scholarly journals The Ovariectomized Rat as a Model for Studying Alveolar Bone Loss in Postmenopausal Women

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Bryan D. Johnston ◽  
Wendy E. Ward

In postmenopausal women, reduced bone mineral density at the hip and spine is associated with an increased risk of tooth loss, possibly due to a loss of alveolar bone. In turn, having fewer natural teeth may lead to compromised food choices resulting in a poor diet that can contribute to chronic disease risk. The tight link between alveolar bone preservation, tooth retention, better nutritional status, and reduced risk of developing a chronic disease begins with the mitigation of postmenopausal bone loss. The ovariectomized rat, a widely used preclinical model for studying postmenopausal bone loss that mimics deterioration of bone tissue in the hip and spine, can also be used to study mineral and structural changes in alveolar bone to develop drug and/or dietary strategies aimed at tooth retention. This review discusses key findings from studies investigating mandible health and alveolar bone in the ovariectomized rat model. Considerations to maximize the benefits of this model are also included. These include the measurement techniques used, the age at ovariectomy, the duration that a rat is studied after ovariectomy and habitual diet consumed.

2020 ◽  
Vol 9 (7) ◽  
pp. R158-R172 ◽  
Author(s):  
Alessandro Brancatella ◽  
Claudio Marcocci

Thyroid hormones stimulate bone turnover in adults by increasing osteoclastic bone resorption. TSH suppressive therapy is usually applied in patients with differentiated thyroid cancer (DTC) to improve the disease outcome. Over the last decades several authors have closely monitored the potential harm suffered by the skeletal system. Several studies and meta-analyses have shown that chronic TSH suppressive therapy is safe in premenopausal women and men. Conversely, in postmenopausal women TSH suppressive therapy is associated with a decrease of bone mineral density, deterioration of bone architecture (quantitative CT, QCT; trabecular bone score, TBS), and, possibly, an increased risk of fractures. The TSH receptor is expressed in bone cells and the results of experimental studies in TSH receptor knockout mice and humans on whether low TSH levels, as opposed to solely high thyroid hormone levels, might contribute to bone loss in endogenous or exogenous thyrotoxicosis remain controversial. Recent guidelines on the use of TSH suppressive therapy in patients with DTC give value not only to its benefit on the outcome of the disease, but also to the risks associated with exogenous thyrotoxicosis, namely menopause, osteopenia or osteoporosis, age >60 years, and history of atrial fibrillation. Bone health (BMD and/or preferably TBS) should be evaluated in postmenopausal women under chronic TSH suppressive therapy or in those patients planning to be treated for several years. Antiresorptive therapy could also be considered in selected cases (increased risk of fracture or significant decline of BMD/TBS during therapy) to prevent bone loss.


2020 ◽  
Vol 21 (19) ◽  
pp. 7119
Author(s):  
Umani S. Walallawita ◽  
Frances M. Wolber ◽  
Ayelet Ziv-Gal ◽  
Marlena C. Kruger ◽  
Julian A. Heyes

Osteoporosis is a metabolic bone disease characterized by reduced bone mineral density, which affects the quality of life of the aging population. Furthermore, disruption of bone microarchitecture and the alteration of non-collagenous protein in bones lead to higher fracture risk. This is most common in postmenopausal women. Certain medications are being used for the treatment of osteoporosis; however, these may be accompanied by undesirable side effects. Phytochemicals from fruits and vegetables are a source of micronutrients for the maintenance of bone health. Among them, lycopene has recently been shown to have a potential protective effect against bone loss. Lycopene is a lipid-soluble carotenoid that exists in both all-trans and cis-configurations in nature. Tomato and tomato products are rich sources of lycopene. Several human epidemiological studies, supplemented by in vivo and in vitro studies, have shown decreased bone loss following the consumption of lycopene/tomato. However, there are still limited studies that have evaluated the effect of lycopene on the prevention of bone loss in postmenopausal women. Therefore, the aim of this review is to summarize the relevant literature on the potential impact of lycopene on postmenopausal bone loss with molecular and clinical evidence, including an overview of bone biology and the pathophysiology of osteoporosis.


Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1250
Author(s):  
Sarah J. Wherry ◽  
Ryan M. Miller ◽  
Sarah H. Jeong ◽  
Kristen M. Beavers

Despite the adverse metabolic and functional consequences of obesity, caloric restriction- (CR) induced weight loss is often contra-indicated in older adults with obesity due to the accompanying loss of areal bone mineral density (aBMD) and subsequent increased risk of fracture. Several studies show a positive effect of exercise on aBMD among weight-stable older adults; however, data on the ability of exercise to mitigate bone loss secondary to CR are surprisingly equivocal. The purpose of this review is to provide a focused update of the randomized controlled trial literature assessing the efficacy of exercise as a countermeasure to CR-induced bone loss among older adults. Secondarily, we present data demonstrating the occurrence of exercise-induced changes in bone biomarkers, offering insight into why exercise is not more effective than observed in mitigating CR-induced bone loss.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Xuan Cai ◽  
Jun Dong ◽  
Teng Lu ◽  
Liqiang Zhi ◽  
Xijing He

Abstract Background Osteoporosis (OP) is a complex bone metabolism disorder characterized by the loss of bone minerals and an increased risk of bone fracture. A recent study reported the relationship of the macrophage erythroblast attacher gene (MAEA) with low bone mineral density in postmenopausal Japanese women. Our study aimed to investigate the association of MAEA with postmenopausal osteoporosis (PMOP) in Han Chinese individuals. Methods A total of 968 unrelated postmenopausal Chinese women comprising 484 patients with PMOP and 484 controls were recruited. Four tag single nucleotide polymorphisms (SNPs) that covered the gene region of MAEA were chosen for genotyping. Single SNP and haplotypic association analyses were performed, and analysis of variance was conducted to test the correlation between blood MAEA protein level and genotypes of associated SNPs. Results SNP rs6815464 was significantly associated with the risk of PMOP. The C allele of rs6815464 was strongly correlated with the decreased risk of PMOP in our study subjects (OR[95% CI]=0.75[0.63-0.89], P=0.0015). Significant differences in MAEA protein blood levels among genotypes of SNP rs6815464 were identified in both the PMOP (F=6.82, P=0.0012) and control groups (F=11.5, P=0.00001). The C allele was positively associated with decreased MAEA protein levels in blood. Conclusion This case-control study on Chinese postmenopausal women suggested an association between SNP rs6815464 of MAEA and PMOP. Further analyses showed that genotypes of SNP rs6815464 were also associated with the blood level of MAEA protein.


2008 ◽  
Vol 67 (2) ◽  
pp. 163-176 ◽  
Author(s):  
Susan A. Lanham-New

Throughout the life cycle the skeleton requires optimum development and maintenance of its integrity to prevent fracture. Bones break because the loads placed on them exceed the ability of the bone to absorb the energy involved. It is now estimated that one in three women and one in twelve men aged >55 years will suffer from osteoporosis in their lifetime and at a cost in the UK of >£1·7×109 per year. The pathogenesis of osteoporosis is multifactorial. Both the development of peak bone mass and the rate of bone loss are determined by key endogenous and exogenous factors. Ca supplements appear to be effective in reducing bone loss in women late post menopause (>5 years post menopause), particularly in those with low habitual Ca intake (<400 mg/d). In women early post menopause (<5 years post menopause) who are not vitamin D deficient, Ca supplementation has little effect on bone mineral density. However, supplementation with vitamin D and Ca has been shown to reduce fracture rates in the institutionalised elderly, but there remains controversy as to whether supplementation is effective in reducing fracture in free-living populations. Re-defining vitamin D requirements in the UK is needed since there is evidence of extensive hypovitaminosis D in the UK. Low vitamin D status is associated with an increased risk of falling and a variety of other health outcomes and is an area that requires urgent attention. The role of other micronutrients on bone remains to be fully defined, although there are promising data in the literature for a clear link between vitamin K nutrition and skeletal integrity, including fracture reduction.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Minsun Kim ◽  
MinBeom Kim ◽  
Jae-Hyun Kim ◽  
SooYeon Hong ◽  
Dong Hee Kim ◽  
...  

Osteoporosis is characterized by a decrease in bone microarchitecture with an increased risk of fracture. Long-term use of primary treatments, such as bisphosphonates and selective estrogen receptor modulators, results in various side effects. Therefore, it is necessary to develop alternative therapeutics derived from natural products. Crataegus pinnatifida Bunge (CPB) is a dried fruit used to treat diet-induced indigestion, loss of appetite, and diarrhea. However, research into the effects of CPB on osteoclast differentiation and osteoporosis is still limited. In vitro experiments were conducted to examine the effects of CPB on RANKL-induced osteoclast differentiation in RAW 264.7 cells. Moreover, we investigated the effects of CPB on bone loss in the femoral head in an ovariectomized rat model using microcomputed tomography. In vitro, tartrate-resistant acid phosphatase (TRAP) staining results showed the number of TRAP-positive cells, and TRAP activity significantly decreased following CPB treatment. CPB also significantly decreased pit formation. Furthermore, CPB inhibited osteoclast differentiation by suppressing NFATc1, and c-Fos expression. Moreover, CPB treatment inhibited osteoclast-related genes, such as Nfatc1, Ca2, Acp5, mmp9, CtsK, Oscar, and Atp6v0d2. In vivo, bone mineral density and structure model index were improved by administration of CPB. In conclusion, CPB prevented osteoclast differentiation in vitro and prevented bone loss in vivo. Therefore, CPB could be a potential alternative medicine for bone diseases, such as osteoporosis.


Retos ◽  
2015 ◽  
pp. 172-179
Author(s):  
Annie A. Bane ◽  
Peter W. Grandjean

The purpose of this review is to summarize the role of fetuin-A in disease processes prevalent in postmenopausal women and synthesize effective interventions in obtaining healthy fetuin-A levels. A review of databases for articles related to fetuin-A and diseases associated with postmenopausal women was conducted. Articles were limited to full-text access, published in English since 1944. High fetuin-A levels are closely associated with decreased bone mineral density, increased cardiovascular disease risks, impairment of insulin signaling and disruption of adipocyte functioning. Postmenopausal women have increased risk of osteoporosis, cardiovascular disease, insulin-resistance, intra-abdominal fat accumulation and vascular calcification. Low-levels of fetuin-A have been shown to be protective against the latter. The role of fetuin-A is multi-factorial and the mechanisms in which it is involved in each of these processes are vast. The present body of literature is inconsistent in defining high versus low levels of fetuin-A and their association with healthy-matched controls. The diseases associated with high levels of fetuin-A mimic diseases most prevalent in postmenopausal women. In addition, there is no research, to date, exploring fetuin-A levels in postmenopausal women and the associations it may or may not have in related diseases.Key words: fetuin-A; Alpha2-Heremans-Schmid glycoprotein; cardiovascular disease; and elderly, insulin-resistance, intra-abdominal fat, metabolic syndrome, exercise, weight-loss, calorie restriction and postmenopausal.Resumen. El propósito de esta revisión es sintetizar el papel de la fetuina A en los procesos de enfermedad prevalentes en mujeres posmenopáusicas y resumir las intervenciones efectivas que permiten obtener niveles saludables de fetuina A. Para ello, se revisaron bases de datos con artículos relacionados con fetuina A y las enfermedades asociadas con mujeres posmenopáusicas. La búsqueda de artículos se limitó a aquellos de texto completo publicados en el idioma inglés desde el año 1944. Se encontró que altos niveles de fetuina A están íntimamente relacionados con una reducción de la densidad mineral ósea, un aumento en el riesgo de enfermedad cardiovascular, deterioro de la señalización de la insulina y la alteración del funcionamiento de los adipocitos. Las mujeres posmenopáusicas tienen un mayor riesgo de osteoporosis, enfermedad cardiovascular, resistencia a la insulina, acumulación de grasa intra abdominal y calcificación vascular. Se ha demostrado que niveles bajos de fetuina A son protectores contra esta última condición. El papel de fetuina A es multifactorial y los mecanismos en los que está involucrado en cada uno de estos procesos son muy amplios. El estado actual de la literatura no es consistente en la definición de niveles de fetuina A altos versus bajos y su asociación con controles sanos. Las enfermedades asociadas con altos niveles de fetuina A asemejan las enfermedades más prevalentes en mujeres posmenopáusicas. Además, no existen investigaciones, hasta la fecha, en las que se   exploren los niveles de fetuina A en mujeres posmenopáusicas y las asociaciones que puede o no puede tener en las enfermedades relacionadas.Palabras claves: fetuina A, glicoproteína Alpha2-Heremans-Schmid, enfermedad cardiovascular, adulto mayor, resistencia a la insulina, grasa intra abdominal, síndrome metabólico, ejercicio, pérdida de peso, restricción calórica, posmenopausia.


2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Lamia Oulkadi ◽  
Bouchra Amine ◽  
Imane El binoune ◽  
Samira Rostom ◽  
Rachid Bahiri

Type 2 diabetes mellitus (T2DM) and osteoporosis are chronic diseases with increasing prevalence. The aim of this study was to determine the prevalence of osteoporosis and osteoporotic fracture in women with T2DM and to identify predictive factors of fracture occurrence. The prevalence of osteoporosis and fractures in postmenopausal women with T2DM was 23.1% and 16.9%, respectively. 46.2% of T2DM patients had normal bone mineral density (BMD) (P<0.01) and 58.5% of control subjects had osteopenia (P<0.01). Incidence of fracture in T2DM patients with osteopenia was significantly increased versus control subjects when stratified according the BMD (P=0.009). By stratifying T2DM patients according to fractures, factors that were significantly associated with occurrence included T2DM duration (P=0.038), use of insulin (P=0.017), and lower BMD (P=0.048). Our study suggests that there was a higher prevalence of fracture in T2DM patients compared to control subjects and a significant difference in BMD was found between the groups. We also showed that insulin use, low BMD, and long duration of T2DM are factors associated with an increased risk of bone fracture.


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