Neurovascular responses to mental stress in prehypertensive humans

Abstract

Neurovascular responses to mental stress have been linked to several cardiovascular diseases, including hypertension. Mean arterial pressure (MAP), muscle sympathetic nerve activity (MSNA), and forearm vascular responses to mental stress are well documented in normotensive (NT) subjects, but responses in prehypertensive (PHT) subjects remain unclear. We tested the hypothesis that PHT would elicit a more dramatic increase of MAP during mental stress via augmented MSNA and blunted forearm vascular conductance (FVC). We examined 17 PHT (systolic 120-139 and/or diastolic 80-89 mmHg; 22 ± 1 yr) and 18 NT (systolic < 120 and diastolic < 80 mmHg; 23 ± 2 yr) subjects. Heart rate, MAP, MSNA, FVC, and calf vascular conductance were measured during 5 min of baseline and 5 min of mental stress (mental arithmetic). Mental stress increased MAP and FVC in both groups, but the increases in MAP were augmented (Δ 10 ± 1 vs. Δ14 ± 1 mmHg; P < 0.05), and the increases in FVC were blunted (Δ95 ± 14 vs. Δ37 ± 8%; P < 0.001) in PHT subjects. Mental stress elicited similar increases in MSNA (Δ7 ± 2 vs. Δ6 ± 2 bursts/min), heart rate (Δ21 ± 3 vs. Δ18 ± 3 beats/min), and calf vascular conductance (Δ29 ± 10 vs. Δ19 ± 5%) in NT and PHT subjects, respectively. In conclusion, mental stress elicits an augmented pressor response in PHT subjects. This augmentation appears to be associated with altered forearm vascular, but not MSNA, responses to mental stress.

A single dose of cannabidiol reduces blood pressure in healthy volunteers in a randomized crossover study

“…Mental arithmetic has been shown to cause a rise in MAP and muscle sympathetic nerve activity (MSNA) (25) and vasodilatation in forearm skeletal muscle (26). In our study, none of the cardiovascular parameters other than HR, DBP, and SV were affected, suggesting that the level of stress to this test was minimal.…”

Impaired Neuronal Nitric Oxide Synthase–Mediated Vasodilator Responses to Mental Stress in Essential Hypertension

“…6 Forearm responses to mental stress have previously been reported to be impaired in patients with essential hypertension (reduced increase in absolute FBF) and in prehypertension (reduced increase in forearm conductance) when compared with normotensive controls, 9,17 potentially implicating dysfunction of the nNOS pathway in essential hypertension. Because nNOS is responsible for tonic vasodilation under resting conditions, 6 this could also contribute to increased basal vascular resistance.…”

Sex differences in sympathetic neural and limb vascular reactivity to mental stress in humans

“…Recent evidence suggests that altered limb vascular responsiveness to mental stress may also play an important role in the pathogenesis of hypertension. Specifically, it has been reported that forearm vasodilatory responses to mental stress are blunted in hypertensive (8) and prehypertensive (46,48) humans. Thus, investigations of limb vascular responsiveness to mental stress are clinically relevant.…”