Patterns of Cognitive Performance in Healthy Ageing in Northern Portugal

Background: The Minho Integrative Neuroscience Database
(MIND)-Ageing project aims to identify predictors of healthy
cognitive ageing, including socio-demographic factors. In this
exploratory analysis we sought to establish baseline cohorts for
longitudinal assessment of age-related changes in cognition.
Methods: The population sample (472 individuals) was strictly a
convenient one, but similar to the Portuguese population in the age
profile. Participants older than 55 years of age were included if
they did not present defined disabling pathologies or dementia. A
standardized clinical interview was conducted to assess medical
history and a battery of neuropsychological tests was administered
to characterize global cognition (Mini Mental State Examination),
memory and executive functions (Selective Reminding Test; Stroop
Color and Word Test; and Block Design subtest of the Wechsler Adult
Intelligence Scale). Cross-sectional analysis of the
neuropsychological performance with individual characteristics such
as age, gender, educational level and setting (retirement home,
senior university, day care center or community), allowed the
establishment of baseline clusters for subsequent longitudinal
studies. Results: Based on different socio-demographic
characteristics, four main clusters that group distinctive patterns
of cognitive performance were identified. The type of institution
where the elders were sampled from, together with the level of
formal education, were the major hierarchal factors for individual
distribution in the four clusters. Of notice, education seems to
delay the cognitive decline that is associated with age in all
clusters. Conclusions: Social-inclusion/engagement and education
seem to have a protective effect on mental ageing, although this
effect may not be effective in the eldest elders.