Metabolic Adaptation to High-frequent Hypoglycaemia in Type 1 Diabetes

Nordsjaellands Hospital60 enrolled

Overview

An experimental mechanistic study. The overall objective is to gain new knowledge about mechanisms involved in adaptation to recurrent hypoglycaemia in diabetes by investigating patients with type 1 diabetes and healthy controls. The knowledge to be obtained may feed into experimental hypoglycaemic clamp studies to further elucidate the effect of the adaptations during acute hypoglycaemia. Ultimately, it may lead to intervention studies aiming at the maintenance of functional capability during hypoglycaemia in patients with type 1 diabetes to reduce their risk of severe hypoglycaemia.

Study rationale The risk of severe hypoglycaemia is a major daily concern for people with diabetes treated with insulin. Severe hypoglycaemia is the main barrier in achieving the recommended glycaemic targets and may indirectly be the main driver for late diabetic complications and related morbidity, mortality and health care costs. In people with diabetes, recurrent exposure to insulin-induced mild hypoglycaemia leads to significant adaptive physiologic responses. While the metabolism of the brain and hormonal responses to hypoglycaemia have been studied extensively, this study will as the first, systematically investigate the chronic adaptation of peripheral metabolism to recurrent hypoglycaemia in diabetes. Knowledge about such responses can lead to interventions that attenuate the devastating effects of acute hypoglycaemia induced by insulin in people with diabetes. Thereby, the risk of developing severe hypoglycaemia can be reduced which ultimately will improve long-term diabetes outcomes and reduce health care costs. Hypothesis Patients with type 1 diabetes that are exposed to high-frequent recurrent hypoglycaemia will adapt their metabolism in a way, which supports the preservation of brain fuelling. Objectives Primary objective The overall objective is to gain new knowledge about mechanisms involved in adaptation to recurrent hypoglycaemia in diabetes by investigating patients with type 1 diabetes and healthy controls. The knowledge to be obtained may feed into experimental hypoglycaemic clamp studies to further elucidate the effect of the adaptations during acute hypoglycaemia. Ultimately, it can lead to intervention studies aiming at the maintenance of functional capability during hypoglycaemia in patients with type 1 diabetes to reduce their risk of severe hypoglycaemia. Secondary objectives * To study the metabolic consequences of recurrent hypoglycaemia in the brain, liver, muscle and adipose tissues * To study the consequences of recurrent hypoglycaemia on resting metabolic rest * To study the consequences of recurrent hypoglycaemia on glucagon and adrenaline sensitivity * To study the consequences of recurrent hypoglycaemia on epigenetic profiles * To study the consequences of recurrent hypoglycaemia on oxidative stress * To study the psychological factors associated with recurrent hypoglycaemia

Conditions

Type1diabetes

Interventions

insulin humanDRUG

Hyperinsulinemic glucose clamp studies require that insulin is administered at a steady continuous rate to achieve stable levels of hyperinsulinemia. To reach this, insulin needs to be infused intravenously using a standard intravenous pump system. The insulin dose will be adjusted according to the body surface area, aiming for insulin levels of \~170 mIU/l, which is within the physiological range. Thus, for a subject with a bodyweight of 70 kg, body length of 180 cm and - consequently - a body surface area of 1.936 m2, the required insulin infusion can be calculated as: 1.936 x 60 x 60 ÷ 1000 = 7.0 units per hour

EpinephrinDRUG

Epinephrine are prepared in 100 ml isotone saline solution according to weight and infused in 3 different infusion rates: 10 ng∙kg-1∙min-1, 25 ng∙kg-1∙min-1 and 50 ng∙kg-1∙min-1, for 20 minutes each. After each adrenaline infusion, substrate response will be measured by blood samples of glucose, lactate, free fatty acids, alanine, β-hydroxybutyrate, glycerol and insulin. Furthermore, cardiovascular measurements such as pulse and blood pressure are monitored as well.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 70 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: 1. Ability to provide written informed consent 2. Male or female aged 18-70 years 3. Must be able to speak and read Danish 4. Type 1 diabetes patients or healthy individuals (control goup) 5. A documented clinically relevant history of type 1 diabetes 6. In insulin treatment regimen 7. The subject must be willing and able to comply with trial protocol Exclusion Criteria: 1. History of severe psychological condition 2. History of severe heart disease 3. History of epilepsy, former apoplexies and dementia 4. History of muscle diseases 5. History of liver disease 6. History of malignancy unless a disease-free period exceeding 5 years 7. Implants not compatible for MRI scans 8. History of alcohol or drug abuse 9. Pregnant or lactating woman

Locations (2)

Steno Diabetes Center Copenhagen

Gentofte Municipality, Denmark

Nordsjaellands Hospital

Hillerød, Denmark

Outcomes

Primary Outcomes

Metabolite- and lipid profiling

Metabolite- and lipid profiling of blood samples using metabolomics profiling platforms during euglycaemia

Time frame: 5 minutes

Brain lactate concentration

Brain lactate concentration using non-invasive magnetic resonance (MR) spectroscopy during euglycaemia

Time frame: 20 minutes

Brain adenosine triphosphate (ATP) concentration

Brain ATP concentration using non-invasive MR spectroscopy during euglycaemia

Time frame: 20 minutes

Glycogen in muscle and adipose tissue

Glycogen in muscle and adipose tissue biopsies during euglycaemia

Time frame: 5 minutes

Non-specific proteins in muscle and adipose tissue

Non-specific proteins in muscle and adipose tissue biopsies during euglycaemia

Time frame: 5 minutes

Glycogen concentration

Glycogen in liver and muscle tissue using non-invasive MR spectroscopy during euglycaemia.

Time frame: 40 minutes

Secondary Outcomes

Estimated glucose production during glucagon stimulation

Area under the curve (AUC) for plasma glucose during glucagon injections. Plasma glucose measurement

Time frame: Every 5 minutes up to 5 hours

Estimated glucose production during epinephrine stimulation

Area under the curve (AUC) for plasma glucose during epinephrine infusion. Plasma glucose measurement

Data from ClinicalTrials.gov

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Study Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

NONE

Enrollment

With the study subject resting in the supine position, the skin is disinfected on the lateral side of the thigh around 15 cm above the knee, with chlorhexidine alcohol. Then 3-4 mL of local anaesthetic (lidocaine 20 mg/mL) is injected into the skin, subcutaneous tissue and in the upper part of the muscle with a very thin needle. When the anaesthetic effect has set in after a couple of minutes an insertion is made in the skin and the subcutaneous tissue through which the biopsy cannula is inserted into the muscle. A small piece (around 150 mg) of the muscle is collected, which may be experienced as somewhat unpleasant, but will last for a very short while ( \~1-2 seconds). The needle is removed, a sterile Band-Aid is applied, and the study subject can leave the site after termination of the trial. The biopsy may cause some muscular tenderness for 2-3 days corresponding to minor muscular trauma.

Adipose tissue biopsyPROCEDURE

With the study subject resting in the supine position, the skin is disinfected on one side of the abdomen around 5-10 cm lateral from the umbilicus to the knee, with chlorhexidine alcohol. Then 3-4 mL of local anaesthetic (lidocaine 20 mg/mL) is injected into the skin, subcutaneous tissue and in the upper part of the adipose tissue with a very thin needle. When the anaesthetic effect has set in after a couple of minutes an insertion is made in the skin and the subcutaneous tissue through which the biopsy cannula is inserted into the adipose tissue. A small piece (around 1 gram) of the adipose tissue is collected, which may be experienced as somewhat unpleasant, but will last for a very short while ( \~1-2 seconds). The needle is removed, a sterile Band-Aid is applied, and the study subject can leave the site after termination of the trial. The biopsy may cause some tenderness for 2-3 days corresponding to minor trauma.

GlucagonDRUG

Glucagon is prepared in doses of 10 µg, 25 µg, and 50 µg and intravenously injected with intervals of 2 hours. After each glucagon injection, blood samples will be drawn to measure plasma glucose, glucagon, lactate, free fatty acids, alanine, amino-acids, β-hydroxybutyrate, glycerol and insulin. Furthermore, cardiovascular measurements such as pulse and blood pressure are monitored as well.

IPRO 2 Medtronic MinimedDEVICE

All potential subjects will receive a blinded continuous glucose sensor at Visit 1. At the following visits, the continuous glucose monitor (CGM) will be reviewed for hypoglycaemia episodes and replaced at the same time. At Visit 2 a final screening of the inclusion criteria will take place, which involves the CGM data of the first week. A blinded CGM will be installed a week before every visit.

7 Tesla (7T) Magnetic Resonance ImagingPROCEDURE

Subjects will undergo a hyperinsulinemic euglycaemic glucose clamp, as mentioned above, in the MRI scanning room. After 30 minutes of stable normoglycaemia, subjects are taken into the MRI scanner (Philips Achieva 7.0 T) where brain, liver, thigh and calf muscle are scanned. After every anatomically different area, the subjects must be taken out of the scanner, while scanning coils are replaced. All subjects are advised to lie still and press the alarm button if necessary.

Indirect Calorimetry using Jaeger Oxycon ChampionPROCEDURE

Resting metabolic rate will be estimated, after reaching stable plasma glucose level, via a hyperinsulinemic euglycaemic clamp, as mentioned above. This will be done by indirect calorimetry, using a ventilated hood system (Jaeger Oxycon Champion, software version 4.3, Jaeger, Mijnhardt). Subjects are instructed to lie down and rest for a period of 30 minutes. Subjects are also instructed not to move, talk or sleep unless necessary during the period of measurement. The recorded measurement after 5 minutes to 30 minutes will be used for analysis.

Core temperature and thermography using Thermovision SC645PROCEDURE

Thermography (Thermovision SC645, FLIR Systems, Wilsonville, OR, USA) is used to determine cutaneous vascular perfusion. Data is analogue-digital converted and sampled at 100 Hz (Powerlab, ADInstruments, Colorado Springs, CO, USA).

Freestyle Libre 2DEVICE

All potential subjects will receive a continuous glucose sensor at Visit 1. At the following visits, the CGM will be reviewed for hypoglycaemia episodes and replaced at the same time. At Visit 2 a final screening of the inclusion criteria will take place, which involves the CGM data of the first week. A CGM will be installed a week before every visit.

Time frame: Every 5 minutes up to 90 minutes

Indirect calorimetry

Estimating resting metabolic rate, before and during hyperinsulinemic-hypoglycemic clamp

Time frame: 60 minutes

Thermography

Estimating skin temperature, before and during hyperinsulinemic-hypoglycemic clamp

Time frame: 5 minutes

Plasma lactate during glucagon injections.

Time frame: Every 40 minutes up to 5 hours

Plasma free fatty acids during glucagon injections.

Time frame: Every 40 minutes up to 5 hours

Plasma glycerol during glucagon injections.

Time frame: Every 40 minutes up to 5 hours

Plasma alanine during glucagon injections.

Time frame: Every 40 minutes up to 5 hours

Plasma β-hydroxybutyrate during glucagon injections.

Time frame: Every 40 minutes up to 5 hours

Plasma insulin during glucagon injections.

Time frame: Every 40 minutes up to 5 hours

Plasma glucagon during glucagon injections.

Time frame: Every 40 minutes up to 5 hours

Plasma metabolomics during glucagon injections.

Time frame: Every 40 minutes up to 5 hours

Plasma lactate during epinephrine infusion