Mild Cognitive Impairment (MCI) is a diagnosis that is less severe than dementia. Some individuals diagnosed with MCI eventually develop dementia, while many continue indefinitely with the MCI diagnosis or even improve in cognitive status. Because MCI is such a diverse diagnosis, it is associated with a wide range of biological and functional markers. A recent article in Neuropsychology examines a large-scale, longitudinal study of older adults to identify risk and protective factors for MCI.
The researchers used data from the Victoria Longitudinal Study (VLS), an ongoing Canadian study of community-dwelling older adults. The VLS collects a wide range of cognitive, biological, behavioral, and other data from individuals at different points in time. This enables both cross-sectional (different kinds of data collected at a single point in time) and longitudinal (the same kind or kinds of data collected at different points in time) data. Cross-sectional data can be used to identify conditions and other markers that occur together at the same time, while longitudinal data can be used to identify risk factors for future conditions.
For the study, the researchers used data from VLS participants between the ages of 64 and 95. Participants included individuals with a diagnosis of MCI and those without any cognitive impairment. At two different points in time, participants were assessed on several measures of functioning (such as physical activity), mood, health, and cognitive status. Some participants had the same cognitive status at the two time points, while some developed MCI between the two time points. Thus, the researchers were able to look at cross-sectional relationships between MCI and other factors, as well as longitudinal risk factors associated with developing MCI between the two time points.
Cross-sectional data identified eight markers on which individuals with and without MCI differed significantly. Five of these were physical or mental health markers: diastolic blood pressure, body mass index, positive and negative mood, and overall cognitive status (which would logically be expected to be associated with MCI). Three of these were lifestyle factors: frequency of self-maintenance (such cooking or grocery shopping), travel, and novel cognitive activities (engaging in new mentally challenging activities). These cross-sectional associations suggest that the eight identified markers might be useful for indicating the presence of MCI. This might one day lead to future treatments for cognitive impairment, as well as more effective diagnosis of MCI.
The longitudinal data found five markers that were associated with greater risk for the developing MCI between the first and second time points. These included diastolic blood pressure, self-maintenance, novel cognitive activities, positive mood, and overall cognitive status. The small subset of individuals who were diagnosed with MCI at the first time point and were without cognitive impairment at the second time point also had healthier diastolic blood pressure and better mood. These findings contribute to future research that will examine whether modifying these risk factors—such as by improving blood pressure or engaging with new, mentally-stimulating activities—might be useful for preventing MCI or other cognitive decline.
Dolcos S, MacDonald SWS. Braslavsky A, et al. (2012). Mild cognitive impairment is associated with selected functional markers: integrating concurrent, longitudinal, and stability effects. Neuropsychology, E-pub ahead of print.