Young, non-Hispanic Black men and women exhibit divergent peripheral and cerebral vascular reactivity.

In the USA, cardiovascular and cerebrovascular diseases remain more prominent in the non-Hispanic Black (BL) population relative to other racial/ethnic groups. Typically, sex differences emerge in the manifestation of these diseases, though these differences may not fully materialize in the BL population. While numerous mechanisms are implicated, differences in vascular function likely contribute. Research has demonstrated blunted vasodilatation in several vascular regions in BL versus non-Hispanic White individuals, though much of this work did not assess sex differences. Therefore, this study aimed to ascertain if indices of vascular function are different between young BL women (BW) and men (BM). Eleven BW and 15 BM (22 (4) vs. 23 (3) years) participated in this study. Each participant underwent testing for brachial artery flow-mediated dilatation (FMD), post-occlusive reactive hyperaemia and cerebral vasomotor reactivity during rebreathing-induced hypercapnia. BW exhibited greater adjusted FMD than BM (P < 0.05 for all), but similar or lower reactive hyperaemia when assessed as blood velocity (P > 0.39 for all) or blood flow reactivity (P < 0.05 for all), respectively. Across a range of hypercapnia, BW had greater middle cerebral artery blood velocity and cerebrovascular conductance index than BM (P < 0.001 for both). These preliminary data suggest that young BW have greater vascular function relative to young BM, though this was inconsistent across different indices. These findings provide insight into the divergent epidemiological findings between BM and BW. Further research is needed to elucidate possible mechanisms and relate these physiological responses to epidemiological observations.