title: Mood and cognitive functions during acute euglycaemia and mild hyperglycaemia in type 2 diabetic patients.
abstract: BACKGROUND
  Hyperglycaemia at levels above 15 mmol/l has been shown to impair cognitive functions in type 2 diabetic patients, while effects of mild hyperglycaemia and acute euglycaemia on mood and cognition have rarely been compared. We examined mood and cognitive functions in patients with T2DM during acute euglycaemia in comparison with moderate hyperglycaemia.
  
  
  METHODS
  One euglycaemic (5 mmol/l) and one hyperglycaemic clamp (10.5 mmol/l) of 90 min each were performed in 15 T2DM patients in a balanced, single-blind, within-subject comparison. Mood, cognitive functions (assessed via short-term memory and attention tests) and symptoms related to glycaemic changes were assessed during a baseline period and during both glycaemic plateaus. In addition, patients estimated their blood glucose level and counterregulatory hormones were measured.
  
  
  RESULTS
  None of the assessed aspects of cognitive functions differed between conditions (all p > or = 0.2). Patients rated higher on the well-being scale (p=0.04) and tended to feel less anger (p=0.08) during hyperglycaemia. Self-estimated blood glucose levels were higher during the hyper- than euglycaemic condition (8.6 +/- 2.5 vs 7.2 +/- 1.2 mmol/l; p<0.05) although most individual estimations did not match the actual glucose levels. Counterregulatory hormone levels did not differ (all p>0.25).
  
  
  CONCLUSIONS
  Data indicate that T2DM patients are not cognitively impaired by moderate hyperglycaemia (10.5 mmol/l), pointing to the possibility of a glycaemic threshold for cognitive impairments at higher glycaemic levels.
authors.affiliation: Department of Internal Medicine I, University of Lübeck, Lübeck, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Pais
authors.forename: M
authors.initials: M
authors.lastname: Hallschmid
authors.forename: K
authors.initials: K
authors.lastname: Jauch-Chara
authors.forename: S M
authors.initials: SM
authors.lastname: Schmid
authors.forename: K M
authors.initials: KM
authors.lastname: Oltmanns
authors.forename: A
authors.initials: A
authors.lastname: Peters
authors.forename: J
authors.initials: J
authors.lastname: Born
authors.forename: B
authors.initials: B
authors.lastname: Schultes
mesh_terms: D000328:Adult; D000339:Affect; D000368:Aged; D003071:Cognition; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology* / Q000523:psychology; D005260:Female; D015309:Glucose Clamp Technique; D006801:Humans; D006943:Hyperglycemia / Q000097:blood / Q000503:physiopathology* / Q000523:psychology; D008297:Male; D008875:Middle Aged; D016037:Single-Blind Method