Memory concerns, memory performance and risk of dementia in patients with mild cognitive impairment

PLoS One. 2014 Jul 14;9(7):e100812. doi: 10.1371/journal.pone.0100812. eCollection 2014.

Abstract

Background: Concerns about worsening memory ("memory concerns"; MC) and impairment in memory performance are both predictors of Alzheimer's dementia (AD). The relationship of both in dementia prediction at the pre-dementia disease stage, however, is not well explored. Refined understanding of the contribution of both MC and memory performance in dementia prediction is crucial for defining at-risk populations. We examined the risk of incident AD by MC and memory performance in patients with mild cognitive impairment (MCI).

Methods: We analyzed data of 417 MCI patients from a longitudinal multicenter observational study. Patients were classified based on presence (n = 305) vs. absence (n = 112) of MC. Risk of incident AD was estimated with Cox Proportional-Hazards regression models.

Results: Risk of incident AD was increased by MC (HR = 2.55, 95%CI: 1.33-4.89), lower memory performance (HR = 0.63, 95%CI: 0.56-0.71) and ApoE4-genotype (HR = 1.89, 95%CI: 1.18-3.02). An interaction effect between MC and memory performance was observed. The predictive power of MC was greatest for patients with very mild memory impairment and decreased with increasing memory impairment.

Conclusions: Our data suggest that the power of MC as a predictor of future dementia at the MCI stage varies with the patients' level of cognitive impairment. While MC are predictive at early stage MCI, their predictive value at more advanced stages of MCI is reduced. This suggests that loss of insight related to AD may occur at the late stage of MCI.

Publication types

  • Multicenter Study
  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Alzheimer Disease / epidemiology*
  • Alzheimer Disease / genetics
  • Apolipoprotein E4 / genetics
  • Cognitive Dysfunction / psychology*
  • Female
  • Genotype
  • Humans
  • Longitudinal Studies
  • Male
  • Memory*
  • Middle Aged
  • Proportional Hazards Models
  • Risk

Substances

  • Apolipoprotein E4

Grants and funding

This study has been supported by a grant from the German Federal Ministry of Education and Research (BMBF): Kompetenznetz Demenzen (01GI0420). Harald Hampel was supported by grants of the Katharina-Hardt-Foundation, Bad Homburg, Germany. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.