Hypoglycaemia leads to a delayed increase in platelet and coagulation activation markers in people with type 2 diabetes treated with metformin only: Results from a stepwise hypoglycaemic clamp study

Abstract

Aims: To investigate the effect of hypoglycaemia on platelet and coagulation activation in people with type 2 diabetes.

Materials and methods: This monocentric, open, single-arm, mechanistic trial included 14 people with established type 2 diabetes (four women, 10 men, age 55 ± 7 years, glycated haemoglobin concentration 51 ± 7 mmol/mol) receiving metformin monotherapy. A stepwise hyperinsulinaemic-hypoglycaemic clamp experiment (3.5 and 2.5 mmol/L, for 30 minutes respectively) was performed, aiming to investigate platelet and coagulation activity during predefined plateaus of hypoglycaemia, as well as 1 day and 7 days later.

Results: While platelet activation assessed by light transmittance aggregometry did not significantly increase after the hypoglycaemic clamp procedure, the more sensitive flow cytometry-based measurement of platelet surface activation markers showed hypoglycaemia-induced activation 24 hours (PAC1^pos CD62P^pos , PAC1^pos CD63P^pos and PAC1^pos CD62P^pos CD63^pos ; P < .01) and 7 days after the hypoglycaemic clamp (P < .001 for PAC1^pos CD63^pos ; P < .01 for PAC1^pos CD62P^pos and PAC1^pos CD62P^pos CD63^pos ) in comparison to baseline. Coagulation markers, such as fibrinogen, D-dimer, plasminogen activator inhibitor-1, von Willebrand factor activity and factor VIII, were also significantly increased, an effect that was most pronounced 24 hours after the hypoglycaemic clamp.

Conclusion: A single event of insulin-induced hypoglycaemia led to an increase in markers of platelet activation and coagulation in people with early stages of type 2 diabetes on metformin therapy. However, the activation occurred with a delay and was evident 24 hours and 7 days after the actual hypoglycaemic episode.

Keywords: clamp; coagulation; hypoglycaemia; hypoglycaemic clamp; metformin; platelet activation; type 2 diabetes.

Figure 1

Study design. HG 1, hypoglycaemic plateau 1 (3.5 mmol/L); HG 2, hypoglycaemic plateau 2 (2.5 mmol/L); V, visit

Figure 2

Effects of hypoglycaemia on platelet function. A, Platelet activation adenosine diphosphate (TAADP). B, CD62P^pos. C, PAC1^posCD62P^pos. D, PAC1^posCD63^pos. E, PAC1^posCD62P^posCD63^pos. F, PFA‐200. *P < .01, **P < .001. Data are displayed as mean ± SE. HG 1, hypoglycaemic plateau 1 (3.5 mmol/L); HG 2, hypoglycaemic plateau 2 (2.5 mmol/L)

Figure 3

Effects of hypoglycaemia on coagulation markers. A, Plasminogen activator inhibitor‐1 (PAI‐1). B, Fibrinogen. C, D‐Dimer. D, Von Willebrand factor (vWF) activity. E, Factor VIII. F, Semaphorin 4D. *P < .01, **P < .001. Data are displayed as mean ± SE. HG1, hypoglycaemic plateau 1 (3.5 mmol/L); HG2, hypoglycaemic plateau 2 (2.5 mmol/L)

Figure 4

Effects of hypoglycaemia on inflammatory markers. A, Interleukin‐6 (IL‐6). B, Intracellular adhesion molecule (ICAM). C, Vascular cell adhesion molecule (VCAM). *P < .01, **P < .001. Data are displayed as mean ± SE. HG 1, hypoglycaemic plateau 1 (3.5 mmol/L); HG 2, hypoglycaemic plateau 2 (2.5 mmol/L)