Association between apolipoprotein E4 and cognitive decline in elderly adults

J Am Geriatr Soc. 2007 Nov;55(11):1777-85. doi: 10.1111/j.1532-5415.2007.01415.x.

Abstract

Objective: To determine the influence of apolipoprotein E on cognitive decline in a cohort of elderly men and women.

Design: Prospective study.

Setting: Scotland, Ireland, and the Netherlands.

Participants: Five thousand eight hundred four subjects aged 70 to 82 from the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER).

Measurements: Subjects were assessed at baseline and over a mean 3.2-year (range 0.7-4.2) follow-up for memory (Picture-Word Recall), speed of information processing (Stroop and Letter-Digit Coding), global cognitive function (Mini-Mental State Examination), and activities of daily living.

Results: At baseline, subjects with apolipoprotein E(4) versus those without E(4) had poorer memory performance (mean score difference -0.20 (95% confidence interval (CI)=-0.31 to -0.09) for immediate recall and -0.32 (95% CI=-0.48 to -0.16) for delayed recall and slower information processing (difference in Stroop, 2.79 seconds, (95% CI=1.20-4.28); Letter-Digit score, -0.36, (95% CI=-0.77-0.05). Subjects with apolipoprotein E(4) showed a greater decline in immediate (-0.22, 95% CI=-0.33 to -0.11) and delayed (-0.30, 95% CI=-0.46 to -0.15) memory scores but no significant change in speed of information processing (Stroop, P=.17; Letter-Digit, P=.06). Memory scores decreased 2.5% from baseline in those without E(4), 4.3% in E(4) heterozygotes (P=.01 for immediate and P=.03 for delayed, vs no E(4)) and 8.9% to 13.8% in E(4) homozygotes (P=.04 for immediate and P=.004 for delayed, vs heterozygotes). Apolipoprotein E(4) was associated with greater decline in instrumental activities of daily living (P<.001). Cognitive decline was not associated with lipoprotein levels.

Conclusion: Findings in PROSPER indicate that E(4) is associated with more-rapid cognitive decline and may, therefore, predispose to dementia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Activities of Daily Living / classification
  • Aged
  • Aged, 80 and over
  • Alzheimer Disease / blood
  • Alzheimer Disease / diagnosis
  • Alzheimer Disease / genetics*
  • Anticholesteremic Agents / therapeutic use
  • Apolipoprotein E4 / genetics*
  • Cholesterol / blood
  • Cholesterol, HDL / blood
  • Cholesterol, LDL / blood*
  • Cognition Disorders / blood
  • Cognition Disorders / genetics*
  • Cohort Studies
  • Cross-Sectional Studies
  • Dementia, Vascular / blood
  • Dementia, Vascular / diagnosis
  • Dementia, Vascular / genetics*
  • Female
  • Follow-Up Studies
  • Genetic Carrier Screening
  • Homozygote
  • Humans
  • Ireland
  • Male
  • Mental Status Schedule
  • Netherlands
  • Neuropsychological Tests
  • Phenotype*
  • Pravastatin / therapeutic use
  • Risk Factors
  • Scotland
  • Statistics as Topic
  • Triglycerides / blood

Substances

  • Anticholesteremic Agents
  • Apolipoprotein E4
  • Cholesterol, HDL
  • Cholesterol, LDL
  • Triglycerides
  • Cholesterol
  • Pravastatin