Worry, gait speed, and inflammation as predictors of processing speed in older adults with amnestic mild cognitive impairments (aMCI)

Efficient processing speed is important for quality of life and can buffer against further cognitive declines for older adults with amnestic mild cognitive impairment (aMCI). Etiologies of processing speed impairments are multifactorial. Slow gait and chronic worry have been suggested to be precursors to cognitive decline in older adults. Furthermore, both slow gait and worry involve inflammatory processes, which contribute to dementia conversion in those with MCI. Despite these links to cognitive decline, no study to date has examined the cumulative association of gait, worry, and inflammation on processing speed. Given the need to study processing speed through a multidisciplinary lens, the current study investigates the contributions of biological (inflammation), physiological (gait speed), and psychological (worry) factors to processing speed in older adults with aMCI. Participants include 65 community-dwelling older adults with aMCI. Linear regressions were used to (1) assess the contributions of each predictor (gait, inflammation, worry) and (2) compare each predictor versus their cumulative contribution to processing speed, controlling for age. The cumulative contribution of gait, worry, and inflammation significantly predicted processing speed compared to just gait alone, with worry being a significant predictor. No significant difference was found when compared to separate models of worry and inflammation. Worry, even at a subclinical level, showed a significant negative association to processing speed. Interestingly, the contribution of worry on processing speed is more pronounced when considering other health factors, reinforcing the importance of a bio-physio-psychological perspective in cognitive aging.