E-cigarettes are tobacco products frequently used by youth and young adults. Little is known about the long-term health effects of their prolonged use. Results from the present study demonstrate that young, apparently healthy, regular users of e-cigarettes exhibit significantly reduced cardiorespiratory fitness, a marker of cardiovascular health and a predictor of all-cause mortality. We also identified that the young users of e-cigarettes present with lower chronotropic response and impaired skeletal muscle oxygen utilization during exercise.

Background: This study sought to determine the impact of an acute prior bout of high-intensity interval aerobic exercise on attenuating the vascular dysfunction associated with a prolonged sedentary bout. Methods: Ten young (24 ± 1 y) healthy males completed two 3-hour sessions of prolonged sitting with (SIT-EX) and without (SIT) a high-intensity interval aerobic exercise session performed immediately prior. Prior to and 3 hours into the sitting bout, leg vascular function was assessed with the passive leg movement technique, and blood samples were obtained from the lower limb to evaluate changes in oxidative stress (malondialdehyde and superoxide dismutase) and inflammation (interleukin-6). Results: No presitting differences in leg vascular function (assessed via passive leg movement technique-induced hyperemia) were revealed between conditions. After 3 hours of prolonged sitting, leg vascular function was significantly reduced in the SIT condition, but unchanged in the SIT-EX. Lower limb blood samples revealed no alterations in oxidative stress, antioxidant capacity, or inflammation in either condition. Conclusions: This study revealed that lower limb vascular dysfunction was significantly attenuated by an acute presitting bout of high-intensity interval aerobic exercise. Further analysis of lower limb blood samples revealed no changes in circulating oxidative stress or inflammation in either condition.

Background: Electronic (e-) cigarettes are increasingly popular tobacco products on the US market. Traditional tobacco products are known to cause vascular dysfunction, one of the earliest indicators of cardiovascular disease (CVD) development. However, little is known about the effect of regular e-cigarette use on vascular function. The purpose of this study was to investigate the impact of regular e-cigarette use on vascular function and cardiovascular health in young, healthy adults. Methods: Twenty-one regular users of e-cigarettes (ECU) and twenty-one demographically matched non-users (NU) completed this study. Vascular health was assessed in the cutaneous microcirculation through different reactivity tests to evaluate overall functionality, endothelium-dependent vasodilation (EDD), and endothelium-independent vasodilation (EID). Macrovascular function was assessed using flow-mediated dilation (FMD). Results: Our results suggest that regular users of e-cigarettes present with premature microvascular impairment when compared to non-users. Specifically, they exhibit lower hyperemic (p = 0.003), thermal (p = 0.010), and EDD (p = 0.004) responses. No differences in EID between the groups were identified. We also identified that individuals who use e-cigarettes for longer than 3 years also present with systemic manifestations, as observed by significantly reduced macrovascular (p = 0.002) and microvascular (p ≤ 0.044) function. Conclusions: Our novel data suggests that young, apparently healthy, regular users of e-cigarettes present with premature vascular dysfunction in the microcirculation when compared to non-users. We have also identified systemic vascular dysfunction affecting both the micro and macrovasculature in those young individuals who used e-cigarettes for longer than 3 years. Taken together, these findings associate regular e-cigarette use with premature vascular dysfunctions and adverse cardiovascular outcomes.

Posttraumatic stress disorder (PTSD) has been associated with an increase in risk of cardiovascular disease (CVD). The goal of this study was to determine if peripheral vascular dysfunction, a precursor to CVD, was present in young adults with PTSD, and if an acute antioxidant (AO) supplementation could modify this potential PTSD-induced vascular dysfunction. Thirteen individuals with PTSD were recruited for this investigation and were compared with 35 age- and sex-matched controls (CTRL). The PTSD group participated in two visits, consuming either a placebo (PTSD-PL) or antioxidants (PTSD-AO; vitamins C and E; α-lipoic acid) before their visits, whereas the CTRL subjects only participated in one visit. Upper and lower limb vascular functions were assessed via flow-mediated dilation and passive leg movement technique. Heart rate variability was utilized to assess autonomic nervous system modulation. The PTSD-PL condition, when compared with the CTRL group, reported lower arm and leg microvascular function as well as sympathetic nervous system (SNS) predominance. After acute AO supplementation, arm, but not leg, microvascular function was improved and SNS predominance was lowered to which the prior difference between PTSD group and CTRL was no longer significant. Young individuals with PTSD demonstrated lower arm and leg microvascular function as well as greater SNS predominance when compared with age- and sex-matched controls. Furthermore, this lower vascular/autonomic function was augmented by an acute AO supplementation to the level of the healthy controls, potentially implicating oxidative stress as a contributor to this blunted vascular/autonomic function.

Purpose: Adequate, robust vascular responses to passive and active movement represent two distinct components linked to normal, healthy cardiovascular function. Currently, limited research exists determining if these vascular responses are altered in premenopausal females (PMF) when compared across sex or menstrual cycle phase. Methods: Vascular responses to passive leg movement (PLM) and handgrip (HG) exercise were assessed in PMF (n = 21) and age-matched men (n = 21). A subset of PMF subjects (n = 11) completed both assessments during the early and late follicular phase of their menstrual cycle. Microvascular function was assessed during PLM via changes in leg blood flow, and during HG exercise, via steady-state arm vascular conductance. Macrovascular (brachial artery [BA]) function was assessed during HG exercise via BA dilation responses as well as BA shear rate-dilation slopes. Results: Leg microvascular function, determined by PLM, was not different between sexes or across menstrual cycle phase. However, arm microvascular function, demonstrated by arm vascular conductance, was lower in PMF compared with men at rest and during HG exercise. Macrovascular function was not different between sexes or across menstrual cycle phase. Conclusions: This study identified similar vascular function across sex and menstrual cycle phase seen in microvasculature of the leg and macrovascular (BA) of the arm. Although arm microvascular function was unaltered by menstrual cycle phase in PMF, it was revealed to be significantly lower when compared with age-matched men highlighting a sex difference in vascular/blood flow regulation during small muscle mass exercise.