Cohort Changes in Cognitive Function Among Mexican Older Adults from 2001 to 2021

Area of Science:

• Gerontology
• Cognitive Neuroscience
• Public Health

Background:

• Multimorbidity, defined as having two or more chronic conditions, is linked to accelerated cognitive decline in older adults.
• Longitudinal data on cognitive decline and multimorbidity in low- and middle-income countries, such as Mexico, are scarce.

Purpose of the Study:

• To investigate cohort differences in the annual rate of cognitive decline among older Mexican adults.
• To determine if the association between multimorbidity and cognitive decline varies between two distinct birth cohorts.

Main Methods:

• Analysis of two 10-year birth cohorts (Cohort 1: 1941-1951; Cohort 2: 1952-1962) with baseline ages 50-60.
• Three waves of data collection over 10-year periods for each cohort (Cohort 1: 2001, 2003, 2012; Cohort 2: 2012, 2015, 2021).
• Growth curve models were employed to assess annual changes in global cognitive function scores (GCFS) and cohort differences.

Main Results:

• The earlier cohort (Cohort 1, baseline 2001) exhibited a significantly faster average annual rate of cognitive decline (GCFS) compared to the later cohort (Cohort 2, baseline 2012).
• The association between multimorbidity and the rate of cognitive decline did not significantly differ between the two cohorts when controlling for potential confounders.

Conclusions:

• The observed slower cognitive decline in the more recent cohort suggests potential benefits from improved educational attainment and enhanced cognitive reserve.
• Improvements in healthcare access over recent decades may have mitigated the adverse effects of multimorbidity on cognitive function, explaining the lack of cohort differences in this association.
• Findings highlight evolving patterns of cognitive aging and the impact of multimorbidity in the Mexican population.