Effects of acute hypoglycemia on motivation and cognitive interference in people with type 1 diabetes.

AIMS

To examine the effect of acute hypoglycemia on motivation and cognitive interference in adult humans with type 1 diabetes.

METHODS

A hyperinsulinemic glucose clamp was used to either maintain euglycemia (arterialized blood glucose 4.5 mmol/L) or induce hypoglycemia (2.6 mmol/L) in 16 adults with type 1 diabetes, each of whom were studied on 2 separate occasions in a counterbalanced order. During each study condition, the subjects completed parallel tests of cognitive function. The Dundee Stress State Questionnaire (DSSQ) was administered before and after the cognitive function tests.

RESULTS

Hypoglycemia decreased task-relevant (P = 0.03) and increased task-irrelevant (P = 0.02) interference. Self-focus of attention was much higher after hypoglycemia than euglycemia (P = 0.02). Motivation declined to a similar extent during the euglycemia and hypoglycemia conditions (P = 0.07). Hypoglycemia produced a negative mood state with a significant fall in energy levels (P = 0.03) and a concomitant rise in anxiety level (P = 0.05). The subjective perception of concentration was unaffected during hypoglycemia (P = 0.14), and the scores for control and confidence did not fall (P = 0.19).

CONCLUSIONS

In people with type 1 diabetes, hypoglycemia causes a state of heightened self-awareness and distraction during active mental activity. This is likely to leave fewer processing resources available to allow completion of cognitive tasks. Acute hypoglycemia induces a state of significant worry and anxiety that is likely to affect the social, personal, and work activities of people with diabetes.