Sascha Ketelhut

Favorable effect of aerobic exercise on arterial pressure and aortic pulse wave velocity during stress testing

BACKGROUND Increased central pulse wave velocity is a major risk factor for cardiovascular disease. The favorable influence of exercise on arterial stiffness (AS) and blood pressure (BP) has been reported exclusively at rest. The present study investigated the influence of a single bout of acute cycling on AS and BP during recovery and, moreover, during cold pressor stress testing. PROBANDS AND METHODS 32 healthy men (33.7 ± 8 years, BMI 24 ± 2.5 kg/m²) performed a 60 minute endurance exercise on a bicycle ergometer (45 % VO2max). Before and after exercise aortic pulse wave velocity (aPWV) as well as central and peripheral BP were measured non-invasively at rest and at the end of a 2 minute cold pressor test (CPT). RESULTS Even after 60 minutes of recovery aPWV (- 0.22 ± 0.3 m / sec) was significantly reduced (p < 0.01). Exercise decreased peripheral (- 8 ± 7 mmHg) and central (- 7 ± 8 mmHg) systolic BP as well as peripheral (- 3 ± 5 mmHg) and central (- 4 ± 7 mmHg) diastolic BP (p < 0.01). In comparison to measurements during CPT pre-exercise, there was a significant reduction in aPWV (- 0.19 ± 0.3 m / sec), peripheral (- 6 ± 10 mmHg) and central (- 5 ± 8 mmHg) systolic BP as well as peripheral (- 3 ± 6 mmHg) and central (- 3 ± 6 mmHg) diastolic BP during CPT after exercise (p < 0.01). CONCLUSIONS The present study suggests that acute endurance exercise leads not only to decreased BP but even more reduces aPWV as a measure of AS even after 60 minutes of recovery. In particular, the investigation provides evidence that acute moderate-intensity exercise has a favorable effect on BP and aPWV during stress testing.

Influence of a high-intensity interval training session on peripheral and central blood pressure at rest and during stress testing in healthy individuals

BACKGROUND Regular physical activity is known to reduce arterial pressure (BP). In a previous investigation, we could prove that even a single bout of moderate-intensity continuous exercise (MICE) causes a prolonged reduction in BP. Whether high-intensity interval training (HIIT) has a favourable influence on BP, and therefore may be followed subjects and methods by a prolonged BP reduction, should be examined on the basis of blood pressure response after exercise and during a subsequent stress test. PATIENTS AND METHODS In 39 healthy men (aged 34 ± 8 years, BMI 24 ± 2), peripheral and central BP were measured noninvasively at rest and at the end of a 2-min cold pressor test (CPT) using a Mobil-O-Graph (24 PWA monitor, IEM). Following HIIT (6 x 1 min at 98% of the previously determined maximum wattage, 4-min rest between intervals) BP was measured again throughout 60 min of rest and thereafter during a CPT. The results were compared with those obtained before HIIT. RESULTS Similar to MICE, peripheral and central BPs were significantly (p < 0.05) lower 45 min after HIIT. When analysing peripheral BP during a CPT before and after exercise, significantly lower systolic (p < 0.001) and diastolic (p = 0.008) pressures were established after HIIT. This was true for systolic (p = 0.002) and diastolic (p = 0.006) central BP as well. Although there were no more significant differences between pressures at rest before and 60 min after exercise, the increase in peripheral systolic pressure due to CPT was significantly slower after HIIT (p = 0.019) when compared with BP during CPT before exercise. This was true for central systolic BP as well (p = 0.017). CONCLUSION HIIT leads to a BP reduction, which can still be detected up to 45 min after completion of the training. Even 60 min after exercise, pressures during a CPT showed a reduced augmentation, indicating an attenuated hemodynamic response to stress testing after HIIT.

Daily Physical Activity Improves Vascular Function and Motor Skills in Children

The literature is consistent that regular physical activity in children has to be increased in order to compensate the negative health effects resulting from growing sedentary lifestyle. Thus, we analyzed in 45 students (aged 6.6 ± 0.7 years) the effects of a regular exercise intervention, on top of the normal physical education classes, on motor performance (MP) and hemodynamic parameters. The students were randomized either to an intervention (INT) (n = 23) or a control (CON) (n = 22) group. Throughout a 9 months period, INT received additional exercise interventions two days a week for 45 minutes. The main outcome measures were MP, peripheral and central blood pressure (BP), augmentation index (Alx) and aortic pulse wave velocity (aPWV). After the exercise intervention, we found significant (P < 0.05) positive effects on various test items of MP and significant decreases in peripheral and central systolic BP in INT. In contrast, in CON the respective parameters increased in CON after the observation period. Moreover, aPWV decreased significantly in INT (P = 0.047) and increased in CON, thus resulting in a significant difference in the mean change (P = 0.043). There were no considerable changes in AIx in both groups. In conclusion, we demonstrated that an increase in regular physical activity has a positive influence on development of MP and hemodynamic parameters even in early childhood. The findings of this study suggest that an increase in exercise time should be initiated as early as possible to improve motor ability and prevent future cardiovascular risk.

MPS 17-02 Acute effects of continuous endurance training on stress test-related pulse pressure and wave reflection in healthy men

Objective: Arterial dysfunction develops early in life even in individuals with modest cardiovascular risk. Physical activity is known to improve arterial compliance under resting conditions. However, chronic as well as acute stress is associated with increased risk in cardiovascular morbidity and mortality. Therefore, our aim was to investigate the acute effects of continuous endurance exercise (CEE) on arterial pulse pressure and wave reflection, established markers of arterial stiffness and cardiovascular risk, during stress testing. Design and Method: A total of 32 young healthy male participants (33.7 ± 8 years, BMI 24 ± 2.5 kg/m2) performed moderate cycle ergometer exercise for 60 minutes with 65% of the previously during cardiopulmonary exercise testing determined maximum heart rate. Before and 60 minutes after exercise peripheral pulse pressure (PP) as well as augmentation index (AIx) were measured at the end of a 2 minute cold pressor test (CPT) using an oscillometric device. Results: In comparison to measurements during CPT before exercise, there was a significant reduction in PP (47.5 ± 10 mmHg to 43.2 ± 9 mmHg, p = 0.03) as well as AIx (10.3 ± 9 % to 5.0 ± 9 %, p = 0.003) during CPT after exercise. Conclusions: The study provides evidence that acute CEE has a favorable effect on peripheral PP during stress testing. At the same time the measurement of AIx during a CPT showed a reduced augmentation after completion of CEE indicating attenuated response to hemodynamic stress after CEE. However, it remains to be investigated whether regular CEE can induce clinically relevant improvements of arterial wave reflection in real-life stress situations.