Effects of Isometric Handgrip Exercise versus Aerobic Exercise on Arterial Stiffness and Brachial Artery Flow-Mediated Dilation in Older Hypertensive Patients / 대한스포츠의학회지

PURPOSE: Isometric handgrip exercise (IHE) is an easy and accessible form of exercise that has beneficial effects on blood pressure (BP). However, it remains unclear whether IHE is similar benefits on arterial stiffness and endothelial function compared with aerobic exercise (AE) in elderly hypertensive patients. The aim of this study was to compare the effects of IHE versus AE on arterial stiffness and endothelial function in elderly hypertensive patients.METHODS: We conducted a randomized controlled trial with a three-arm design. Fifty-four elderly hypertensive patients (15 men; mean age, 69±6 years; systolic blood pressure, 131.2±14.7; diastolic blood pressure, 80.2±7.9 mm Hg) were randomized to IHE training (n=18), AE training (n=21), or non-exercise control group (n=21) for 12 weeks. Bilateral IHE training was performed four times of 2 minutes at 30% of maximal voluntary contraction with three times per week. AE training was performed brisk walking for 30 minutes at moderate intensity with three times per week. Carotid-femoral pulse wave velocity (PWV), augmentation index heart rate corrected (AIx@75 bpm) and brachial artery flow-mediated vasodilation (FMD) as indices of arterial stiffness and endothelial function were measured at baseline and after the intervention.RESULTS: Following 12-week intervention, resting BP was significantly decreased in both IHE (p=0.001) and AE groups (p=0.002). AIx@75 bpm and FMD were unchanged in the all groups. However, PWV was significantly decreased in both IHE and AE groups (IHE, 10.9±2.3 to 9.9±2.1 m/s [p<0.001]; AE, 10.5±2.0 to 9.4±1.6 m/s [p=0.001]), without any change in the control group.CONCLUSION: These findings suggest that both IHE and AE trainings were comparable effect in improving arterial stiffness in elderly hypertensive patients.

Effect of Remote Ischemic Preconditioning on Maximal Exercise Tolerance in Young Adults / 대한스포츠의학회지

PURPOSE: Remote ischemic preconditioning (RIPC), induced by repeated bouts of ischemia followed by reperfusion of the arm or leg is a noninvasive strategy to protect a target organ against oxidative stress and injury caused by ischemia and reperfusion. Interestingly, recent evidence suggests that RIPC may also improve exercise performance by increasing maximal oxygen consumption, but such finding remain equivocal. As such, the purpose of the study was to examine the effect of RIPC on exercise performance in healthy individuals. METHODS: In a randomized cross-over design, 17 healthy male participants (age, 23±3 years) were exposed to either a sham control (six cycles of 5 minutes bilateral thigh cuff occlusion at 20 mm Hg) or RIPC (six cycles of 5 minutes bilateral thigh cuff occlusion at 180 mm Hg) an hour before a maximal exercise test. We measured maximal oxygen consumption, power output, heat rate, blood pressure, and blood lactate as exercise performance parameters during a maximal exercise test performed on an upright bicycle. RESULTS: Compared with the sham control, RIPC improved maximal oxygen consumption (7.4%, p=0.025) and maximal power output (11.5%, p=0.010), whereas other exercise performance parameters remained unchanged with RIPC (p>0.05). CONCLUSION: Taken together, the improvements in maximal oxygen consumption and maximal power output induced by RIPC may suggest that RIPC should be considered as a method for improving exercise performance.

Effect of an Exergaming on Postprandial Endothelial Dysfunction Following a High Fat Meal in Individuals with Spinal Cord Injury / 대한스포츠의학회지

Endothelial dysfunction induced with a high-fat meal may be attenuated with an exercise in abled bodies individuals. Exergaming may be an exercise type applicable for disabled bodied individuals. We tested the hypothesis that an acute bout of exergaming following a high-fat meal would decrease postprandial lipemia, and endothelial dysfunction among individuals with spinal cord injury. Forty participants (age, 41±8 years; 24 males) were randomly assigned to either an exergaming group (n=20) or control group with seated rest (n=20) following a high-fat meal. Hemodynamic and blood parameters and flow-mediated vasodilation (FMD) as an index of endothelial function were measured at baseline and 4 hours after a high-fat meal. In half an hour following a high-fat meal, the exergaming group performed 50 minutes of moderate intensity active video games (Nintendo Wii Sports: boxing, tennis). Levels of blood triglycerides increased in both group (p<0.05) following high-fat meal. FMD significantly decreased in the control group (10.4%±4.9% to 7.9%±4.4%) but significantly increased in the exergaming group (10.9%±5.3% to 12.3%±5.3%), with a significant interaction (p=0.004). These results show that a high-fat meal causes endothelial dysfunction in persons with spinal cord injury, but endothelial dysfunction following a high-fat meal was attenuated by an acute bout of exergaming regardless of postprandial lipemia. Therefore, exergaming for individuals with spinal cord injury may have a cardioprotective effect from postprandial endothelial dysfunction induced with an exposure of a high-fat meal.

Comparison of Physical Activity and Health-related Quality of Life in Adolescents with and without Congenital Heart Disease: A Propensity Matched Comparison / 대한스포츠의학회지

Physical activity and health-related quality of life (HRQOL) are associated with overall health outcomes in adolescents with congenital heart disease (CHD). The purpose of this study was to compare the levels of physical activity and HRQOL in adolescents with CHD and healthy controls. In addition, we compared these variables using a propensity score matching to reduce the confounding effects. Participants were divided into three groups with simple CHD (n=55), complex CHD (n=173), and healthy controls (n=181). Self-reported physical activity levels (metabolic equivalent of task [MET]-hr/wk) were obtained using the Global Physical Activity Questionnaire. HRQOL was evaluated using the Pediatric Quality of Life Inventory questionnaire. Total scores of HRQOL in adolescents with complex CHD were significantly lower than those with simple CHD (p=0.022) and healthy controls (p<0.001), respectively; however, there was no significant difference in total scores of HRQOL between adolescents with simple CHD and healthy controls. Levels of physical activity in adolescents with complex CHD were significantly lower than those with simple CHD (p=0.001) and healthy controls (p<0.001). After propensity matched analysis (44 pairs), the results were consistent with the above results. In conclusion, HRQOL scores and physical activity levels are significantly lower in adolescents with complex CHD, but not in adolescents with simple CHD, than in healthy adolescents.

Association of Occupational Stress and Cardiorespiratory Fitness with Cardiovascular Disease Risk Factors in Office Workers / 대한스포츠의학회지

Occupational stress is associated with increased risk of cardiovascular disease (CVD), while cardiorespiratory fitness (CRF) is associated with decreased risk of CVD. We tested the hypothesis that high occupational stress would be associated with increased cardiovascular risk profiles, but CRF may attenuate this association. We conducted a cross-sectional analysis in 70 healthy office workers (male, 28; female, 42; mean age, 38±8 years). Occupational stress was assessed using a validated self-reported questionnaire. Total CVD risk score (sum of z-standardized residuals) was calculated by blood pressure, body mass index, lipid profiles and glucose. CRF was estimated by predicted equation during maximal treadmill exercise test. The results showed that an interpersonal conflict as an index of occupational stress was positively correlated with cardiovascular risk score (r=0.43, p0.05). Furthermore, Participants with high stress but high CRF had lower cardiovascular risk score than those with high stress but low CRF (p<0.05). In conclusion, occupational stress is associated with an increased CVD risk, but CRF attenuated this association in office worker with increased occupational stress.

Acute Resistance Exercise Attenuates the Cardiovascular Reactivity to Cold Pressor Test in Healthy Adults / 대한스포츠의학회지

Increased cardiovascular reactivity to sympathetic challenge is associated with increased risk of hypertension and cardiovascular disease. Acute aerobic exercise blunts stress related cardiovascular reactivity, but whether acute resistance exercise attenuates cardiovascular reactivity is unknown. We tested the hypothesis that acute resistance exercise will attenuate hemodynamic reactivity to a cold pressor test in healthy adults. Using a randomized cross-over trial, 20 healthy adults (9 males, 11 females; age, 26±5 years; body mass index, 23.85±3.19 kg/m2) completed two testing sessions, separated by 1 week. Sessions consisted of either a control condition or an acute resistance exercise prior to cold pressor testing (two sets, eight exercises, 40%-60% of 1 repetition maximum for upper and lower extremity). Blood pressure and heart rate measured at baseline, 30 seconds, and 120 seconds during a 3-minute cold pressor test (ice water, 4℃), and 30 seconds and 120 seconds post-cold pressor testing, respectively. During the cold pressor test, there were significant increases in blood pressures and heart rate (p<0.05) in both groups. However, acute resistance exercise attenuated increases in systolic blood pressure, but not heart rate, compared with the control (all p<0.05 for interact effects). These findings show that the cold pressor test significantly increases blood pressures and heart rate in healthy adults, but an acute bout of resistance exercise attenuated the hemodynamic response to the cold pressor test. Therefore, resistance exercise may have a favorable effect on cardiovascular reactivity to sympathetic activation in healthy adults.

The Effects of Acute Resistance Exercise on Ischemia-Reperfusion Injury-Induced Macro and Microvascular Dysfunction in Healthy Young Adults / 대한스포츠의학회지

Ischemia reperfusion injury (IRI) leads to a temporary decrease in macrovascular function, but whether IRI causes microvascular dysfunction is not known. Resistance exercise involves muscular contractions that can make downstream tissues ischemic and may ischemic preconditioning the vasculature against endothelial IRI. We tested the hypothesis that an acute resistance exercise prior to IRI would prevent or attenuate IRI induced macro- and microvascular dysfunction in healthy young adults. Nineteen healthy young subjects (age 22+/-2 years) were randomly assigned to either a resistance exercise group (n=10) as a model to produce ischemic preconditioning or a control group (n=9). The resistance exercise was performed eight types of systemic resistance exercise. Ischemia was induced by inflating a cuff placed around the upper arm to 200 mm Hg for 20 minutes. carotid-femoral pulse wave velocity (cfPWV) as index of macrovascular function and reactive hyperemia index (RHI) using by fingertip arterial tonometry as index of microvascular function were measured at baselines and 15 and 30 minutes after ischemia reperfusion injury. cfPWV was increased in control group but decreased in resistance exercise group following IRI. There was a significant interaction effect between resistance exercise group and control group for cfPWV (p=0.022). The RHI was unaffected following IRI and also unchanged by a resistance exercise. These findings show that ischemia reperfusion caused macrovascular dysfunction but not microvascular dysfunction. However, this macrovascular dysfunction following IRI was not shown in the resistance exercise group. Thus, an acute bout of resistance exercise prior to ischemia may prevent against ischemia reperfusion injury induced macrovascular dysfunction.

Effects of Acute Resistance Exercise on Arterial Stiffness in Young Men

BACKGROUND AND OBJECTIVES: Increased central arterial stiffness is an emerging risk factor for cardiovascular disease. Acute aerobic exercise reduces arterial stiffness, while acute resistance exercise may increase arterial stiffness, but this is not a universal finding. We tested whether an acute resistance exercise program was associated with an increase in arterial stiffness in healthy young men. SUBJECTS AND METHODS: Thirteen healthy subjects were studied under parallel experimental conditions on 2 separate days. The order of experiments was randomized between resistance exercise (8 resistance exercises at 60% of 1 repeated maximal) and sham control (seated rest in the exercise room). Carotid-femoral pulse wave velocity (PWV) and aortic augmentation index as indices of aortic stiffness were measured using applanation tonometry. Measurements were made at baseline before treatments, 20 minutes, and 40 minutes after treatments (resistance exercise and sham control). RESULTS: There was no difference in resting heart rate or in arterial stiffness between the two experimental conditions at baseline. At 20 minutes after resistance exercise, heart rate, carotid-femoral PWV and augmentation index@75(%) were significantly increased in the resistance exercise group compared with the sham control (p<0.05). Brachial blood pressure, central blood pressure and pulse pressure were not significantly increased after resistance exercise. CONCLUSION: An acute resistance exercise program can increase arterial stiffness in young healthy men. Further studies are needed to clarify the effects of long-term resistance training on arterial stiffness.