Daily Acute Bouts of Weight-bearing During Hindlimb Unloading Mitigate Disuse-Induced Deficits in Cancellous Bone

2020 ◽  
Vol 6 (2) ◽  
pp. 2-11 ◽  
Author(s):  
Rihana S. Bokhari ◽  
Corinne E. Metzger ◽  
Matthew R. Allen ◽  
Susan A. Bloomfield

AbstractInternational Space Station crewmembers experience microgravity, resulting in musculoskeletal losses. It remains unclear how much mechanical loading during disuse is sufficient to mitigate disuse-induced bone loss. We examined 75 minutes of weight-bearing per day on disuse-induced bone loss during hindlimb unloading (HU). Female C57BL/6J mice, 17 weeks (n=10/group), were exposed to HU for 28 days or were ambulatory controls (CC). Half of the HU animals were continuously unloaded while the remainder were removed from tail suspension for ~75 min/day for cage activity weight-bearing (HU+WB). HU and HU+WB led to total body mass and bone mineral density loss. HU+WB mitigated HU-induced losses in total body fat and lean mass and, in the distal femur, prevented losses in μCT measures of cancellous bone volume and microarchitecture. These findings support the robust impact of short durations of normal loading on preventing or mitigating HU-induced bone loss.

2012 ◽  
Vol 303 (11) ◽  
pp. E1354-E1362 ◽  
Author(s):  
Mohammad Shahnazari ◽  
Pam Kurimoto ◽  
Benjamin M. Boudignon ◽  
Benjamin E. Orwoll ◽  
Daniel D. Bikle ◽  
...  

Loss of skeletal weight bearing or skeletal unloading as occurs during spaceflight inhibits bone formation and stimulates bone resorption. These are associated with a decline in the osteoblast (Ob.S/BS) and an increase in the osteoclast (Oc.S/BS) bone surfaces. To determine the temporal relationship between changes in the bone cells and their marrow precursor pools during sustained unloading, and whether genetic background influences these relationships, we used the hindlimb unloading model to induce bone loss in two strains of mice known to respond to load and having significantly different cancellous bone volumes (C57BL/6 and DBA/2 male mice). Skeletal unloading caused a progressive decline in bone volume that was accompanied by strain-specific changes in Ob.S/BS and Oc.S/BS. These were associated with a sustained reduction in the osteoprogenitor population and a dramatic but transient increase in the osteoclast precursor pool size in both strains. The results reveal that bone adaptation to skeletal unloading involves similar rapid changes in the osteoblast and osteoclast progenitor populations in both strains of mice but striking differences in Oc.S/BS dynamics, BFR, and cancellous bone structure. These strain-specific differences suggest that genetics plays an important role in determining the osteoblast and osteoclast populations on the bone surface and the dynamics of bone loss in response to skeletal unloading.


2011 ◽  
Vol 1 (1) ◽  
pp. 10
Author(s):  
Haiyan Chen

Osteoporosis is a disease characterized by fragile bones and high susceptibility to low trauma fractures. Tai Chi, an ancient Chinese mind-body exercise that is reported to enhance muscle function, balance and flexibility, and to reduce pain, depression and anxiety, may safely and effectively be used to prevent or treat osteoporosis. The aim of this review is to evaluate the evidence for Tai Chi as an intervention to reduce rate of bone loss in postmenopausal women. A literature search on randomized controlled trials (RCTs), prospective cohort studies, and cross-sectional studies that included Tai Chi as an intervention, and had at least 1 outcome related to measurement of bone metabolism were identified in PubMed/Medline. Twenty-one controlled studies were identified in the database, which suggested Tai Chi slowed down the loss of bone mineral density in most postmenopausal women, improved balance and strength, relieves pain from arthritis, and improved mental strength so they can cope better with chronic diseases. Regular Tai Chi Chuan exercise is beneficial for retarding bone loss in the weight-bearing bones of postmenopausal women.


2015 ◽  
Vol 112 (48) ◽  
pp. 14972-14977 ◽  
Author(s):  
Sofia Movérare-Skrtic ◽  
Jianyao Wu ◽  
Petra Henning ◽  
Karin L. Gustafsson ◽  
Klara Sjögren ◽  
...  

Wingless-type MMTV integration site family (WNT)16 is a key regulator of bone mass with high expression in cortical bone, and Wnt16−/− mice have reduced cortical bone mass. As Wnt16 expression is enhanced by estradiol treatment, we hypothesized that the bone-sparing effect of estrogen in females is WNT16-dependent. This hypothesis was tested in mechanistic studies using two genetically modified mouse models with either constantly high osteoblastic Wnt16 expression or no Wnt16 expression. We developed a mouse model with osteoblast-specific Wnt16 overexpression (Obl-Wnt16). These mice had several-fold elevated Wnt16 expression in both trabecular and cortical bone compared with wild type (WT) mice. Obl-Wnt16 mice displayed increased total body bone mineral density (BMD), surprisingly caused mainly by a substantial increase in trabecular bone mass, resulting in improved bone strength of vertebrae L3. Ovariectomy (ovx) reduced the total body BMD and the trabecular bone mass to the same degree in Obl-Wnt16 mice and WT mice, suggesting that the bone-sparing effect of estrogen is WNT16-independent. However, these bone parameters were similar in ovx Obl-Wnt16 mice and sham operated WT mice. The role of WNT16 for the bone-sparing effect of estrogen was also evaluated in Wnt16−/− mice. Treatment with estradiol increased the trabecular and cortical bone mass to a similar extent in both Wnt16−/− and WT mice. In conclusion, the bone-sparing effects of estrogen and WNT16 are independent of each other. Furthermore, loss of endogenous WNT16 results specifically in cortical bone loss, whereas overexpression of WNT16 surprisingly increases mainly trabecular bone mass. WNT16-targeted therapies might be useful for treatment of postmenopausal trabecular bone loss.


2010 ◽  
Vol 108 (1) ◽  
pp. 152-161 ◽  
Author(s):  
Hisataka Kondo ◽  
Kenji Yumoto ◽  
Joshua S. Alwood ◽  
Rose Mojarrab ◽  
Angela Wang ◽  
...  

Exposure of astronauts in space to radiation during weightlessness may contribute to subsequent bone loss. Gamma irradiation of postpubertal mice rapidly increases the number of bone-resorbing osteoclasts and causes bone loss in cancellous tissue; similar changes occur in skeletal diseases associated with oxidative stress. Therefore, we hypothesized that increased oxidative stress mediates radiation-induced bone loss and that musculoskeletal disuse changes the sensitivity of cancellous tissue to radiation exposure. Musculoskeletal disuse by hindlimb unloading (1 or 2 wk) or total body gamma irradiation (1 or 2 Gy of 137Cs) of 4-mo-old, male C57BL/6 mice each decreased cancellous bone volume fraction in the proximal tibiae and lumbar vertebrae. The extent of radiation-induced acute cancellous bone loss in tibiae and lumbar vertebrae was similar in normally loaded and hindlimb-unloaded mice. Similarly, osteoclast surface in the tibiae increased 46% as a result of irradiation, 47% as a result of hindlimb unloading, and 64% as a result of irradiation + hindlimb unloading compared with normally loaded mice. Irradiation, but not hindlimb unloading, reduced viability and increased apoptosis of marrow cells and caused oxidative damage to lipids within mineralized tissue. Irradiation also stimulated generation of reactive oxygen species in marrow cells. Furthermore, injection of α-lipoic acid, an antioxidant, mitigated the acute bone loss caused by irradiation. Together, these results showed that disuse and gamma irradiation, alone or in combination, caused a similar degree of acute cancellous bone loss and shared a common cellular mechanism of increased bone resorption. Furthermore, irradiation, but not disuse, may increase the number of osteoclasts and the extent of acute bone loss via increased reactive oxygen species production and ensuing oxidative damage, implying different molecular mechanisms. The finding that α-lipoic acid protected cancellous tissue from the detrimental effects of irradiation has potential relevance to astronauts and radiotherapy patients.


1992 ◽  
Vol 82 (4) ◽  
pp. 429-432 ◽  
Author(s):  
J. E. Compston ◽  
M. A. Laskey ◽  
P. I. Croucher ◽  
A. Coxon ◽  
S. Kreitzman

1. Total body areal bone mineral density was measured by dual-energy X-ray absorptiometry in eight women before and 10 weeks after a very-low-calorie diet [405 kcal (1701 kJ)/day]. 2. The mean weight loss of 15.6 kg was accompanied by a statistically significant reduction in total body bone mineral density from 1.205 ± 0.056 to 1.175 ± 0.058 g/cm2 (mean ± sd, P < 0.005). 3. After cessation of the diet, weight gradually increased and by 10 months was similar to baseline values. Total body bone mineral density also increased after stopping the diet and mean values obtained 10 months after the diet did not differ significantly from initial values. Throughout the study total body bone mineral density values in all subjects were well within the range reported for normal subjects. 4. These data indicate that diet-induced weight loss is associated with rapid bone loss, subsequent weight gain being accompanied by increases in bone mass. Further studies are required to establish the clinical significance of these findings and, in particular, the skeletal distribution of bone loss.


2019 ◽  
pp. 1197-1205
Author(s):  
Khalid Ghanim Majeed ◽  
Husham A Thanon ◽  
Basim Idrees Dhannoon ◽  
Haitham B. Fathi

In this research, we discussed bone density for women taking into consideration the method of research, we measure the total body mass of women in premenopausal and comparing it with postmenopausal, since the amount of the bone mineral content and bone mineral density, fat mass and lean mass.A cross sectional study conducted at DXA laboratory, Physiology Department, College of Medicine, University of Ninevah, Mosul-Iraq from Jan. 1 - Dec. 31, 2013. Since 174 healthy women recruited from reviewing of college medical academic center. They were divided into two groups: pre menopause group (n = 42) and post menopause group (n= 130). Detailed anthropometric data were gathered from study subjects. The mean age SD of pre-menopause group was (43.37 7.49) year while the mean age SD postmenopausal group (63.63 9.23) years .The T-score, Z-score, Bone Mineral Density (BMD), Bone Mineral Content (BMC), Fat Mass and Lean Mass were measured in the supine position by the use of DXA bone densitometer scanner type (STRATOS) from (DMS) group, France.Bone Mineral Content (BMC) was significantly lower in arm, rib, and thoracic spines. Bone Mineral Density (BMD) in arm, rib, leg and total were significantly low in postmenopausal women. Non-significant differences were noticed between both groups for lean mass. Postmenopausal women having more fat mass than pre menopause group. Both T-score and Z-score for pre menopause and post menopause groups were from class of osteopenia, but it was significantly lower in post menopause group (p-value =0.001, 0.008 respectively).Postmenopausal women were at higher risk of osteoporosis due to lowered Bone Mineral Density , T & Z scores.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Cori N. Booker ◽  
Christopher L. Haga ◽  
Siddaraju V. Boregowda ◽  
Jacqueline Strivelli ◽  
Donald G. Phinney

AbstractDisuse osteoporosis (DO) results from mechanical unloading of weight-bearing bones and causes structural changes that compromise skeletal integrity, leading to increased fracture risk. Although bone loss in DO results from imbalances in osteoblast vs. osteoclast activity, its effects on skeletal stem/progenitor cells (SSCs) is indeterminate. We modeled DO in mice by 8 and 14 weeks of hindlimb unloading (HU) or 8 weeks of unloading followed by 8 weeks of recovery (HUR) and monitored impacts on animal physiology and behavior, metabolism, marrow adipose tissue (MAT) volume, bone density and micro-architecture, and bone marrow (BM) leptin and tyrosine hydroxylase (TH) protein expression, and correlated multi-systems impacts of HU and HUR with the transcript profiles of Lin−LEPR+ SSCs and mesenchymal stem cells (MSCs) purified from BM. Using this integrative approach, we demonstrate that prolonged HU induces muscle atrophy, progressive bone loss, and MAT accumulation that paralleled increases in BM but not systemic leptin levels, which remained low in lipodystrophic HU mice. HU also induced SSC quiescence and downregulated bone anabolic and neurogenic pathways, which paralleled increases in BM TH expression, but had minimal impacts on MSCs, indicating a lack of HU memory in culture-expanded populations. Although most impacts of HU were reversed by HUR, trabecular micro-architecture remained compromised and time-resolved changes in the SSC transcriptome identified various signaling pathways implicated in bone formation that were unresponsive to HUR. These findings indicate that HU-induced alterations to the SSC transcriptome that persist after reloading may contribute to poor bone recovery.


Nutrients ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 2043
Author(s):  
Yuko Tousen ◽  
Ryota Ichimaru ◽  
Takashi Kondo ◽  
Masaki Inada ◽  
Chisato Miyaura ◽  
...  

It is well known that physical inactivity during space flight or prolonged bed rest causes rapid bone loss. Soy isoflavones (ISOs) and resveratrol (RES) have been reported to be useful to maintain a positive balance for bone turnover. Therefore, we examined the combined effects of ISO and RES on bone loss that was induced by hindlimb-unloading in mice. Female eight-week-old ddY mice were divided into the following six groups (n = 6–8 each): normally housed mice, loading mice, hindlimb-unloading (UL) mice fed a control diet, UL mice fed a 0.16% ISO conjugates, UL mice fed a 0.15% RES diet, and UL mice fed a 0.16% ISO and 0.15% RES diet. After three weeks, femoral bone mineral density was markedly decreased in unloading mice. The combination of ISO and RES prevented bone loss and especially maintained the trabecular bone mineral density more effectively compared with cortical bones. ISO and/or RES inhibited the increase in the RANKL/OPG expression ratio in bone marrow cells in UL mice. These results suggest that the combination of ISO and RES had a preventive effect against bone loss induced by hindlimb-unloading in mice. These osteoprotective effects of ISO and RES may result from the inhibition of bone resorption.


2019 ◽  
Vol 104 (8) ◽  
pp. 3576-3584 ◽  
Author(s):  
Sarah M Bristow ◽  
Anne M Horne ◽  
Greg D Gamble ◽  
Borislav Mihov ◽  
Angela Stewart ◽  
...  

Abstract Context Calcium intakes are commonly lower than the recommended levels, and increasing calcium intake is often recommended for bone health. Objective To determine the relationship between dietary calcium intake and rate of bone loss in older postmenopausal women. Participants Analysis of observational data collected from a randomized controlled trial. Participants were osteopenic (hip T-scores between −1.0 and −2.5) women, aged >65 years, not receiving therapy for osteoporosis nor taking calcium supplements. Women from the total cohort (n = 1994) contributed data to the analysis of calcium intake and bone mineral density (BMD) at baseline, and women from the placebo group (n = 698) contributed data to the analysis of calcium intake and change in BMD. BMD and bone mineral content (BMC) of the spine, total hip, femoral neck, and total body were measured three times over 6 years. Results Mean calcium intake was 886 mg/day. Baseline BMDs were not related to quintile of calcium intake at any site, before or after adjustment for baseline age, height, weight, physical activity, alcohol intake, smoking status, and past hormone replacement use. There was no relationship between bone loss and quintile of calcium intake at any site, with or without adjustment for covariables. Total body bone balance (i.e., change in BMC) was unrelated to an individuals’ calcium intake (P = 0.99). Conclusions Postmenopausal bone loss is unrelated to dietary calcium intake. This suggests that strategies to increase calcium intake are unlikely to impact the prevalence of and morbidity from postmenopausal osteoporosis.


2001 ◽  
Vol 90 (2) ◽  
pp. 565-570 ◽  
Author(s):  
Dana L. Creighton ◽  
Amy L. Morgan ◽  
Debra Boardley ◽  
P. Gunnar Brolinson

Weight-bearing activity provides an osteogenic stimulus, while effects of swimming on bone are unclear. We evaluated bone mineral density (BMD) and markers of bone turnover in female athletes ( n = 41, age 20.7 yr) comparing three impact groups, high impact (High, basketball and volleyball, n= 14), medium impact (Med, soccer and track, n = 13), and nonimpact (Non, swimming, n = 7), with sedentary age-matched controls (Con, n = 7). BMD was assessed by dual-energy X-ray absorptiometry at the lumbar spine, femoral neck (FN), Ward's triangle, and trochanter (TR); bone resorption estimated from urinary cross-linked N-telopeptides (NTx); and bone formation determined from serum osteocalcin. Adjusted BMD (g/cm; covariates: body mass index, weight, and calcium and calorie intake) was greater at the FN and TR in the High group (1.27 ± 0.03 and 1.05 ± 0.03) than in the Non (1.05 ± 0.04 and 0.86 ± 0.04) and Con (1.03 ± 0.05 and 0.85 ± 0.05) groups and greater at the TR in the Med group (1.01 ± 0.03) than in the Non (0.86 ± 0.04) and Con (0.85 ± 0.05) groups. Total body BMD was higher in the High group (4.9 ± 0.12) than in the Med (4.5 ± 0.12), Non (4.2 ± 0.14), and Con (4.1 ± 0.17) groups and greater in the Med group than in the Non and Con groups. Bone formation was lower in the Non group (19.8 ± 2.6) than in the High (30.6 ± 3.0) and Med (32.9 ± 1.9, P ≤ 0.05) groups. No differences in a marker of bone resorption (NTx) were noted. This indicates that women who participate in impact sports such as volleyball and basketball had higher BMDs and bone formation values than female swimmers.


Sign in / Sign up

Export Citation Format

Share Document