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.