The association between low cognitive reserve and subjective memory complaints in functionally independent older women.

Background: Several factors have been found to defend against pathologic cognitive decline in aging (i.e., cognitive reserve [CR]); however, other factors, including subjective memory complaints (SMC) and decreased functionality are considered early indicators of underlying neurocognitive dysfunction. Despite these known associations, the relationship between the presence of CR and SMC remains equivocal. This study sought to determine the relationship between objectively measured CR and SMC in a sample of functionally independent older women.

Methods: This cross-sectional study recruited women aged ≥60 years who attended fitness or continuing education programs at the University for Seniors in Mexico City. Participants underwent a battery of physical and cognitive evaluations, including the Cognitive Reserve Questionnaire (CRQ), and were asked probing questions used to identify the presence of SMC.

Results: The 269 participants had a median age of 69 years; most were single (40.5 %), lived alone (32.7 %), retired (58.2 %), well-educated (≥12 years of education), and functionally independent (89.2 %). 62 % scored "high" on the CRQ, while 9.3 % scored "low". After adjusting for multiple covariates, an independent association between CRQ score and the probability to have SMC was found (adjusted OR = 0.87, 95% CI 0.80-0.95, p-value = 0.002).

Conclusions: This study identified a relationship between low CR and the presence of SMC, independently of the cognitive function and motoric marker of muscle strength (i.e., low gait speed and handgrip strength) in functionally independent older women over 60y. This relationship remains independent of other variables such as age, symptoms of depression and instrumented activities of daily living.