PRESERVED ENDOTHELIAL FUNCTION IN IDDM PATIENTS, BUT NOT IN NIDDM PATIENTS, COMPARED WITH HEALTHY-SUBJECTS

OBJECTIVE - To examine endothelial function (EF) noninvasively in IDDM and NIDDM patients with long diabetes duration. RESEARCH DESIGN AND M ETHODS - We studied EF in 17 IDDM patients without diabetic complicati ons and in 25 NIDDM patients with comparable glycemic control and with diabetic complications and compared both with nondiabetic control sub jects matched for age, sex, and lumen diameter. Using high-resolution ultrasound, we measured the endothelial-dependent (FAD%) and independe nt vasodilation (GTN%); the blood flow at rest, postocclusive, and aft er application of 400 mu g glyceroltrinitrate of the brachial artery; and the intima media thickness (IMT) of the common carotid artery RESU LTS - 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 subj ects. IMT (0.59 +/- 0.10 vs. 0.55 +/- 0.14 mm) was slightly, but not s ignificantly, elevated. In contrast, the NIDDM patients showed an impa ired FAD% (3.8 +/- 3.3 vs. 6.9 +/- 4.4%, P < 0.01), no difference in G TN%, 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 pat ients (0.77 +/- 0.14 vs. 0.62 +/- 0.10 mm, P < 0.001). CONCLUSIONS - I n contrast to NIDDM patients with cardiovascular complications, IDDM p atients with long diabetes duration and good long-term metabolic contr ol do not have impaired EF compared with control subjects.