Impact of Hypoglycaemia in Patients With Diabetes Mellitus Type 2 on Platelet Activation

Not Applicable

Completed

Conditions: Diabetes Mellitus With Hypoglycemia
Hypoglycemic Episode
Hypoglycemia
Diabetes Mellitus, Type 2

Interventions: Other: Euglycaemic Clamp
Other: Hyperinsulinaemic/Hypoglycaemic Clamp

Registration Number: NCT03460899

Lead Sponsor: Medical University of Graz

Brief Summary: This experimental study is planned to investigate the impact of hypoglycaemia on platelet activation parameters (PAP) during a hyperinsulinaemic hypoglycaemic clamp study. The hypothesis that hypoglycaemia in patients with Diabetes Mellitus, Type 2 (T2DM) leads to increased platelet activation will be tested.

Detailed Description: Increased platelet activation is significantly involved in the pathophysiology of micro- and macrovascular diabetic complications. Previously performed studies suggested platelet activation in both, hyper- and hypoglycaemic states, leading to a potentially increased risk for thromboembolic complications. Hypoglycaemia, in particular severe hypoglycaemic episodes, has been associated with increased cardiovascular or overall mortality in previous studies. Potential mechanisms include arrhythmias or increased risk for thromboembolism, based on platelet activation and/or hypercoagulability.

The aim of this experimental study is to investigate the impact of hypoglycaemia on platelet activation parameters (PAP) during a hyperinsulinaemic hypoglycaemic clamp study. We hypothesize that Hypoglycaemia in patients with T2DM leads to increased platelet activation.

The primary objective is to investigate platelet activation during different levels of hypoglycaemia induced by a stepwise hyperinsulinaemic, hypoglycemic clamp experiment in patients with T2DM.

Active study duration will be 5 days for each study participant. 14 subjects with T2DM without history of cardiovascular events or manifest atherosclerosis will be enrolled. During this monocentric, single arm, open, mechanistic trial platelet activation and recovery at one week after the clamp experiment, changes of pro-atherothrombotic markers during the hypoglycaemic clamp as well as counter regulatory hormone response during the clamp will be investigated.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 14

Inclusion Criteria

Male or female aged 18-64 years (both inclusive) at the time of signing informed consent
Subjects diagnosed with type 2 diabetes (diagnosed regarding world health organization [WHO] criteria) and on stable treatment for a period of 90 days prior to screening with metformin as monotherapy or diet only. Stable is defined as unchanged dose
Body mass index (BMI) between 20.0 and 35.0 kg/m2 (both inclusive)
HbA1c between 43 and 64 mmol/mol (6.0% - 8.0%) (both inclusive)
No use of platelet inhibiting therapy (e.g. aspirin, clopidogrel, ticagrelor, prasugrel)

Exclusion Criteria

All other forms of diabetes (type 1 diabetes, gestational diabetes) than type 2 diabetes mellitus
Treatment with any glucose lowering agent(s) other than metformin in a period of 60 days before screening. An exception is short-term treatment (≤ 7 days in total) with insulin due to intercurrent illness
Impaired hypoglycaemic awareness determined at the discretion of the investigator
Medical history of arrhythmia as atrial fibrillation, atrial flutter, atrioventricular dissociation disorders or ventricular arrhythmias
Previously known cardiovascular disease and / or past cardiovascular events, or past episodes of a congestive heart failure syndrome (NYHA II - NYHA IV)
Severe hypoglycaemic event requiring third party help in the last 6 months
Known allergy to human insulin or dextrose solution
Clinically significant abnormal haematology, biochemistry, lipids, hormones, coagulation or urinalysis
Uncontrolled hypertension defined as resting blood pressure at screening (after resting for 5 min, measured in sitting position) outside the range of 90-160 mmHg for systolic or 50-100 mmHg for diastolic
Chronic liver failure with severe liver dysfunction as assessed by the investigator
Alanine Aminotransferase (ALT) or Aspartate Aminotransferase (AST) levels > 3x upper Limit of normal (ULN)
estimated Glomerular Filtration Rate (eGFR) <45 ml/min/1,73 m2
Any musculoskeletal disorders holding back from stay in bed in a lying position during the time of the clamp experiments
Treatment with beta-blockers, antiarrhythmic agents or neuroleptic drugs
Active smoker or intake of illicit substances
Regular intake of nonsteroidal anti-inflammatory drugs (NSAIDs)
Any mental disorders or psychiatric conditions which may interfere with understanding or conduction of study related procedures
Females of child bearing potential without adequate contraceptive methods (i.e. sterilisation, intrauterine device, vasectomised partner; or medical history of hysterectomy)

Study & Design

Study Type: INTERVENTIONAL

Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Clamp Arm	Euglycaemic Clamp	All 14 subjects will undergo an Euglycaemic Clamp at Visit 2 as well as a Hyperinsulinaemic/Hypoglycaemic Clamp at Visit 3 with the Intervention of reaching certain plasma glucose levels for blood sampling regarding platelet activity parameters. Infusion of Dextrose and human soluble insulin (Actrapid) will be used to reach certain plasma glucose levels.
Clamp Arm	Hyperinsulinaemic/Hypoglycaemic Clamp	All 14 subjects will undergo an Euglycaemic Clamp at Visit 2 as well as a Hyperinsulinaemic/Hypoglycaemic Clamp at Visit 3 with the Intervention of reaching certain plasma glucose levels for blood sampling regarding platelet activity parameters. Infusion of Dextrose and human soluble insulin (Actrapid) will be used to reach certain plasma glucose levels.

Primary Outcome Measures

Name	Time	Method
Changes in Platelet Activation Marker Adenosin Diphosphate (%)	Measurement during different levels of hypoglycaemia as well as 1 and 7 days after the clamp experiment	Changes in platelet activation measured by light transmittance aggregometry (LTA) on a Chronolog 700 Lumi-Aggregometer based on Adenosin Diphosphate (ADP %) activation. Visit 3, Hyperinsulinaemic/Hypoglycaemic clamp Experiment: Timepoint 0 (Baseline = Plasma Glucose 100mg/dL \[5.5mmol/L\]) Timepoint 1 (Hypoglycaemia Plateau 1 = Plasma Glucose 63mg/dL \[3.5mmol/L\]) Timepoint 2 (Hypoglycaemia Plateau 2 = Plasma Glucose 45mg/dL \[2.5mmol/L\]) Timepoint 3 (Recovery = Plasma Glucose 100mg/dL \[5.5mmol/L\] Follow up 1 (1 Day after the Clamp Experiment) Follow up 2 (7 +/- 1 day after the Clamp Experiment)

Secondary Outcome Measures

Name	Time	Method
Quantification of Platelet Function and Activation PAC1CD62PCD63POS (%)	Measurement during different levels of hypoglycaemia as well as 1 and 7 days after the clamp experiment	Quantification of platelet activation markers by flow cytometry in unstimulated blood samples (CD62P, CD63 and binding of PAC-1) using a BD LSRFortessa flow cytometer. Hyperinsulinaemic/Hypoglycaemic clamp Experiment: Timepoint 0 (Baseline = Plasma Glucose 100mg/dL \[5.5mmol/L\]) Timepoint 1 (Hypoglycaemia Plateau 1 = Plasma Glucose 63mg/dL \[3.5mmol/L\]) Timepoint 2 (Hypoglycaemia Plateau 2 = Plasma Glucose 45mg/dL \[2.5mmol/L\]) Timepoint 3 (Recovery = Plasma Glucose 100mg/dL \[5.5mmol/L\] Follow up 1 (1 Day after the Clamp Experiment) Follow up 2 (7 +/- 1 day after the Clamp Experiment)
Markers of Coagulation Plasminogen Activator Inhibitor-1 (ng/mL)	Measurement during different levels of hypoglycaemia as well as 1 and 7 days after the clamp experiment	Effects on coagulation parameter plasminogen activator Inhibitor-1 (PAI-1) measured by Enzyme-linked immunosorbent assays. Visit 3, Hyperinsulinaemic/Hypoglycaemic clamp Experiment: Timepoint 0 (Baseline = PG 100mg/dL \[5.5mmol/L\]) Timepoint 1 (Hypoglycaemia Plateau 1 = PG 63mg/dL \[3.5mmol/L\]) Timepoint 2 (Hypoglycaemia Plateau 2 = PG 45mg/dL \[2.5mmol/L\]) Timepoint 3 (Recovery = PG 100mg/dL \[5.5mmol/L\] Follow up 1 (1 Day after the Clamp Experiment) Follow up 2 (7 +/- 1 day after the Clamp Experiment)
Changes in Coagulation Marker Fibrinogen (g/L)	Measurement during different levels of hypoglycaemia as well as 1 and 7 days after the clamp experiment	Changes in coagulation marker Fibrinogen, measured on a Behring Coagulation System BCS XP Analyzer. Visit 3, Hyperinsulinaemic/Hypoglycaemic clamp Experiment: Timepoint 0 (Baseline = PG 100mg/dL \[5.5mmol/L\]) Timepoint 1 (Hypoglycaemia Plateau 1 = PG 63mg/dL \[3.5mmol/L\]) Timepoint 2 (Hypoglycaemia Plateau 2 = PG 45mg/dL \[2.5mmol/L\]) Timepoint 3 (Recovery = PG 100mg/dL \[5.5mmol/L\] Follow up 1 (1 Day after the Clamp Experiment) Follow up 2 (7 +/- 1 day after the Clamp Experiment)