Brain, Behavior, and Immunity · Mar 28, 2026

Suppressed brain-derived neurotrophic factor response to 6 min walking exercise in mild cognitive impairment

By Kang MC, Wandel S, Perez CN et al.

BACKGROUND: Myokines and cytokines are signaling proteins released by skeletal muscle cells during exercise that act as messengers, influencing the function of various organs, including the brain. We examined whether a single bout of walking exercise induces distinct changes in plasma myokine and cytokine concentrations in older adults with and without mild cognitive impairment (MCI). METHODS: In 146 older adults characterized based on the Montreal Cognitive Assessment (MoCA) scores in non-MCI (MoCA score ≥26, n = 55) vs MCI (MoCA score <26, n = 91), we measured cognitive performance by battery, body composition by DXA, and functional performance by 6 min walk test (6MWT) distance. In addition, plasma myokine and cytokine concentrations were assessed before and immediately after 6MWT by MILLIPLEX® Human Myokine Magnetic Bead Panel (HMYOMAG-56K) and Immunology Multiplex Assay (HCYTA-60K-PXBK38) using Luminex® 200™ and MagPix system. Analysis was performed by GLMM to test the effects of group (Non-MCI vs MCI) and walking exercise. RESULTS: The MCI group had worse cognitive performance on trail-making test, stroop color word test (SCWT), phonemic and semantic fluency test, digit span backward, and the Rey auditory verbal learning test (AVLT) delayed memory (all P < 0.02). Body weight, BMI, lean mass, and (visceral) fat mass were comparable between non-MCI and MCI groups. There was a trend toward significantly lower 6MWT distance in the MCI (P = 0.067). We found lower baseline GM-csF concentration (P = 0.006) and a smaller increase in BDNF, FABP-3, and Osteocrin concentration in response to 6MWT in the MCI, even after adjustment for age and 6MWT distance (P < 0.003). Lower BDNF response to exercise was further associated with advancing age and worse cognitive function (MoCA, SCWT) (P < 0.04), but not with changes in lifestyle (habitual physical activity or dietary intake). We observed 6MWT-induced increases for the other myokines (apelin, BDNF, EPO, osteonectin, IL-15, myostatin, FABP-3, FSTL-1, IL-6, FGF-21, and osteocrin), and nearly all cytokines were independent of the group studied (all P < 0.02). CONCLUSION: A single bout of 6-minute walking exercise elicits a suppressed increase in BDNF, FABP-3, and Osteocrin in individuals with MCI, with a particularly blunted BDNF response in those who are older and more cognitively impaired. Whether disturbances in muscle-brain crosstalk, mediated by suppressed exercise induced BDNF response, contribute to cognitive decline in older adults warrants further investigation.

doi.org/10.1016/j.bbi.2026.106561Open accessPubMed 41912101Mechanisms