Malin Nilsson1, Nicole Jensen2, Michael Gejl3, Marianne L Bergmann4, Heidi Storgaard5, Mette Zander2, Kamilla Miskowiak6,7, Jørgen Rungby2,3,8. 1. Department of Endocrinology, Bispebjerg University Hospital, Bispebjerg Bakke 23, 2400, Copenhagen, NV, Denmark. malin.sofia.desiree.nilsson@regionh.dk. 2. Department of Endocrinology, Bispebjerg University Hospital, Bispebjerg Bakke 23, 2400, Copenhagen, NV, Denmark. 3. Department of Endocrinology, Aarhus University Hospital, Aarhus, Denmark. 4. Department of Biochemistry and Immunology, University Hospital of Southern Denmark, Vejle, Denmark. 5. Clinical Metabolic Physiology, Steno Diabetes Center Copenhagen, Gentofte Hospital, Hellerup, Denmark. 6. Department of Psychology and Mental Health Services, University of Copenhagen, Copenhagen, Denmark. 7. Psychiatric Centre Copenhagen, Rigshospitalet, Denmark. 8. Copenhagen Center for Translational Research, Bispebjerg University Hospital, Copenhagen, Denmark.
Abstract
AIMS/HYPOTHESIS: Previous studies have demonstrated a relationship between cognitive impairment and hypoglycaemia (<3 mmol/l). This study hypothesised that non-severe insulin-induced hypoglycaemia reduces cognitive function in individuals with type 2 diabetes. METHODS: In this randomised crossover study, 25 participants with type 2 diabetes attended two experimental visits with hyperinsulinaemic glucose clamping: one hypoglycaemic clamp (plasma glucose 3.0 ± 0.2 mmol/l) and one euglycaemic clamp (plasma glucose 6.0 ± 0.2 mmol/l). Participants were eligible if their diabetes was treated withdiet or glucose-lowering medications (except sulfonylureas or insulin), age was 35-70 years, BMI was 23-35 kg/m2 and HbA1c was below 75 mmol/mol (9%). Cognitive function was assessed with a neurocognitive test battery measuring verbal memory, executive function, sustained attention and psychomotor speed. From the examined cognitive domains, a global cognition score was constructed estimating global cognition. A measurement for psychomotor speed was selected as the primary outcome. Participants and people assessing the outcomes were blinded to group assignment. RESULTS:Cognitive performance was impaired during hypoglycaemia with a mean score in the primary outcome test, Symbol Digit Modalities Test measuring psychomotor speed, of 48.7 ± 9.8 (hypoglycaemia) vs 56.6 ± 12.0 (euglycaemia); i.e. a change of -7.9 points (95% CI -10.9, -4.9; p < 0.0001). In addition, hypoglycaemia reduced global cognitive score by -0.7 (95% CI -0.9, -0.6; p < 0.0001). A stable glucose plateau was achieved during both experimental visits. For the hypoglycaemic clamp, mean plasma glucose concentration (± SD) during neurocognitive testing was 3.1 (± 0.3) mmol/l. Age, sex, fasting C-peptide, counter-regulatory hormones and the severity of hypoglycaemic symptoms did not influence cognitive function. CONCLUSIONS/ INTERPRETATION: Acute non-severe hypoglycaemia (mean plasma glucose 3.1 mmol/l) has a substantial negative impact on cognitive function in individuals with type 2 diabetes. TRIAL REGISTRATION: ClinicalTrials.gov NCT03014011. FUNDING: The study was supported in part by a research grant from the Investigator Initiated Studies Program of Merck Sharp & Dohme Corp (MSD-MA-NORD-007-01). The opinions expressed in this paper are those of the authors and do not necessarily represent those of Merck Sharp & Dohme Corp. Funding was also received from Skibsreder Per Henriksen, R. og hustrus Foundation, The Danish Alzheimer Foundation and Savværksejer Jeppe Juhl og hustrus Foundation.
RCT Entities:
AIMS/HYPOTHESIS: Previous studies have demonstrated a relationship between cognitive impairment and hypoglycaemia (<3 mmol/l). This study hypothesised that non-severe insulin-induced hypoglycaemia reduces cognitive function in individuals with type 2 diabetes. METHODS: In this randomised crossover study, 25 participants with type 2 diabetes attended two experimental visits with hyperinsulinaemic glucose clamping: one hypoglycaemic clamp (plasma glucose 3.0 ± 0.2 mmol/l) and one euglycaemic clamp (plasma glucose 6.0 ± 0.2 mmol/l). Participants were eligible if their diabetes was treated with diet or glucose-lowering medications (except sulfonylureas or insulin), age was 35-70 years, BMI was 23-35 kg/m2 and HbA1c was below 75 mmol/mol (9%). Cognitive function was assessed with a neurocognitive test battery measuring verbal memory, executive function, sustained attention and psychomotor speed. From the examined cognitive domains, a global cognition score was constructed estimating global cognition. A measurement for psychomotor speed was selected as the primary outcome. Participants and people assessing the outcomes were blinded to group assignment. RESULTS: Cognitive performance was impaired during hypoglycaemia with a mean score in the primary outcome test, Symbol Digit Modalities Test measuring psychomotor speed, of 48.7 ± 9.8 (hypoglycaemia) vs 56.6 ± 12.0 (euglycaemia); i.e. a change of -7.9 points (95% CI -10.9, -4.9; p < 0.0001). In addition, hypoglycaemia reduced global cognitive score by -0.7 (95% CI -0.9, -0.6; p < 0.0001). A stable glucose plateau was achieved during both experimental visits. For the hypoglycaemic clamp, mean plasma glucose concentration (± SD) during neurocognitive testing was 3.1 (± 0.3) mmol/l. Age, sex, fasting C-peptide, counter-regulatory hormones and the severity of hypoglycaemic symptoms did not influence cognitive function. CONCLUSIONS/ INTERPRETATION: Acute non-severe hypoglycaemia (mean plasma glucose 3.1 mmol/l) has a substantial negative impact on cognitive function in individuals with type 2 diabetes. TRIAL REGISTRATION: ClinicalTrials.gov NCT03014011. FUNDING: The study was supported in part by a research grant from the Investigator Initiated Studies Program of Merck Sharp & Dohme Corp (MSD-MA-NORD-007-01). The opinions expressed in this paper are those of the authors and do not necessarily represent those of Merck Sharp & Dohme Corp. Funding was also received from Skibsreder Per Henriksen, R. og hustrus Foundation, The Danish Alzheimer Foundation and Savværksejer Jeppe Juhl og hustrus Foundation.
Entities:
Keywords:
Cognitive function; Hypoglycaemia; Type 2 diabetes