Resistive exercise versus resistive vibration exercise to counteract vascular adaptations to bed rest

Bed rest results in marked vascular adaptations, and resistive vibration exercise (RVE) has been shown to be an effective countermeasure. As vibration exercise has practical and logistical limitations, the use of resistive exercise (RES) alone has the preference under specific circumstances. However, it is unknown if RES is sufficient to prevent vascular adaptations to bed rest. Therefore, the purpose of the present study was to examine the impact of RES and RVE on the vascular function and structure of the superficial femoral artery in young men exposed to 60 days of bed rest. Eighteen healthy men (age: 31 ± 8 yr) were assigned to bed rest and randomly allocated to control, RES, or RVE groups. Exercise was applied 3 times/wk for 5–7 min/session. Resting diameter, blood flow, flow-mediated dilation (FMD), and dilator capacity of the superficial femoral artery were measured using echo-Doppler ultrasound. Bed rest decreased superficial femoral artery diameter and dilator capacity ( P < 0.001), which were significantly attenuated in the RVE group ( P < 0.01 and P < 0.05, respectively) but not in the RES group ( P = 0.202 and P = 0.696, respectively). Bed rest significantly increased FMD ( P < 0.001), an effect that was abolished by RVE ( P < 0.005) but not RES ( P = 0.078). Resting and hyperemic blood flow did not change in any of the groups. Thus, RVE abolished the marked increase in FMD and decrease in baseline diameter and dilator capacity normally associated with prolonged bed rest. However, the stimulus provided by RES alone was insufficient to counteract the vascular adaptations to bed rest.

Download Full-text

Vascular adaptation to deconditioning and the effect of an exercise countermeasure: results of the Berlin Bed Rest study

Journal of Applied Physiology ◽

10.1152/japplphysiol.00118.2005 ◽

2005 ◽

Vol 99 (4) ◽

pp. 1293-1300 ◽

Cited By ~ 95

Author(s):

Michiel W. P. Bleeker ◽

Patricia C. E. De Groot ◽

Gerard A. Rongen ◽

Jörn Rittweger ◽

Dieter Felsenberg ◽

...

Keyword(s):

Nitric Oxide ◽

Blood Flow ◽

Femoral Artery ◽

Bed Rest ◽

Common Femoral Artery ◽

Vascular Adaptation ◽

Vibration Exercise ◽

Before And After ◽

Echo Doppler Ultrasound ◽

And Function

Deconditioning is a risk factor for cardiovascular disease. The physiology of vascular adaptation to deconditioning has not been elucidated. The purpose of the present study was to assess the effects of bed rest deconditioning on vascular dimension and function of leg conduit arteries. In addition, the effectiveness of resistive vibration exercise as a countermeasure for vascular deconditioning during bed rest was evaluated. Sixteen healthy men were randomly assigned to bed rest (BR-Ctrl) or to bed rest with resistive vibration exercise (BR-RVE). Before and after 25 and 52 days of strict horizontal bed rest, arterial diameter, blood flow, flow-mediated dilatation (FMD), and nitroglycerin-mediated dilatation were measured by echo Doppler ultrasound. In the BR-Ctrl group, the diameter of the common femoral artery decreased by 13 ± 3% after 25 and 17 ± 1% after 52 days of bed rest ( P < 0.001). In the BR-RVE group this decrease in diameter was significantly attenuated (5 ± 2% after 25 days and 6 ± 2% after 52 days, P < 0.01 vs. BR-Ctrl). Baseline blood flow did not change after bed rest in either group. After 52 days of bed rest, FMD and nitroglycerin-mediated dilatation of the superficial femoral artery were increased in both groups, possibly by increased nitric oxide sensitivity. In conclusion, bed rest deconditioning is accompanied by a reduction in the diameter of the conduit arteries and by an increased reactivity to nitric oxide. Resistive vibration exercise effectively attenuates the diameter decrease of leg conduit arteries after bed rest.

Download Full-text

Hourly staircase sprinting exercise “snacks” improve femoral artery shear patterns but not flow-mediated dilation or cerebrovascular regulation: A pilot study

Applied Physiology Nutrition and Metabolism ◽

10.1139/apnm-2020-0562 ◽

2020 ◽

Author(s):

Hannah G Caldwell ◽

Geoff B Coombs ◽

Hossein Rafiei ◽

Philip N Ainslie ◽

Jonathan P. Little

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Femoral Artery ◽

Vascular Function ◽

Regional Blood Flow ◽

Cerebral Metabolism ◽

Neurovascular Coupling ◽

Duplex Ultrasound ◽

Transcranial Doppler Ultrasound ◽

Flow Mediated Dilation

Healthy males (n=10; 24±4 years; BMI: 24±2 kg/m2) completed two randomized conditions separated by ≥48 hours involving 6-8.5 hours of sitting with (“stair snacks”) and without (sedentary) hourly staircase sprint interval exercise (approx. 14-20 s each). Resting blood flow and shear rates were measured in the femoral artery, internal carotid artery, and vertebral artery (Duplex ultrasound). Flow-mediated dilation (FMD) was quantified as an index of peripheral endothelial function in the femoral artery. Neurovascular coupling (NVC; regional blood flow response to local increases in cerebral metabolism) was assessed in the posterior cerebral artery (transcranial Doppler ultrasound). Femoral artery hemodynamics were higher following the active trial with no change in the sedentary trial, including blood flow (+32±23% vs. -10±28%; P=0.015 and P=0.253, respectively), vascular conductance (+32±27% vs. -15±26%; P=0.012 and P=0.098, respectively), and mean shear rate (+17±8% vs. -8±28%; P=0.004 and P=0.310, respectively). The change in FMD was not different within or between conditions (P=0.184). Global cerebral blood flow (CBF), conductance, shear patterns, and NVC were not different within or between conditions (all P>0.05). Overall, exercise “stair snacks” improve femoral artery blood flow and shear patterns but not peripheral (e.g., FMD) or cerebral (e.g., CBF and NVC) vascular function following prolonged sitting. The study was registered at ClinicalTrials.gov (NCT03374436) Key findings: ● Breaking up 8.5 hours of sitting with hourly staircase sprinting exercise “snacks” improves resting femoral artery shear patterns but not flow-mediated dilation. ● Cerebral blood flow and neurovascular coupling were unaltered following 6 hours of sitting with and without hourly exercise breaks.

Download Full-text

The Impact of Different Exercise Intensities on Vasodilation and Shear Rate Patterns in Children

Pediatric Exercise Science ◽

10.1123/pes.2019-0003 ◽

2019 ◽

Vol 31 (3) ◽

pp. 282-289 ◽

Cited By ~ 1

Author(s):

Ali M. McManus ◽

Nathan R. Sletten ◽

Daniel J. Green

Keyword(s):

Shear Rate ◽

Femoral Artery ◽

Superficial Femoral Artery ◽

Acute Effect ◽

Moderate Intensity ◽

Flow Mediated Dilation ◽

External Work ◽

Interval Exercise ◽

High Intensity Interval ◽

The Impact

Purpose: The effect of exercise intensity on vasodilator function is poorly understood in children. The authors compared the acute effect of high-intensity interval exercise (HIIE) with moderate-intensity steady-state exercise (MISS) on postexercise vasodilation and shear patterns in 7- to 12- year-old children. Methods: Superficial femoral artery diameter, shear rates, and flow-mediated dilation were measured pre, immediately following (post), and 1 hour after (post60) HIIE (six 1-min sprints at 90% peak power [Wmax], with 1-min recovery) and MISS (15 min at 44% Wmax). Results: Baseline superficial femoral artery diameter increased similarly following both HIIE (pre 4.23 [0.41] mm, post 4.73 [0.56] mm) and MISS (pre 4.28 [0.56] mm, post 4.59 [0.64] mm), returning to preexercise values post60. Blood flow and antegrade shear rate were increased post HIIE and MISS, but to a greater extent, post HIIE (P < .05). Retrograde shear rate was attenuated post both exercise conditions and remained post60 (P < .001). There was a decline in flow-mediated dilation postexercise (HIIE Δ −2.9%; MISS Δ −2.4%), which was no longer apparent when corrected for baseline diameter. Conclusion: Acute bouts of external work-matched HIIE or MISS exert a similar impact on shear-mediated conduit artery vasodilation and flow-mediated dilation in children, and this is reversed 1 hour after exercise.

Download Full-text

Vascular adaptation to 4 wk of deconditioning by unilateral lower limb suspension

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00966.2004 ◽

2005 ◽

Vol 288 (4) ◽

pp. H1747-H1755 ◽

Cited By ~ 58

Author(s):

Michiel W. P. Bleeker ◽

Patricia C. E. De Groot ◽

Fleur Poelkens ◽

Gerard A. Rongen ◽

Paul Smits ◽

...

Keyword(s):

Blood Flow ◽

Femoral Artery ◽

Superficial Femoral Artery ◽

Lower Limb ◽

Venous Pressure ◽

Venous Occlusion ◽

Calf Blood Flow ◽

Volume Curve ◽

Pressure Volume Curve ◽

Echo Doppler Ultrasound

Physical inactivity or deconditioning is an independent risk factor for atherosclerosis and cardiovascular disease. In contrast to exercise, the vascular changes that occur as a result of deconditioning have not been characterized. We used 4 wk of unilateral lower limb suspension (ULLS) to study arterial and venous adaptations to deconditioning. In contrast to previous studies, this model is not confounded by denervation or microgravity. Seven healthy subjects participated in the study. Arterial and venous characteristics of the legs were assessed by echo Doppler ultrasound and venous occlusion plethysmography. The diameter of the common and superficial femoral artery decreased by 12% after 4 wk of ULLS. Baseline calf blood flow, as measured by plethysmography, decreased from 2.1 ± 0.2 to 1.6 ± 0.2 ml·min−1·dl tissue−1. Both arterial diameter and calf blood flow returned to baseline values after 4 wk of recovery. There was no indication of a decrease in flow-mediated dilation of the superficial femoral artery after ULLS deconditioning. This means that functional adaptations to inactivity are not simply the inverse of adaptations to exercise. The venous pressure-volume curve is shifted downward after ULLS, without any effect on compliance. In conclusion, deconditioning by 4 wk of ULLS causes significant changes in both the arterial and the venous system.

Download Full-text

Impact of chronic outward force on arterial responses of proximal and distal of long superficial femoral artery stent

BMC Cardiovascular Disorders ◽

10.1186/s12872-021-02141-z ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Hu Li ◽

Seung-Woon Rha ◽

Byoung Geol Choi ◽

Se Yeon Choi ◽

Sang Ki Moon ◽

...

Keyword(s):

Femoral Artery ◽

Superficial Femoral Artery ◽

Distal Segment ◽

Vessel Diameter ◽

Distal Portion ◽

Control Group ◽

Stent Restenosis ◽

Histopathologic Analysis ◽

Stent Diameter ◽

The Impact

Abstract Background Self-expanding nitinol stent (SENS) implantation is commonly oversized in the superficial femoral artery (SFA), and leads to chronic outward force (COF) and in-stent restenosis (ISR). This study aimed to investigate the impact of COF of oversizing SENS on ISR of SFA. Methods In patients with implanted SENS in SFA, intimal hyperplasia especially between proximal segment and distal segment was evaluated by quantitative angiography, and the impact of COF on mid-term angiographic outcomes was investigated. In addition, porcine model with implanted SENS was used to evaluate the impact of COF on angiographic and histopathologic outcomes at 1 month. Excised stented arteries were evaluated by histopathologic analysis. Results We analyzed 65 SENS in 61 patients with follow-up angiography at 6 months to 1 year. The baseline diameter was 6.8 ± 0.71 mm and length were 97.0 ± 33.8 mm for the SENS. The ratio of the diameter of the stent to the reference vessel was 1.3 ± 0.24 at the proximal portion and 1.53 ± 0.27 at the distal portion (P < 0.001). In the long SFA stent, stent-to-vessel ratio was significantly higher in the distal stent than in the proximal stent (1.3 ± 0.2 vs. 1.55 ± 0.25, P = 0.001). ISR incidence was higher at the distal stent (37.3% vs 52.6%, P = 0.029). All 11 pigs survived for 4 weeks after SENS implantation. The vessel diameter was 4.04 ± 0.40 mm (control group) vs 4.45 ± 0.63 mm (oversized group), and the implanted stent diameter was 5.27 ± 0.46 mm vs. 7.18 ± 0.4 mm (P = 0.001). The stent-to-vessel diameter ratio was 1.31 ± 0.12 versus 1.63 ± 0.20 (P < 0.001). After 4 weeks, restenosis % was 29.5 ± 12.9% versus 46.8 ± 21.5% (P = 0.016). The neointimal area was 5.37 ± 1.15 mm2 vs. 8.53 ± 5.18 mm2 (P = 0.05). The restenosis % was 39.34 ± 8.53% versus 63.97 ± 17.1% (P = 0.001). Conclusions COF is an important cause of restenosis in the distal portion of the SFA stent. Optimal sizing of the SFA stent is important to reduce the incidence of restenosis. Therefore, COF was an important factor of restenosis following distal SFA stenting.

Download Full-text

The passive leg movement technique for assessing vascular function: the impact of baseline blood flow

Experimental Physiology ◽

10.1113/ep089818 ◽

2021 ◽

Vol 106 (10) ◽

pp. 2133-2147

Author(s):

Katherine L. Shields ◽

Ryan M. Broxterman ◽

Catherine L. Jarrett ◽

Angela V. Bisconti ◽

Soung Hun Park ◽

...

Keyword(s):

Blood Flow ◽

Vascular Function ◽

Leg Movement ◽

The Impact

Download Full-text

The passive leg movement technique for assessing vascular function: defining the distribution of blood flow and the impact of occluding the lower leg

Experimental Physiology ◽

10.1113/ep087845 ◽

2019 ◽

Vol 104 (10) ◽

pp. 1575-1584 ◽

Cited By ~ 2

Author(s):

Katherine L. Shields ◽

Ryan M. Broxterman ◽

Catherine L. Jarrett ◽

Angela V. Bisconti ◽

Soung Hun Park ◽

...

Keyword(s):

Blood Flow ◽

Vascular Function ◽

Lower Leg ◽

Leg Movement ◽

The Impact

Download Full-text

The Vascular Side of Chronic Bed Rest: When a Therapeutic Approach Becomes Deleterious

Journal of Clinical Medicine ◽

10.3390/jcm9040918 ◽

2020 ◽

Vol 9 (4) ◽

pp. 918 ◽

Cited By ~ 1

Author(s):

Anna Pedrinolla ◽

Alessandro L. Colosio ◽

Roberta Magliozzi ◽

Elisa Danese ◽

Emine Kirmizi ◽

...

Keyword(s):

Blood Flow ◽

Shear Rate ◽

Vascular Function ◽

Inflammatory Markers ◽

Near Infrared ◽

Vastus Lateralis ◽

Vascular Inflammation ◽

Bed Rest ◽

Total Hemoglobin ◽

No Bioavailability

The interplay between chronic constraint and advanced aging on blood flow, shear-rate, vascular function, nitric oxide (NO)-bioavailability, microcirculation, and vascular inflammation factors is still a matter of debate. Ninety-eight individuals (Young, n = 28, 23 ± 3 yrs; Old, n = 36, 85 ± 7 yrs; Bedridden, n = 34, 88 ± 6 yrs) were included in the study. The bedridden group included old individuals chronically confined to bed (3.8 ± 2.3 yrs). A blood sample was collected and analyzed for plasma nitrate, and vascular inflammatory markers. Hyperemic response (∆peak) during the single passive leg movement (sPLM) test was used to measure vascular function. Skeletal muscle total hemoglobin was measured at the vastus lateralis during the sPLM test, by means of near infrared spectroscopy (NIRS). Bedridden subjects revealed a depletion of plasma nitrates compared with Old (−23.8%) and Young (−31.1%). Blood flow was lower in the Bedridden in comparison to Old (−20.1%) and Young (−31.7%). Bedridden presented lower sPLM ∆peak compared Old (−72.5%) and the Young (−83.3%). ∆peak of NIRS total hemoglobin was lower in the Bedridden compared to that in the Young (−133%). All vascular inflammatory markers except IL-6 were significantly worse in the Bedridden compared to Old and Young. No differences were found between the Old and Young in inflammatory markers. Results of this study confirm that chronic physical constraint induces an exacerbation of vascular disfunction and differential regulation of vascular-related inflammatory markers. The mechanisms involved in these negative adaptations seems to be associated with endothelial dysfunction and consequent diminished NO-bioavailability likely caused by the reduced shear-rate consequential to long-term reduction of physical activity.

Download Full-text