Age-Related Cancellous Bone Loss in the Proximal Femur of Caucasian Females

2000 ◽  
Vol 11 (6) ◽  
pp. 505-511 ◽  
Author(s):  
G. A. Lundeen ◽  
E. G. Vajda ◽  
R. D. Bloebaum
Keyword(s):  
Bone Loss ◽  
Cancellous Bone ◽  
Proximal Femur ◽  
Age Related

scholarly journals Hypothalamic leptin gene therapy reduces body weight without accelerating age-related bone loss

2015 ◽  
Vol 227 (3) ◽  
pp. 129-141 ◽  
Author(s):  
Russell T Turner ◽  
Michael Dube ◽  
Adam J Branscum ◽  
Carmen P Wong ◽  
Dawn A Olson ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Body Weight ◽  
Bone Loss ◽  
Bone Mass ◽  
Bone Turnover ◽  
Cancellous Bone ◽  
Mass Density ◽  
Female Rats ◽  
Bone Mass Density ◽  
Age Related

Excessive weight gain in adults is associated with a variety of negative health outcomes. Unfortunately, dieting, exercise, and pharmacological interventions have had limited long-term success in weight control and can result in detrimental side effects, including accelerating age-related cancellous bone loss. We investigated the efficacy of using hypothalamic leptin gene therapy as an alternative method for reducing weight in skeletally-mature (9 months old) female rats and determined the impact of leptin-induced weight loss on bone mass, density, and microarchitecture, and serum biomarkers of bone turnover (CTx and osteocalcin). Rats were implanted with cannulae in the 3rd ventricle of the hypothalamus and injected with either recombinant adeno-associated virus encoding the gene for rat leptin (rAAV-Leptin,n=7) or a control vector encoding green fluorescent protein (rAAV-GFP,n=10) and sacrificed 18 weeks later. A baseline control group (n=7) was sacrificed at vector administration. rAAV-Leptin-treated rats lost weight (−4±2%) while rAAV-GFP-treated rats gained weight (14±2%) during the study. At study termination, rAAV-Leptin-treated rats weighed 17% less than rAAV-GFP-treated rats and had lower abdominal white adipose tissue weight (−80%), serum leptin (−77%), and serum IGF1 (−34%). Cancellous bone volume fraction in distal femur metaphysis and epiphysis, and in lumbar vertebra tended to be lower (P<0.1) in rAAV-GFP-treated rats (13.5 months old) compared to baseline control rats (9 months old). Significant differences in cancellous bone or biomarkers of bone turnover were not detected between rAAV-Leptin and rAAV-GFP rats. In summary, rAAV-Leptin-treated rats maintained a lower body weight compared to baseline and rAAV-GFP-treated rats with minimal effects on bone mass, density, microarchitecture, or biochemical markers of bone turnover.

scholarly journals Sex Steroids and the Construction and Conservation of the Adult Skeleton

2002 ◽  
Vol 23 (3) ◽  
pp. 279-302 ◽  
Author(s):  
B. Lawrence Riggs ◽  
Sundeep Khosla ◽  
L. Joseph Melton
Keyword(s):  
Bone Loss ◽  
Bone Mass ◽  
Cancellous Bone ◽  
Sex Steroids ◽  
Peak Bone Mass ◽  
Dietary Calcium Intake ◽  
Growth Spurt ◽  
Slow Phase ◽  
Age Related ◽  
Aging Men

Abstract Here we review and extend a new unitary model for the pathophysiology of involutional osteoporosis that identifies estrogen (E) as the key hormone for maintaining bone mass and E deficiency as the major cause of age-related bone loss in both sexes. Also, both E and testosterone (T) are key regulators of skeletal growth and maturation, and E, together with GH and IGF-I, initiate a 3- to 4-yr pubertal growth spurt that doubles skeletal mass. Although E is required for the attainment of maximal peak bone mass in both sexes, the additional action of T on stimulating periosteal apposition accounts for the larger size and thicker cortices of the adult male skeleton. Aging women undergo two phases of bone loss, whereas aging men undergo only one. In women, the menopause initiates an accelerated phase of predominantly cancellous bone loss that declines rapidly over 4–8 yr to become asymptotic with a subsequent slow phase that continues indefinitely. The accelerated phase results from the loss of the direct restraining effects of E on bone turnover, an action mediated by E receptors in both osteoblasts and osteoclasts. In the ensuing slow phase, the rate of cancellous bone loss is reduced, but the rate of cortical bone loss is unchanged or increased. This phase is mediated largely by secondary hyperparathyroidism that results from the loss of E actions on extraskeletal calcium metabolism. The resultant external calcium losses increase the level of dietary calcium intake that is required to maintain bone balance. Impaired osteoblast function due to E deficiency, aging, or both also contributes to the slow phase of bone loss. Although both serum bioavailable (Bio) E and Bio T decline in aging men, Bio E is the major predictor of their bone loss. Thus, both sex steroids are important for developing peak bone mass, but E deficiency is the major determinant of age-related bone loss in both sexes.

Impact direction from a fall influences the failure load of the proximal femur as much as age-related bone loss

1996 ◽  
Vol 58 (4) ◽  
pp. 231-235 ◽  
Author(s):  
T. P. Pinilla ◽  
K. C. Boardman ◽  
M. L. Bouxsein ◽  
E. R. Myers ◽  
W. C. Hayes
Keyword(s):  
Bone Loss ◽  
Proximal Femur ◽  
Failure Load ◽  
Age Related

scholarly journals Room temperature housing results in premature cancellous bone loss in growing female mice: implications for the mouse as a preclinical model for age-related bone loss

2016 ◽  
Vol 27 (10) ◽  
pp. 3091-3101 ◽  
Author(s):  
U. T. Iwaniec ◽  
K. A. Philbrick ◽  
C. P. Wong ◽  
J. L. Gordon ◽  
A. M. Kahler-Quesada ◽  
...  
Keyword(s):  
Bone Loss ◽  
Cancellous Bone ◽  
Room Temperature ◽  
Preclinical Model ◽  
Female Mice ◽  
Age Related

Impact Direction from a Fall Influences the Failure Load of the Proximal Femur as Much as Age-Related Bone Loss

1996 ◽  
Vol 58 (4) ◽  
pp. 231-235 ◽  
Author(s):  
T. P. Pinilla ◽  
K. C. Boardman ◽  
M. L. Bouxsein ◽  
E. R. Myers ◽  
W. C. Hayes
Keyword(s):  
Bone Loss ◽  
Proximal Femur ◽  
Failure Load ◽  
Age Related

scholarly journals The Dual Role of Vitamin K2 in “Bone-Vascular Crosstalk”: Opposite Effects on Bone Loss and Vascular Calcification

Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1222
Author(s):  
Domitilla Mandatori ◽  
Letizia Pelusi ◽  
Valeria Schiavone ◽  
Caterina Pipino ◽  
Natalia Di Pietro ◽  
...  
Keyword(s):  
Bone Loss ◽  
Vascular Calcification ◽  
Vascular System ◽  
The Elderly ◽  
Food Supplement ◽  
Vitamin K2 ◽  
Bioactive Molecules ◽  
Calcium Deposition ◽  
Age Related

Osteoporosis (OP) and vascular calcification (VC) represent relevant health problems that frequently coexist in the elderly population. Traditionally, they have been considered independent processes, and mainly age-related. However, an increasing number of studies have reported their possible direct correlation, commonly defined as “bone-vascular crosstalk”. Vitamin K2 (VitK2), a family of several natural isoforms also known as menaquinones (MK), has recently received particular attention for its role in maintaining calcium homeostasis. In particular, VitK2 deficiency seems to be responsible of the so-called “calcium paradox” phenomenon, characterized by low calcium deposition in the bone and its accumulation in the vessel wall. Since these events may have important clinical consequences, and the role of VitK2 in bone-vascular crosstalk has only partially been explained, this review focuses on its effects on the bone and vascular system by providing a more recent literature update. Overall, the findings reported here propose the VitK2 family as natural bioactive molecules that could be able to play an important role in the prevention of bone loss and vascular calcification, thus encouraging further in-depth studies to achieve its use as a dietary food supplement.

Physiological plasma levels of androgens reduce bone loss in the ovariectomized rat

1998 ◽  
Vol 274 (2) ◽  
pp. E328-E335 ◽  
Author(s):  
C. K. Lea ◽  
A. M. Flanagan
Keyword(s):  
Bone Resorption ◽  
Bone Loss ◽  
Protective Effect ◽  
Cancellous Bone ◽  
Plasma Levels ◽  
Slow Release ◽  
Bone Volume ◽  
Ovariectomized Rat ◽  
Ovx Rats ◽  
Reduce Bone Loss

The effect of androstenedione (ADIONE) slow-release pellets on cancellous bone volume (BV/TV) at the tibial metaphysis was investigated in ovariectomized (OVX) rats at various times from 21 to 180 days. Plasma levels of ADIONE and testosterone (T) in OVX rats were significantly reduced at 21 days and were restored close to levels in the sham rats with the 1.5-mg ADIONE pellet. OVX animals with and without ADIONE pellets resulted in close to a 50% reduction in BV/TV by day 21. By day 180, OVX rats had only ∼5% BV/TV, whereas that in ADIONE-treated OVX rats was significantly greater at ∼12%. The reduced BV/TV was associated with increased bone resorption and formation. In a separate 90-day experiment, we found that the antiandrogen, Casodex, abrogated the ADIONE-induced skeletal-protective effect in OVX rats, whereas the antiaromatase, Arimidex, had no effect. This provides evidence that ADIONE protects against the development of osteopenia in the estrogen-deficient rat and mediates its effect through androgens and not estrogens.

The archaeology of osteoporosis

2001 ◽  
Vol 4 (2) ◽  
pp. 263-269 ◽  
Author(s):  
Gordon Turner-Walker ◽  
Unni Syversen ◽  
Simon Mays
Keyword(s):  
Bone Loss ◽  
Femoral Neck ◽  
Young Women ◽  
Rapid Decline ◽  
Mineral Density ◽  
Medieval Women ◽  
Age Related ◽  
Pregnancy And Lactation ◽  
Post Menopausal ◽  
The Uk

The application of medical scanning technologies to archaeological skeletons provides novel insights into the history and potential causes of osteoporosis. The present study investigated bone mineral density (BMD) in medieval skeletons from England and Norway. Comparisons between the two adult populations found no statistically significant differences. This compares with a modern fracture incidence for the femoral neck in women from Norway that is almost three times that in the UK. The pattern of age-related bone loss in medieval men was similar to that seen in men today. In contrast, the pattern in medieval women differed from that of modern young women. On average, medieval women experienced a decrease in BMD at the femoral neck of approximately 23 per cent between the ages of 22 and 35. These losses were partially recovered by age 45, after which BMD values show a decline consistent with post-menopausal bone loss in modern western women. A possible explanation of the rapid decline in BMD in young medieval women is bone loss in connection with pregnancy and lactation in circumstances of insufficient nutrition.

scholarly journals CB2 cannabinoid receptor agonist enantiomers HU-433 and HU-308: An inverse relationship between binding affinity and biological potency

2015 ◽  
Vol 112 (28) ◽  
pp. 8774-8779 ◽  
Author(s):  
Reem Smoum ◽  
Saja Baraghithy ◽  
Mukesh Chourasia ◽  
Aviva Breuer ◽  
Naama Mussai ◽  
...  
Keyword(s):  
Bone Loss ◽  
Binding Affinity ◽  
Cannabinoid Receptors ◽  
Cannabinoid Receptor ◽  
Osteoclast Differentiation ◽  
Protective Mechanism ◽  
Binding Studies ◽  
Age Related ◽  
Comparative Binding ◽  
Biological Potency

Activation of the CB2 receptor is apparently an endogenous protective mechanism. Thus, it restrains inflammation and protects the skeleton against age-related bone loss. However, the endogenous cannabinoids, as well as Δ9-tetrahydrocannabinol, the main plant psychoactive constituent, activate both cannabinoid receptors, CB1 and CB2. HU-308 was among the first synthetic, selective CB2 agonists. HU-308 is antiosteoporotic and antiinflammatory. Here we show that the HU-308 enantiomer, designated HU-433, is 3–4 orders of magnitude more potent in osteoblast proliferation and osteoclast differentiation culture systems, as well as in mouse models, for the rescue of ovariectomy-induced bone loss and ear inflammation. HU-433 retains the HU-308 specificity for CB2, as shown by its failure to bind to the CB1 cannabinoid receptor, and has no activity in CB2-deficient cells and animals. Surprisingly, the CB2 binding affinity of HU-433 in terms of [3H]CP55,940 displacement and its effect on [35S]GTPγS accumulation is substantially lower compared with HU-308. A molecular-modeling analysis suggests that HU-433 and -308 have two different binding conformations within CB2, with one of them possibly responsible for the affinity difference, involving [35S]GTPγS and cAMP synthesis. Hence, different ligands may have different orientations relative to the same binding site. This situation questions the usefulness of universal radioligands for comparative binding studies. Moreover, orientation-targeted ligands have promising potential for the pharmacological activation of distinct processes.

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