Effects of Exercise and Nutrition on the Coagulation System During Bedrest Immobilization

Abstract

Immobilization in hospitalized medical patients or during simulation of spaceflight induced deconditioning has been shown to be associated with loss of muscle mass and bone. Resistance vibrating exercise (RVE) and/or high protein diet are countermeasures, which are capable of mitigating the adverse effects of immobilization. We investigated the effect of these countermeasures on the coagulation system. Two groups of volunteers, each of whom performed such countermeasures, were enrolled in the study. Volunteers, who did nothing while bed rested, served as controls.The berest and the intervention protocols were carried out at Clinique d’ Investigation, MEDES, Toulouse, France.Eleven healthy men volunteered for this randomized crossover study. The subjects underwent 21 day of 6° head down bed rest (HDBR) followed by a washout period of 4 months. The first group followed an exercise schedule using resistance-vibrating exercise (RVE group). The second group also used the RVE but complemented it with high-protein supplement diet (NeX group). The third group only did bed rest.The highly sensitive methods calibrated automated thrombography (CAT) and thrombelastometry (TEM) were applied to monitor hemostatic changes.In all 3 groups, the hemostatic system shifted toward hypocoagulability during bed rest. For example, peak and thrombin formation velocity (VELINDEX) reduced in this period. Interestingly, a tendency toward hypercoagulation was observed during re-ambulation. In all 3 groups, ttPeak and StartTail were reduced, and Peak and VELINDEX (except in the RVE group) were significantly higher in relation to baseline values.Influence of bed rest on the coagulation system in the 2 groups performing countermeasures (RVE and NeX group) was the same as in the control bed-rested group. Clotting does not seem to be worsened by prolonged immobilization, or by countermeasures such as RVE/exercise or high-protein supplementation during immobilization. Therefore, only hospitalized medical patients at an elevated risk for thrombosis should be treated with anticoagulants. However, clinicians have to be aware that the re-ambulation period following immobilization might be associated with an elevated risk of thrombotic events.

Research update for articles published in EJCI in 2015

“…Furthermore, in the original article, we reported that the reambulation period is associated with a tendency towards hypercoagulability [92]. The evidence has accumulated in the meanwhile that reinforces this statement, as a tendency towards hypercoagulation was also observed during re-ambulation in the two groups [93] as well as in patients poststroke [94]. These data suggest that orthostatic challenge following bedrest confinement and poststroke might be associated with higher clotting risk.…”

“…We have compared bedrest subjects to two bedrest groups carrying out countermeasures incorporating resistive vibration exercise (RVE), with and without additional supplementation of high-protein diet, to prevent the negative deconditioning of bedrest confinement. We observed that in both groups the haemostatic system shifted towards hypocoagulability [93]. Furthermore, in the original article, we reported that the reambulation period is associated with a tendency towards hypercoagulability [92].…”

“…The evidence has accumulated in the meanwhile that reinforces this statement [93]. We have compared bedrest subjects to two bedrest groups carrying out countermeasures incorporating resistive vibration exercise (RVE), with and without additional supplementation of high-protein diet, to prevent the negative deconditioning of bedrest confinement.…”

Artificial Gravity as a Countermeasure to the Cardiovascular Deconditioning of Spaceflight: Gender Perspectives

“…Furthermore, since bed rest is used as a model to study effects of spaceflight de-conditioning ( Cvirn et al, 2015 ; Goswami et al, 2015a ; O’Shea et al, 2015 ; Waha et al, 2015 ) and hospitalized older persons spend a large part of their time in bed, the de-conditioning effects of bed rest confinement on physiological functions and its parallels with spaceflight deconditioning can be exploited to understand and combat both variations of de-conditioning. This knowledge is important as de-conditioning due to bed confinement in older persons can lead to a (downward) spiral of increasing frailty, OI, falls, and fall-related injury.…”

Falls and Fall-Prevention in Older Persons: Geriatrics Meets Spaceflight!

“…The bedrest study protocol, in which subjects lie in supine position over variable time periods, is a highly controllable experimental set-up which provides excellent possibilities to investigate physiological function changes during lowered gravitational stress (Trappe et al, 2007 ; Arzeno et al, 2013 ; Cvirn et al, 2015 ; Florian et al, 2015 ; O'Shea et al, 2015 ). Bedrest is also an important platform that allows for the testing of (potential) countermeasures to overcome the physiological deconditioning effects of lowered gravitational loading due to microgravity as well as the effects of bedrest deconditioning during hospitalization (Schneider et al, 2009 ; Waha et al, 2015 ). Insights and countermeasures to combat deconditioning obtained from these experiments would also be of great value in addressing the problem of increasing frailty in older persons which could arise due to bedrest confinement.…”