Endocrine Abstracts

Background and aims: Hypoglycemia can be a risk factor for adverse cardiovascular and cerebrovascular events. However, changes in platelets and coagulation hemostasis during hypoglycemia have not been extensively studied. During hypoglycemia, a wide spectrum of physiologic responses are activated that could have potential vascular biological effects. To date, the role played by catecholamines, the sympathetic nervous system, and neuroendocrine hormones on activating adhesion molecules and influencing fibrinolytic balance is incompletely understood. The aim of this study was to assess the impact of insulin-induced hypoglycemia on the platelet activity, and fibrinolysis in patients with type 1 diabetes.

Research design and methods: We studied 15 patients with type 1 diabetes (9 male and 6 female, age 24.4±5.6, A1C 9.07±2.3%) without microvascular complications during hyperinsulinemic (1 mU/kg per min) hypoglycemic clamp protocol. Induced platelet aggregation in whole blood using thrombin receptor activating peptide 6 (tRaP-6), collagen, arachidonic acid, adenosine-diphosphate, ristomycin was measured during hypoglycemia (plasma glucose(pg) 2.3±0.1 mmol/l), euglycaemia (pg 4.4±0.4 mmol/l), hyperglycemia (pg ≥12 mmol/l) and recovery phase by multiple electrode platelet aggregometry (Multiplate). Plasminogen activator inhibitor (PAI-1), tissue plasminogen activator (tPA) was determined by ELISA. Statistical analysis was performed with SPSS 22,0 for Windows, P<0.05.

Results: Platelets aggregation induced collagen (P=0.001), thrombin (P=0.003), adenosine- diphosphate (P=0.016), arachidonic acid (P=0.05) was significantly increased during 20-min of hypoglycemia compared with euglycemia. Plasma PAI-1 activity were significantly different during hypoglycemia as compared with euglycemia (P=0.001) and as compared with recovery phase (P=0.018). Plasma concentrations of tPA did not alter during either hypoglycemic clamp in individuals with type 1 diabetes.

Conclusions: The present study confirmed that platelet activation is promoted by hypoglycemia and that hypoglycemia decreases systemic fibrinolytic balance by increasing PAI-1 activity while maintaining tPA values. Thus, at least two separate mechanisms for increasing thrombosis are activated by hypoglycemia in individuals with type 1 diabetes.