Identifying Neuroplasticity-related Biomarkers Linked With Processing Speed Following Water-based and Land-based Aerobic Exercise in Older Adults With MCI

Objective: Previous research has shown that exercise can produce cognitive benefits through neuroplastic mechanisms in older adults with mild cognitive impairment (MCI). This study builds on prior research by identifying biomarkers of neurological-related proteins that mediate improvement in processing speed in different exercise environments, water-based and land-based, in older adults with MCI. Methods: Plasma protein levels were measured using SomaScan’s Neuroscience panel, which includes 1316 analytes. Processing speed was measured using well-validated neuropsychological measures, including the Trail Making Test Trails A (TMT-A), the Stroop Color (SC) and Word (SW) trials, and the Symbol Digit Modalities Test (SDMT). Primary analyses consisted of linear mixed effects models to determine the impact of exercise-induced proteomic changes on processing speed measures. Results: After water-based exercise, KIF3C and TBX3 were found to mediate improvement in SC, a rapid automatic color-naming task. By contrast, after land-based exercise, none of the proteins analyzed were found to mediate improvement in processing speed. Conclusions: These findings support the continued exploration of water-based exercise as a cognitive intervention for older MCI adults. In addition, these results suggest differences in underlying neuroplasticity-related mechanisms in land-based and water-based exercise.