ristocetin and Diabetes-Mellitus--Type-1

Platelets-endothelial cells interaction appears to cause vascular damage in diabetes. Platelet aggregation was studied in 24 diabetic children and adolescents (mean age: 12.2 years, mean duration of diabetes: 3.3 years), with only one presenting microangiopathy complications (retinopathy). Platelet aggregation was found to be normal, suggesting that there is usually no platelet hyperactivity in diabetic children.

Topics: Adenosine Diphosphate; Adolescent; Adult; Child; Child, Preschool; Diabetes Mellitus, Type 1; Female; Humans; Male; Platelet Aggregation; Ristocetin

We have studied the temporal relationship of plasma von Willebrand Factor (vWF), a marker of endothelial damage, with the development of complications in 63 young diabetic patients (56 of whom were insulin-dependent) who took part in a prospective study. Results are presented from baseline to follow-up. In the group as a whole, no significant changes were found in any autonomic function tests, temperature discrimination threshold or nerve conduction velocities. Median motor and peroneal latency were significantly increased, while median motor, peroneal motor and sural sensory potentials were significantly decreased at follow-up compared with baseline (p < 0.001). There was a significant fall in mean plasma vWF antigen and ristocetin co-factor activity in the entire group. Within the group, we identified eight patients whose peroneal motor and sural sensory conduction velocities had decreased by over 2 ms-1. In these patients (Group A), baseline vWF antigen and activity were significantly higher than in the rest of the patients (Group B), (p = 0.04) and vWF antigen was still significantly higher after 3 years (p = 0.02). There were no differences between the groups in incidence of retinopathy, urinary albumin excretion rate or macrovascular disease. To assess the influence of glycaemic control on vWF, we first compared a matched group (C) of diabetic patients with similar HbA1 to that of group A, but with normal nerve conduction velocities: vWF was still significantly higher in group A compared with group C (p = 0.02). Furthermore, hierarchical regression showed that vWF predicted deteriorating nerve function independently of glycaemic control or the type of diabetes. Endothelial dysfunction may be associated with development of peripheral neuropathy in young diabetic patients.

Topics: Adult; Autonomic Nervous System; Biomarkers; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diabetic Neuropathies; Female; Follow-Up Studies; Glycated Hemoglobin; Humans; Male; Motor Neurons; Neural Conduction; Neurons, Afferent; Peroneal Nerve; Predictive Value of Tests; Prognosis; Reference Values; Ristocetin; Sural Nerve; Time Factors; von Willebrand Factor

Topics: Adenosine Diphosphate; Adolescent; Adult; beta-Thromboglobulin; Blood Vessels; Collagen; Diabetes Mellitus, Type 1; Humans; Male; Middle Aged; Platelet Aggregation; Ristocetin; von Willebrand Factor