Effects of acute insulin-induced hypoglycaemia on psychomotor function: people with type 1 diabetes are less affected than non-diabetic adults

Diabetologia. 2008 Oct;51(10):1814-21. doi: 10.1007/s00125-008-1112-y. Epub 2008 Aug 16.


Aims/hypothesis: We examined the effects of acute insulin-induced hypoglycaemia on psychomotor function in non-diabetic volunteers and in adults with type 1 diabetes.

Methods: Non-diabetic adults (n = 20) and adults with type 1 diabetes mellitus (n = 16) each underwent a euglycaemic-hyperinsulinaemic glucose clamp on two separate occasions. Arterialised blood glucose was maintained for 1 h at either 4.5 mmol/l (euglycaemia) or 2.5 mmol/l (hypoglycaemia). During this time participants underwent neuropsychological tests to assess psychomotor function.

Results: During hypoglycaemia the non-diabetic participants showed a significant deterioration in the following: (1) four-choice reaction time (p = 0.008); (2) grooved pegboard (a test of manual dexterity; p = 0.004); (3) hand steadiness (p = 0.003); (4) pursuit rotor (a test of fine motor function, attention and coordination; p = 0.018); and (5) test of total body coordination (p = 0.004). No significant differences were observed between euglycaemia and hypoglycaemia in hand-grip (p = 0.897) and line tracing time (p = 0.480) tests. In type 1 diabetes mellitus patients, only four-choice reaction time (p = 0.023) and pursuit rotor (p = 0.045) were impaired significantly during hypoglycaemia.

Conclusions/interpretation: Although acute hypoglycaemia caused significant impairment of several psychomotor functions in non-diabetic adults, a lower magnitude of impairment was observed in those with type 1 diabetes. The mechanism underlying this discrepant effect of hypoglycaemia on psychomotor function remains unknown, but may be related to the difference in sympathoadrenal activation observed between the groups. People with type 1 diabetes may also have had a behavioural advantage of over non-diabetic participants derived from their previous exposure to hypoglycaemia or potentially the disparate results arose from hypoglycaemia-induced cerebral adaptation.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Blood Glucose / analysis
  • Diabetes Mellitus, Type 1 / blood
  • Diabetes Mellitus, Type 1 / physiopathology*
  • Epinephrine / blood
  • Female
  • Humans
  • Hypoglycemia / blood
  • Hypoglycemia / physiopathology*
  • Insulin / administration & dosage*
  • Insulin / blood
  • Male
  • Norepinephrine / blood
  • Psychomotor Performance / drug effects*
  • Psychomotor Performance / physiology


  • Blood Glucose
  • Insulin
  • Norepinephrine
  • Epinephrine