Severe hypoglycemia and cognitive decline in older people with type 2 diabetes: the Edinburgh type 2 diabetes study

Diabetes Care. 2014 Feb;37(2):507-15. doi: 10.2337/dc13-1384. Epub 2013 Oct 8.

Abstract

Objective: People with type 2 diabetes are at increased risk of age-related cognitive decline and dementia. Hypoglycemia is a candidate risk factor, but the direction of association between episodes of severe hypoglycemia and cognitive decline in type 2 diabetes remains uncertain.

Research design and methods: In the Edinburgh Type 2 Diabetes Study, cognitive function was assessed in 831 adults with type 2 diabetes (aged 60-75 years) at baseline and after 4 years. Scores on seven neuropsychological tests were combined into a standardized general ability factor g. Self-reported history of severe hypoglycemia at baseline (history of hypoglycemia) and at follow-up (incident hypoglycemia) was recorded.

Results: A history of hypoglycemia was reported by 9.3% of subjects, and 10.2% reported incident hypoglycemia. Incident hypoglycemia was associated with poorer cognitive ability at baseline (age- and sex-adjusted odds ratio for lowest tertile of g 2.04 [95% CI 1.25-3.31], P = 0.004). Both history of hypoglycemia and incident hypoglycemia were also associated with greater cognitive decline during follow-up (mean follow-up g adjusted for age, sex, and baseline g -0.25 vs. 0.03 [P = 0.02] and -0.28 vs. 0.04 [P = 0.01], respectively), including after addition of vascular risk factors and cardiovascular and microvascular disease to the models (-0.23 vs. 0.03 [P = 0.04] and -0.21 vs. 0.05 [P = 0.03], respectively).

Conclusions: The relationship between cognitive impairment and hypoglycemia appeared complex, with severe hypoglycemia associated with both poorer initial cognitive ability and accelerated cognitive decline.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Cognition
  • Cognition Disorders / etiology*
  • Diabetes Mellitus, Type 2 / blood*
  • Diabetes Mellitus, Type 2 / complications
  • Diabetes Mellitus, Type 2 / psychology*
  • Female
  • Humans
  • Hypoglycemia / complications*
  • Male
  • Middle Aged
  • Neuropsychological Tests