scholarly journals Healthy women confined to 60 days of bed rest showed no change in Achilles tendon dimensions but reduced calcaneal bone density

2020 ◽  
Author(s):  
T. Mark Campbell ◽  
Bahareh Ghaedi ◽  
Hans K. Uhthoff ◽  
Guy Trudel
Keyword(s):  
Bone Density ◽  
Achilles Tendon ◽  
Bed Rest ◽  
Healthy Women

scholarly journals Trabecular and cortical bone density and architecture in women after 60 days of bed rest using high-resolution pQCT: WISE 2005

2011 ◽  
Vol 26 (10) ◽  
pp. 2399-2410 ◽  
Author(s):  
Gabriele Armbrecht ◽  
Daniel Ludovic Belavý ◽  
Magdalena Backström ◽  
Gisela Beller ◽  
Christian Alexandre ◽  
...  
Keyword(s):  
High Resolution ◽  
Bone Density ◽  
Cortical Bone ◽  
Bed Rest ◽  
Cortical Bone Density

Changes in plasma volume during bed rest: effects of menstrual cycle and estrogen administration

1988 ◽  
Vol 65 (2) ◽  
pp. 525-533 ◽  
Author(s):  
S. M. Fortney ◽  
W. S. Beckett ◽  
A. J. Carpenter ◽  
J. Davis ◽  
H. Drew ◽  
...  
Keyword(s):  
Menstrual Cycle ◽  
Plasma Volume ◽  
Bed Rest ◽  
Transient Effects ◽  
Menstrual Cycles ◽  
Healthy Women ◽  
Exogenous Estrogen ◽  
Estrogen Administration ◽  
Estrogen Concentration

Bed rest (BR) is associated with a decrease in plasma volume (PV), which may contribute to the impaired orthostatic and exercise tolerances seen immediately after BR. The purpose of this study was to determine whether increases in blood estrogen concentration, either during normal menstrual cycles or during exogenous estrogen administration, would attenuate this loss of PV. Nineteen healthy women (21-39 yr of age) completed the study. Twelve women underwent duplicate 11-day BR without estrogen supplementation. PV decreased significantly (P less than or equal to 0.01) during both BR's, from 2,531 +/- 113 to 2,027 +/- 102 ml during BR1 and from 2,445 +/- 115 to 2,244 +/- 96 ml during BR2. The women who began BR in the periovulatory stage of the menstrual cycle (n = 3), a time of elevated endogenous estrogens, had a transient delay in loss of PV during the first 5 days of BR. Women who began BR during other stages of the menstrual cycle (n = 17) showed the established trend to decrease PV primarily during the first few days of BR. Seven additional women underwent a single 12-day BR while taking estrogen supplementation (1.25 mg/day premarin). PV decreased during the first 4-5 days of BR, then returned toward the pre-BR level during the remainder of the BR (pre-BR PV, 2,525 +/- 149 ml; post-BR PV, 2,519 +/- 162 ml). Thus menstrual fluctuations in endogenous estrogens appear to have only small transient effects on the loss of PV during BR, whereas exogenous estrogen supplementation significantly attenuates PV loss.

Oral contraceptives, surgery and prolonged bed rest

1969 ◽  
Vol 7 (12) ◽  
pp. 45-46
Keyword(s):  
Blood Coagulation ◽  
Oral Contraceptives ◽  
Bed Rest ◽  
Pelvic Surgery ◽  
Blood Levels ◽  
Combined Oral Contraceptives ◽  
Operative Complication ◽  
Healthy Women

The administration of combined oestrogen/progestagen oral contraceptives raises blood levels of many factors concerned with blood coagulation1–3 and increases the incidence of thrombo-embolism in healthy women,4 5 though the connection between these phenomena is obscure. Thrombo-embolism is also a post-operative complication, especially of pelvic surgery, and it seems quite likely that combined oral contraceptives may further increase the incidence of thrombosis after surgery. Prolonged rest in bed also predisposes to thrombosis and this risk too may be increased by such contraceptives. The incidence of thrombosis after surgery in women taking oral contraceptives is not yet known.

Increase in lumbar spine bone density during bed-rest and relationship to paraspinal muscle atrophy

Bone ◽  
2009 ◽  
Vol 44 ◽  
pp. S101
Author(s):  
D.L. Belavy ◽  
G. Armbrecht ◽  
C.A. Richardson ◽  
J.A. Hides ◽  
D. Felsenberg
Keyword(s):  
Lumbar Spine ◽  
Bone Density ◽  
Muscle Atrophy ◽  
Bed Rest ◽  
Paraspinal Muscle

Total body evaluation of bone density changes in healthy women and in postmenopausal osteoporosis

1992 ◽  
Vol 17 ◽  
pp. 184
Author(s):  
R. Nutl ◽  
G. Martini ◽  
B. Frediani ◽  
S. Giovani ◽  
A. Marcocci ◽  
...  
Keyword(s):  
Bone Density ◽  
Postmenopausal Osteoporosis ◽  
Healthy Women ◽  
Total Body

scholarly journals FemHab: The effects of bed rest and hypoxia on oxidative stress in healthy women

2016 ◽  
Vol 120 (8) ◽  
pp. 930-938 ◽  
Author(s):  
Tadej Debevec ◽  
Vincent Pialoux ◽  
Sabine Ehrström ◽  
Alexandra Ribon ◽  
Ola Eiken ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Antioxidant Status ◽  
Bed Rest ◽  
Hypoxic Exposure ◽  
Activity Levels ◽  
Antioxidant Power ◽  
Healthy Women ◽  
Stress Markers ◽  
Habitual Activity ◽  
Ferric Reducing Antioxidant Power

Independently, both inactivity and hypoxia augment oxidative stress. This study, part of the FemHab project, investigated the combined effects of bed rest-induced unloading and hypoxic exposure on oxidative stress and antioxidant status. Healthy, eumenorrheic women were randomly assigned to the following three 10-day experimental interventions: normoxic bed rest (NBR; n = 11; PiO2 = 133 mmHg), normobaric hypoxic bed rest (HBR; n = 12; PiO2 = 90 mmHg), and ambulatory hypoxic confinement (HAMB; n = 8: PiO2 = 90 mmHg). Plasma samples, obtained before (Pre), during (D2, D6), immediately after (Post) and 24 h after (Post+1) each intervention, were analyzed for oxidative stress markers [advanced oxidation protein products (AOPP), malondialdehyde (MDA), and nitrotyrosine], antioxidant status [superoxide dismutase (SOD), catalase, ferric-reducing antioxidant power (FRAP), glutathione peroxidase (GPX), and uric acid (UA)], NO metabolism end-products (NOx), and nitrites. Compared with baseline, AOPP increased in NBR and HBR on D2 (+14%; +12%; P < 0.05), D6 (+19%; +15%; P < 0.05), and Post (+22%; +21%; P < 0.05), respectively. MDA increased at Post+1 in NBR (+116%; P < 0.01) and D2 in HBR (+114%; P < 0.01) and HAMB (+95%; P < 0.05). Nitrotyrosine decreased (−45%; P < 0.05) and nitrites increased (+46%; P < 0.05) at Post+1 in HAMB only. Whereas SOD was higher at D6 (+82%) and Post+1 (+67%) in HAMB only, the catalase activity increased on D6 (128%) and Post (146%) in HBR and HAMB, respectively ( P < 0.05). GPX was only reduced on D6 (−20%; P < 0.01) and Post (−18%; P < 0.05) in HBR. No differences were observed in FRAP and NOx. UA was higher at Post in HBR compared with HAMB ( P < 0.05). These data indicate that exposure to combined inactivity and hypoxia impairs prooxidant/antioxidant balance in healthy women. Moreover, habitual activity levels, as opposed to inactivity, seem to blunt hypoxia-related oxidative stress via antioxidant system upregulation.

No effect of artificial gravity on lung function with exercise training during head-down bed rest

2015 ◽  
pp. 1-7
Author(s):  
Longxiang Su ◽  
Yinghua Guo ◽  
Yajuan Wang ◽  
Delong Wang ◽  
Changting Liu
Keyword(s):  
Lung Function ◽  
Pulse Rate ◽  
Vital Capacity ◽  
Pulmonary Ventilation ◽  
Bed Rest ◽  
Forced Expiratory Volume ◽  
Observation Time ◽  
Artificial Gravity ◽  
Postural Changes ◽  
Expiratory Flow

AbstractTo explore the effectiveness of microgravity simulated by head-down bed rest (HDBR) and artificial gravity (AG) with exercise on lung function. Twenty-four volunteers were randomly divided into control and exercise countermeasure (CM) groups for 96 h of 6° HDBR. Comparisons of pulse rate, pulse oxygen saturation (SpO2) and lung function were made between these two groups at 0, 24, 48, 72, 96 h. Compared with the sitting position, inspiratory capacity and respiratory reserve volume were significantly higher than before HDBR (0° position) (P&lt; 0.05). Vital capacity, expiratory reserve volume, forced vital capacity, forced expiratory volume in 1 s, forced inspiratory vital capacity, forced inspiratory volume in 1 s, forced expiratory flow at 25, 50 and 75%, maximal mid-expiratory flow and peak expiratory flow were all significantly lower than those before HDBR (P&lt; 0.05). Neither control nor CM groups showed significant differences in the pulse rate, SpO2, pulmonary volume and pulmonary ventilation function over the HDBR observation time. Postural changes can lead to variation in lung volume and ventilation function, but a HDBR model induced no changes in pulmonary function and therefore should not be used to study AG CMs.

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