SEVERE HYPOGLYCEMIA AND INTELLIGENCE IN ADULT PATIENTS WITH INSULIN-TREATED DIABETES

The 10 scores (WAIS-R) of 100 patients with insulin-treated diabetes (aged 25-52 yr) were compared with those of 100 healthy control subjects who were matched to the diabetic patients for sex, age, education, and social class. The diabetic group had lower WAIS-R performance and verbal IQ scores than the control group (P = 0.01 7 and P = 0.033, respectively) after controlling for premorbid IQ. The extent of the difference was modest, representing approximately 33% of an SD in 10. When frequency of severe hypoglycemia was controlled for the difference in performance 10 between the diabetic patient group and the control group was abolished, whereas the difference between the groups in verbal 10 persisted. It is hypothesised that cumulative severe hypoglycemia might be the major factor in the slight performance 10 differences between diabetic patients and control subjects. The origin of the verbal 10 differences, although obscure, might be related to the social impact of the disorder.