Attentional functioning is impaired during acute hypoglycaemia in people with Type 1 diabetes.
OBJECTIVE
To examine the effects of acute insulin-induced hypoglycaemia on different aspects of attention and on general non-verbal reasoning in people with Type 1 diabetes.


METHODS
A hyperinsulinaemic glucose clamp was used to maintain euglycaemia (4.5 mmol/l) or induce hypoglycaemia (2.6 mmol/l) on separate occasions in 16 adults with Type 1 diabetes each of whom were studied on two occasions in a counterbalanced order. During each study condition, the subjects completed parallel tests of cognitive function assessed by the Test of Everyday Attention and the Raven's Progressive Matrices.


RESULTS
Hypoglycaemia caused a significant deterioration in tests sensitive to visual and auditory selective attention. During hypoglycaemia, attentional flexibility deteriorated and speed of information processing was delayed. Sustained attention and intelligence scores were preserved during hypoglycaemia.


CONCLUSIONS
In people with Type 1 diabetes, hypoglycaemia causes a significant deterioration in attentional abilities, while non-verbal reasoning is preserved. It is likely therefore that many complex cognitive tasks which involve attention will be impaired during moderate hypoglycaemia during everyday life.
McAulay
V
V
Department of Diabetes, Royal Infirmary, Edinburgh and Department of Psychology, University of Edinburgh, Edinburgh, UK.
Deary
I J
IJ
Sommerfield
A J
AJ
Frier
B M
BM
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D001288:Attention; D001307:Auditory Perception; D003071:Cognition; D003922:Diabetes Mellitus, Type 1 / Q000188:drug therapy / Q000523:psychology*; D006801:Humans; D007003:Hypoglycemia / Q000139:chemically induced / Q000523:psychology*; D007004:Hypoglycemic Agents / Q000009:adverse effects; D007328:Insulin / Q000009:adverse effects; D007361:Intelligence Tests; D014796:Visual Perception
D007004:Hypoglycemic Agents; D007328:Insulin