Effects of Mild Hypoglycaemia on Cognitive Function in Type 2 Diabetes

January 14, 2020 updated by: Malin Nilsson, Bispebjerg Hospital

Hypoglycaemia in subjects suffering from type 2 diabetes may have substantial consequences including a significant negative impact on quality of life. Further, repeated minor hypoglycaemias may result in significant productivity losses.

Here, the investigators propose to provide quantitative results on cognition during an acute mild hypoglycaemic episode (target plasma glucose 3 mmol/L) in 28 subjects with type 2 diabetes. Data will be provided on executive function, attention and memory.

Study Overview

Detailed Description

Hypoglycaemia in subjects suffering from type 2 diabetes may have substantial consequences including a significant negative impact on quality of life. Further, repeated minor hypoglycaemias may result in significant productivity losses. In healthy subjects a number of studies show that during a hypoglycaemic episode with plasma levels of 2.2 - 2.5 mmol/L (40-45 mg/dl) brain areas responsible for cognition have an altered neuronal function when measuring cerebral blood flow. This is accompanied by severely impaired cognitive function with a reduced ability to solve simple cognitive tasks. At higher levels of glucose (above 3 mmol/L (54 mg/dl)), it remains to be settled whether cognitive functions are also affected negatively and whether this may be accompanied by changes in brain metabolism. Apart from raising the blood glucose directly or indirectly via glucagon, no treatment for hypoglycaemia exists, but since Glucagon-like peptide-1 (GLP-1) based therapies used in type 2 diabetes may affect brain glucose consumption, therapeutic interventions to prevent negative results of hypoglycaemia may eventually become clinically possible.

Here, the investigators propose to provide quantitative results on cognition during an acute mild hypoglycaemic episode (target plasma glucose 3 mmol/L). Data will be provided on executive function, attention and memory.

Study Type

Interventional

Enrollment (Actual)

28

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

      • Copenhagen, Denmark
        • Department of Research in Endocrinology, Bispebjerg University Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

35 years to 70 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Informed and written consent
  • Clinically diagnosed type 2 diabetes mellitus for at least 3 months (diagnosed according to the criteria of the World Health Organization (WHO)).
  • Normal haemoglobin ≥ 8.0 mmol/L (male) or ≥ 6.4 mmol/L (female)
  • Male or female participants aged 35-70 years, both inclusive.
  • Treated with diet or any antidiabetic medication except sulfonylureas, meglitinides or insulin.
  • HbA1c ≤ 9.0 % by local laboratory analysis.
  • BMI >23 kg/m2 and <35 kg/m2

Exclusion Criteria:

  • Receipt of any investigational medicinal product within 3 months before screening in this trial.
  • Liver disease (alanine aminotransferase (ALAT) and/or serum aspartate aminotransferase (ASAT) >2 times normal values) or history of hepatobiliary disorder.
  • Nephropathy (serum creatinine levels ≥ 126 μmol/L (male) or ≥ 111 μmol/L (female)).
  • Cardiac problems defined as decompensated heart failure (New York Heart Association (NYHA) class III and IV) at any time and/or angina pectoris within the last 12 months and/or acute myocardial infarction at any time.
  • Active or recent malignant disease.
  • Treatment with drugs that cannot be paused for 12 hours.
  • Repeated resting blood pressure at screening outside the range 90-140 mmHg for systolic or 50-90 mmHg for diastolic. This exclusion criterion also pertains to subjects taking antihypertensives.
  • Visual impairment or auditory impairment.
  • Known abnormalities of the central nervous system or any endocrinological (with the exception of diabetes mellitus and euthyroid goiter), haematological, neurological, psychiatric diseases or other major disorders that in the opinion of the investigator precludes compliance with the protocol, evaluation of the results or represent an unacceptable risk for the participant's safety.
  • Proliferative retinopathy (funduscopy performed within 3 months before the screening is acceptable) and/or severe neuropathy.
  • Current treatment with systemic drugs, which may interfere with glucose metabolism.
  • Significant history of alcoholism or drug/chemical abuse as per investigator's judgement.
  • Current tobacco user (smoking or nicotinic product use 3 months prior to screening).
  • Severe hypoglycaemic event during the past 6 months.
  • Known hypoglycaemia unawareness.
  • Participants with mental incapacity or language barriers precluding adequate understanding or co-operation or who, in the opinion of the investigator or their general practitioner, should not participate in the trial.
  • For females only: Pregnancy, breast-feeding status or intention of becoming pregnant during the trial.
  • Any chronic disorder or severe disease that in the opinion of the investigator might endanger participant's safety or compliance with the protocol.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: Hypoglycaemic clamp first, then euglyceamic clamp
First intervention with a hypoglycaemic clamp (one examination day of approximately 5 hours), there after a wash out period of 21-42 days, then second and final intervention day with an euglycaemic clamp (approximately 5 hours).
The clamp is performed by insulin and adjustable 20% glucose infusions, with the aim to lower and keep plasma blood glucose levels at 3 mmol/L for outcome measurements.
The clamp is performed by insulin and adjustable 20% glucose infusions, with the aim to keep plasma blood glucose levels at 6 mmol/L for outcome measurements.
Other: Euglycaemic clamp first, then hypoglycaemic clamp
First intervention with an euglycaemic clamp (one examination day of approximately 5 hours), there after a wash out period of 21-42 days, then second and final intervention day with a hypoglycaemic clamp (approximately 5 hours).
The clamp is performed by insulin and adjustable 20% glucose infusions, with the aim to lower and keep plasma blood glucose levels at 3 mmol/L for outcome measurements.
The clamp is performed by insulin and adjustable 20% glucose infusions, with the aim to keep plasma blood glucose levels at 6 mmol/L for outcome measurements.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Psychomotor Speed
Time Frame: All neurocognitive testing was assessed at each intervention when glucose levels had been stabile for 40 minutes, an average of 2 hours after clamp procedure start. The duration of neurocognitive testing was approximately 40 min.

Symbol Digit Modalities Test was used as a measurement of psychomotor speed.

For the Symbol Digit Modalities Test, participants were required to use a coded key to match nine abstract symbols paired with numerical digits. The final score is the correct number of substitutions in 120 s, and scores range between 0 and 110. Higher values represent a better outcome.

All neurocognitive testing was assessed at each intervention when glucose levels had been stabile for 40 minutes, an average of 2 hours after clamp procedure start. The duration of neurocognitive testing was approximately 40 min.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Jørgen Rungby, Professor, Department of Endocrinology, Bispebjerg University Hospital, Denmark

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 13, 2017

Primary Completion (Actual)

July 23, 2018

Study Completion (Actual)

July 24, 2018

Study Registration Dates

First Submitted

December 21, 2016

First Submitted That Met QC Criteria

January 5, 2017

First Posted (Estimate)

January 9, 2017

Study Record Updates

Last Update Posted (Actual)

January 28, 2020

Last Update Submitted That Met QC Criteria

January 14, 2020

Last Verified

December 1, 2019

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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