Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 185
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
J Endocrinol Invest ; 2024 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-38807014

RESUMEN

BACKGROUND: Active and Environmental Tobacco Smoke (ETS) are a global cause of death. Osteoporosis (Op) is the most common metabolic bone disorder worldwide, impacting on mortality and disability, with high health and welfare costs. Active smoking is a known risk factor for Op, but there is few information regarding Op and ETS in men. PURPOSE: The study aim is to evaluate the association between smoking habits and Op in community-dwelling men that have been subjected to Dual-X-ray Absorptiometry and completed a questionnaire about their own and cohabiter's smoking habits. METHODS: We performed a cross-sectional study based on administrative data. This study is part of the SIMON protocol. The binary logistic regression analysis was used to estimate the role of ETS on the risk of Op, adjusting for age, body mass index (BMI), type 2 diabetes mellitus (T2DM) and eGFR. RESULTS: Four hundred sixteen men were selected and, based on questionnaire replies, 167 were classified as current smokers (CS), 93 as passive smokers (PS) and 156 as never smokers (NS). NS showed a lower prevalence of past fragility fracture, radiological features of osteoporosis and hypovitaminosis D compared to PS and CS (p < 0.05). NS showed a lower prevalence of Op compared to PS and CS, also after correction for age, BMI, T2DM and eGFR (p < 0.05). CONCLUSION: The study results demonstrate that PS and CS have a higher risk of Op, fragility fractures and vitamin D deficiency compared to NS.

2.
J Endocrinol Invest ; 47(4): 937-946, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37819412

RESUMEN

PURPOSE: Current smoking is a risk factor for osteoporosis (Op), but few data are available regarding the passive smoke impact on Op susceptibility. This cross-sectional study aimed to evaluate the association between the smoking habits and Op in community-dwelling women undergoing dual-energy X-ray absorptiometry (DXA). METHODS: On 01/06/2018, general practitioners from "COMEGEN" Medical Cooperative, Naples, Italy, selected the medical records from the last 10 years of women who had a measurement of bone mineral density performed and simultaneously completed a questionnaire about their smoking behaviour and their cohabiters'. The binary logistic regression analysis was used to estimate the role of passive smoke on the risk of Op, adjusting for age and body mass index (BMI). RESULTS: Among 10,616 subjects, 3942 were currently smokers [CS; mean age 69.4 ± 10.4 years; BMI 27.0 ± 4.9 kg/m2], 873 were passive smokers (PS; mean age 67.8 ± 11.6 years; BMI 27.0 ± 4.9 kg/m2) and 5781 were never smokers (NS; mean age 67.8 ± 11.6 years; body mass index (BMI) 27.0 ± 4.9 kg/m2). Of all, 8562 women (mean age 70.3 ± 10.2 yrs; BMI 27.0 ± 4.9 kg/m2) received the Op diagnosis. PS showed an increased Op risk compared to NS [odds ratio (OR) 1.38 (1.14-1.67)] and comparable to CS [OR 1.02 (0.84-1.24)]. CONCLUSION: The study results demonstrate an association between passive smoke and Op in community-dwelling women already presenting with susceptibility to Op according to Italian essential assistance levels, suggesting that passive and active smoke are equivalent Op risk factors in women.


Asunto(s)
Osteoporosis , Contaminación por Humo de Tabaco , Femenino , Humanos , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años , Absorciometría de Fotón/métodos , Contaminación por Humo de Tabaco/efectos adversos , Estudios Transversales , Osteoporosis/inducido químicamente , Densidad Ósea , Factores de Riesgo
3.
J Endocrinol Invest ; 47(6): 1335-1360, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38488978

RESUMEN

INTRODUCTION: Paget's disease of bone is a focal skeletal disorder causing bone deformities and impairing bone quality. Despite the prevalence of asymptomatic cases is increasing, the progression of the disease can lead to invalidating complications that compromise the quality of life. Doubts on clinical and therapeutic management aspects exist, although beneficial effects of antiresorptive drugs, particularly bisphosphonates are known. However, limited information is available from randomized controlled trials on the prevention of disease complications so that somewhat contrasting positions about treatment indications between expert panels from the main scientific societies of metabolic bone diseases exist. This task force, composed by expert representatives appointed by the Italian Society of Osteoporosis, Mineral Metabolism and Skeletal Diseases and members of the Italian Association of Paget's disease of bone, felt the necessity for more specific and up to date indications for an early diagnosis and clinical management. METHODS: Through selected key questions, we propose evidence-based recommendations for the diagnosis and treatment of the disease. In the lack of good evidence to support clear recommendations, available information from the literature together with expert opinion of the panel was used to provide suggestions for the clinical practice. RESULTS AND CONCLUSION: Description of the evidence quality and support of the strength of the statements was provided on each of the selected key questions. The diagnosis of PDB should be mainly based on symptoms and the typical biochemical and radiological features. While treatment is mandatory to all the symptomatic cases at diagnosis, less evidence is available on treatment indications in asymptomatic as well as in previously treated patients in the presence of biochemical recurrence. However, given the safety and long-term efficacy of potent intravenous bisphosphonates such as zoledronate, a suggestion to treat most if not all cases at the time of diagnosis was released.


Asunto(s)
Osteítis Deformante , Humanos , Osteítis Deformante/diagnóstico , Osteítis Deformante/terapia , Osteítis Deformante/epidemiología , Osteítis Deformante/tratamiento farmacológico , Italia/epidemiología , Conservadores de la Densidad Ósea/uso terapéutico , Sociedades Médicas/normas , Difosfonatos/uso terapéutico
4.
J Endocrinol Invest ; 44(8): 1581-1596, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33394454

RESUMEN

PURPOSE: Classic Cushing's syndrome (CS) is a severe disease characterized by central obesity, hypertension, easy bruising, striae rubrae, buffalo hump, proximal myopathy and hypertricosis. However, several CS cases have also been reported with unusual or camouflaged manifestations. In recent years, several authors investigated the prevalence of "hidden hypercortisolism" (HidHyCo) among subjects affected with bone fragility, hypertension and type 2 diabetes mellitus (DM2). The prevalence of the HidHyCo is estimated to be much higher than that of classic CS. However, similarly to classic CS, HidHyCo is known to increase the risk of fractures, cardiovascular disease and mortality. METHODS: We reviewed all published cases of unusual presentations of hypercortisolism and studies specifically assessing the HidHyCo prevalence in diabetic, osteoporotic and hypertensive patients. RESULTS: We found 49 HidHyCo cases, in whom bone fragility, hypertension and diabetes were the presenting manifestations of an otherwise silent hypercortisolism. Amongst these cases, 34.7%, 32.7%, 6.1% and 19.0%, respectively, had bone fragility, hypertension, DM2 or hypertension plus DM2 as the sole clinical manifestations of HidHyCo. Overall, 25% of HidHyCo cases were of pituitary origin, and bone fragility was the very prevalent first manifestation among them. In population studies, it is possible to estimate that 1-4% of patients with apparent primary osteoporosis has a HidHyCo and the prevalence of this condition among diabetics ranges between 3.4 and 10%. CONCLUSION: These data indicate that patients with resistant or suddenly worsening hypertension or DM2 or unexplainable bone fragility should be screened for HidHyCo using the most recently approved sensitive cut-offs.


Asunto(s)
Síndrome de Cushing , Diabetes Mellitus Tipo 2/diagnóstico , Hipertensión/diagnóstico , Osteoporosis/diagnóstico , Síndrome de Cushing/sangre , Síndrome de Cushing/diagnóstico , Síndrome de Cushing/fisiopatología , Diabetes Mellitus Tipo 2/etiología , Errores Diagnósticos/prevención & control , Humanos , Hidrocortisona/metabolismo , Hipertensión/etiología , Osteoporosis/etiología , Hipófisis/fisiopatología
5.
Osteoporos Int ; 28(4): 1191-1213, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-27904930

RESUMEN

MicroRNAs are small, noncoding single-stranded RNAs that have emerged as important posttranscriptional regulators of gene expression, with an essential role in vertebrate development and different biological processes. This review highlights the recent advances in the function of miRNAs and their roles in bone remodeling and bone diseases. MicroRNAs (miRNAs) are a class of small (∼22 nt), noncoding single-stranded RNAs that have emerged as important posttranscriptional regulators of gene expression. They are essential for vertebrate development and play critical roles in different biological processes related to cell differentiation, activity, metabolism, and apoptosis. A rising number of experimental reports now indicate that miRNAs contribute to every step of osteogenesis and bone homeostasis, from embryonic skeletal development to maintenance of adult bone tissue, by regulating the growth, differentiation, and activity of different cell systems inside and outside the skeleton. Importantly, emerging information from animal studies suggests that targeting miRNAs might become an attractive and new therapeutic approach for osteoporosis or other skeletal diseases, even though there are still major concerns related to potential off target effects and the need of efficient delivery methods in vivo. Moreover, besides their recognized effects at the cellular level, evidence is also gathering that miRNAs are excreted and can circulate in the blood or other body fluids with potential paracrine or endocrine functions. Thus, they could represent suitable candidates for becoming sensitive disease biomarkers in different pathologic conditions, including skeletal disorders. Despite these promising perspectives more work remains to be done until miRNAs can serve as robust therapeutic targets or established diagnostic tools for precision medicine in skeletal disorders.


Asunto(s)
Enfermedades Óseas/genética , MicroARNs/genética , Diferenciación Celular/genética , Regulación de la Expresión Génica/fisiología , Humanos , Osteoblastos/fisiología , Osteoclastos/fisiología , Osteogénesis/genética , Osteoporosis/genética
6.
Calcif Tissue Int ; 89(6): 456-63, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21986718

RESUMEN

We investigated the associations of body composition and sex hormones with quantitative ultrasound (QUS) parameters carried out at different skeletal sites. In 897 postmenopausal women (64.1 ± 6.6 years) we measured QUS at the calcaneus (stiffness) by Achilles-GE and at phalanxes (amplitude-dependent speed of sound [AD-SOS], bone transmission time [BTT], and ultrasound bone profile index [UBPI]) by Bone Profiler-IGEA. In all subjects we measured fat mass (FM), lean mass (LM), android fat, and gynoid fat by DXA. In all subjects we also assessed serum testosterone (T), estradiol (E(2)), sex-hormone binding globulin, free estrogen index (FEI), free androgen index, 25-hydroxyvitamin D (25OHD), bone alkaline phosphatase (B-ALP), and type I collagen ß carboxy telopeptide. Both E(2) and FEI showed weak but significant correlations with stiffness and QUS parameters at phalanxes. No significant relationships were found between T and QUS. BMI and LM were positively correlated with stiffness (r = 0.14 and r = 0.17, respectively), whereas BMI and FM showed negative correlations with AD-SOS, BTT, and UBPI. 25OHD showed positive relationships with stiffness and QUS at phalanxes. In multivariate models LM and age were associated with stiffness whereas E(2) and age were significant predictors of BTT. AD-SOS was negatively associated with FM, B-ALP, and age but positively with E(2) and 25OHD. In postmenopausal women QUS parameters at the calcaneus and at phalanxes are significantly, but diversely, associated with body composition, sex hormones, 25OHD, and bone turnover markers.


Asunto(s)
Composición Corporal , Calcáneo/diagnóstico por imagen , Falanges de los Dedos de la Mano/diagnóstico por imagen , Hormonas Esteroides Gonadales/sangre , Anciano , Enfermedades Óseas Metabólicas/diagnóstico , Enfermedades Óseas Metabólicas/diagnóstico por imagen , Estudios Transversales , Estradiol/sangre , Femenino , Hormonas Esteroides Gonadales/metabolismo , Humanos , Persona de Mediana Edad , Posmenopausia/metabolismo , Testosterona/sangre , Ultrasonografía , Vitamina D/análogos & derivados , Vitamina D/metabolismo
7.
J Endocrinol Invest ; 34(7 Suppl): 45-9, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21985980

RESUMEN

Vitamin D via its receptor has essential actions on parathyroid cells, inhibiting PTH secretion, and parathyroid cell proliferation. While the effects of vitamin D depletion in the pathogenesis of secondary hyperparathyroidism in elderly individuals or in the occurrence of parathyroid hyperplasia in patients with renal insufficiency are well established, the association between hypovitaminosis D and primary hyperparathyroidism (P-HPT) has only recently become appreciated. In different cohorts of patients with P-HPT, vitamin D deficiency has been recently associated with higher PTH levels, larger adenomas, and a more severe phenotype (including osteitis fibrosa cystica) as well as negative post-operative outcomes following parathyroidectomy. Despite current guidelines recommend measurement of serum 25OHD (25-hydroxy-cholecalciferol) in P-HPT and their repletion if the levels are <20 ng/ml, future well-designed trials of vitamin D supplementation in P-HPT patients with coexisting vitamin D deficiency are needed to evaluate the risk/benefit profile of this treatment.


Asunto(s)
Hiperparatiroidismo Primario/etiología , Deficiencia de Vitamina D/complicaciones , 25-Hidroxivitamina D 2/sangre , Adenoma/patología , Huesos/efectos de los fármacos , Huesos/metabolismo , Femenino , Humanos , Hiperparatiroidismo Primario/terapia , Hormona Paratiroidea/sangre , Paratiroidectomía/efectos adversos , Posmenopausia , Vitamina D/uso terapéutico
8.
Nutr Metab Cardiovasc Dis ; 20(9): 683-90, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20934862

RESUMEN

Diabetes and osteoporosis are common and complex disorders with an enormous health burden that can be often associated especially in middle-age and elderly individuals. Although there is raising awareness of the higher fractures rates among patients with type 1 (DM1) and 2 (DM2) diabetes, there are few data available on the pathogenetic mechanisms responsible for this increased risk. Importantly, several experimental and clinical observations suggest that bone abnormalities associated with diabetes may differ, at least in part, from those associated with senile or post-menopausal osteoporosis. This implies that specific preventive and therapeutic strategies have to be developed and tested to prevent fractures in DM1 and DM2 patients. It is also likely that shared (i.e. due to glucose-toxicity) as well as different (i.e. due to insulin levels or other hormones) mechanisms may be associated with bone fragility in DM1 and DM2. Moreover, the hypothesis of an endocrine role of the skeleton in the regulation of glucose metabolism and insulin sensitivity has been recently proposed by experimental observations. This review summarizes the recent clinical and experimental advances on glucose tolerance, bone fragility and osteoporosis associated with diabetes.


Asunto(s)
Huesos/fisiopatología , Diabetes Mellitus Tipo 1/complicaciones , Diabetes Mellitus Tipo 2/complicaciones , Osteoporosis/complicaciones , Anciano , Densidad Ósea , Remodelación Ósea , Huesos/efectos de los fármacos , Diabetes Mellitus Tipo 1/fisiopatología , Diabetes Mellitus Tipo 2/fisiopatología , Femenino , Fracturas Óseas/complicaciones , Fracturas Óseas/epidemiología , Fracturas Óseas/prevención & control , Humanos , Hiperglucemia/complicaciones , Hipoglucemiantes/uso terapéutico , Masculino , Persona de Mediana Edad , Osteoporosis/epidemiología , Factores de Riesgo , Resistencia a la Tracción
9.
J Endocrinol Invest ; 33(8): 519-25, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20061786

RESUMEN

BACKGROUND: The prevalence of Paget's disease of bone (PDB) is unknown in peninsular Southern Italy, although an elevated clinical severity of the disease was reported in patients from Campania. AIM: This study was performed to evaluate the epidemiological and genetic characteristics of PDB in a rural area of Calabria, the southernmost region in the Italian peninsula. SUBJECTS AND METHODS: We examined 1068 consecutive pelvic radiographs of patients older than 40 yr referred for any reason to the "Spinelli" Hospital, Belvedere Marittimo, from January 1st 2004 to December 31st 2006. In subjects with radiological findings of pelvic PDB, a 99m Technetium methylene diphosphonate bone scan and the sequence analysis of the sequestosome 1 (SQSTM1) gene were subsequently performed. RESULTS: In the examined geographic area, the crude radiographic prevalence of pelvic PDB was 0.74% (8/1068; male:female 5:3, mean age 71.6 ± 13.1 yr) whereas the estimated overall prevalence of PDB between 0.82% and 1.21%. PDB patients from Calabria showed clinical characteristics similar to those reported in patients from Campania. The disease was also frequently complicated by osteoarthritis and the right side of the body was more affected than the left. The SQSTM1 gene analysis revealed the presence of a novel missense mutation (M401V) in exon 8 in one subject with a familial and aggressive form of PDB. CONCLUSION: The study results confirmed that patients with PDB from rural districts of Southern Italy show an earlier onset and an increased clinical severity of the disease that appears mostly independent from the presence of germinal SQSTM1 mutations.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/genética , Osteítis Deformante/epidemiología , Osteítis Deformante/genética , Adulto , Edad de Inicio , Anciano , Huesos/diagnóstico por imagen , Femenino , Humanos , Italia/epidemiología , Masculino , Persona de Mediana Edad , Mutación , Osteítis Deformante/diagnóstico por imagen , Prevalencia , Radiografía , Cintigrafía , Proteína Sequestosoma-1 , Medronato de Tecnecio Tc 99m
10.
J Diabetes Res ; 2020: 7608964, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32566682

RESUMEN

Individuals with type 2 diabetes mellitus (T2DM) have an increased risk of bone fragility fractures compared to nondiabetic subjects. This increased fracture risk may occur despite normal or even increased values of bone mineral density (BMD), and poor bone quality is suggested to contribute to skeletal fragility in this population. These concepts explain why the only evaluation of BMD could not be considered an adequate tool for evaluating the risk of fracture in the individual T2DM patient. Unfortunately, nowadays, the bone quality could not be reliably evaluated in the routine clinical practice. On the other hand, getting further insight on the pathogenesis of T2DM-related bone fragility could consent to ameliorate both the detection of the patients at risk for fracture and their appropriate treatment. The pathophysiological mechanisms underlying the increased risk of fragility fractures in a T2DM population are complex. Indeed, in T2DM, bone health is negatively affected by several factors, such as inflammatory cytokines, muscle-derived hormones, incretins, hydrogen sulfide (H2S) production and cortisol secretion, peripheral activation, and sensitivity. All these factors may alter bone formation and resorption, collagen formation, and bone marrow adiposity, ultimately leading to reduced bone strength. Additional factors such as hypoglycemia and the consequent increased propensity for falls and the direct effects on bone and mineral metabolism of certain antidiabetic medications may contribute to the increased fracture risk in this population. The purpose of this review is to summarize the literature evidence that faces the pathophysiological mechanisms underlying bone fragility in T2DM patients.


Asunto(s)
Enfermedades Óseas Metabólicas/etiología , Enfermedades Óseas Metabólicas/terapia , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/terapia , Densidad Ósea , Remodelación Ósea/efectos de los fármacos , Huesos/efectos de los fármacos , Huesos/metabolismo , Complicaciones de la Diabetes/etiología , Complicaciones de la Diabetes/terapia , Diabetes Mellitus Tipo 2/metabolismo , Fracturas Óseas/etiología , Fracturas Óseas/terapia , Humanos , Hipoglucemiantes/uso terapéutico
11.
Expert Opin Pharmacother ; 20(7): 805-811, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30856013

RESUMEN

INTRODUCTION: Osteoporosis is a skeletal disorder characterized by loss of bone mass and strength affecting up to 30-50% of postmenopausal women worldwide. Current therapeutic options include antiresorptives such as aminobisphosphonates or denosumab and osteoanabolic compounds such as teriparatide. Areas covered: In this review, the authors summarize the clinical development, safety and efficacy profile of abaloparatide, a new osteoanabolic agent recently marketed in the US for the treatment of postmenopausal osteoporosis in women who are at high risk for fracture or who fail antiresorptive therapy. Expert opinion: Abaloparatide is a 1-34 PTH related peptide-like molecule that has been modified in order to potentiate the osteoanabolic effect. In its pivotal phase 3 trial in postmenopausal women with osteoporosis, subcutaneous abaloparatide 80 mcg/day reduced the risk of vertebral, nonvertebral, major osteoporotic, and clinical fractures compared with placebo and reduced the risk of major osteoporotic fractures compared with teriparatide. These results, together with a reduced prevalence of hypercalcemia and a lower cost of the marketed compound, point toward improved cost effectiveness with abaloparatide versus teriparatide. However, some concerns have been raised due to a somewhat higher occurrence of adverse effects (particularly with palpitations and increased heart rate) or the resultant discontinuation due to these adverse effects when compared to teriparatide.


Asunto(s)
Conservadores de la Densidad Ósea/uso terapéutico , Osteoporosis Posmenopáusica/tratamiento farmacológico , Proteína Relacionada con la Hormona Paratiroidea/uso terapéutico , Conservadores de la Densidad Ósea/química , Conservadores de la Densidad Ósea/farmacología , Femenino , Semivida , Humanos , Hipercalcemia/etiología , Fracturas Osteoporóticas/prevención & control , Proteína Relacionada con la Hormona Paratiroidea/efectos adversos , Proteína Relacionada con la Hormona Paratiroidea/química , Proteína Relacionada con la Hormona Paratiroidea/farmacocinética , Resultado del Tratamiento
12.
Expert Opin Drug Discov ; 13(8): 741-752, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29869573

RESUMEN

INTRODUCTION: Osteoporosis is a growing health and health-economic problem due to the increased proportion of elderly people in the population. Basic and clinical advances in research over the past two decades have led to the development of different compounds with antiresorptive or anabolic activity on bone that improved substantially the management of patients with osteoporosis over calcitonin or estrogen replacement. New compounds are in preclinical and clinical development. Areas covered: In this review, the authors review the approaches for the preclinical and clinical development of antiresorptive and anabolic agents for osteoporosis, particularly focusing on the recent advances in technology and in the understanding of skeletal biology, together with their implications on novel osteoporosis drug discovery. Expert opinion: Based on the available evidence from the approved drugs for the treatment osteoporosis as well as from the different compounds under clinical development, it has become clear that long term nonclinical pharmacological studies with either bone quality and off-target effects as the main outcomes should be required for new drugs intended to treat osteoporosis. At the same time, basic and clinical advances in research have underlined the necessity to develop new technologies and new models for a thorough screening of the effects of new drugs on the different components of skeletal aging and bone fragility that cannot be assessed by bone mass measurement.


Asunto(s)
Conservadores de la Densidad Ósea/uso terapéutico , Desarrollo de Medicamentos/métodos , Osteoporosis/tratamiento farmacológico , Anciano , Anabolizantes/farmacología , Anabolizantes/uso terapéutico , Animales , Conservadores de la Densidad Ósea/farmacología , Descubrimiento de Drogas/métodos , Evaluación Preclínica de Medicamentos/métodos , Humanos , Osteoporosis/patología
13.
J Clin Invest ; 99(4): 692-700, 1997 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-9045872

RESUMEN

To assess whether liver transplantation (LTx) can correct the metabolic alterations of chronic liver disease, 14 patients (LTx-5) were studied 5+/-1 mo after LTx, 9 patients (LTx-13) 13+/-1 mo after LTx, and 10 patients (LTx-26) 26+/-2 months after LTx. Subjects with chronic uveitis (CU) and healthy volunteers (CON) were also studied. Basal plasma leucine and branched-chain amino acids were reduced in LTx-5, LTx-13, and LTx-26 when compared with CU and CON (P < 0.01). The basal free fatty acids (FFA) were reduced in LTx-26 with respect to CON (P < 0.01). To assess protein metabolism, LTx-5, LTx-13, and LTx-26 were studied with the [1-14C]leucine turnover combined with a 40-mU/m2 per min insulin clamp. To relate changes in FFA metabolism to glucose metabolism, eight LTx-26 were studied with the [1-14C]palmitate and [3-3H]glucose turnovers combined with a two-step (8 and 40 mU/m2 per min) euglycemic insulin clamp. In the postabsorptive state, LTx-5 had lower endogenous leucine flux (ELF) (P < 0.005), lower leucine oxidation (LO) (P < 0.004), and lower non-oxidative leucine disposal (NOLD) (P < 0.03) with respect to CON (primary pool model). At 2 yr (LTx-26) both ELF (P < 0.001 vs. LTx-5) and NOLD (P < 0.01 vs. LTx-5) were normalized, but not LO (P < 0.001 vs. CON) (primary and reciprocal pool models). Suppression of ELF by insulin (delta-reduction) was impaired in LTx-5 and LTx-13 when compared with CU and CON (P < 0.01), but normalized in LTx-26 (P < 0.004 vs. LTx-5 and P = 0.3 vs. CON). The basal FFA turnover rate was decreased in LTx-26 (P < 0.01) and CU (P < 0.02) vs. CON. LTx-26 showed a lower FFA oxidation rate than CON (P < 0.02). Tissue glucose disposal was impaired in LTx-5 (P < 0.005) and LTx-13 (P < 0.03), but not in LTx-26 when compared to CON. LTx-26 had normal basal and insulin-modulated endogenous glucose production. In conclusion, LTx have impaired insulin-stimulated glucose, FFA, and protein metabolism 5 mo after surgery. Follow-up at 26 mo results in (a) normalization of insulin-dependent glucose metabolism, most likely related to the reduction of prednisone dose, and, (b) maintenance of some alterations in leucine and FFA metabolism, probably related to the functional denervation of the graft and to the immunosuppressive treatment.


Asunto(s)
Cirrosis Hepática/metabolismo , Cirrosis Hepática/cirugía , Trasplante de Hígado , Adulto , Aminoácidos/sangre , Glucemia/metabolismo , Ácidos Grasos no Esterificados/metabolismo , Ácidos Grasos no Esterificados/farmacocinética , Hormonas/sangre , Humanos , Insulina/administración & dosificación , Sistemas de Infusión de Insulina , Cetoácidos/sangre , Leucina/sangre , Cirrosis Hepática/sangre , Tasa de Depuración Metabólica , Persona de Mediana Edad , Palmitatos/sangre
14.
J Clin Invest ; 97(11): 2611-8, 1996 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-8647955

RESUMEN

The intraportal injection of human pancreatic islets has been indicated as a possible alternative to the pancreas transplant in insulin-dependent diabetic patients. Aim of the present work was to study the effect of intraportal injection of purified human islets on: (a) the basal hepatic glucose production; (b) the whole body glucose homeostasis and insulin action; and (c) the regulation of insulin secretion in insulin-dependent diabetes mellitus patients bearing a kidney transplant. 15 recipients of purified islets from cadaver donors (intraportal injection) were studied by means of the infusion of labeled glucose to quantify the hepatic glucose production. Islet transplanted patients were subdivided in two groups based on graft function and underwent: (a) a 120-min euglycemic insulin infusion (1 mU/kg/min) to assess insulin action; (b) a 120-min glucose infusion (+75 mg/di) to study the pattern of insulin secretion. Seven patients with chronic uveitis on the same immunosuppressive therapy as grafted patients, twelve healthy volunteers, and seven insulin-dependent diabetic patients with combined pancreas and kidney transplantation were also studied as control groups. Islet transplanted patients have: (a) a higher basal hepatic glucose production (HGP: 5.1 +/- 1.4 mg/kg/ min; P < 0.05 with respect to all other groups) if without graft function, and a normal HGP (2.4 +/- 0.2 mg/kg/min) with a functioning graft; (b) a defective tissue glucose disposal (3.9 +/- 0.5 mg/kg/min in patients without islet function and 5.3 +/- 0.4 mg/kg/min in patients with islet function) with respect to normals (P < 0.01 for both comparisons); (c) a blunted first phase insulin peak and a similar second phase secretion with respect to controls. In conclusion, in spite of the persistence of an abnormal pattern of insulin secretion, successful intraportal islet graft normalizes the basal HGP and improves total tissue glucose disposal in insulin-dependent diabetes mellitus.


Asunto(s)
Diabetes Mellitus Tipo 1/fisiopatología , Diabetes Mellitus Tipo 1/cirugía , Trasplante de Islotes Pancreáticos/fisiología , Uveítis/fisiopatología , Adulto , Glucemia/metabolismo , Péptido C/sangre , Nefropatías Diabéticas/cirugía , Femenino , Glucagón/sangre , Glucosa/metabolismo , Técnica de Clampeo de la Glucosa , Homeostasis , Humanos , Infusiones Intravenosas , Insulina/administración & dosificación , Insulina/sangre , Insulina/farmacología , Trasplante de Riñón/fisiología , Hígado/metabolismo , Trasplante de Hígado/fisiología , Masculino , Persona de Mediana Edad
15.
Bone ; 40(2): 457-63, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16979395

RESUMEN

Paget's disease of bone (PDB) is a focal disorder of bone remodeling characterized by increased osteoclast-mediated bone resorption. Even though increasing evidence indicates enhanced nuclear factor-kB (NF-kB) signaling as a common mechanism involved in PDB and other related disorders, few studies investigated circulating osteoprotegerin (OPG) and receptor of activator of NF-kB-ligand (RANKL) levels in PDB patients. In this study we explored the relationships between OPG or RANKL levels and bone turnover markers in a group of patients with PDB, before and after intravenous bisphosphonate treatment (pamidronate 60 mg). Both OPG and RANKL were markedly elevated in PDB patients with respect to control groups (healthy or osteoporotic postmenopausal women and elderly men) and were positively associated with bone turnover markers. Higher levels of these cytokines were observed in polyostotic than monostotic PDB cases. The ratio between RANKL and OPG was more than 3-fold higher in PDB patients than in controls. Interestingly, in the group of patients treated with pamidronate, we found an increase in OPG levels that become statistically significant after 3 and 6 months from treatment. A trend toward a decrease in RANKL levels after treatment was also observed. The RANKL/OPG ratio was significantly reduced after 3 and 6 months of therapy. In contrast, in patients classified as non-responders, OPG and RANKL levels after pamidronate infusion did not significantly differ with respect to pre-treatment values. Thus, the positive effect of amino bisphosphonates in the treatment of PDB may be due to either direct or indirect suppression of RANKL-induced bone resorption through decreased RANKL and increased OPG production.


Asunto(s)
Conservadores de la Densidad Ósea/uso terapéutico , Difosfonatos/uso terapéutico , Osteítis Deformante/tratamiento farmacológico , Osteoprotegerina/sangre , Ligando RANK/sangre , Anciano , Anciano de 80 o más Años , Fosfatasa Alcalina/sangre , Colágeno Tipo I/sangre , Femenino , Humanos , Masculino , Persona de Mediana Edad , Osteítis Deformante/sangre , Pamidronato
16.
J Endocrinol Invest ; 30(6 Suppl): 18-23, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17721069

RESUMEN

Sex steroid hormones play an important role in the maintenance of bone mass in males and in females. Even though androgens are the major sex steroids in men, direct and indirect evidence emerged suggesting that estrogens may also play a major role in male skeletal health. Since the testes account for only 15% of circulating estrogens in males, the remaining 85% comes from peripheral aromatization of androgen precursors in different tissues, including bone. Human models of aromatase deficiency clearly demonstrated the critical importance of the conversion of androgens into estrogens in regulating male skeletal homeostasis. Aromatase- deficient men showed tall stature due to continued longitudinal growth, unfused epiphyses, high bone turnover, and osteopenia. Interventional studies in adult men using aromatase inhibition confirmed that estrogens are important in controlling bone remodeling. Importantly either inherited (i.e. due to common polymorphisms at the human aromatase CYP19 gene) or acquired (i.e. by diseases or different compounds) variation in aromatase ability to convert androgen precursors into estrogen may also be relevant for skeletal homeostasis.


Asunto(s)
Aromatasa/metabolismo , Huesos/metabolismo , Envejecimiento/fisiología , Aromatasa/deficiencia , Estrógenos/metabolismo , Femenino , Homeostasis , Humanos , Masculino , Testosterona/metabolismo
17.
J Clin Oncol ; 15(5): 2008-14, 1997 May.
Artículo en Inglés | MEDLINE | ID: mdl-9164212

RESUMEN

PURPOSE: We analyzed the relation between phenotypic (DNA ploidy) and functional markers (S-phase cell fraction, p53, and bcl-2 protein expression) and defined their relevance on clinical outcome on a retrospective series of radically resected liver metastases from colorectal cancer. PATIENTS AND METHODS: Among 104 patients with resectable liver metastases from colorectal cancer, DNA ploidy was determined by flow cytometry, 3H-thymidine labeling index (TLI) by autoradiography, and expression of p53 and bcl-2 by immunohistochemistry. RESULTS: TLI was a significant indicator for relapse at 4 years from radical surgery, DNA ploidy was a suggestive indicator of clinical outcome, and p53 and bcl-2 expression provided no clinical information. By multivariate analysis, cell proliferation rate and Dukes' stage remained independent prognostic parameters. In the most representative subgroup of patients with H1 liver lesions (86 cases), TLI was always associated with relapse, and DNA ploidy and p53 expression provided discriminant information within slowly proliferating liver lesions. CONCLUSION: Tumor-cell proliferation of liver lesions should be used with stage of the primary colorectal cancer for a more accurate prognosis in patients submitted to curative hepatic resection.


Asunto(s)
Biomarcadores de Tumor/análisis , Neoplasias Colorrectales/patología , Neoplasias Hepáticas/química , Neoplasias Hepáticas/secundario , Ploidias , Proteínas Proto-Oncogénicas c-bcl-2/análisis , Proteína p53 Supresora de Tumor/análisis , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/genética , División Celular , Femenino , Humanos , Neoplasias Hepáticas/genética , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos
18.
J Bone Miner Res ; 14(8): 1379-86, 1999 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10457270

RESUMEN

A novel T/C polymorphism (ATG to ACG) at the translation initiation site of the vitamin D receptor (VDR) gene, defined by FokI restriction endonuclease, has been recently associated with variation in bone mineral density (BMD) and rates of bone loss in a group of postmenopausal Mexican-American women. The presence of the restriction site, designated as f, allows protein translation to initiate from the first ATG, while the allele lacking the site, indicated as F, initiates translation at a second ATG. In this study, we investigated the role of FokI polymorphism in a group of 400 postmenopausal women of Italian descent stratified for BMD into osteoporotic (n = 164), osteopenic (n = 117), and normal (n = 119) groups. There were 159 (41%) FF homozygotes, 55 (14%) ff homozygotes, and 186 (45%) Ff heterozygotes. In the whole population, we observed a weak association between FokI polymorphism and lumbar BMD (p = 0.06, analysis of covariance [ANCOVA]) but not with femoral neck BMD (p = 0.5, ANCOVA). Interestingly, the effect of FokI genotypes on lumbar BMD was influenced by the years since menopause such that differences in BMD related to different VDR allelic variants were greater among women in the first 5 years of menopause (p = 0.04, ANCOVA), progressively declining afterward. In addition, a significantly higher prevalence of ff genotype in osteoporotic than in osteopenic and normal women was observed (p = 0.04, Chi-square test). Finally, ff genotype resulted significantly over-represented in the group of women with a vertebral fracture as compared with controls (p = 0.003, Chi-square test), equivalent to a relative risk of 2.58 (95% confidence intervals 1.36-4.91). We conclude that in this population, FokI polymorphism at the VDR gene locus accounts for a part of the heritable component of BMD at the lumbar spine.


Asunto(s)
Densidad Ósea/fisiología , Desoxirribonucleasas de Localización Especificada Tipo II/genética , Iniciación de la Cadena Peptídica Traduccional/genética , Polimorfismo Genético , Posmenopausia/fisiología , Receptores de Calcitriol/genética , Fracturas de la Columna Vertebral/genética , Anciano , Análisis de Varianza , Enfermedades Óseas Metabólicas/genética , Femenino , Genotipo , Humanos , Italia , Persona de Mediana Edad , Osteoporosis Posmenopáusica/genética
19.
J Clin Endocrinol Metab ; 83(3): 939-44, 1998 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-9506753

RESUMEN

Bone mass and bone turnover are under genetic control. Restriction fragment length polymorphisms (RFLPs) at the vitamin D receptor (VDR) gene locus have been recently correlated to bone mineral density (BMD) and rate of bone loss. However, agreement on this relationship is not universal. The existence of ethnical and environmental differences between populations, a health-based selection bias in several previous studies, and the involvement of other genes could explain these discordant findings. In this study, we examined the relationship of VDR and estrogen receptor (ER) gene RFLPs with lumbar spine and upper femur BMD in 426 Italian postmenopausal women, 57.7 +/- 0.4 yr old (144 normal, 106 osteopenic, and 176 osteoporotic). VDR gene RFLPs for ApaI, Bsm I, and TaqI restriction endonucleases and ER RFLPs for PvuII and XbaI restriction endonucleases were assessed by Southern blotting analysis and were indicated, respectively, as A-a, B-b, T-t, P-p, and X-x (uppercase letters signifying the absence and lowercase letters the presence of the restriction site). After correcting for potential confounding factors (age, height, weight, age since menopause, osteophytosis, and facet joint osteoarthritis), a statistically significant VDR genotype effect on lumbar BMD (P = 0.01, analysis of covariance), but not on femoral BMD, was detected, with subjects in AABBtt genotype showing a 13% lower BMD than those with aabbTT genotype (P < 0.05, Tukey's test). Moreover, a statistically significant prevalence of AABBtt genotype in osteoporotics, and of AabbTT and aabbTT genotypes in nonosteoporotics, were detected. Conversely, there was no significant relationship of ER genotype to either lumbar or femoral BMD, even though a trend for higher BMD values in women with the ER PP genotype (with respect to those with ER pp genotype) was detected. When mean lumbar BMD was calculated for women grouped by ER and VDR genotype, we observed a significant difference between those within the 2 opposite associations AABBtt-PPXX and aabbTT-ppxx (0.71 +/- 0.05 vs. 0.97 +/- 0.03 g/cm2, P < 0.05 Tukey's test). These results are consistent with a segregation of the VDR AABBtt genotype with a higher risk of developing osteoporosis, in the Italian female population. The introduction of another variable, the ER genotype, in the analysis of VDR genetic determination of BMD, may represent a useful model in the identification of patients at risk of developing a multigenic disorder like osteoporosis.


Asunto(s)
Alelos , Densidad Ósea/fisiología , Variación Genética/genética , Posmenopausia/fisiología , Receptores de Calcitriol/genética , Receptores de Estrógenos/genética , Enfermedades Óseas Metabólicas/genética , Femenino , Frecuencia de los Genes , Genotipo , Humanos , Persona de Mediana Edad , Osteoporosis/genética , Polimorfismo de Longitud del Fragmento de Restricción , Valores de Referencia
20.
J Clin Endocrinol Metab ; 86(5): 2263-9, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11344237

RESUMEN

Conversion of C(19) steroids to estrogens is catalyzed by the aromatase enzyme. Inactivating mutations of the aromatase gene are associated with decreased bone mineral density in both men and women. Genetic studies suggest that several genes contribute to the regulation of bone mass via interaction with the modeling and remodeling processes. Among these genes, the aromatase gene is a potential candidate to be evaluated for segregation with bone metabolism and bone mass. A tetranucleotide simple tandem repeat polymorphism in intron 4 at the human aromatase cytochrome P-450 gene has been recently described. In the present study we evaluated the distribution of this polymorphism in a cohort of Italian postmenopausal women, both normal and osteoporotic. We observed that the NN genotype was significantly more frequent in nonosteoporotic women than in osteoporotic women (72.7% vs. 27.2%), whereas the DN genotype was significantly more represented in osteoporotic women (90.48% vs. 9.5%; Pearson's chi(2) test = 42.8; df = 10; P = or < 0.01). The allele containing the longer TTTA repeats was statistically more represented in nonosteoporotic women (Pearson's chi(2) test = 19.14; df = 2; P = 0.00007). In addition, women with a high number of TTTA repeats had a significantly higher lumbar bone mineral density than women with alleles containing 8-11 TTTA repeats (P = 0.03). Finally, considering the spine fractures, a significantly higher incidence was observed in women with shorter TTTA repeats than in those with longer TTTA repeats (Pearson's chi(2) test = 7.3; df = 2; P = 0.02), equivalent to a relative risk of 4.1 (95% confidence interval, 1.19-13.87). In conclusion, the aromatase gene can be one of the several genes potentially involved in the maintenance of bone mass and in the regulation of bone mass loss.


Asunto(s)
Aromatasa/genética , Densidad Ósea , Fracturas Óseas/etiología , Polimorfismo Genético , Posmenopausia/genética , Anciano , Estudios de Cohortes , Femenino , Genotipo , Humanos , Repeticiones de Microsatélite , Persona de Mediana Edad , Riesgo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA