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OBJECTIVE To examine endothelial function (EF) noninvasively in IDDM and NIDDM patients with long diabetes duration. RESEARCH DESIGN AND METHODS We studied EF in 17 IDDM patients without diabetic complications and in 25 NIDDM patients with comparable glycemic control and with diabetic complications and compared both with nondiabetic control subjects matched for age, sex, and lumen diameter. Using high-resolution ultrasound, we measured the endothelialdependent (FAD%) and independent vasodilation (GTN%); the blood flow at rest, postocclusive, and after application of 400 μg glyceroltrinitrate of the brachial artery; and the intima media thickness (IMT) of the common carotid artery. RESULTS In the IDDM patients, neither FAD% (8.2 ± 4.6 vs. 7.6 ± 4.2%), GTN% (16.3 ± 4.9 vs. 18.4 ± 6.4%), nor postocclusive blood flow (40.6 ± 19.1 vs. 39.3 ± 23.6 cm/s) differed from the control subjects. IMT (0.59 ± 0.10 vs. 0.55 ± 0.14 mm) was slightly, but not significantly, elevated. In contrast, the NIDDM patients showed an impaired FAD% (3.8 ± 3.3 vs. 6.9 ± 4.4%, P < 0.01), no difference in GTN%, and a decreased postocclusive blood flow (18.5 ± 13.8 vs. 32.7 ± 20.0 cm/s, P < 0.01). IMT was significantly increased in NIDDM patients (0.77 ± 0.14 vs. 0.62 ± 0.10 mm, P < 0.001). CONCLUSIONS In contrast to NIDDM patients with cardiovascular complications, IDDM patients with long diabetes duration and good long-term metabolic control do not have impaired EF compared with control subjects.

OBJECTIVE To determine the contribution of altered pain perception to the impaired blood pressure reactions during a cold pressor test in diabetic patients. Reduced blood pressure increases have been observed in diabetic patients during a cold pressor test and have been attributed to an impaired efferent sympathetic function. RESEARCH DESIGN AND METHODS We investigated pain intensities and blood pressure reactions simultaneously during a cold pressor test in 30 IDDM patients (diabetes duration 12 ± 6 years, HbA1c 7.5 ± 1.4%) and in 30 normal control subjects with comparable sex distribution, age, height, BMI, physical fitness, and smoking habits. RESULTS Initial pain intensities and respective time courses did not differ between the two groups. The initial blood pressure response was significantly smaller in diabetic patients (P < 0.002). Correlations of diastolic blood pressure increases in diabetic patients with initial pain intensity, standard cardiovascular reflex tests, age, clock time, smoking habits, disease duration, and actual blood glucose concentrations did not reach statistical significance. Pain intensity and diastolic blood pressure increases, however, were correlated to HbA1c concentrations in diabetic patients. CONCLUSIONS Impaired pain perception is not the cause of the impaired reactions of blood pressure in diabetic patients during the cold pressor test, leaving very early deterioration of either cerebral processing of pain stimuli, cardiac function, efferent sympathetic nerves, or decreased vascular reactivity as possible explanations.