title: Cognitive deficits associated with impaired awareness of hypoglycaemia in type 1 diabetes.
abstract: The aim of this study was to compare cognitive function in adults with type 1 diabetes who have impaired awareness of hypoglycaemia with those who have normal awareness of hypoglycaemia. A putative association was sought between cognitive test scores and a history of severe hypoglycaemia.
  
  
  
  A total of 68 adults with type 1 diabetes were included: 33 had impaired and 35 had normal awareness of hypoglycaemia, as confirmed by formal testing. The groups were matched for age, sex and diabetes duration. Cognitive tests of verbal memory, object-location memory, pattern separation, executive function, working memory and processing speed were administered.
  
  
  
  Participants with impaired awareness of hypoglycaemia scored significantly lower on the verbal and object-location memory tests and on the pattern separation test (Cohen's d -0.86 to -0.55 [95% CI -1.39, -0.05]). Participants with impaired awareness of hypoglycaemia had reduced planning ability task scores, although the difference was not statistically significant (Cohen's d 0.57 [95% CI 0, 1.14]). Frequency of exposure to severe hypoglycaemia correlated with the number of cognitive tests that had not been performed according to instructions.
  
  
  
  Impaired awareness of hypoglycaemia was associated with diminished learning, memory and pattern separation. These cognitive tasks all depend on the hippocampus, which is vulnerable to neuroglycopenia. The findings suggest that hypoglycaemia contributes to the observed correlation between impaired awareness of hypoglycaemia and impaired cognition.
authors.affiliation: Department of Neuromedicine and Movement Science, Faculty of Medicine and Health Sciences, NTNU - Norwegian University of Science and Technology, Trondheim, Norway.|Department of Radiology, St Olavs Hospital, Trondheim University Hospital, Trondheim, Norway.
authors.forename: Tor I
authors.initials: TI
authors.lastname: Hansen
authors.affiliation: Department of Cancer Research and Molecular Medicine, Faculty of Medicine and Health Sciences, NTNU - Norwegian University of Science and Technology, PO Box 8905, N-7491, Trondheim, Norway.
authors.forename: Sandra E
authors.initials: SE
authors.lastname: Olsen
authors.affiliation: Department of Radiology, St Olavs Hospital, Trondheim University Hospital, Trondheim, Norway.
authors.forename: Elise C D
authors.initials: ECD
authors.lastname: Haferstrom
authors.affiliation: Department of Neuromedicine and Movement Science, Faculty of Medicine and Health Sciences, NTNU - Norwegian University of Science and Technology, Trondheim, Norway.|Department of Neurology and Clinical Neurophysiology, St Olavs Hospital, Trondheim University Hospital Trondheim, Trondheim, Norway.
authors.forename: Trond
authors.initials: T
authors.lastname: Sand
authors.affiliation: British Heart Foundation Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK.
authors.forename: Brian M
authors.initials: BM
authors.lastname: Frier
authors.affiliation: Department of Neuromedicine and Movement Science, Faculty of Medicine and Health Sciences, NTNU - Norwegian University of Science and Technology, Trondheim, Norway.|Department of Radiology, St Olavs Hospital, Trondheim University Hospital, Trondheim, Norway.
authors.forename: Asta K
authors.initials: AK
authors.lastname: Håberg
authors.affiliation: Department of Cancer Research and Molecular Medicine, Faculty of Medicine and Health Sciences, NTNU - Norwegian University of Science and Technology, PO Box 8905, N-7491, Trondheim, Norway. marit.bjorgaas@ntnu.no.|Department of Endocrinology, St Olavs Hospital, Trondheim University Hospital, Trondheim, Norway. marit.bjorgaas@ntnu.no.
authors.forename: Marit R
authors.initials: MR
authors.lastname: Bjørgaas
mesh_terms: D000328:Adult; D003071:Cognition / Q000502:physiology; D003072:Cognition Disorders / Q000097:blood / Q000188:drug therapy / Q000378:metabolism / Q000503:physiopathology; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000188:drug therapy / Q000378:metabolism / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007003:Hypoglycemia / Q000097:blood* / Q000188:drug therapy / Q000378:metabolism / Q000503:physiopathology*; D007328:Insulin / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011795:Surveys and Questionnaires
chemical_list: D007328:Insulin
keywords: Cognitive function; Hypoglycaemia; Impaired awareness of hypoglycaemia; Memory; Pattern separation; Type 1 diabetes