Diabetes mellitus and risk of Alzheimer disease and decline in cognitive function

Arch Neurol. 2004 May;61(5):661-6. doi: 10.1001/archneur.61.5.661.


Background: Few prospective studies have assessed diabetes mellitus as a risk factor for incident Alzheimer disease (AD) and decline in cognitive function.

Objective: To evaluate the association of diabetes mellitus with risk of AD and change in different cognitive systems.

Design: Longitudinal cohort study.

Participants: For up to 9 years, 824 older (those >55 years) Catholic nuns, priests, and brothers underwent detailed annual clinical evaluations.

Main outcome measures: Clinically diagnosed AD and change in global and specific measures of cognitive function.

Results: Diabetes mellitus was present in 127 (15.4%) of the participants. During a mean of 5.5 years of observation, 151 persons developed AD. In a proportional hazards model adjusted for age, sex, and educational level, those with diabetes mellitus had a 65% increase in the risk of developing AD compared with those without diabetes mellitus (hazard ratio, 1.65; 95% confidence interval, 1.10-2.47). In random effects models, diabetes mellitus was associated with lower levels of global cognition, episodic memory, semantic memory, working memory, and visuospatial ability at baseline. Diabetes mellitus was associated with a 44% greater rate of decline in perceptual speed (P =.02), but not in other cognitive systems.

Conclusions: Diabetes mellitus may be associated with an increased risk of developing AD and may affect cognitive systems differentially.

Publication types

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

MeSH terms

  • Alzheimer Disease / complications*
  • Cognition Disorders / complications*
  • Diabetes Complications*
  • Female
  • Humans
  • Male
  • Neuropsychological Tests
  • Prospective Studies
  • Risk Factors