Skip to content

Effects of Mild Hypoglycaemia on Cognitive Function in Type 2 Diabetes

Effects of Mild Hypoglycaemia on Cognitive Function in Type 2 Diabetes

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03014011
Enrollment
28
Registered
2017-01-09
Start date
2017-06-13
Completion date
2018-07-24
Last updated
2020-01-28

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Cognitive Change, Diabetes Mellitus, Type II, Hypoglycemia

Brief summary

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.

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.

Interventions

OTHERHypoglycaemic clamp

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.

Sponsors

University Hospital, Gentofte, Copenhagen
CollaboratorOTHER
Psychiatric Centre Rigshospitalet
CollaboratorOTHER
Bispebjerg Hospital
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
35 Years to 70 Years
Healthy volunteers
No

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.

Design outcomes

Primary

MeasureTime frameDescription
Psychomotor SpeedAll 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.

Countries

Denmark

Participant flow

Recruitment details

37 participants were screened between May 2017 and July 2018 at the Department of Endocrinology, Bispebjerg University Hospital, Denmark.

Pre-assignment details

Of the 37 screened participants, 28 met inclusion criteria and were randomised. 25 completed both intervention visits. Three participants (one man, two women) withdrew from the study after randomisation for reasons not related to the intervention. Baseline characteristics are based on the 25 participants that completed the study.

Participants by arm

ArmCount
All Participants
Randomised, double-blinded, crossover study design
25
Total25

Withdrawals & dropouts

PeriodReasonFG000FG001
First InterventionWithdrawal by Subject10
WashoutWithdrawal by Subject10

Baseline characteristics

CharacteristicAll Participants
Age, Continuous60.2 years
STANDARD_DEVIATION 7.3
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants
Race (NIH/OMB)
Asian
0 Participants
Race (NIH/OMB)
Black or African American
0 Participants
Race (NIH/OMB)
More than one race
0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants
Race (NIH/OMB)
White
25 Participants
Region of Enrollment
Denmark
25 Participants
Sex: Female, Male
Female
10 Participants
Sex: Female, Male
Male
15 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
0 / 250 / 25
other
Total, other adverse events
0 / 250 / 25
serious
Total, serious adverse events
0 / 250 / 25

Outcome results

Primary

Psychomotor Speed

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.

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.

Population: The two interventions were hypoglycaemia (aiming for a plasma glucose target of 3.0 ± 0.2 mmol/l) and euglycaemia (plasma glucose clamp target 6.0 ± 0.2 mmol/l).

ArmMeasureValue (MEAN)Dispersion
HypoglycaemiaPsychomotor Speed48.7 score on a scaleStandard Deviation 9.8
EuglycaemiaPsychomotor Speed56.6 score on a scaleStandard Deviation 12

Source: ClinicalTrials.gov · Data processed: Mar 2, 2026