title: Effects of acute hypoglycemia on working memory and language processing in adults with and without type 1 diabetes.
abstract: OBJECTIVE
  To examine the effects of hypoglycemia on language processing in adults with and without type 1 diabetes.
  
  
  METHODS
  Forty adults were studied (20 with type 1 diabetes and 20 healthy volunteers) using a hyperinsulinemic glucose clamp to lower blood glucose to 2.5 mmol/L (45 mg/dL) (hypoglycemia) for 60 min, or to maintain blood glucose at 4.5 mmol/L (81 mg/dL) (euglycemia), on separate occasions. Language tests were applied to assess the effects of hypoglycemia on the relationship between working memory and language (reading span), grammatical decoding (self-paced reading), and grammatical encoding (subject-verb agreement).
  
  
  RESULTS
  Hypoglycemia caused a significant deterioration in reading span (P < 0.001; η(2) = 0.37; Cohen d = 0.65) and a fall in correct responses (P = 0.005; η(2) = 0.19; Cohen d = 0.41). On the self-paced reading test, the reading time for the first sentence fragment increased during hypoglycemia (P = 0.039; η(2) = 0.11; Cohen d = 0.25). For the reading of the next fragment, hypoglycemia affected the healthy volunteer group more than the adults with type 1 diabetes (P = 0.03; η(2) = 0.12; Cohen d = 0.25). However, hypoglycemia did not significantly affect the number of errors in sentence comprehension or the time taken to answer questions. Hypoglycemia caused a deterioration of subject-verb agreement (correct responses: P = 0.011; η(2) = 0.159; Cohen d = 0.31).
  
  
  CONCLUSIONS
  Hypoglycemia caused a significant deterioration in reading span and in the accuracy of subject-verb agreement, both of which are practical aspects of language involved in its everyday use. Language processing is therefore impaired during moderate hypoglycemia.
authors.affiliation: Department of Diabetes, Royal Infirmary of Edinburgh, Edinburgh, Scotland, U.K.
authors.forename: Kate V
authors.initials: KV
authors.lastname: Allen
authors.affiliation: Department of Psychology, University of Edinburgh, Edinburgh, Scotland, U.K.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Pickering
authors.affiliation: Department of Diabetes, Royal Infirmary of Edinburgh, Edinburgh, Scotland, U.K.
authors.forename: Nicola N
authors.initials: NN
authors.lastname: Zammitt
authors.affiliation: Department of Psychology, University of Edinburgh, Edinburgh, Scotland, U.K. Department of Experimental Psychology, Ghent University, Ghent, Belgium.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Hartsuiker
authors.affiliation: Department of Psychology, University of California, Davis, Davis, CA.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Traxler
authors.affiliation: Department of Diabetes, Royal Infirmary of Edinburgh, Edinburgh, Scotland, U.K. Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, Scotland, U.K.
authors.forename: Brian M
authors.initials: BM
authors.lastname: Frier
authors.affiliation: Department of Psychology, University of Edinburgh, Edinburgh, Scotland, U.K. Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, Scotland, U.K. ian.deary@staffmail.ed.ac.uk.
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Deary
mesh_terms: D000208:Acute Disease; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D016022:Case-Control Studies; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000523:psychology*; D005260:Female; D006801:Humans; D007003:Hypoglycemia / Q000097:blood / Q000523:psychology*; D007806:Language Disorders / Q000209:etiology*; D008297:Male; D008569:Memory Disorders / Q000209:etiology*; D008570:Memory, Short-Term / Q000502:physiology*; D011581:Psychological Tests; D055815:Young Adult
chemical_list: D001786:Blood Glucose