Cognitive dysfunction in adults with type 1 (insulin-dependent) diabetes mellitus of long duration: effects of recurrent hypoglycaemia and other chronic complications

Diabetologia. 1993 Apr;36(4):329-34. doi: 10.1007/BF00400236.


To examine the long-term effects of recurrent severe hypoglycaemia and other biomedical complications on mental efficiency, a battery of cognitive tests was administered to 142 Type 1 (insulin-dependent) diabetic adult patients (age 33.5 +/- 5.6 years; mean +/- SD) and 100 demographically similar non-diabetic control subjects. All diabetic subjects had been diagnosed before the age of 17 years. Diabetic subjects with one or more complications (distal symmetrical polyneuropathy; advanced background or proliferative retinopathy; overt nephropathy; one or more episodes of severe hypoglycaemia) performed significantly (p < 0.001) more poorly than non-diabetic control subjects on tests requiring sustained attention, rapid analysis of visuospatial detail, and hand eye co-ordination. Regression analyses indicated that the best biomedical predictor of cognitive test performance was a diagnosis of polyneuropathy. Although severe recurrent hypoglycaemia was not associated with performance on any test, the neuropathy x recurrent hypoglycaemia interaction term was significant. These results suggest that in adults with Type 1 diabetes of long duration, recurrent hypoglycaemia does not appear to influence cognitive performance directly, but may interact with neuropathy to exaggerate or otherwise magnify the extent of neurobehavioural dysfunction.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Blood Glucose / analysis
  • Cognition Disorders / etiology*
  • Diabetes Mellitus, Type 1 / blood
  • Diabetes Mellitus, Type 1 / physiopathology*
  • Diabetes Mellitus, Type 1 / psychology*
  • Diabetic Neuropathies / physiopathology
  • Diabetic Neuropathies / psychology*
  • Diabetic Retinopathy / physiopathology
  • Diabetic Retinopathy / psychology*
  • Female
  • Glycated Hemoglobin A / analysis
  • Humans
  • Hypoglycemia / etiology
  • Hypoglycemia / physiopathology
  • Hypoglycemia / psychology*
  • Intelligence Tests
  • Male
  • Neuropsychological Tests


  • Blood Glucose
  • Glycated Hemoglobin A