and [6] 24-h urine collection for albumin excretion rate [AER] Arterial compliance was 23.1% lower in IDDM subjects compared with control subjects [4.86 +/- 0.445 vs. 6.32 +/- 0.889 cm4/dyn. 10[-7], P = 0.000]. IMT and all indexes of systolic and diastolic ventricular function were similar in both groups. Flow-mediated dilatation [FMD] was significantly impaired in diabetic patients. The ratio of FMD to isosorbide dinitrate induced dilatation was significantly lower in the diabetic subjects indicating that impaired dilatation to increased flow was out of the proportion to the impairment of the isosorbide dinitrate response in these subjects. The median AER was 5.98 micro g/min in the DM group and 2.92 micro g/min in the control group [P = 0.005]. Hemoglobin A1c correlated inversely with compliance [r = -0.993, P = 0.000], FMD [r = -0.929, P = 0.000] and isosorbide dinitrate -induced dilatation [r = -0.938, P = 0.000] in diabetic patients A significant positive correlation was found between arterial compliance and both FMD [r = 0.900, P = 0.000] and isosorbide dinitrate-mediated dilatation [r = 0.911, P= 0.000]. This study indicates that early changes in macrovascular function namely impaired arterial compliance and reactivity, may precede abnormalities in cardiac function or in arterial IMT in young individuals with short duration type 1 DM. Arterial compliance and reactivity may prove to be predictive of future atherosclerotic complications in patients with diabetes; therefore the noninvasive long-term assessment of arterial physiology and its relationship to the progression of cardiovascular risk factors is required. The present study also supports a relationship between metabolic control, arterial compliance and endothelial function