An examination of the relationship among plasma brain derived neurotropic factor, peripheral vascular function, and body composition with cognition in midlife African Americans/Black individuals

Abstract

African American/Black individuals have been excluded from several lines of prominent neuroscience research, despite exhibiting disproportionately higher risk factors associated with the onset and magnitude of neurodegeneration. Therefore, the objective of the current investigation was to examine potential relationships among brain derived neurotropic factor (BDNF), peripheral vascular function, and body composition with cognition in a sample of midlife, African American/Black individuals. Midlife adults (men: n = 3, 60 ± 4 years; women: n = 9, 58 ± 5 years) were invited to complete two baseline visits separated by 4 weeks. Peripheral vascular function was determined by venous occlusion plethysmography, a dual-energy X-ray absorptiometry was used to determine body composition, and plasma was collected to quantify BDNF levels. The CNS Vital Signs computer-based test was used to provide scores on numerous cognitive domains. The principal results included that complex attention (r = 0.629) and processing speed (r = 0.734) were significantly (p < 0.05) related to the plasma BDNF values. However, there was no significant (p > 0.05) relationship between any vascular measure and any cognitive domain or BDNF value. Secondary findings included the relationship between lean mass and peak hyperemia (r = 0.758) as well as total hyperemia (r = 0.855). The major conclusion derived from these results was that there is rationale for future clinical trials to use interventions targeting increasing BDNF to potentially improve cognition. Additionally, these results strongly suggest that clinicians aiming to improve cognitive health via improvements in the known risk factor of vascular function should consider interventions capable of promoting the size and function of skeletal muscle, especially in the African American/Black population.

Aerobic Exercise, Training Dose, and Cardiorespiratory Fitness: Effects and Relationships with Resting Plasma Neurotrophic Factors in Alzheimer’s Dementia

“…The predominantly White Caucasian sample also limits the generalizability of this pilot study. The lack of a diverse sample has been reported as a shortcoming in other neuroscience and AD-based research [66], and must be addressed in future studies [67]. Lastly, the ancillary blood study was not powered to test the statistical significance of intervention effects or other associations; accordingly, the focal results were estimates of effect sizes (standardized mean differences and r 2 values).…”

Sex‐specific microvascular and hemodynamic responses to passive limb heating in young adults

“…Aligned with this notion, at rest males regularly exhibit greater relative and absolute values of blood volume 21,22 . Also, compared to females, males on average typically present with greater lean mass, which has been hypothesized as a major contributor to related to reactive hyperemia responses 19,23 . Importantly, whole‐body lean mass is positively associated with capillary‐to‐fiber ratios, and thus, despite NIRS devices relying on discrete detection sites, individuals with greater lean mass may be exhibited a greater number of capillaries within a respective detection area 24 .…”

“…21,22 Also, compared to females, males on average typically present with greater lean mass, which has been hypothesized as a major contributor to related to reactive hyperemia responses. 19,23 Importantly, wholebody lean mass is positively associated with capillary-to-fiber ratios, and thus, despite NIRS devices relying on discrete detection sites, individuals with greater lean mass may be exhibited a greater number of capillaries within a respective detection area. 24 Considering this aspect is further supported by the notion that differences in capillary density may explain NIRS-VOT discrepancies between lean individuals and adults with obesity 25 such that lean individuals reportedly present 20% greater capillary-to-fiber ratios.…”

Near-Infrared Spectroscopy Does Not Track Forearm Blood Flow during Venous Occlusion Plethysmography

“…It is acknowledged that many approaches are available to capture associated RH responses [7,12], but, here, strain-gauge venous occlusion plethysmography (VOP) [10] and near-infrared spectroscopy (NIRS) [3,11,[13][14][15] are of particular interest. These two approaches seemingly garner substantial interest as demonstrated by their high usage among research scientists [16][17][18][19]. Venous occlusion plethysmography uses a strain-gauge to record changes in circumference (i.e., limb volume) provoked by venous occlusion to provide measures of the arterial inflow rate [20,21].…”