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1.
Calcif Tissue Int ; 103(1): 50-54, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29380013

RESUMO

The aim of the present study was to document the changes in bone mineral density (BMD) 1 year after denosumab loss-of-effect following long-term treatment with subcutaneous denosumab 60 mg Q6M during 7 or 10 years and in the absence of any treatment with a bone active substance. All postmenopausal women with osteoporosis who participated to the randomized placebo-controlled FREEDOM core trial and its open-label extension at the University Hospital of Bern, Switzerland, and who accepted to undergo off-treatment follow-up during 1 year after discontinuation, were included (N = 12). After 10 years of denosumab, mean lumbar spine (LS) BMD had increased by 21.2% vs. baseline. One year after discontinuation LS BMD had decreased by - 9.1% vs. Year 10, resulting in a net gain of 10.2% vs. baseline. At total hip (TH) and femoral neck (FN), BMD had increased by 8.3 and 8.1% in Year 10 vs. baseline, respectively. 1 Year after discontinuation, BMD had decreased by - 12.7 and - 11.0% vs. Year 10, respectively, corresponding to net BMD losses of - 5.5 and - 3.8% vs. baseline, respectively. Similar albeit less pronounced changes were observed in those treated with denosumab during 7 years. Stopping denosumab after long-term exposure resulted in BMD losses of large order of magnitude at all measured sites, suggesting that treatment duration may predict the rate and amount of bone lost.


Assuntos
Conservadores da Densidade Óssea/administração & dosagem , Densidade Óssea/efeitos dos fármacos , Denosumab/administração & dosagem , Osteoporose Pós-Menopausa/tratamento farmacológico , Idoso , Feminino , Humanos
2.
Eur Spine J ; 25(11): 3432-3438, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-26014806

RESUMO

PURPOSE: To determine the predictive value of the vertebral trabecular bone score (TBS) alone or in addition to bone mineral density (BMD) with regard to fracture risk. METHODS: Retrospective analysis of the relative contribution of BMD [measured at the femoral neck (FN), total hip (TH), and lumbar spine (LS)] and TBS with regard to the risk of incident clinical fractures in a representative cohort of elderly post-menopausal women previously participating in the Swiss Evaluation of the Methods of Measurement of Osteoporotic Fracture Risk study. RESULTS: Complete datasets were available for 556 of 701 women (79 %). Mean age 76.1 years, LS BMD 0.863 g/cm2, and TBS 1.195. LS BMD and LS TBS were moderately correlated (r 2 = 0.25). After a mean of 2.7 ± 0.8 years of follow-up, the incidence of fragility fractures was 9.4 %. Age- and BMI-adjusted hazard ratios per standard deviation decrease (95 % confidence intervals) were 1.58 (1.16-2.16), 1.77 (1.31-2.39), and 1.59 (1.21-2.09) for LS, FN, and TH BMD, respectively, and 2.01 (1.54-2.63) for TBS. Whereas 58 and 60 % of fragility fractures occurred in women with BMD T score ≤-2.5 and a TBS <1.150, respectively, combining these two thresholds identified 77 % of all women with an osteoporotic fracture. CONCLUSIONS: Lumbar spine TBS alone or in combination with BMD predicted incident clinical fracture risk in a representative population-based sample of elderly post-menopausal women.


Assuntos
Densidade Óssea/fisiologia , Osso Esponjoso/patologia , Vértebras Lombares/patologia , Osteoporose/patologia , Fraturas por Osteoporose/epidemiologia , Fraturas por Osteoporose/prevenção & controle , Idoso , Feminino , Humanos , Estudos Retrospectivos , Fatores de Risco
3.
Growth Horm IGF Res ; 24(2-3): 83-8, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24735836

RESUMO

OBJECTIVE: We investigated the skeletal growth profile of female rats from birth to senescence (100weeks) on the basis of sequential radiometrical, hormonal and biochemical parameters. DESIGN: Weaning rats entered the study which was divided into two sections: a) sequential measurements of vertebral and tibial growths and bone mineral density (BMD), estimation of mineral content of the entire skeleton (BMC) and chemical analysis of vertebral Ca; and b) determination of basal and pulsatile growth hormone (rGH), insulin-like growth hormone (IGF-I), estradiol (E2), parathyroid hormone (PTH), osteocalcin (OC) and urinary d-pyridinoline (dp) throughout the experimental period. RESULTS: Vertebral and tibial growths ceased at week 25 whereas BMD and BMC as well as total vertebral Ca exhibited a peak bone mass at week 40. rGH pulsatile profiles were significantly higher in younger animals coinciding with the period of active growth and IGF-I peaked at 7weeks, slowly declining thereafter and stabilizing after week 60. OC and dp closely paralleled IGF-I coinciding with the period of enhanced skeletal growth, remaining thereafter in the low range indicative of reduced bone turnover. E2 increased during reproductive life but the lower values subsequently recorded were still in the physiological range, strongly suggesting a protective role of this steroid on bone remodeling. PTH followed a similar profile to E2, but the significance of this after completion of growth remains unclear. CONCLUSIONS: Mechanisms governing skeletal growth in the female rat appear similar to those in humans. Bone progression and attainment of peak bone mass are under simultaneous control of rGH, IGF-I and calciotropic hormones and are modulated by E2. This steroid seems to protect the skeleton from resorption before senescence whereas the role of PTH in this context remains uncertain.


Assuntos
Envelhecimento/fisiologia , Desenvolvimento Ósseo/fisiologia , Osso e Ossos/química , Hormônios/sangue , Parto/fisiologia , Absorção de Radiação , Animais , Densidade Óssea , Osso e Ossos/metabolismo , Cálcio/análise , Cálcio/metabolismo , Feminino , Minerais/análise , Minerais/metabolismo , Radiometria , Ratos , Ratos Wistar
4.
J Bone Miner Res ; 28(3): 449-54, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23018784

RESUMO

The trabecular bone score (TBS) is an index of bone microarchitectural texture calculated from anteroposterior dual-energy X-ray absorptiometry (DXA) scans of the lumbar spine (LS) that predicts fracture risk, independent of bone mineral density (BMD). The aim of this study was to compare the effects of yearly intravenous zoledronate (ZOL) versus placebo (PLB) on LS BMD and TBS in postmenopausal women with osteoporosis. Changes in TBS were assessed in the subset of 107 patients recruited at the Department of Osteoporosis of the University Hospital of Berne, Switzerland, who were included in the HORIZON trial. All subjects received adequate calcium and vitamin D3. In these patients randomly assigned to either ZOL (n = 54) or PLB (n = 53) for 3 years, BMD was measured by DXA and TBS assessed by TBS iNsight (v1.9) at baseline and 6, 12, 24, and 36 months after treatment initiation. Baseline characteristics (mean ± SD) were similar between groups in terms of age, 76.8 ± 5.0 years; body mass index (BMI), 24.5 ± 3.6 kg/m(2) ; TBS, 1.178 ± 0.1 but for LS T-score (ZOL-2.9 ± 1.5 versus PLB-2.1 ± 1.5). Changes in LS BMD were significantly greater with ZOL than with PLB at all time points (p < 0.0001 for all), reaching +9.58% versus +1.38% at month 36. Change in TBS was significantly greater with ZOL than with PLB as of month 24, reaching +1.41 versus-0.49% at month 36; p = 0.031, respectively. LS BMD and TBS were weakly correlated (r = 0.20) and there were no correlations between changes in BMD and TBS from baseline at any visit. In postmenopausal women with osteoporosis, once-yearly intravenous ZOL therapy significantly increased LS BMD relative to PLB over 3 years and TBS as of 2 years.


Assuntos
Densidade Óssea/efeitos dos fármacos , Difosfonatos/uso terapêutico , Imidazóis/uso terapêutico , Osteoporose/tratamento farmacológico , Pós-Menopausa , Coluna Vertebral/efeitos dos fármacos , Absorciometria de Fóton , Idoso , Difosfonatos/farmacologia , Método Duplo-Cego , Feminino , Humanos , Imidazóis/farmacologia , Pessoa de Meia-Idade , Osteoporose/patologia , Placebos , Estudos Retrospectivos , Ácido Zoledrônico
5.
Osteoporos Int ; 16(11): 1353-62, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15711776

RESUMO

Mass screening for osteoporosis using DXA measurements at the spine and hip is presently not recommended by health authorities. Instead, risk factor questionnaires and peripheral bone measurements may facilitate the selection of women eligible for axial bone densitometry. The aim of this study was to validate a case finding strategy for postmenopausal women who would benefit most from subsequent DXA measurement by using phalangeal radiographic absorptiometry (RA) alone or in combination with risk factors in a general practice setting. The sensitivity and specificity of this strategy in detecting osteoporosis (T-score < or =2.5 SD at the spine and/or the hip) were compared with those of the current reimbursement criteria for DXA measurements in Switzerland. Four hundred and twenty-three postmenopausal women with one or more risk factors for osteoporosis were recruited by 90 primary care physicians who also performed the phalangeal RA measurements. All women underwent subsequent DXA measurement of the spine and the hip at the Osteoporosis Policlinic of the University Hospital of Berne. They were allocated to one of two groups depending on whether they matched with the Swiss reimbursement conditions for DXA measurement or not. Logistic regression models were used to predict the likelihood of osteoporosis versus "no osteoporosis" and to derive ROC curves for the various strategies. Differences in the areas under the ROC curves (AUC) were tested for significance. In women lacking reimbursement criteria, RA achieved a significantly larger AUC (0.81; 95% CI 0.72-0.89) than the risk factors associated with patients' age, height and weight (0.71; 95% C.I. 0.62-0.80). Furthermore, in this study, RA provided a better sensitivity and specificity in identifying women with underlying osteoporosis than the currently accepted criteria for reimbursement of DXA measurement. In the Swiss environment, RA is a valid case finding tool for patients with risk factors for osteoporosis, especially for those who do not qualify for DXA reimbursement.


Assuntos
Densidade Óssea , Falanges dos Dedos da Mão/diagnóstico por imagem , Programas de Rastreamento/métodos , Osteoporose Pós-Menopausa/diagnóstico , Seleção de Pacientes , Absorciometria de Fóton , Idoso , Idoso de 80 Anos ou mais , Métodos Epidemiológicos , Medicina de Família e Comunidade , Feminino , Colo do Fêmur/diagnóstico por imagem , Humanos , Reembolso de Seguro de Saúde , Vértebras Lombares/diagnóstico por imagem , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/fisiopatologia , Medição de Risco/métodos , Suíça
6.
J Bone Miner Res ; 19(7): 1067-74, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15176988

RESUMO

UNLABELLED: To assess the effects of long-term treatment of bone loss with alendronate in a group of paraplegic men, 55 patients were evaluated in a prospective randomized controlled open label study that was 2 years in duration comparing alendronate and calcium with calcium alone. Bone loss was stopped at all cortical and trabecular infralesional sites (distal tibial epiphysis, tibial diaphysis, total hip) with alendronate 10 mg daily. INTRODUCTION: Bone loss after spinal cord injury (SCI) leads to increased fracture risk in the lower limbs of paraplegics. The aim of this study was to document long-term treatment of bone loss with alendronate in a group of paraplegic men with complete motor lesion after SCI. MATERIALS AND METHODS: Sixty-five men with complete motor post-traumatic medullary lesion between T1 and L2 with total motor and sensory loss (Frankel classification, stage A) or with total motor and partial sensory loss (Frankel classification, stage B) after SCI were included in this prospective randomized controlled open label study that was 2 years in duration. The patients were randomized to either the treatment group with alendronate 10 mg daily and elemental calcium 500 mg daily or to the control group with elemental calcium 500 mg daily alone. The primary endpoint was defined as the effect over 24 months of alendronate and calcium compared with calcium alone on the BMD values at the distal tibial epiphysis (as a surrogate for trabecular bone in the paralyzed zone). The secondary endpoints were changes in BMD at supra- and infralesional sites of measurement. Biochemical markers of bone turnover were assessed. RESULTS: Fifty-five subjects, 0.1-29.5 years post-SCI, completed the study over 24 months. BMD at the distal tibial epiphysis significantly decreased from baseline in the calcium group (-10.8 +/- 2.7% at 24 months, p < 0.001), whereas it remained stable in the alendronate plus calcium group (-2.0 +/- 2.9% at 24 months, p = not significant versus baseline), leading to a significant intergroup difference over time (p = 0.017). At the tibial diaphysis, similar significant results were observed. At the ultradistal radius and the radial shaft, BMD did not change significantly from baseline in either treatment group. At the total hip, BMD decreased significantly in the calcium group (-4.1 +/- 1.6%, p = 0.038) but remained stable in the alendronate plus calcium group (+0.43 +/- 1.2%), with a significant intergroup difference (p = 0.037). At the lumbar spine, BMD increased significantly (p < 0.0001) from baseline in both groups. Biochemical markers of bone resorption were significantly decreased with alendronate versus baseline and control. Alendronate and calcium were generally safe and well tolerated. CONCLUSIONS: In paraplegic men, SCI bone loss was stopped at all measured cortical and trabecular infralesional sites over 24 months with alendronate 10 mg daily.


Assuntos
Alendronato/uso terapêutico , Densidade Óssea/efeitos dos fármacos , Reabsorção Óssea/prevenção & controle , Paraplegia/complicações , Adulto , Aminoácidos/urina , Remodelação Óssea/efeitos dos fármacos , Reabsorção Óssea/etiologia , Cálcio/uso terapêutico , Creatinina/urina , Diáfises/metabolismo , Epífises/metabolismo , Fêmur/metabolismo , Humanos , Masculino , Tíbia/metabolismo
7.
Osteoporos Int ; 15(3): 180-9, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14722626

RESUMO

To study the time course of demineralization and fracture incidence after spinal cord injury (SCI), 100 paraplegic men with complete motor loss were investigated in a cross-sectional study 3 months to 30 years after their traumatic SCI. Fracture history was assessed and verified using patients' files and X-rays. BMD of the lumbar spine (LS), femoral neck (FN), distal forearm (ultradistal part = UDR, 1/3 distal part = 1/3R), distal tibial diaphysis (TDIA), and distal tibial epiphysis (TEPI) was measured using DXA. Stiffness of the calcaneus (QUI.CALC), speed of sound of the tibia (SOS.TIB), and amplitude-dependent SOS across the proximal phalanges (adSOS.PHAL) were measured using QUS. Z-Scores of BMD and quantitative ultrasound (QUS) were plotted against time-since-injury and compared among four groups of paraplegics stratified according to time-since-injury (<1 year, stratum I; 1-9 years, stratum II; 10-19 years, stratum III; 20-29 years, stratum IV). Biochemical markers of bone turnover (deoxypyridinoline/creatinine (D-pyr/Cr), osteocalcin, alkaline phosphatase) and the main parameters of calcium phosphate metabolism were measured. Fifteen out of 98 paraplegics had sustained a total of 39 fragility fractures within 1,010 years of observation. All recorded fractures were fractures of the lower limbs, mean time to first fracture being 8.9 +/- 1.4 years. Fracture incidence increased with time-after-SCI, from 1% in the first 12 months to 4.6%/year in paraplegics since >20 years ( p<.01). The overall fracture incidence was 2.2%/year. Compared with nonfractured paraplegics, those with a fracture history had been injured for a longer time ( p<.01). Furthermore, they had lower Z-scores at FN, TEPI, and TDIA ( p<.01 to <.0001), the largest difference being observed at TDIA, compared with the nonfractured. At the lower limbs, BMD decreased with time at all sites ( r=.49 to.78, all p<.0001). At FN and TEPI, bone loss followed a log curve which leveled off between 1 to 3 years after injury. In contrast, Z-scores of TDIA continuously decreased even beyond 10 years after injury. LS BMD Z-score increased with time-since-SCI ( p<.05). Similarly to DXA, QUS allowed differentiation of early and rapid trabecular bone loss (QUI.CALC) vs slow and continuous cortical bone loss (SOS.TIB). Biochemical markers reflected a disproportion between highly elevated bone resorption and almost normal bone formation early after injury. Turnover declined following a log curve with time-after-SCI, however, D-pyr/Cr remained elevated in 30% of paraplegics injured >10 years. In paraplegic men early (trabecular) and persistent (cortical) bone loss occurs at the lower limbs and leads to an increasing fracture incidence with time-after-SCI.


Assuntos
Densidade Óssea , Osso e Ossos/metabolismo , Paraplegia/fisiopatologia , Traumatismos da Medula Espinal/fisiopatologia , Absorciometria de Fóton , Adulto , Biomarcadores/sangue , Biomarcadores/urina , Remodelação Óssea , Osso e Ossos/diagnóstico por imagem , Estudos Transversais , Seguimentos , Fraturas Ósseas/etiologia , Humanos , Incidência , Masculino , Paraplegia/etiologia , Paraplegia/metabolismo , Traumatismos da Medula Espinal/complicações , Traumatismos da Medula Espinal/metabolismo , Fatores de Tempo , Ultrassonografia
8.
Horm Res ; 61(1): 7-16, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-14646396

RESUMO

OBJECTIVES: To compare the effects of vitamin D analogs versus calcitriol on serum levels of Ca, P and parathyroid hormone (PTH). A compound better than calcitriol should increase the Ca x P product less than calcitriol for an equivalent decrease in PTH levels. METHODS: Biological activity of 4 vitamin D analogs, 1,25-(OH)(2)-16ene- D(3) (RO(1)), 1,25-(OH)(2)-16ene-23yne-D(3) (RO(2)), 1,25-(OH)(2)-26,27-hexafluoro-16ene-23yne-D(3) (RO(3)) and 1,25-(OH)(2)-16ene-23yne-26,27-hexafluoro-19nor-D(3) (RO(4)) was tested vs. calcitriol in parathyroidectomized rats. In a second set of experiments, the effects of RO(2), RO(4) and calcitriol were studied in 5/6 nephrectomized rats with secondary hyperparathyroidism. RESULTS: In parathyroidectomized rats, all analogs (250 pmol/day) led calcemia to rise after 7 days. In uremic rats, all treatments reduced PTH levels. RO(4) revealed toxicity. RO(2) was as effective as calcitriol in suppressing PTH in a dose dependent manner. Mean plasma ionized calcium did not change from baseline to day 14 and day 28 on RO(2) (250 or 500 pmol/day) whereas it increased significantly on RO(2) (1,000 pmol/day) and calcitriol (125 or 250 pmol/day). Increasing the dose of calcitriol led Ca x P to rise more dramatically than increasing the dose of RO(2), which appears to have a wider therapeutic window than calcitriol. CONCLUSION: 1,25-(OH)(2)-16ene-23yne-D(3) (RO(2)) may represent a novel candidate for the treatment of renal osteodystrophy in humans.


Assuntos
Calcitriol/análogos & derivados , Calcitriol/administração & dosagem , Calcitriol/efeitos adversos , Hiperparatireoidismo Secundário/tratamento farmacológico , Hiperparatireoidismo Secundário/etiologia , Uremia/complicações , Animais , Cálcio/sangue , Hipercalcemia/sangue , Hipercalcemia/induzido quimicamente , Hiperparatireoidismo Secundário/sangue , Injeções Intraperitoneais , Masculino , Hormônio Paratireóideo/sangue , Fósforo/sangue , Fósforo na Dieta/administração & dosagem , Ratos , Ratos Wistar , Uremia/sangue
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