Mood and Cognitive Functions During Acute Euglycaemia and Mild Hyperglycaemia in Type 2 Diabetic Patients

Abstract

Introduction: 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≥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.

Key words

type 2 diabetes mellitus - hyperglycaemia - mood - cognitive functions

References

• 1 Benedict C, Hallschmid M, Hatke A, Schultes B, Fehm HL, Born J, Kern W. Intranasal insulin improves memory in humans.  Psychoneuroendocrinology. 2004;  29 1326-1334
• 2 Cox DJ, Kovatchev BP, Gonder-Frederick LA, Summers KH, McCall A, Grimm KJ, Clarke WL. Relationships between hyperglycemia and cognitive performance among adults with type 1 and type 2 diabetes.  Diabetes Care. 2005;  28 71-77
• 3 Brody S, Keller U, Degen L, Cox DJ, Schachinger H. Selective processing of food words during insulin-induced hypoglycemia in healthy humans.  Psychopharmacology (Berl). 2004;  173 217-220
• 4 Davis EA, Soong SA, Byrne GC, Jones TW. Acute hyperglycaemia impairs cognitive function in children with IDDM.  J Pediatr Endocrinol Metab. 1996;  9 455-461
• 5 Draelos MT, Jacobson AM, Weinger K, Widom B, Ryan CM, Finkelstein DM, Simonson DC. Cognitive function in patients with insulin-dependent diabetes mellitus during hyperglycemia and hypoglycemia.  Am J Med. 1995;  98 135-144
• 6 Elias PK, Elias MF, D'Agostino RB, Cupples LA, Wilson PW, Silbershatz H, Wolf PA. NIDDM and blood pressure as risk factors for poor cognitive performance. The Framingham Study.  Diabetes Care. 1997;  20 1388-1395
• 7 Expert Committee on the Diagnosis and Classification of Diabetes Mellitus: . Report of the expert committee on the diagnosis and classification of diabetes mellitus.  Diabetes Care. 2003;  26 S5-20
• 8 Fontbonne A, Berr C, Ducimetiere P, Alperovitch A. Changes in cognitive abilities over a 4-year period are unfavorably affected in elderly diabetic subjects: results of the Epidemiology of Vascular Aging Study.  Diabetes Care. 2001;  24 366-370
• 9 Fruehwald-Schultes B, Born J, Kern W, Peters A, Fehm HL. Adaptation of cognitive function to hypoglycemia in healthy men.  Diabetes Care. 2000;  23 1059-1066
• 10 Hewer W, Mussell M, Rist F, Kulzer B, Bergis K. Short-term effects of improved glycemic control on cognitive function in patients with type 2 diabetes.  Gerontology. 2003;  49 86-92
• 11 Hoffman RG, Speelman DJ, Hinnen DA, Conley KL, Guthrie RA, Knapp RK. Changes in cortical functioning with acute hypoglycemia and hyperglycemia in type I diabetes.  Diabetes Care. 1989;  12 193-197
• 12 Holmes CS, Hayford JT, Gonzalez JL, Weydert JA. A survey of cognitive functioning at difference glucose levels in diabetic persons.  Diabetes Care. 1983;  6 180-185
• 13 Janke W, Debus G. Die Eigenschaftswörterliste (EWL). Hogrefe: Göttingen 1978
• 14 Lindeman RD, Romero LJ, LaRue A, Yau CL, Schade DS, Koehler KM, Baumgartner RN, Garry PJ. A biethnic community survey of cognition in participants with type 2 diabetes, impaired glucose tolerance, and normal glucose tolerance: the New Mexico Elder Health Survey.  Diabetes Care. 2001;  24 1567-1572
• 15 Mussell M, Hewer W, Kulzer B, Bergis K, Rist F. Effects of improved glycaemic control maintained for 3 months on cognitive function in patients with Type 2 diabetes.  Diabet Med. 2004;  21 1253-1256
• 16 Ott A, Stolk RP, Hofman A, van Harskamp F, Grobbee DE, Breteler MM. Association of diabetes mellitus and dementia: the Rotterdam Study.  Diabetologia. 1996;  39 1392-1397
• 17 Perras B, Smolnik R, Fehm HL, Born J. Signs of sexual behaviour are not increased after subchronic treatment with LHRH in young men.  Psychoneuroendocrinology. 2001;  26 1-15
• 18 Peters A, Rohloff F, Kerner W. Preserved counterregulatory hormone release and symptoms after short term hypoglycemic episodes in normal men.  J Clin Endocrinol Metab. 1995;  80 2894-2898
• 19 Ryan CM, Geckle M. Why is learning and memory dysfunction in Type 2 diabetes limited to older adults?.  Diabetes Metab Res Rev. 2000;  16 308-315
• 20 Schultes B, Peters A, Kern W, Gais S, Oltmanns KM, Fehm HL, Born J. Processing of food stimuli is selectively enhanced during insulin-induced hypoglycemia in healthy men.  Psychoneuroendocrinology. 2005;  30 496-504
• 21 Sommerfield AJ, Deary IJ, Frier BM. Acute hyperglycemia alters mood state and impairs cognitive performance in people with type 2 diabetes.  Diabetes Care. 2004;  27 2335-2340
• 22 Spyer G, Hattersley AT, MacDonald IA, Amiel S, MacLeod KM. Hypoglycaemic counter-regulation at normal blood glucose concentrations in patients with well controlled type-2 diabetes.  Lancet. 2000;  356 1970-1974
• 23 Stewart R, Liolitsa D. Type 2 diabetes mellitus, cognitive impairment and dementia.  Diabet Med. 1999;  16 93-112
• 24 Strachan MW, Deary IJ, Ewing FM, Frier BM. Is type II diabetes associated with an increased risk of cognitive dysfunction? A critical review of published studies.  Diabetes Care. 1997a;  20 438-445
• 25 Strachan MW, Frier BM, Deary IJ. Cognitive assessment in diabetes: the need for consensus.  Diabet Med. 1997b;  14 421-422
• 26 Strachan MW, Frier BM, Deary IJ. Type 2 diabetes and cognitive impairment.  Diabet Med. 2003;  20 1-2
• 27 Veneman T, Mitrakou A, Mokan M, Cryer P, Gerich J. Induction of hypoglycemia unawareness by asymptomatic nocturnal hypoglycemia.  Diabetes. 1993;  42 1233-1237

Correspondence