Relation of diabetes to mild cognitive impairment

Arch Neurol. 2007 Apr;64(4):570-5. doi: 10.1001/archneur.64.4.570.

Abstract

Background: Type 2 diabetes mellitus is an important risk factor for Alzheimer disease and is more prevalent in elderly minority persons compared with non-Hispanic white persons.

Objective: To determine whether diabetes is related to a higher risk of mild cognitive impairment (MCI), a transitional stage between normal cognition and Alzheimer disease, in a multiethnic cohort with a high prevalence of diabetes.

Design: Longitudinal cohort study.

Setting: Northern Manhattan in New York, NY.

Participants: We studied persons without prevalent MCI or dementia at baseline and with at least 1 follow-up interval. Of 1772 participants with a complete neuropsychological evaluation, 339 (19.1%) were excluded because of prevalent dementia, 304 were excluded because of prevalent MCI (17.2%), and 211 were excluded because of loss to follow-up (11.9%), resulting in a final sample of 918 participants for longitudinal analyses.

Main outcome measures: We related diabetes defined by self-report to incident all-cause MCI, amnestic MCI, and nonamnestic MCI. We conducted multivariate analyses with proportional hazards regression adjusting for age, sex, years of education, ethnic group, apolipoprotein E (APOE) epsilon4 allele, hypertension, low-density lipoprotein level, current smoking, heart disease, and stroke.

Results: A total of 334 persons had incident MCI, 160 (47.9%) had amnestic MCI, and 174 (52.1%) had nonamnestic MCI. Diabetes was related to a significantly higher risk of all-cause MCI and amnestic MCI after adjustment for all covariates. Diabetes was also related to a higher risk of nonamnestic MCI, but this association was appreciably attenuated after adjustment for socioeconomic variables and vascular risk factors. The risk of MCI attributable to diabetes was 8.8% for the whole sample and was higher for African American persons (8.4%) and Hispanic persons (11.0%) compared with non-Hispanic white persons (4.6%), reflecting the higher prevalence of diabetes in minority populations in the United States.

Conclusion: Diabetes is related to a higher risk of amnestic MCI in a population with a high prevalence of this disorder.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • African Americans / statistics & numerical data
  • Aged
  • Aged, 80 and over
  • Analysis of Variance
  • Apolipoproteins E / genetics
  • Cognition Disorders / epidemiology
  • Cognition Disorders / etiology*
  • Cognition Disorders / psychology
  • Cohort Studies
  • Diabetes Mellitus, Type 2 / complications*
  • Diabetes Mellitus, Type 2 / ethnology
  • Diabetes Mellitus, Type 2 / genetics
  • European Continental Ancestry Group / statistics & numerical data
  • Female
  • Follow-Up Studies
  • Genotype
  • Hispanic Americans / statistics & numerical data
  • Humans
  • Male
  • Middle Aged
  • Neuropsychological Tests
  • New York / epidemiology
  • Prevalence
  • Risk Factors

Substances

  • Apolipoproteins E