Neurovascular mechanisms underlying augmented cold‐induced reflex cutaneous vasoconstriction in human hypertension

Abstract

In hypertensive adults (HTN), cardiovascular risk increases disproportionately during environmental cold exposure. Despite ample evidence of dysregulated sympathetic control of the peripheral vasculature in hypertension, no studies have examined integrated neurovascular function during cold stress in HTN. The findings of the present study show that whole‐body cold stress elicits greater increases in sympathetic outflow directed to the cutaneous vasculature and, correspondingly, greater reductions in skin blood flow in HTN. We further demonstrate an important role for non‐adrenergic sympathetic co‐transmitters in mediating the vasoconstrictor response to cold stress in hypertension. In the context of thermoregulation and the maintenance of core temperature, sympathetically‐mediated control of the cutaneous vasculature is not only preserved, but also exaggerated in hypertension. Given the increasing prevalence of hypertension, clarifying the mechanistic underpinnings of hypertension‐induced alterations in neurovascular function during cold exposure is clinically relevant.