Single and 7-day handgrip and squat exercise prevents endothelial ischemia-reperfusion injury in individuals with cardiovascular disease risk factors.

Whole body exercise provides protection against endothelial ischemia-reperfusion (IR) injury. In this crossover study, we examined the effects of ) single bout of local exercise (handgrip, squats) on endothelial responses to IR, and ) if 7 days of daily local exercise bolsters these effects in individuals with cardiovascular disease (CVD) risk factors. Fifteen participants (9 women, 58 ± 5 yr, ≥2 CVD risk factors) attended the laboratory for six visits.

Menopausal stage differences in endothelial resistance to ischemia-reperfusion injury.

Background: In postmenopausal women, reduced ovarian function precedes endothelial dysfunction and attenuated endothelial resistance to ischemia-reperfusion (IR) injury. We hypothesized that IR injury would lower endothelial function, with premenopausal women demonstrating the greatest protection from injury, followed by early, then late postmenopausal women.

Methods: Flow-mediated dilation (FMD) was assessed at baseline and following IR injury in premenopausal (n = 11), early (n = 11; 4 ± 1.

Exercise-induced release of cardiac troponin is attenuated with repeated bouts of exercise: impact of cardiovascular disease and risk factors.

Prolonged exercise can induce cardiac troponin release. As single bouts of exercise may protect against cardiac injury, we explored the hypothesis that the magnitude of exercise-induced release of troponin attenuates upon successive days of exercise. We also examined whether effects of successive exercise bouts differ between healthy participants and individuals with cardiovascular risk factors (CVRFs) and established cardiovascular disease (CVD).

Impact of handgrip exercise and ischemic preconditioning on local and remote protection against endothelial reperfusion injury in young men.

Ischemic preconditioning (IPC), cyclical bouts of nonlethal ischemia, provides immediate protection against ischemic injury, which is evident both locally and remotely. Given the similarities in protective effects of exercise with ischemic preconditioning, we examined whether handgrip exercise also offers protection against endothelial ischemia-reperfusion (IR) injury and whether this protection is equally present in the local (exercised) and remote (contralateral, nonexercised) arm. Fifteen healthy males (age, 24 ± 3 yr; body mass index, 25 ± 2 kg/m) attended the laboratory on three occasions.

Inorganic nitrate supplementation and blood flow restricted exercise tolerance in post-menopausal women.

Exercise tolerance appears to benefit most from dietary nitrate (NO) supplementation when muscle oxygen (O) availability is low. Using a double-blind, randomized cross-over design, we tested the hypothesis that acute NO supplementation would improve blood flow restricted exercise duration in post-menopausal women, a population with reduced endogenous nitric oxide bioavailability. Thirteen women (57-76 yr) performed rhythmic isometric handgrip contractions (10% MVC, 30 per min) during progressive forearm blood flow restriction (upper arm cuff gradually inflated 20 mmHg each min) on three study visits, with 7-10 days between visits.

Aging women and their endothelium: probing the relative role of estrogen on vasodilator function.

Despite significant decreases in cardiovascular disease (CVD) mortality in the past three decades, it still remains the leading cause of death in women. Following menopause and the accompanying loss of estrogen, women experience a unique, accelerated rise in CVD risk factors. Dysfunction of the endothelium represents an important antecedent to CVD development, with rapid declines in endothelial vasodilator function reportedly taking place across the menopause transition.

Near-infrared spectroscopy detects transient decrements and recovery of microvascular responsiveness following prolonged forearm ischemia.

Background: Impairments at the microvascular level might lead to more overt cardiovascular complications, therefore, being able to early detect microvascular dysfunction would be beneficial. Thus, the present study investigated whether near-infrared spectroscopy (NIRS) assessment of microvascular responsiveness (reoxygenation slope, %.s) would detect the detrimental effects on the forearm microvasculature following a period of arterial occlusion.

Effects of acute dietary nitrate supplementation on aortic blood pressures and pulse wave characteristics in post-menopausal women.

Purpose: Consumption of nitrate-rich beetroot juice can lower blood pressure in peripheral as well as central arteries and may exert additional hemodynamic benefits (e.g. reduced aortic wave reflections).

Retrograde and oscillatory shear increase across the menopause transition.

Declines in endothelial function can take place rapidly across the menopause transition, placing women at heightened risk for atherosclerosis. Disturbed patterns of conduit artery shear, characterized by greater oscillatory and retrograde shear, are associated with endothelial dysfunction but have yet to be described across menopause. Healthy women, who were not on hormone therapy or contraceptives, were classified into early perimenopausal, late perimenopausal, and early postmenopausal stage.

The association between near-infrared spectroscopy-derived and flow-mediated dilation assessment of vascular responsiveness in the arm.

Introduction: Following a period of blood flow occlusion, the near-infrared spectroscopy (NIRS)-derived reperfusion slope of the oxygen saturation signal (StO) is a measure of microvascular responsiveness that has been shown to be positively correlated with flow-mediated dilation (FMD) assessment of conduit artery function in the lower limb vasculature. Given that previously established differences in structure and function of the vessels in the upper compared to the lower limbs may change this relationship, investigating whether this correlation between the reperfusion slope of the StO and the FMD response is maintained in upper limbs is important. Accordingly, this study investigated the correlation between the reperfusion slope of the StO and FMD in the arm vasculature.

Acute Response to a 2-Minute Isometric Exercise Test Predicts the Blood Pressure-Lowering Efficacy of Isometric Resistance Training in Young Adults.

Background: This work aimed to explore whether different forms of a simple isometric exercise test could be used to predict the blood pressure (BP)-lowering efficacy of different types of isometric resistance training (IRT) in healthy young adults. In light of the emphasis on primary prevention of hypertension, identifying those with normal BP who will respond to IRT is important. Also, heightened BP reactivity increases hypertension risk, and as IRT reduces BP reactivity in patients with hypertension, it warrants further investigation in a healthy population.