scholarly journals Invited Review: Pathogenesis of osteoporosis

2003 ◽  
Vol 95 (5) ◽  
pp. 2142-2151 ◽  
Author(s):  
Ego Seeman

Patients with fragility fractures may have abnormalities in bone structural and material properties such as larger or smaller bone size, fewer and thinner trabeculae, thinned and porous cortices, and tissue mineral content that is either too high or too low. Bone models and remodels throughout life; however, with advancing age, less bone is replaced than was resorbed within each remodeling site. Estrogen deficiency at menoause increases remodeling intensity: a greater proportion of bone is remodeled on its endosteal (inner) surface, and within each of the many sites even more bone is lost as more bone is resorbed while less is replaced, accelerating architectural decay. In men, there is no midlife increase in remodeling. Bone loss within each remodeling site proceeds by reduced bone formation, producing trabecular and cortical thinning. Hypogonadism in 20-30% of elderly men contributes to bone loss. In both sexes, calcium malabsorption and secondary hyperparathyroidism increase remodeling: more bone is removed from an ever-diminishing bone mass. As bone is removed from the endosteal envelope, concurrent bone formation on the periosteal (outer) bone surface during aging partly offsets bone loss and increases bone's cross-sectional area. Periosteal apposition is less in women than in men; therefore, women have more net bone loss because they gain less on the periosteal surface, not because they resorb more on the endosteal surface. More women than men experience fractures because their smaller skeleton incurs greater architectural damage and adapts less by periosteal apposition.

2021 ◽  
Vol 92 (2) ◽  
pp. 65-74
Author(s):  
Anita V. Mantri ◽  
Heather C. M. Allaway ◽  
Jessica E. Brezicha ◽  
Harry A. Hogan ◽  
Susan A. Bloomfield

BACKGROUND: The impact of the spaceflight environment on endogenous estrogen production in female crewmembers and the resulting impact on other adaptations, like bone loss, is an under-investigated topic. Hence, we investigated the interaction of exogenous 17- estradiol (E2) treatment and disuse to test the hypothesis that E2 treatment would mitigate disuse-induced bone loss.METHODS: There were 40 virgin female Sprague-Dawley rats (5 mo old) randomized to placebo (PL; 0 ppm E2) or estrogen (E2; 10 ppm E2) treatments, delivered via custom-made rodent diets; half of each group was randomized to either weightbearing (WB) or hindlimb unloading (HU) for 39 d.RESULTS: We observed expected lower values after HU (615%) in volumetric BMD and cross-sectional areas at the proximal tibia metaphysis (PTM, by pQCT), 20% lower %BV/TV (nonsignificant) at the PTM, and 11% lower femoral neck maximal load; none of these HU-induced impacts were modified by E2. Impaired PTM periosteal expansion was observed in all E2-treated rats, with smaller (13 to 18%) cross-sectional areas. Midshaft tibial geometry was unaffected by E2 treatment, but large reductions (73 to 81%) in periosteal bone formation indices were observed in E2-treated rats.DISCUSSION: In summary, modest supplementation of exogenous E2 did not mitigate decrements in volumetric BMD, PTM cross-sectional geometry, or femoral neck strength observed with HU. However, numerous independent impacts of E2 treatment were observed, with significant suppression of periosteal bone formation indices. If maintained over time, this might impact negatively on cortical bone integrity during prolonged nonweightbearing.Mantri AV, Allaway HCM, Brezicha JE, Hogan HA, Bloomfield SA. Oral estradiol impact on mitigating unloading-induced bone loss in ovary-intact rats. Aerosp Med Hum Perform. 2021; 92(2):6574.


1982 ◽  
Vol 62 (3) ◽  
pp. 329-336 ◽  
Author(s):  
B. Krølner ◽  
S. Pors Nielsen

1. Bone mineral content of the second, third and fourth lumbar vertebrae was determined in normal women and women with clinical osteoporosis by using dual-photon (153Gd) absorptiometry. 2. A cross-sectional study of 70 normal women (aged 19–88 years) showed a bone loss of 44% from the age of around 34 years throughout life. 3. Longitudinal data from 59 normal women confirmed that the vertebral bone loss started before the menopause. An accelerated bone loss amounting to nearly 6% per year was seen immediately after the menopause. The bone loss of older women was slower. 4. Mean lumbar bone mineral content of 36 women (aged 48–93 years) with recent fractures of their femoral neck after minor trauma equalled that of age-matched normal women. Lumbar bone mineral content of the women with intratrochanteric femoral neck fractures was lower than that of the women with medial femoral neck fractures. 5. Mean lumbar bone mineral content of 72 women (aged 58–89 years) with primary osteoporosis was 41% lower than that of normal premenopausal women and 18% lower than that of age-matched controls. A weak inverse relationship between lumbar bone mineral content and the number of compression fractures was found. A weak inverse relationship between lumbar bone mineral content and the number of compression fractures was found. 6. Women with lumbar bone mineral content values below the 95% confidence limits for normal premenopausal women are at risk of future vertebral compression fractures, the fracture risk being inversely related to lumbar bone mineral content.


Author(s):  
Corey J. Miller ◽  
Silvia Trichilo ◽  
Edmund Pickering ◽  
Saulo Martelli ◽  
Peter Delisser ◽  
...  

The aim of the current study was to quantify the local effect of mechanical loading on cortical bone formation response at the periosteal surface using previously obtained μCT data from a mouse tibia mechanical loading study. A novel image analysis algorithm was developed to quantify local cortical thickness changes (ΔCt.Th) along the periosteal surface due to different peak loads (0N ≤ F ≤ 12N) applied to right-neurectomised mature female C57BL/6 mice. Furthermore, beam analysis was performed to analyse the local strain distribution including regions of tensile, compressive, and low strain magnitudes. Student’s paired t-test showed that ΔCt.Th in the proximal (25%), proximal/middle (37%), and middle (50%) cross-sections (along the z-axis of tibia) is strongly associated with the peak applied loads. These changes are significant in a majority of periosteal positions, in particular those experiencing high compressive or tensile strains. No association between F and ΔCt.Th was found in regions around the neutral axis. For the most distal cross-section (75%), the association of loading magnitude and ΔCt.Th was not as pronounced as the more proximal cross-sections. Also, bone formation responses along the periosteum did not occur in regions of highest compressive and tensile strains predicted by beam theory. This could be due to complex experimental loading conditions which were not explicitly accounted for in the mechanical analysis. Our results show that the bone formation response depends on the load magnitude and the periosteal position. Bone resorption due to the neurectomy of the loaded tibia occurs throughout the entire cross-sectional region for all investigated cortical sections 25, 37, 50, and 75%. For peak applied loads higher than 4 N, compressive and tensile regions show bone formation; however, regions around the neutral axis show constant resorption. The 50% cross-section showed the most regular ΔCt.Th response with increased loading when compared to 25 and 37% cross-sections. Relative thickness gains of approximately 70, 60, and 55% were observed for F = 12 N in the 25, 37, and 50% cross-sections. ΔCt.Th at selected points of the periosteum follow a linear response with increased peak load; no lazy zone was observed at these positions.


2021 ◽  
Vol 20 (10) ◽  
pp. 2199-2204
Author(s):  
Yujun Qi ◽  
Wenyuan Wang ◽  
Wenlin Sun ◽  
Qiuyin Pan

Purpose: To compare the effect of teriparatide and alendronate (bisphosphonate, BPP) among Chinese patients with osteoporosis (OoP).Method: Chinese subjects aged > 40 years with a history of vertebral/non-vertebral osteoporotic fragility/fractures were enrolled, and administered either teriparatide (TPT 20 μg/day) subcutaneously or alendronate (BPP)10 mg orally once daily for 12 months. Bone mineral density (BMD), measured using x-ray techniques, and bone formation biomarkers such as osteocalcin [OTC] and bone alkaline phosphatase, were assessed at baseline, and after 6 and 12 months of treatment. The proportion of patients with fractures as well as fracture rate were also recorded. The safety of the drugs was evaluated based treatment emergent adverse events.Result: In Chinese men with OoP, substantially greater improvement in BMD was observed in TPT group, compared to BPP group. TPT demonstrated substantially greater improvement in OTC and, bone alkaline phosphatase than in BPP. Also, patients treated with TPT had significantly lower incidence of new fracture than BPP group during the study period, irrespective of gender distribution (relative risk reduction at 6 and 12 months was 45 and 47 % respectively). The results showed that TPT was superior to BPP in increasing BMD and bone formation biomarkers and reducing new fractures in both male and female patients with osteoporosis.Conclusion: Teriparatide is effective and safe in reducing bone loss and preventing vertebral fractures in Chinese patients with osteoporosis. Furthermore, the results show that there is no gender difference in the efficacy and safety of teriparatide in osteoporosis.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 186.1-187
Author(s):  
E. Wiebe ◽  
D. Freier ◽  
D. Huscher ◽  
G. Dallagiacoma ◽  
R. Biesen ◽  
...  

Background:Rheumatoid arthritis (RA) is associated with increased systemic bone loss, leading to a high risk for fragility fractures. Especially anti-citrullinated protein antibody (ACPA) positivity is considered a risk factor for local bone erosions and systemic bone loss1.Objectives:The purpose of this study was to compare ACPA positive versus ACPA negative RA patients in terms of the prevalence of osteoporosis and fragility fractures and to identify differences in underlying risk factors that influence bone health.Methods:Rh-GIOP is an ongoing prospective observational study collecting and analyzing disease- and bone-related data from patients with chronic rheumatic diseases or psoriasis treated with glucocorticoids (GC). In this cross-sectional analysis, we performed a matched-pair analysis, matching 114 ACPA positive to 114 ACPA negative RA patients according to age (5-year-steps), sex, and body mass index (BMI, 2-unit-steps). Descriptive analyses were performed, with values displayed as mean ± standard deviation for continuous variables. Non-parametric tests were used at a two-sided significance level of 5% to compare differences in underlying and potential risk factors without adjustment for multiple testing.Results:At same mean age (63.9 ±10.2 years) and BMI (27.9 ±5.6kg/m2), the matched groups had a female proportion of 82.5%. APCA positive patients had a significantly longer mean disease duration (13.9 vs 9.9 years, p<0.001), a higher mean cumulative GC-dose (22.3 vs 13.2g, p<0.01) and mean duration of GC therapy (10.1 vs 6.6 years, p<0.01). There was no significant difference in the prevalence of osteoporosis as defined by dual-energy X-ray absorptiometry (DXA) (18.4 vs 20.2%), nor in the prevalence of vertebral (7.0 vs 5.3%) or non-vertebral fractures (31.6 vs 29.8%). C-reactive protein levels as a marker of disease activity were significantly higher in ACPA positive patients (mean: 8.8 vs 4.3mg/l, p= 0.02), while mean disease activity score (DAS)28 levels were slightly lower in ACPA positive patients (2.4 vs 2.7, p= 0.05). No difference in health assessment questionnaire (HAQ) score was found. RA-specific treatments were similar, especially concerning current mean daily GC-dose (6.7 vs 4.9mg/day), except for Rituximab and targeted synthetic disease modifying anti-rheumatic drugs (DMARDs) which were more commonly used in ACPA positive patients (9.6 vs 2.6%, p=0.05) and (5.3 vs 0%, p=0.029), respectively. ACPA positive patients did not differ significantly from ACPA negative patients in specific anti-osteoporotic treatment, nor in the prevalence of comorbidities or concomitant medication. There were no significant differences in bone-specific laboratory parameters.Conclusion:In a cross-sectional analysis of our cohort, the prevalence of osteoporosis and fragility fractures was similar between ACPA positive and ACPA negative RA patients, despite longer disease duration and GC-treatment in ACPA positive patients. This is remarkable since it implies that ACPA negative patients are at a similar risk for osteoporosis and associated fractures. Optimal management of disease activity with or without GCs may represent a mainstay in preventing disease-related comorbidities such as osteoporosis.References:[1]Steffen, U., Schett, G., & Bozec, A. (2019). How Autoantibodies Regulate Osteoclast Induced Bone Loss in Rheumatoid Arthritis. Frontiers in immunology, 10, 1483. doi:10.3389/fimmu.2019.01483Disclosure of Interests:Edgar Wiebe: None declared, Desiree Freier: None declared, Dörte Huscher: None declared, gloria dallagiacoma: None declared, Robert Biesen: None declared, Sandra Hermann: None declared, Gerd Rüdiger Burmester Consultant of: AbbVie Inc, Eli Lilly, Gilead, Janssen, Merck, Roche, Pfizer, and UCB Pharma, Speakers bureau: AbbVie Inc, Eli Lilly, Gilead, Janssen, Merck, Roche, Pfizer, and UCB Pharma, Frank Buttgereit Grant/research support from: Amgen, BMS, Celgene, Generic Assays, GSK, Hexal, Horizon, Lilly, medac, Mundipharma, Novartis, Pfizer, Roche, and Sanofi.


2021 ◽  
Vol 10 (13) ◽  
pp. 2849
Author(s):  
Piotr Kuligowski ◽  
Aleksandra Jaroń ◽  
Olga Preuss ◽  
Ewa Gabrysz-Trybek ◽  
Joanna Bladowska ◽  
...  

Odontogenic infections can directly trigger maxillary sinusitis. CBCT is an excellent choice for precise examination of maxillary sinuses and hard tissues within the oral cavity. The objective of this retrospective and the cross-sectional study was to analyze the influence of odontogenic conditions on the presence and intensity of maxillary sinus mucous membrane thickening using CBCT imaging. Moreover, periodontal bone loss and anatomic relationship between adjacent teeth and maxillary sinuses were assessed to evaluate its possible impact on creating maxillary thickening. The study sample consisted of 200 maxillary sinuses of 100 patients visible on CBCT examination with a field of view of 13 × 15 cm. The presented study revealed a significant influence of periapical lesions, inappropriate endodontic treatment, severe caries, and extracted teeth on the presence of increased thickening of maxillary sinus mucous membrane. In addition, an increase in the distance between root apices and maxillary sinus floor triggered a significant reduction of maxillary sinus mucous membrane thickening. The presence of periodontal bone loss significantly increases maxillary sinus mucous membrane thickening.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1182.2-1182
Author(s):  
E. Wiebe ◽  
D. Freier ◽  
D. Huscher ◽  
R. Biesen ◽  
S. Hermann ◽  
...  

Background:Rheumatic diseases are associated with increased systemic bone loss and fracture risk related to chronic inflammation, disease-specific, general and demographic risk factors as well as treatment with glucocorticoids (GC). Yet, there is evidence that GCs may, by adequately suppressing systemic inflammation, also have a positive effect on bone mineral density (BMD) and fracture risk1.Objectives:The purpose of this study was to investigate the prevalence of osteoporosis and fragility fractures in patients with inflammatory rheumatic diseases and to analyze the impact that treatment with GCs, other known risk factors and preventive measures have on bone health in these patients.Methods:Rh-GIOP is an ongoing prospective observational study collecting and analyzing disease- and bone-related data from patients with chronic inflammatory rheumatic diseases and psoriasis treated with GCs. In this cross-sectional analysis, we evaluated the initial visit of 1091 patients. A multivariate linear regression model with known or potentially influential factors adjusted for age and sex was used to identify predictors of BMD as measured by dual-energy X-ray absorptiometry (DXA). Multiple imputation was applied for missing baseline covariate data.Results:In the total cohort of 1091 patients (75% female of which 87.5% were postmenopausal) with a mean age of 62.1 (±13.2) years, the prevalence of osteoporosis by DXA was 21.7%, while fragility fractures have occurred in 31.2% of the study population (6.7% vertebral, 27.7% non-vertebral). Current GC therapy was common (64.9%), with a median daily dose of 5.0mg [0.0;7.5], a mean life-time total GC dose of 17.7g (±24.6), and a mean GC therapy duration of 7.8 years (±8.5). Bisphosphonates were the most commonly used anti-osteoporotic drug (12.6%).Multivariate analysis showed that BMD as expressed by the minimum T-Score at all measured sites was negatively associated with higher age, female sex and menopause as well as Denosumab and Bisphosphonate treatment. A positive association with BMD was found for body mass index as well as current and life-time (cumulative) GC dose. While comedication with proton-pump-inhibitors significantly predicted low bone mass, concomitant use of non-steroidal anti-inflammatory drugs showed a positive association with BMD. Of the measured bone-specific laboratory parameters, higher alkaline phosphatase levels were determinants of low DXA-values, while the association was positive for gamma-glutamyltransferase.BMD was neither predicted by duration of GC treatment nor by treatment with disease modifying anti-rheumatic drugs.Predictive variables for BMD differed at the respective anatomical site. While treatment with Denosumab predicted low bone mass at the lumbar spine and not at the femoral neck, the opposite was true for health assessment questionnaire (HAQ) score. Current and life-time GC-dose as well as direct sun-exposure of more than 30 minutes daily were positively associated with bone mass at the femoral sites only.Conclusion:This cross-sectional analysis of a prospective cohort study quantified the prevalence of osteoporosis and identified predictive variables of BMD in patients with rheumatic diseases.Multivariate analyses corroborated low BMD to be predicted by traditional factors like age, female sex and menopause but showed current and well as life-time GC dose to be positively associated with BMD in our cohort of patients with chronic inflammatory rheumatic diseases. This suggests that optimal management of disease activity with GCs might be beneficial in order to avoid bone loss due to inflammation.References:[1]Güler-Yüksel et al. “Glucocorticoids, Inflammation and Bone.” Calcified Tissue International (January 08 2018).Disclosure of Interests:Edgar Wiebe: None declared, Desiree Freier: None declared, Dörte Huscher: None declared, Robert Biesen: None declared, Sandra Hermann: None declared, Frank Buttgereit Grant/research support from: Amgen, BMS, Celgene, Generic Assays, GSK, Hexal, Horizon, Lilly, medac, Mundipharma, Novartis, Pfizer, Roche, and Sanofi.


Author(s):  
Annie M. Constable ◽  
Josie E. Porter ◽  
Danielle Benger ◽  
Dimitris Vlachopoulos ◽  
Alan R. Barker ◽  
...  

Purpose: Moderate-to-vigorous physical activity (MVPA) positively influences bone mineral content (BMC) in prepubertal children, but it is unknown whether this relationship is partially mediated by free leptin index. The aim of this study was to examine whether the relationship between MVPA and total body less head (TBLH) BMC is mediated or moderated by free leptin index in prepubertal children. Methods: We performed a cross-sectional analysis on 401 children (194 girls) from baseline examinations of the Physical Activity and Nutrition in Childhood Study. We applied the four-way decomposition mediation analysis method to assess whether free leptin index, measured from fasted blood samples, mediated the relationship between accelerometer-measured MVPA and TBLH BMC measured by dual-energy X-ray absorptiometry. Results: MVPA had a positive controlled direct effect on TBLH BMC in girls and boys (β = 0.010 to 0.011, p < 0.05). There was no mediation or interaction between MVPA, free leptin index and TBLH BMC in girls or boys (β = −0.000 to 0.001, p > 0.05). Conclusion: Our study indicates that MVPA positively influences TBLH BMC through pathways not related to free leptin index in predominantly normal-weight prepubertal children, likely primarily through mechanical loading. The relationships between MVPA, free leptin index and TBLH BMC may be influenced by other factors such as pubertal status and adiposity, so it is unknown whether these observations extend to overweight and obese children at different stages of puberty.


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