The effect of maintaining cognition on risk of disability and death
- PMID: 20406308
- PMCID: PMC2924918
- DOI: 10.1111/j.1532-5415.2010.02818.x
The effect of maintaining cognition on risk of disability and death
Abstract
Objectives: To determine whether long-term maintenance of cognition is associated with health advantages such as lower mortality or incident disability in older adults.
Design: Longitudinal cohort study.
Setting: Community clinics at two sites.
Participants: Two thousand seven hundred thirty-three adults with a mean age of 74 at baseline and 80 at follow-up.
Measurements: Cognitive function was assessed using the Modified Mini-Mental State Examination (3MS), a test of global cognition, at least two times. Three cognitive groups were defined based on 4-year participant-specific slopes (maintainers, slopes of >or=0; minor decliners, slopes <0 but no more than 1 standard deviation (SD) below the mean; major decliners, slopes >1 SD below the mean). Whether the cognitive groups differed in mortality and incident disability during the subsequent 3 years was determined.
Results: Nine hundred eighty-four (36%) participants were maintainers, 1,314 (48%) were minor decliners, and 435 (16%) were major decliners. Maintainers had lower mortality (7% vs 14%, hazard ratio (HR)=0.48, 95% confidence interval (CI)=0.36-0.63) and incident disability (22% vs 29%, HR=0.74, 95% CI=0.62-0.89) than minor decliners. After adjustment for age, race, sex, education, apolipoprotein E epsilon4, depression, body mass index, stroke, hypertension, and diabetes mellitus, these differences remained. As expected, major decliners had greater mortality (20%) and incident disability (40%) than minor decliners.
Conclusion: A substantial proportion of older adults maintain cognitive function in their eighth and ninth decades of life. These older adults demonstrate lower risk of death and functional decline than those with minor cognitive decline, supporting the concept of "successful" cognitive aging.
Conflict of interest statement
Figures
References
-
- Christensen H, Mackinnon AJ, Korten AE, et al. An analysis of diversity in the cognitive performance of elderly community dwellers: individual differences in change scores as a function of age. Psychol Aging. 1999 Sep;14(3):365–379. - PubMed
-
- Howieson DB, Camicioli R, Quinn J, et al. Natural history of cognitive decline in the old old. Neurology. 2003 May 13;60(9):1489–1494. - PubMed
-
- Wilson RS, Beckett LA, Barnes LL, et al. Individual differences in rates of change in cognitive abilities of older persons. Psychol Aging. 2002 Jun;17(2):179–193. - PubMed
-
- Guehne U, Luck T, Busse A. Angermeyer MC, Riedel-Heller SG. Mortality in individuals with mild cognitive impairment. Results of the Leipzig Longitudinal Study of the Aged (LEILA75+) Neuroepidemiology. 2007;29(3–4):226–234. - PubMed
-
- Yaffe K, Petersen RC, Lindquist K, Kramer J, Miller B. Subtype of mild cognitive impairment and progression to dementia and death. Dement Geriatr Cogn Disord. 2006;22(4):312–319. - PubMed
Publication types
MeSH terms
Grants and funding
LinkOut - more resources
Full Text Sources
Medical
Research Materials
