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1.
Gastroenterology ; 146(4): 989-94, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24389306

RESUMO

BACKGROUND & AIMS: We aimed to assess the risk of death, cancer, and comorbidities among patients with alcoholic and nonalcoholic chronic pancreatitis (CP). METHODS: We performed a nationwide retrospective cohort study, collecting data from Danish registries from 1995 through 2010. We evaluated the prevalences and incidences of death, cancers, and comorbidities among subjects with CP (cases) compared with age- and sex-matched individuals (controls). In total, 11,972 cases (71,814 person-years) and 119,720 controls (917,436 person-years) were included in the analysis. Hazard ratios (HR) were estimated by Cox proportional hazards regression. RESULTS: Forty-six percent of the cases died during the follow-up period, compared with 13.0% of controls (mean age, 63.7 vs 72.1 y; P < .0001), corresponding to a HR of 5.0 for CP (95% confidence interval [CI], 4.8-5.2). Cancer was a frequent cause of death among cases (10.2%) and controls (3.3%). Cancer (particularly pancreatic cancer) was a frequent cause of death among cases; the HR was 6.9 (95% CI, 7.5-11.8). Alcoholic CP did not produce a higher risk for cancer or death than nonalcoholic CP. Cerebrovascular disease (HR, 1.3; 95% CI, 1.2-1.4), chronic pulmonary disease (HR, 1.9; 95% CI, 1.8-2.1), ulcer disease (HR, 3.6; 95% CI, 3.3-3.9), diabetes (HR, 5.2; 95% CI, 5.0-5.6), and chronic renal disease (HR, 1.7; 95% CI, 1.5-1.9) occurred more frequently among patients with CP, but myocardial infarction did not (HR, 0.9; 95% CI, 0.8-1.0). CONCLUSIONS: Based on a Danish nationwide cohort study, individuals with CP are at higher risk for death from cancer (particularly pancreatic cancer) and have a higher incidence of comorbidities than people without CP.


Assuntos
Neoplasias/mortalidade , Pancreatite Alcoólica/mortalidade , Pancreatite Crônica/mortalidade , Adulto , Idoso , Distribuição de Qui-Quadrado , Comorbidade , Dinamarca/epidemiologia , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Neoplasias Pancreáticas/mortalidade , Prevalência , Prognóstico , Modelos de Riscos Proporcionais , Sistema de Registros , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo
2.
Environ Res ; 137: 287-91, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25601730

RESUMO

Industrially produced chemicals have been a major environmental concern across our entire Globe since the onset of rapid industrial development around the early 1900. Many of the substances being used are known to be endocrine disrupting chemicals (EDCs) and are also known to be long-range dispersed and to biomagnify to very high concentrations in the tissues of Arctic apex predators such as polar bears (Ursus maritimus). A major concern relating to EDCs is their effects on vital organ-tissues such as bone and it is possible that EDCs represent a more serious challenge to the species' survival than the more conventionally proposed prey reductions linked to climate change. We therefore analyzed penile bone mineral density (BMD) as a key phenotype for reproductive success in 279 polar bear samples born 1990-2000 representing eight polar bear subpopulations. Since EDC concentrations were not available from the same specimens, we compared BMD with published literature information on EDC concentrations. Latitudinal and longitudinal BMD and EDC gradients were clearly observed, with Western Hudson bears having the highest BMD and lowest EDCs, and North East Greenland polar bears carrying the lowest BMD and highest EDCs. A BMD vs. polychlorinated biphenyls (PCB) regression analysis showed that BMD decreased as a function of the eight subpopulations' PCB concentrations and this relationship was close to being significant (p=0.10, R(2)=0.39). Risk quotient (RQ) estimation demonstrated that PCBs could be in a range that may lead to disruption of normal reproduction and development. It is therefore likely that EDCs directly affect development and bone density in polar bears. Canadian bears had in general the best health and the North East Greenland subpopulation being at the highest risk of having negative health effects. While reductions in BMD is in general unhealthy, reductions in penile BMD could lead to increased risk of species extinction because of mating and subsequent fertilization failure as a result of weak penile bones and risk of fractures. Based on this, future studies should assess how polar bear subpopulations respond upon EDC exposure since information and understanding about their circumpolar reproductive health is vital for future conservation.


Assuntos
Densidade Óssea/efeitos dos fármacos , Disruptores Endócrinos/toxicidade , Exposição Ambiental , Poluentes Ambientais/toxicidade , Bifenilos Policlorados/toxicidade , Ursidae/fisiologia , Absorciometria de Fóton , Animais , Canadá , Monitoramento Ambiental , Groenlândia , Masculino , Pênis/efeitos dos fármacos , Pênis/fisiologia , Medição de Risco
3.
Clin Gastroenterol Hepatol ; 12(2): 320-6, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23644391

RESUMO

BACKGROUND & AIMS: Cirrhosis and chronic pancreatitis (CP) are accompanied by inflammation and malnutrition. Both conditions can have negative effects on bone metabolism and promote fractures. We evaluated the risk of fractures among patients with CP or cirrhosis and determined the effect of fat malabsorption on fracture risk among patients with CP. METHODS: We performed a retrospective cohort study using the Danish National Patient Register to identify patients diagnosed with CP or cirrhosis. We analyzed data collected from January 1, 1995, to December 31, 2010, on 20,769 patients (35.5% women with cirrhosis and 11,972 patients (33.5% women) with CP. Each patient was compared with 10 age- and sex-matched controls. We also assessed the risk of fractures among patients with CP who received pancreatic enzyme substitution (PES) for fat malabsorption. RESULTS: During the study period, bone fractures occurred in 3954 patients with cirrhosis and 2594 patients with CP. The adjusted hazard ratio (HR) for any fracture was 2.4 in patients with cirrhosis (95% confidence interval [CI], 2.2-2.5) and 1.7 in patients with CP (95% CI, 1.6-1.8). The relative risk of low-trauma fractures was highest among individuals younger than 50 years old. Alcohol as an etiology was associated with an increased risk of fracture compared with patients with nonalcoholic cirrhosis (HR, 2.4 vs 1.5; P < .0001) and CP (HR, 2.0 vs 1.5; P < .0001). Patients with CP receiving PES for fat malabsorption had a lower risk of fractures than other CP patients (HR, 0.8; 95% CI, 0.7-0.9). However, increasing the duration of treatment with PES was associated with an increased risk of fracture. CONCLUSIONS: Patients, especially younger patients, with cirrhosis or CP have an increased risk of fractures of all types.


Assuntos
Fraturas Ósseas/epidemiologia , Cirrose Hepática/epidemiologia , Síndromes de Malabsorção/epidemiologia , Pancreatite Crônica/epidemiologia , Adulto , Fatores Etários , Consumo de Bebidas Alcoólicas/epidemiologia , Comorbidade , Gorduras na Dieta/metabolismo , Feminino , Fraturas do Fêmur/epidemiologia , Traumatismos do Antebraço/epidemiologia , Humanos , Traumatismos da Perna/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Medição de Risco
4.
Pancreatology ; 11(4): 376-82, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21894054

RESUMO

BACKGROUND: Patients with chronic pancreatitis (CP) often develop fat malabsorption and are susceptible to hypovitaminosis D. AIM: We wanted to evaluate the intestinal uptake of cholecalciferol in patients with CP and fat malabsorption. METHODS: We did a prospective placebo-controlled study including patients with verified CP and fat malabsorption. They were randomized to 10 weeks of (A) ultraviolet radiation B (UVB) 6 min weekly in a commercial tanning bed, (B) vitamin D supplement 1,520 IU/daily, or (C) placebo. The vitamin D metabolites 25-hydroxyvitamin D (25OHD) and 1,25-dihydroxyvitamin D (calcitriol) were quantified at the start and end of the study. RESULTS: In total 30 patients were randomized and 27 completed the study. Compliance to tablets and tanning sessions was >80%. The changes in 25OHD levels in group B (32.3 nmol/l; 95% CI 15-50) were significantly greater than changes in group A (p < 0.001) and group C (p < 0.001). Changes in group A (1.1 nmol/l) did not differ from the placebo group (p = 0.9). Changes in calcitriol levels were identical between groups. CONCLUSIONS: Daily vitamin D supplements increased 25OHD in patients with CP compared to placebo whereas weekly tanning bed sessions did not.


Assuntos
Colecalciferol/administração & dosagem , Gorduras na Dieta/metabolismo , Insuficiência Pancreática Exócrina/terapia , Pancreatite Crônica/terapia , Terapia Ultravioleta/métodos , Deficiência de Vitamina D/terapia , Vitaminas/administração & dosagem , Administração Oral , Adulto , Idoso , Colecalciferol/metabolismo , Insuficiência Pancreática Exócrina/metabolismo , Feminino , Humanos , Absorção Intestinal/efeitos dos fármacos , Absorção Intestinal/fisiologia , Absorção Intestinal/efeitos da radiação , Masculino , Pessoa de Meia-Idade , Pancreatite Crônica/metabolismo , Cooperação do Paciente , Radioterapia , Banho de Sol , Raios Ultravioleta , Deficiência de Vitamina D/metabolismo , Vitaminas/metabolismo
5.
Bone Rep ; 15: 101101, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34258332

RESUMO

BACKGROUND: Hypophosphatasia (HPP) is an inborn disease caused by pathogenic variants in ALPL. Low levels of alkaline phosphatase (ALP) are a biochemical hallmark of the disease. Scarce knowledge about the prevalence of HPP in Scandinavia exists, and the variable clinical presentations make diagnostics challenging. The aim of this study was to investigate the prevalence of ALPL variants as well as the clinical and biochemical features among adults with endocrinological diagnoses and persistent hypophosphatasaemia. METHODS: A biochemical database containing ALP measurements of 26,121 individuals was reviewed to identify adults above 18 years of age with persistently low levels of ALP beneath range (≤ 35 ± 2.7 U/L). ALPL genetic testing, biochemical evaluations and assessment of clinical features by a systematic questionnaire among included patients, were performed. RESULTS: Among 24 participants, thirteen subjects (54.2%) revealed a disease-causing variant in ALPL and reported mild clinical features of HPP, of which musculoskeletal pain was the most frequently reported (n = 9). The variant c. 571G > A; p.(Glu191Lys) was identified in six subjects, and an unreported missense variant (c.1019A > C; p.(His340Pro)) as well as a deletion of exon 2 were detected by genetic screening. Biochemical analyses showed no significant differences in ALP (p = 0.059), the bone specific alkaline phosphatase (BALP) (p = 0.056) and pyridoxal-5'-phosphate (PLP) (p = 0.085) between patients with an ALPL variant and negative genetic screening. Patients with a variant in ALPL had significantly higher PLP levels than healthy controls (p = 0.002). We observed normal ALP activity in some patients classified as mild HPP, and slightly increased levels of PLP in two subjects with normal genetic screening and four healthy controls. Among 51 patients with persistent hypophosphatasaemia, fifteen subjects (29.4%) received antiresorptive treatment. Two patients with unrecognized HPP were treated with bisphosphonates and did not show complications due to the treatment. CONCLUSIONS: Pathogenic variants in ALPL are common among patients with endocrinological diagnoses and low ALP. Regarding diagnostics, genetic testing is necessary to identify mild HPP due to fluctuating biochemical findings. Antiresorptive treatment is a frequent reason for hypophosphatasaemia and effects of these agents in adults with a variant in ALPL and osteoporosis remain unclear and require further studies.

6.
JBMR Plus ; 5(11): e10546, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34761149

RESUMO

Increases in bone mineral density (BMD) with osteoporosis treatment are associated with reduced fracture risk. Increasing BMD is therefore a goal of osteoporosis therapy. Here, we compare the probability of achieving a T-score of > -2.5 over 3 years at the total hip (TH) or lumbar spine (LS) in women with osteoporosis, ≥55 years of age, after the following treatment sequences: 1 year romosozumab followed by 2 years denosumab (FRAME and FRAME extension trials), 1 year romosozumab followed by 2 years alendronate, or alendronate-only for 3 years (ARCH trial). Probabilities of attaining the BMD target within 1 year of treatment were also determined. At both skeletal sites, in women with a baseline Tscore ≥ -2.7, there was >50% probability of achieving the BMD target with any 3-year regimen. The probability of achieving the target BMD in those with a baseline TH Tscore equal to -3.0 was 61% with romosozumab/denosumab, 38% with romosozumab/alendronate, and 9% with alendronate. In those with a baseline LS Tscore equal to -3.0, the probability of achieving a T-score > -2.5 was 93% with romosozumab/denosumab, 81% with romosozumab/alendronate, and 55% with alendronate. With 1 year of treatment, in patients with a baseline TH T-score equal to -2.7, the probability of reaching the target Tscore with romosozumab was 71% to 78% and 38% with alendronate. For patients with an initial LS T-score equal to -3.0, the probability of achieving the target T-score over 1 year was 85% to 86% with romosozumab and 25% for alendronate. Our findings suggest baseline BMD and the probability of achieving BMD T-score goals are factors to consider when selecting initial treatment for patients with osteoporosis. As baseline T-score falls below -2.7 (TH) and -3.0 (LS), alendronate has <50% likelihood of achieving a BMD goal above osteoporosis range, whereas these probabilities remain relatively high for regimens beginning with romosozumab. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

7.
J Bone Miner Res ; 36(8): 1448-1458, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33852173

RESUMO

Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-2 (GLP-2) are gut hormones secreted postprandially. In healthy humans, both hormones decrease bone resorption accompanied by a rapid reduction in parathyroid hormone (PTH). The aim of this study was to investigate whether the changes in bone turnover after meal intake and after GIP- and GLP-2 injections, respectively, are mediated via a reduction in PTH secretion. This was tested in female patients with hypoparathyroidism given a standardized liquid mixed-meal test (n = 7) followed by a peptide injection test (n = 4) using a randomized crossover design. We observed that the meal- and GIP- but not the GLP-2-induced changes in bone turnover markers were preserved in the patients with hypoparathyroidism. To understand the underlying mechanisms, we examined the expression of the GIP receptor (GIPR) and the GLP-2 receptor (GLP-2R) in human osteoblasts and osteoclasts as well as in parathyroid tissue. The GIPR was expressed in both human osteoclasts and osteoblasts, whereas the GLP-2R was absent or only weakly expressed in osteoclasts. Furthermore, both GIPR and GLP-2R were expressed in parathyroid tissue. Our findings suggest that the GIP-induced effect on bone turnover may be mediated directly via GIPR expressed in osteoblasts and osteoclasts and that this may occur independent of PTH. In contrast, the effect of GLP-2 on bone turnover seems to depend on changes in PTH and may be mediated through GLP-2R in the parathyroid gland. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).


Assuntos
Hipoparatireoidismo , Receptores dos Hormônios Gastrointestinais , Estudos Cross-Over , Feminino , Peptídeo 2 Semelhante ao Glucagon , Humanos , Hipoparatireoidismo/tratamento farmacológico
9.
PLoS One ; 15(5): e0231579, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32401753

RESUMO

INTRODUCTION: In pregnancy after Roux-en-Y gastric bypass (RYGB), there is increased risk of low birthweight in the offspring. The present study examined how offspring body composition was affected by RYGB. MATERIAL AND METHODS: Mother-newborn dyads, where the mothers had undergone RYGB were included. Main outcome measure was neonatal body composition. Neonatal body composition was assessed by dual-energy X-ray absorptiometry scanning (DXA) within 48 hours after birth. In a statistical model offspring born after RYGB were compared with a reference material of offspring and analyses were made to estimate the effect of maternal pre-pregnancy body mass index (BMI), gestational weight gain, parity, gestational age at birth and newborn sex on newborn body composition. Analyses were made to estimate the impact of maternal weight loss before pregnancy and of other effects of bariatric surgery respectively. The study was performed at a university hospital between October 2012 and December 2013. RESULTS: We included 25 mother-newborn dyads where the mothers had undergone RYGB and compared them to a reference material of 311 mother-newborn dyads with comparable pre-pregnancy BMI. Offspring born by mothers after RYGB had lower birthweight (335g, p<0.001), fat-free mass (268g, p<0.001) and fat% (2.8%, p<0.001) compared with reference material. Only 2% of the average reduction in newborn fat free mass could be attributed to maternal pre-pregnancy weight loss whereas other effects of RYGB accounted for 98%. Regarding reduction in fat mass 52% was attributed to weight loss and 47% to other effects of surgery. CONCLUSION: Offspring born after maternal bariatric surgery, had lower birthweight, fat-free mass and fat percentage when compared with a reference material. RYGB itself and not the pre-pregnancy weight loss seems to have had the greatest impact on fetal growth.


Assuntos
Cirurgia Bariátrica/efeitos adversos , Peso ao Nascer , Composição Corporal , Recém-Nascido Pequeno para a Idade Gestacional/fisiologia , Obesidade Mórbida/cirurgia , Complicações Pós-Operatórias/etiologia , Complicações na Gravidez/etiologia , Adulto , Índice de Massa Corporal , Feminino , Desenvolvimento Fetal , Humanos , Recém-Nascido , Masculino , Gravidez
10.
Environ Int ; 34(6): 811-20, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18342937

RESUMO

There is a great need for understanding the impact from dietary OHCs (organohalogen compounds) on bone mineral composition - and thereby osteoporosis - in especially arctic wildlife such as polar bears (Ursus maritimus) as well as humans. For that purpose, we measured BMD (bone mineral density) by DXA scanning (g/cm(-2)) in 15 age and weight normalized sledge dog (Canis familiaris) bitches and their 26 pups divided into a control group (n=26) given 50-200 g/day clean pork (Suis scrofa) fat and a treated group (n=15) given 50-200 g/day OHC polluted minke whale (Balaenoptera acutorostrata) blubber as main lipid sources. The results showed that BMD increased significantly with age (linear regression: p<0.0001, r(2)=0.83, n=41) while no sex difference was found in the F-generation (two-way ANOVA: all p>0.3). No differences in BMD(femur) or BMD(vertebrae) between exposed and control individuals in the bitch generation were found (linear mixed effect model: both p>0.38). Likewise, no difference between exposed and control subadults and juveniles in the F-generation was found (two-way ANOVA: all p>0.33). Correlation analyses between BMD(femur), BMD(vertebrae) and groups of OHCs, respectively, did not show any statistically significant relationships nor a clear or decreasing trend (Pearson's: p: 0.07-0.78; r: -0.2-0.59; n: 10-18). As the groups were similar regarding genetics, age and sex are the only factors that can explain this observation. Either the pollutants did not have an impact on BMD using the present time frame and OHC concentrations (threshold levels not reached), or the difference in food composition (mainly vitamins and n3 fatty acids) conceal the potential OHC impact on BMD. Such information is important when evaluating the positive and negative health consequences from eating polluted marine species.


Assuntos
Densidade Óssea/efeitos dos fármacos , Cães/fisiologia , Ácidos Graxos/farmacologia , Hidrocarbonetos Halogenados/toxicidade , Micronutrientes/farmacologia , Animais , Dieta , Feminino , Groenlândia , Carne/toxicidade , Mercúrio/toxicidade
11.
Ugeskr Laeger ; 180(49)2018 Dec 03.
Artigo em Dinamarquês | MEDLINE | ID: mdl-30520719

RESUMO

Phytoestrogens (PE) are widely used as a dietary supplement. PE affect oestrogen receptors. PE have been investigated regarding menopausal hot flushes, bone mineral density and prostate hyperplasia/cancer. It seems consistent, that PE increase bone mineral density, whereas the effect on hot flushes is controversial. Due to the effect on oestrogen receptors, concerns exist on the risk of cancer and venous thromboembolism related to the intake of PE. To date, no studies with PE have been large enough to clarify their safety. Widespread use of PE should therefore be discouraged.


Assuntos
Suplementos Nutricionais , Fitoestrógenos , Densidade Óssea/efeitos dos fármacos , Fogachos/tratamento farmacológico , Humanos
12.
J Bone Miner Res ; 28(4): 736-45, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23044908

RESUMO

Whereas the beneficial effects of intermittent treatment with parathyroid hormone (PTH) (intact PTH 1-84 or fragment PTH 1-34, teriparatide) on vertebral strength is well documented, treatment may not be equally effective in the peripheral skeleton. We used high-resolution peripheral quantitative computed tomography (HR-pQCT) to detail effects on compartmental geometry, density, and microarchitecture as well as finite element (FE) estimated integral strength at the distal radius and tibia in postmenopausal osteoporotic women treated with PTH 1-34 (20 µg sc daily, n = 18) or PTH 1-84 (100 µg sc daily, n = 20) for 18 months in an open-label, nonrandomized study. A group of postmenopausal osteoporotic women receiving zoledronic acid (5 mg infusion once yearly, n = 33) was also included. Anabolic therapy increased cortical porosity in radius (PTH 1-34 32 ± 37%, PTH 1-84 39 ± 32%, both p < 0.001) and tibia (PTH 1-34 13 ± 27%, PTH 1-84 15 ± 22%, both p < 0.001) with corresponding declines in cortical density. With PTH 1-34, increases in cortical thickness in radius (2.0 ± 3.8%, p < 0.05) and tibia (3.8 ± 10.4%, p < 0.01) were found. Trabecular number increased in tibia with both PTH 1-34 (4.2 ± 7.1%, p < 0.05) and PTH 1-84 (5.3 ± 8.3%, p < 0.01). Zoledronic acid did not impact cortical porosity at either site but increased cortical thickness (3.0 ± 3.5%, p < 0.01), total (2.7 ± 2.5%, p < 0.001) and cortical density (1.5 ± 2.0%, p < 0.01) in tibia as well as trabecular volume fraction in radius (2.5 ± 5.1%, p < 0.05) and tibia (2.2 ± 2.2%, p < 0.01). FE estimated bone strength was preserved, but not increased, with PTH 1-34 and zoledronic acid at both sites, whereas it decreased with PTH 1-84 in radius (-2.8 ± 5.8%, p < 0.05) and tibia (-3.9 ± 4.8%, p < 0.001). Conclusively, divergent treatment-specific effects in cortical and trabecular bone were observed with anabolic and zoledronic acid therapy. The finding of decreased estimated strength with PTH 1-84 treatment was surprising and warrants confirmation.


Assuntos
Osso e Ossos/patologia , Difosfonatos/uso terapêutico , Imidazóis/uso terapêutico , Osteoporose/diagnóstico por imagem , Osteoporose/tratamento farmacológico , Hormônio Paratireóideo/uso terapêutico , Pós-Menopausa , Tomografia Computadorizada por Raios X , Absorciometria de Fóton , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/metabolismo , Fenômenos Biomecânicos/efeitos dos fármacos , Remodelação Óssea/efeitos dos fármacos , Osso e Ossos/diagnóstico por imagem , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/fisiopatologia , Difosfonatos/farmacologia , Feminino , Análise de Elementos Finitos , Humanos , Imidazóis/farmacologia , Pessoa de Meia-Idade , Osteoporose/fisiopatologia , Hormônio Paratireóideo/farmacologia , Rádio (Anatomia)/efeitos dos fármacos , Rádio (Anatomia)/patologia , Rádio (Anatomia)/fisiopatologia , Tíbia/efeitos dos fármacos , Tíbia/patologia , Tíbia/fisiopatologia , Fatores de Tempo , Ácido Zoledrônico
13.
J Bone Miner Res ; 28(10): 2145-55, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23585311

RESUMO

Parathyroid hormone (PTH) and PTH(1-34) have been shown to promote bone healing in several animal studies. It is known that the mechanical environment is important in fracture healing. Furthermore, PTH and mechanical loading has been suggested to have synergistic effects on intact bone. The aim of the present study was to investigate whether the effect of PTH(1-34) on fracture healing in rats was influenced by reduced mechanical loading. For this purpose, we used female, 25-week-old ovariectomized rats. Animals were subjected to closed midshaft fracture of the right tibia 10 weeks after ovariectomy. Five days before fracture, half of the animals received Botulinum Toxin A injections in the muscles of the fractured leg to induce muscle paralysis (unloaded group), whereas the other half received saline injections (control group). For the following 8 weeks, half of the animals in each group received injections of hPTH(1-34) (20 µg/kg/day) and the other half received vehicle treatment. Fracture healing was assessed by radiology, dual-energy X-ray absorptiometry (DXA), histology, and bone strength analysis. We found that unloading reduced callus area significantly, whereas no effects of PTH(1-34) on callus area were seen in neither normally nor unloaded animals. PTH(1-34) increased callus bone mineral density (BMD) and bone mineral content (BMC) significantly, whereas unloading decreased callus BMD and BMC significantly. PTH(1-34) treatment increased bone volume of the callus in both unloaded and control animals. PTH(1-34) treatment increased ultimate force of the fracture by 63% in both control and unloaded animals and no interaction of the two interventions could be detected. PTH(1-34) was able to stimulate bone formation in normally loaded as well as unloaded intact bone. In conclusion, the study confirms the stimulatory effect of PTH(1-34) on fracture healing, and our data suggest that PTH(1-34) is able to promote fracture healing, as well as intact bone formation during conditions of reduced mechanical loading.


Assuntos
Consolidação da Fratura/efeitos dos fármacos , Hormônio Paratireóideo/farmacologia , Absorciometria de Fóton , Animais , Fenômenos Biomecânicos , Densidade Óssea/efeitos dos fármacos , Calo Ósseo/diagnóstico por imagem , Calo Ósseo/efeitos dos fármacos , Calo Ósseo/patologia , Calo Ósseo/fisiopatologia , Feminino , Fêmur/diagnóstico por imagem , Fêmur/efeitos dos fármacos , Fêmur/patologia , Fêmur/fisiopatologia , Humanos , Movimento/efeitos dos fármacos , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Tíbia/diagnóstico por imagem , Tíbia/efeitos dos fármacos , Tíbia/patologia , Tíbia/fisiopatologia , Suporte de Carga
14.
J Bone Miner Res ; 28(4): 746-52, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23109251

RESUMO

Osteoporosis is a chronic disease and requires long-term treatment with pharmacologic therapy to ensure sustained antifracture benefit. Denosumab reduced the risk for new vertebral, nonvertebral, and hip fractures over 36 months in the Fracture Reduction Evaluation of Denosumab in Osteoporosis Every 6 Months (FREEDOM) trial. Whereas discontinuation of denosumab has been associated with transient increases in bone remodeling and declines in bone mineral density (BMD), the effect on fracture risk during treatment cessation is not as well characterized. To understand the fracture incidence between treatment groups after cessation of investigational product, we evaluated subjects in FREEDOM who discontinued treatment after receiving two to five doses of denosumab or placebo, and continued study participation for ≥7 months. The off-treatment observation period for each individual subject began 7 months after the last dose and lasted until the end of the study. This subgroup of 797 subjects (470 placebo, 327 denosumab), who were evaluable during the off-treatment period, showed similar baseline characteristics for age, prevalent fracture, and lumbar spine and total hip BMD T-scores. During treatment, more placebo-treated subjects as compared with denosumab-treated subjects sustained a fracture and had significant decreases in BMD. During the off-treatment period (median 0.8 years per subject), 42% versus 28% of placebo- and denosumab-treated subjects, respectively, initiated other therapy. Following discontinuation, similar percentages of subjects in both groups sustained a new fracture (9% placebo, 7% denosumab), resulting in a fracture rate per 100 subject-years of 13.5 for placebo and 9.7 for denosumab (hazard ratio [HR] 0.82; 95% confidence interval [CI], 0.49-1.38), adjusted for age and total hip BMD T-score at baseline. There was no apparent difference in fracture occurrence pattern between the groups during the off-treatment period. In summary, there does not appear to be an excess in fracture risk after treatment cessation with denosumab compared with placebo during the off-treatment period for up to 24 months.


Assuntos
Denosumab/uso terapêutico , Osteoporose/complicações , Fraturas por Osteoporose/tratamento farmacológico , Fraturas por Osteoporose/epidemiologia , Suspensão de Tratamento , Idoso , Demografia , Relação Dose-Resposta a Droga , Feminino , Humanos , Incidência , Fraturas por Osteoporose/etiologia
15.
J Osteoporos ; 2012: 391097, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22934234

RESUMO

The purinergic P2X7 receptor is expressed by bone cells and has been shown to be important in both bone formation and bone resorption. In this study we investigated the importance of the genetic background of the mouse strains on which the P2X7 knock-out models were based by comparing bone status of a new BALB/cJ P2X7(-/-) strain with a previous one based on the C57BL/6 strain. Female four-month-old mice from both strains were DXA scanned on a PIXImus densitometer; femurs were collected for bone strength measurements and serum for bone marker analysis. Bone-related parameters that were altered only slightly in the B6 P2X7(-/-) became significantly altered in the BALB/cJ P2X7(-/-) when compared to their wild type littermates. The BALB/cJ P2X7(-/-) showed reduced levels of serum C-telopeptide fragment (s-CTX), higher bone mineral density, and increased bone strength compared to the wild type littermates. In conclusion, we have shown that the genetic background of P2X7(-/-) mice strongly influences the bone phenotype of the P2X7(-/-) mice and that P2X7 has a more significant regulatory role in bone remodeling than found in previous studies.

16.
J Bone Miner Res ; 25(9): 1941-7, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20499376

RESUMO

Patients with primary hyperparathyroidism (PHPT) have continuously elevated parathyroid hormone (PTH) and consequently increased bone turnover with negative effects on cortical (Ct) bone with preservation of trabecular (Tb) bone. High-resolution peripheral quantitative computed tomography (HR-pQCT) is a new technique for in vivo assessment of geometry, volumetric density, and microarchitecture at the radius and tibia. In this study we aimed to evaluate bone status in women with PHPT compared with controls using HR-pQCT. The distal radius and tibia of 54 women--27 patients with PHPT (median age 60, range 44-75 years) and 27 randomly recruited age-matched healthy controls (median age 60, range 44-76 years)--were imaged using HR-pQCT along with areal bone mineral density (aBMD) by dual-energy X-ray absorptiomentry (DXA) of the ultradistal forearm, femoral neck, and spine (L1-L4). Groups were comparable regarding age, height, and weight. In the radius, patients had reduced Ct area (Ct.Ar) (p = .008), Ct thickness (Ct.th) (p = .01) along with reduced total (p = .002), Ct (p = .02), and Tb (p = .02) volumetric density and reduced Tb number (Tb.N) (p = .04) and increased Tb spacing (Tb.sp) (p = .05). Ct porosity did not differ. In the tibia, no differences in HR-pQCT parameters were found. Moreover, patients had lower ultradistal forearm (p = .005), spine (p = .04), and femoral neck (p = 0.04) aBMD compared with controls. In conclusion, a negative bone effect of continuously elevated PTH with alteration of HR-pQCT assessed geometry, volumetric density, and both trabecular and cortical microarchitecture in radius but not tibia was found along with reduced aBMD by DXA at all sites in female patients with PHPT. © 2010 American Society for Bone and Mineral Research.


Assuntos
Hiperparatireoidismo Primário/patologia , Rádio (Anatomia)/patologia , Tíbia/patologia , Absorciometria de Fóton , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Hiperparatireoidismo Primário/diagnóstico por imagem , Pessoa de Meia-Idade
17.
Eur J Nutr ; 43(4): 246-57, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15309425

RESUMO

BACKGROUND: Given concerns over the use of hormone replacement therapy (HRT), women are seeking natural alternatives to cope with the symptoms and effects of menopause. The bone sparing effects of soy protein and its isoflavones is well established in animal studies, while 5 previous human studies on soy and bone have yielded variable outcomes due in part to their short duration of study. Progesterone has been suggested as a bone-trophic hormone, but the effect of long-term, low dose transdermal progesterone is unknown. AIM: The aim of the study was to compare for the first time the long-term effects of soymilk, with or without isoflavones with natural transdermal progesterone, or the combination, on bone mineral density in the lumbar spine and hip. METHODS: Postmenopausal, Caucasian women with established osteoporosis or at least 3 risk-factors for osteoporosis, were randomly assigned, double-blind to one of four treatment-groups: soymilk containing isoflavones (soy+, n = 23), transdermal progesterone (TPD+, n = 22), or the combination of soy+ and TDP+,(n = 22) or placebo (isoflavone-poor soymilk, soy/ and progesterone-free-cream TDP/, n = 22). All subjects received comparable intakes of calcium, minerals and vitamins. Bone mineral content (BMC) and density (BMD) were measured in lumbar spine and hip by using dual-energy X-ray absorptiometry (DEXA) at baseline and after 2 years. FINDINGS: The percentage change in lumbar spine BMD and BMC respectively, did not differ from zero in the soy+ group (+1.1%, +2.0%) and TDP+ group (/1.1%, +0.4 %) but significant bone loss occurred in the control group (/4.2%,/4.3 %) and the combined treatment group (/2.8%, /2.4 %). No significant changes occurred for femoral neck BMD or BMC. INTERPRETATION: Daily intake of two glasses of soymilk containing 76 mg isoflavones prevents lumbar spine bone loss in postmenopausal women. Transdermal progesterone had bone-sparing effects but when combined with soy milk a negative interaction between the two treatments occurs resulting in bone-loss to a greater extent than either treatment alone.


Assuntos
Densidade Óssea/efeitos dos fármacos , Osso e Ossos/efeitos dos fármacos , Isoflavonas/farmacologia , Osteoporose Pós-Menopausa/prevenção & controle , Progesterona/farmacologia , Leite de Soja/administração & dosagem , Absorciometria de Fóton , Administração Cutânea , Análise de Variância , Densidade Óssea/fisiologia , Osso e Ossos/diagnóstico por imagem , Osso e Ossos/metabolismo , Método Duplo-Cego , Interações Medicamentosas , Feminino , Colo do Fêmur/diagnóstico por imagem , Colo do Fêmur/efeitos dos fármacos , Colo do Fêmur/metabolismo , Humanos , Isoflavonas/análise , Estudos Longitudinais , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/efeitos dos fármacos , Vértebras Lombares/metabolismo , Pessoa de Meia-Idade , Cooperação do Paciente , Progesterona/administração & dosagem , Leite de Soja/química
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