Year: 2015
Type: article
Study design: Observational Study
Abstract: Cognition generally begins to decline at variable rates in the seventh decade and mortality rises sharply after age 80. Our goal was to determine if there is an association between cognitive trajectories from age 65-80 and risk of death after 80. We studied community-dwelling, non-demented women aged 65+ (mean age = 71) who were enrolled in a prospective study of aging and followed for up to 20 years. Two cognitive tests, a modified version of the Mini-Mental State Examination (mMMSE) and the Trails B, were administered at multiple visits during follow-up. We examined the association between cognitive trajectories from baseline to age 80 (n=7,477 for mMMSE and n=6,503 for Trails B) and all-cause mortality after age 80 using Cox regression models, both unadjusted and adjusted for education, physical activity, alcohol, depression score, current smoking, and history of hypertension and diabetes. Based on an average seven years of mMMSE data (SD=4.4) and six years of Trails B data (SD=3.5), we calculated cognitive trajectories (analyzed by quintiles) based on the estimated change in cognition between baseline and age 80. After age 80, women were followed for an average of 10 years to assess mortality. Cause of death was determined from death certificates; we classified causes of death as cardiovascular, cancer, and other. Women with greater rate of decline were older, less educated, less physically active, had higher depression score, and were more likely to have a history of hypertension and diabetes (all p < 0.01). Participants with the greatest decline (quintile 1) had an increased risk of death [mMMSE Hazard Ratio (HR)=1.28; Trails B HR=1.43] and those with the least decline (quintile 5) had a decreased risk of death (mMMSE HR=0.73; Trails B HR=0.61) compared to intermediate decliners (quintiles 2-4); see table for unadjusted HR and all confidence intervals. Cognitive trajectories were associated with cardiovascular mortality and other causes of death, but not cancer deaths. Our study suggested that greater decline in either general cognition or executive function was associated with higher rates of mortality in non-demented oldest-old women.
Source: Alzheimer s & Dementia
Institutions: San Francisco VA Medical Center, University of California, San Francisco, Northern California Institute for Research and Education, University of Pittsburgh, Kaiser Permanente Center for Health Research, University of Minnesota, Minneapolis VA Health Care System, Minneapolis VA Medical Center
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2358939616