Cognitive function and 10 year mortality in an 85 year-old community-dwelling population

Area of Science:

• Gerontology
• Neuroscience
• Public Health

Background:

• The link between cognitive function and mortality in the very elderly is understudied.
• Specific associations between Mini-Mental State Examination (MMSE) subscale scores and cause-specific mortality are largely unknown.
• Community-dwelling elderly populations require focused investigation.

Purpose of the Study:

• To investigate the relationship between global and subscale Mini-Mental State Examination (MMSE) scores and all-cause and cause-specific mortality.
• To analyze these associations in a Japanese cohort of 85-year-old community-dwelling individuals.
• To identify cognitive predictors of mortality in advanced age.

Main Methods:

• Longitudinal study of 207 Japanese individuals aged 85 in 2003, with 205 completing the MMSE.
• 10-year follow-up period to track mortality outcomes.
• Analysis of all-cause mortality and deaths due to cardiovascular disease, senility, respiratory disease, and cancer, correlated with MMSE scores.

Main Results:

• A 1-point increase in global MMSE score was associated with a 6.3% decrease in all-cause mortality (adjusted for sex and education).
• Cardiovascular and senility mortality decreased by 7.6% and 9.2% respectively per 1-point MMSE increase.
• Specific MMSE subscales (time/place orientation, delayed recall, naming, listening/obeying) predicted all-cause mortality; naming, time, and place orientation predicted cardiovascular and senility mortality.

Conclusions:

• Impaired cognitive function, as measured by global and specific MMSE subscale scores, independently predicts all-cause mortality in 85-year-olds.
• Cognitive deficits are significant predictors of mortality due to cardiovascular disease and senility in this population.
• MMSE subscale performance offers valuable insights into mortality risks in the very elderly.