Cigarette Smoking after Aerobic Exercise: The Unfavorable Impacts on Vascular Function

It is well-accepted that vascular dysfunction plays a key role in the pathophysiology of cardiovascular diseases. Although vascular dysfunction is multi-faceted, exercise is a commonly recommended prophylactic strategy to preserve vascular function. We and others have shown that exercise training can elicit beneficial effects on vascular function (e.g., blood pressure and conduit artery function) in healthy and clinical populations1-4. In fact, indices of vascular function are enhanced shortly after acute exercise5,6, suggesting that the postexercise recovery period may be a crucial component for facilitating long-term vascular adaptations7. Poor habits may be detrimental to this recovery window, such as cigarette smoking. Cigarette smoking is considered a common modifiable risk factor for cardiovascular diseases and is associated with arterial stiffness and endothelial dysfunction8,9. Since exercise is often recommended to individuals with cardiovascular risk factors to prevent disease, it is imperative to understand how smoking can impact acute exercise recovery. Previous studies have investigated cigarette smoking prior to acute exercise and revealed that this can impair normal vascular and exercise pressor responses, thus inducing greater cardiac and arterial strain10-12. However, until recently, the impacts of cigarette smoking on hemodynamics and conduit artery function during recovery after aerobic exercise have not been explored. In this issue of The Korean Journal of Sports Medicine, Cho et al.13 investigated the effects of cigarette smoking on blood pressure and conduit artery function during recovery after an acute bout of moderate-intensity aerobic exercise

Microvascular Dysfunction in Peripheral Artery Disease: Is Heat Therapy a Viable Treatment?

Peripheral artery disease (PAD) is characterized by the development of atherosclerotic plaques in the lower-body conduit arteries. PAD is commonly accompanied by microvascular disease, which may result in poor wound healing, plantar ulcer development, and subsequent limb amputation. Understanding the mechanisms underlying the development of plantar ulcers is a critical step in the development of adequate treatment options for patients with PAD. Skin is classified into two major components: glabrous and non-glabrous. These skin types have unique microcirculation characteristics, making it important to differentiate between the two when investigating mechanisms for plantar ulcer development in PAD. There is evidence for a microcirculation compensatory mechanism in PAD. This is evident by the maintenance of basal microcirculation perfusion and capillary filling pressure despite a reduced pressure differential beyond an occlusion in non-critical limb ischemia PAD. The major mechanism for this compensatory system seems to be progressive vasodilation of the arterial network below an occlusion. Recently, heat therapies have emerged as novel treatment options for attenuating the progression of PAD. Heat therapies are capable of stimulating the cardiovascular system, which may lead to beneficial adaptations that may ultimately reduce fatigue during walking in PAD. Early work in this area has shown that full-body heating is capable of generating an acute cardiovascular response, similar to exercise, which has been suggested as the most efficient treatment modality and may generate adaptations with chronic exposure. Heat therapies may emerge as a conservative treatment option capable of attenuating the progression of PAD and ultimately impeding the development of plantar ulcers

Impacts of aquatic walking on arterial stiffness, exercise tolerance, and physical function in patients with peripheral artery disease: a randomized clinical trial

Peripheral artery disease (PAD) is an atherosclerotic disease that is associated with attenuated vascular function, cardiorespiratory capacity, physical function, and muscular strength. It is essential to combat these negative effects on health by incorporating lifestyle interventions to slow disease progression, such as exercise. We sought to examine the effects of aquatic walking exercise on cardiovascular function, cardiorespiratory capacity [maximal volume of oxygen consumption (V̇o2max)], exercise tolerance [6-min walking distance (6MWD)], physical function, muscular strength, and body composition in patients with PAD. Patients with PAD (n = 72) were recruited and randomly assigned to a 12-wk aquatic walking training group (AQ, n = 35) or a control group (CON, n = 37). The AQ group performed walking and leg exercises in waist-to-chest-deep water. Leg arterial stiffness [femoral-to-ankle pulse wave velocity (legPWV)], heart rate (HR), blood pressure (BP), ankle-to-brachial index (ABI), V̇o2max, 6MWD, physical function, muscular strength, body composition, resting metabolic rate (RMR), and flexibility were measured before and after 12 wk. There were significant group × time interactions (P \u3c 0.05) after 12 wk for legPWV and HR, which significantly decreased (P \u3c 0.05) in AQ, and V̇o2max, 6MWD, physical function, and muscular strength, which significantly increased (P \u3c 0.05) in AQ, compared with no changes in CON. There were no significant differences (P \u3e 0.05) for BP, ABI, RMR, or flexibility after 12 wk. Interestingly, there was relatively high adherence (84%) to the aquatic walking exercise program in this population. These results suggest that aquatic walking exercise is an effective therapy to reduce arterial stiffness and resting HR and improve cardiorespiratory capacity, exercise tolerance, physical function, and muscular strength in patients with PAD

Attenuated skeletal muscle metabolism explains blunted reactive hyperemia after prolonged sitting

Introduction: Although reduced post-occlusive reactive hyperemia (PORH) after prolonged sitting (PS) has been reported as impaired microvascular function, no specific mechanism(s) have been elucidated. One potential mechanism, independent of microvascular function, is that an altered muscle metabolic rate (MMR) may change the magnitude of PORH by modifying the oxygen deficit achieved during cuff-induced arterial occlusions. We speculated that if MMR changes during PS, this may invalidate current inferences about microvascular function during PS. Objective: Therefore, the objective of this study was to examine if peripheral leg MMR changes during PS and to ascertain whether the change in the oxygen deficit explains the change in PORH after PS. Hypothesis: We hypothesized that peripheral leg MMR would decrease during sitting and that the reduced oxygen deficit would explain the attenuation in PORH after PS. Methods: 31 subjects sat for 2.5 hours. A near-infrared spectroscopy (NIRS) sensor was placed on the medial gastrocnemius. PORH was quantified with the reoxygenation rate of the NIRS tissue oxygenation index (TOI) after 5-min of a cuff-induced arterial occlusion. MMR was quantified with the TOI slope during a cuff-induced arterial occlusion. Measurements were made before and after sitting. To determine if changes in MMR and the oxygen deficit explains the change in the reoxygenation rate, an artificial neural network (ANN) was trained to define the stimulus-response relationship between the oxygen deficit (i.e., difference in TOI during arterial occlusion (ΔTOI) and the area under baseline TOI during arterial occlusion (AUC)), and the reoxygenation rate with 65 retrospectively collected PORH recordings. The ANN was then used to predict the experimentally collected reoxygenation rates at baseline and post-sitting. Therefore, if the ANN can replicate the experimental results, this provides evidence that the reoxygenation rate after sitting is dependent on MMR and the oxygen deficit during an arterial occlusion. Results: Consistent with other studies, the reoxygenation rate was reduced after PS (Δ -0.27±0.55 ln TOI%·s-1, p-1, pConclusions: Since the oxygen deficit plays a significant role in the reduced reoxygenation rate after PS, current inferences about microvascular function with PORH after PS are not valid. Therefore, these data provide evidence that microvascular function may be preserved during PS. Interestingly, the blunted MMR after PS may not be trivial and could be an important mechanism underlying the relationship between PS and disease development

Effects of heated water-based versus land-based exercise training on vascular function in individuals with peripheral artery disease

Peripheral artery disease (PAD) is an atherosclerotic disease that is associated with poor vascular function, walking impairment, and reduced quality of life. Land-based exercise therapy (LBET) is frequently recommended to improve walking and reduce symptoms. Recently, evidence has suggested that heated-water exercise therapy (HWET) is an effective intervention for PAD. However, the efficacy of LBET versus HWET in PAD patients had not been elucidated. Therefore, we sought to compare effects of LBET with HWET on cardiovascular function, exercise tolerance, physical function, and body composition in PAD patients. PAD patients (n = 53) were recruited and randomly assigned to a LBET group (n = 25) or HWET group (n = 28). The LBET group performed treadmill walking, whereas the HWET group performed walking in heated water for 12 wk. Leg (legPWV) and brachial-to-ankle arterial stiffness (baPWV), blood pressure (BP), ankle-brachial index (ABI), 6-min walking distance (6MWD), claudication onset time (COT), physical function, and body composition were assessed before and after 12 wk. There were significant group-by-time interactions (P \u3c 0.05) for legPWV, BP, 6MWD, COT, body composition, and resting metabolic rate (RMR). Both groups significantly reduced (P \u3c 0.05) legPWV, BP, and body fat percentage, and HWET measures were significantly lower than LBET measures. Both groups significantly increased 6MWD, COT, and RMR, and HWET group measures were significantly greater than LBET measures. A time effect was noted for baPWV reduction in both groups (P \u3c 0.05). These results suggest that both LBET and HWET improve cardiovascular function, exercise tolerance, and body composition, and HWET showed considerably greater improvements compared with LBET in patients with PAD

Body mass-normalized moderate dose of dietary nitrate intake improves endothelial function and walking capacity in patients with peripheral artery disease

Peripheral artery disease (PAD) is characterized by the accumulation of atherosclerotic plaques in the lower extremity conduit arteries, which impairs blood flow and walking capacity. Dietary nitrate has been used to reduce blood pressure (BP) and improve walking capacity in PAD. However, a standardized dose for PAD has not been determined. Therefore, we sought to determine the effects of a body mass-normalized moderate dose of nitrate (0.11 mmol nitrate/kg) as beetroot juice on serum nitrate/nitrite, vascular function, walking capacity, and tissue oxygen utilization capacity in patients with PAD. A total of 11 patients with PAD received either nitrate supplement or placebo in a randomized crossover design. Total serum nitrate/nitrite, resting BP, brachial and popliteal artery endothelial function (flow-mediated dilation, FMD), arterial stiffness (pulse-wave velocity, PWV), augmentation index (AIx), maximal walking distance and time, claudication onset time, and skeletal muscle oxygen utilization were measured pre- and postnitrate and placebo intake. There were significant group × time interactions (P \u3c 0.05) for serum nitrate/nitrite, FMD, BP, walking distance and time, and skeletal muscle oxygen utilization. The nitrate group showed significantly increased serum nitrate/nitrite (Δ1.32 μM), increased brachial and popliteal FMD (Δ1.3% and Δ1.7%, respectively), reduced peripheral and central systolic BP (Δ−4.7 mmHg and Δ−8.2 mmHg, respectively), increased maximal walking distance (Δ92.7 m) and time (Δ56.3 s), and reduced deoxygenated hemoglobin during walking. There were no changes in PWV, AIx, or claudication (P \u3e 0.05). These results indicate that a body-mass normalized moderate dose of nitrate may be effective and safe for reducing BP, improving endothelial function, and improving walking capacity in patients with PAD

The Impact of Aspirin Intake on Lactate Dehydrogenase, Arterial Stiffness, and Oxidative Stress During High-Intensity Exercise: A Pilot Study

Aspirin is a common nonsteroidal anti-inflammatory drug used to reduce fever, pain, and inflammation. However, aspirin\u27s anti-inflammatory properties may also prevent increased levels of blood lactate dehydrogenase, vascular arterial stiffness and oxidative stress induced by high-intensity exercise. The purpose of this study was to investigate the effects of 4 weeks of aspirin supplementation on lactate dehydrogenase activity, lactate, arterial stiffness, and antioxidant capacity during high-intensity exercise in Taekwondo athletes. Participants were randomly divided into two groups: aspirin supplementation (n = 10) and placebo-control (n = 10). Blood levels of lactate dehydrogenase (LDH) enzyme activity and lactate were assessed to examine muscle damage and carotid-to-radial pulse wave velocity and the augmentation index were measured to examine arterial stiffness. Blood levels of superoxide dismutase, malondialdehyde, and glutathione peroxidase were assessed to determine antioxidant capacity and levels of oxidative stress. There were significant group × time interactions for enzyme activity of LDH (Δ-60 ± 24.36 U/L) and carotid-to-radial pulse wave velocity (Δ-1.33 ± 0.54 m/s), which significantly decreased (p \u3c 0.05) following aspirin supplementation compared to placebo-control. Superoxide dismutase (Δ359 ± 110 U/gHb) and glutathione peroxidase (Δ28.2 ± 10.1 U/gHb) significantly decreased while malondialdehyde (0Δ3.0 ± 0.1 mmol/mL) significantly increased (p \u3c 0.05) in the placebo-control group compared to the supplementation group. However, there were no changes in lactate concentration levels or augmentation index. These results reveal that low-dose aspirin supplementation would be a useful supplementation therapy to prevent high-intensity exercise training-induced increases in oxidative damage, inflammation, skeletal muscle fatigue, and arterial stiffness in elite Taekwondo athletes

IMPACT OF SEX ON MACROVASCULAR ENDOTHELIAL FUNCTION DURING PROLONGED SITTING WITH A MILD HYPERCAPNIC ENVIRONEMNT

IMPACT OF SEX ON MACROVASCULAR ENDOTHELIAL FUNCTION DURING PROLONGED SITTING WITH A MILD HYPERCAPNIC ENVIORNMENT Andres Benitez-Albiter1, Michael F. Allen1, Elizabeth J. Pekas1, Cody P. Anderson1, and Song-Young Park1 1 - School of Health & Kinesiology University of Nebraska Omaha, Omaha, NE Introduction: Prolonged sitting (PS), defined as sitting for 2+ hours at a time[SYP1] , has been identified as an independent risk factor for cardiovascular disease. It has been well-documented that an acute PS bout can impair macro- and microvascular dysfunction in healthy young individuals. Recently, we reported that PS in mild hypercapnic environments (elevated CO2 concentrations equivalent to crowded areas such as offices or auditoriums) can further exacerbate these impairments in healthy young adults, and these impairments can be partially prevented by intermittent bouts of passive and active leg movements. Office workers are one of the largest sectors of the US workforce, and have been reported to be frequently exposed to PS with mild hypercapnic environments. Therefore, there is a need of study to examine if our previous findings can be seen in office workers. Additionally, it is crucial to investigate if there is any differential contribution of biological sex on these findings. The purpose of this study was to examine the impact of active and passive muscular contraction on macrovascular endothelial function during PS with mild-hypercapnic environment in middle-aged office workers, and further compare potential differences between sex. Methods: Healthy office workers (n=13, 6 males and 7 females, 39±4, 41±9, respectively) participated in three experimental visits and consisted of 2.5 h of prolonged sitting in a mild-hypercapnic environment (CO2 = 1500 ppm): control (CON, no movement), passive (PASS, passive limb movement), and active (ACT, active limb movement). Brachial artery and popliteal artery endothelial function were measured pre- and post-sitting for all visits using flow-mediated dilation (FMD). Results: Following 2.5 h of sitting, ACT showed greater popliteal artery FMD compared to CON. Additionally, females exhibited a significant reduction in popliteal artery FMD in the CON but was preserved in males after PS. No changes in Brachial artery FMD after PS, and no sex difference was found. Conclusion: PS significantly reduces leg vascular function in middle-aged office workers. Additionally, females showed greater reduction in leg vascular function compared to males. We conclude that uninterrupted prolonged sitting may induce a greater impairment on leg vascular function in females, indicating that this population may be at a greater risk compared to males. Additionally, intermittent bouts of active movement required to preserve leg vascular function during bouts of PS

Habitual Combined Exercise Protects against Age-Associated Decline in Vascular Function and Lipid Profiles in Elderly Postmenopausal Women

Postmenopausal status is associated with increased risks for cardiovascular diseases (CVD). This study investigated differences in vascular function, lipids, body composition, and physical fitness in elderly postmenopausal women active in combined resistance and aerobic exercise (CRAE) training for 1 year versus a sedentary cohort of similar-in-age counterparts. Elderly postmenopausal women performing habitual CRAE training for 1 year (age ~75 year; CRAE, n = 57) and elderly sedentary postmenopausal women (age ~78 year; SED, n = 44) were recruited. Arterial stiffness (brachial-to-ankle pulse-wave velocity, baPWV), blood pressure, blood lipids, anthropometrics, 2-min walking distance, and muscular strength were assessed for both groups. There were significant differences for baPWV, systolic blood pressure, low-density lipoprotein, and body fat percentage, which were significantly lower (p \u3c 0.05) in CRAE vs. SED, and both 2 min walking distance and muscular strength were significantly greater (p \u3c 0.05) in CRAE vs. SED. These results indicate that elderly postmenopausal women participating in habitual CRAE training may have better protection against risks for CVD and have better physical fitness compared to SED counterparts

Improvement of Lipids and Reduction of Oxidative Stress With Octacosanol After Taekwondo Training

Athletes in combat sports undergo rapid changes in body weight prior to competition in order to gain a size advantage over their opponent. However, these large weight changes with concomitant high-intensity exercise training create poor lipid profiles and high levels of oxidative stress, which can be detrimental to health and sport performance. Therefore, the purpose of this study was to investigate the ability of the nutritional supplement octacosanol to combat the physiological detriments that occur in taekwondo players during rapid weight loss with high-intensity exercise training. Methods: A total of 26 male taekwondo players were randomly divided into 2 groups: An experimental group performed a 5% weight-loss and taekwondo training program with 40-mg octacosanol intake (OCT; n = 13) for 6 d, and a control group performed the same weight-loss and taekwondo training program with a placebo (CON; n = 13). Results: There were significant (P \u3c .05) group × time interactions for low-density lipoprotein and triglycerides, which significantly decreased (Δ18 [5] mg/dL and Δ80 [7] mg/dL, respectively), and high-density lipoprotein, which significantly increased (Δ10 [7] mg/dL), in the OCT group compared with the CON group. There were also significant (P \u3c .05) group × time interactions for superoxide dismutase (SOD), glutathione peroxidase (GPx), and malondialdehyde (MDA), with SOD increasing (Δ226 [121] U/gHb) in the OCT group, while GPx decreased (Δ20 [13] U/gHb) and MDA increased (Δ72 [0.04] nmol/mL) in the CON group. Conclusion: These results suggest that octacosanol may be a beneficial supplement to protect against the poor cholesterol levels and oxidative stress that occurs during taekwondo training