Contribution of sensory nerves to cutaneous reactive hyperaemia in non‐Hispanic Black and White young adults

Abstract

AbstractThe aim of this study was to assess cutaneous sensory nerve function, independent of nitric oxide, in non‐Hispanic Black and White young adults. We tested the hypothesis that cutaneous reactive hyperaemia and sensory nerve‐mediated vasodilatation would be lower in non‐Hispanic Black young adults relative to non‐Hispanic White young adults. Twenty‐four participants who self‐identified as non‐Hispanic Black (n = 12) or non‐Hispanic White (n = 12) were recruited. All participants underwent three bouts of reactive hyperaemia. An index of skin blood flow was measured continuously using laser‐Doppler flowmetry at a control site and at a site treated with topical 4% lignocaine to inhibit sensory nerve function. Peak reactive hyperaemia was lower in non‐Hispanic Black relative to non‐Hispanic White participants (P < 0.001). Total reactive hyperaemia was lower in non‐Hispanic Black [mean (SD); control, 4085 (955)%CVCmax s; lignocaine, 2127 (639) percent maximal cutaneous vascular conductance * seconds, %CVCmax s] relative to non‐Hispanic White [control: 6820 (1179)%CVCmax s; lignocaine, 3573 (712)%CVCmax s] participants (P < 0.001 for both sites). There was no difference between groups for the calculated contribution of sensory nerves to either the peak [non‐Hispanic Black, 25 (14)%; non‐Hispanic White, 19 (13)%] or total reactive hyperaemic response [non‐Hispanic Black, 48 (10)%; non‐Hispanic White, 47 (10)%]. These data suggest that cutaneous reactive hyperaemia is lower in non‐Hispanic Black young adults, but the sensory nerve contribution is similar in non‐Hispanic Black and White young adults.