The natural isoflavone phytoestrogen genistein has been shown to stimulate osteoblastic bone formation, inhibit osteoclastic bone resorption, and prevent bone loss in ovariectomized rats. However, no controlled clinical trial has been performed so far to evaluate the effects of the phytoestrogen on bone loss in postmenopausal women. We performed a randomized double-blind placebo-controlled study to evaluate and compare with hormone-replacement therapy (HRT) the effect of the phytoestrogen genistein on bone metabolism and bone mineral density (
Twenty-four months of treatment with genistein has positive effects on BMD in osteopenic postmenopausal women. ClinicalTrials.gov registration number: NCT00355953.
This study shows for the first time that long-term immobilized patients present hypersclerostinemia associated with reduced bone formation, and suggests that sclerostin could be a link between mechanical unloading and disuse osteoporosis in humans.
These results show for the first time that T2DM patients have serum concentrations of β-catenin lower than controls. The negative association of β-catenin with sclerostin suggests a biological effect of increased sclerostin on the Wnt signaling, which appears impaired in T2DM.
These results suggest that 54 mg genistein plus calcium, vitamin D(3), and a healthy diet was associated with favorable effects on both glycemic control and some cardiovascular risk markers in a cohort of osteopenic, postmenopausal women.
Osteoporosis represents an important cause of morbidity in adult thalassemic patients, and its pathogenesis has not, as yet, been completely clarified. In our study, we observed that thalassemic patients showed a significantly lower OPG/RANKL ratio than normal subjects. These data are extremely important for the possible therapeutic use of RANKL antagonists such as OPG in thalassemia-induced osteoporosis.Introduction: Osteoporosis represents an important cause of morbidity in adult thalassemic patients who display increased fracture risk. The etiology of this bone disease is multifactorial, but it is thought that the main role is played by hypogonadism. The mechanisms by which the skeletal effects of sex steroids are mediated are still not fully understood. Recently, two new cytokines, osteoprotegerin (OPG) and RANKL, have been implicated in the pathogenesis of postmenopausal osteoporosis and other metabolic bone diseases. Thus, the aim of this study was to characterize the possible role of the OPG/RANKL system in thalassemia-related bone loss. Materials and Methods: We measured, in 30 thalassemic patients and in 20 healthy control subjects, serum OPG and RANKL levels, and determined their correlations with bone turnover markers, BMD, sex steroid levels, erythropoietin, and hemoglobin. Results: Thalassemic patients had an unbalanced bone turnover with an increased resorption phase (shown by high levels of pyridinium cross-links) and a decreased neoformation phase (shown by the slightly low levels of osteocalcin). Moreover, they displayed lower BMD values than controls both at the lumbar and femoral level. As far as the OPG/RANKL system is concerned, thalassemic patients showed no differences in plasma levels of OPG compared with controls, and significantly higher plasma levels of RANKL, with a consequent significantly lower OPG/RANKL ratio. Conclusions: Our data suggest that, in thalassemic patients, an altered modulation of the OPG/RANKL system, resulting in increased expression of RANKL by stromal or osteoblastic cells, could contribute to the enhanced osteoclastic bone resorption and bone loss characteristic of these patients.
Abstract-The endothelium is thought to play an important role in the genesis of atherosclerosis, and several lines of evidence suggest that the effect of an intervention on endothelial function might predict its involvement in coronary disease progression and in the rate of cardiovascular events. Estrogen has direct effects on the blood vessel wall, indicating that vascular endothelium may play a key role in the cardiovascular protective effects of hormone replacement therapy (HRT). Raloxifene relaxes coronary arteries in vitro by an estrogen receptor-dependent and NO-dependent mechanism, thus suggesting that this selective estrogen receptor modulator could also have beneficial effects on endothelial function. This study compared the effects of HRT and raloxifene on NO products, endothelin-1 plasma levels, and endothelium-dependent vasodilatation in postmenopausal women. Healthy postmenopausal women (nϭ90) were enrolled in a double-blind, randomized, placebocontrolled, 6-month trial. Women were randomly assigned to receive continuous HRT (1 mg 17-estradiol combined with 0.5 mg norethisterone acetate), raloxifene (60 mg/d), or placebo for 6 months. Flow-mediated endothelium-dependent vasodilation of the brachial artery, plasma NO concentrations, and endothelin levels were measured at baseline and after 6 months of therapy. The mean baseline level of NO breakdown products was 26.5Ϯ10.7 mol/L and increased to 36.3Ϯ11.4 mol/L after 6 months of treatment with raloxifene. The mean baseline plasma endothelin level was 17.3Ϯ8.9 pg/mL and decreased to 11.5Ϯ2.1 pg/mL after 6 months of treatment with the selective estrogen receptor modulator. The mean baseline ratio of NO (breakdown products) to endothelin was also significantly increased at the end of treatment with raloxifene. Postmenopausal women treated with HRT had similar changes in plasma nitrites/nitrates and endothelin levels as well as in the ratio of NO to endothelin. In contrast, these markers of endothelial function did not change in the placebo-treated women. Flow-mediated endothelium-dependent vasodilation of the brachial artery was 8.3Ϯ2.1% at baseline and increased to 12.3Ϯ2.1% after 6 months of treatment with raloxifene. HRT also caused a significant and similar increase in flow-mediated endothelium-dependent vasodilation. No change in flow-mediated vasodilation was observed in the participants treated with placebo. We conclude that raloxifene therapy and HRT influence endothelial function and improve flow-mediated endothelium-dependent vasodilation to a comparable extent in healthy postmenopausal women at least after a 6-month treatment period. However, further investigation is warranted to enhance our understanding of the mechanisms of the effect of raloxifene on vascular function and to determine whether its effect on endothelial function may contribute to the reduction in cardiovascular-related morbidity and mortality. Key Words: raloxifene Ⅲ hormone replacement therapy Ⅲ nitric oxide Ⅲ endothelin-1 Ⅲ endothelium P opulation-based observational studi...
The aim of our cross-sectional study was to evaluate the effects of hormonal replacement therapy (HRT) on a population of young thalassemics in order to understand better the role of hypogonadism in the balance of bone metabolism. Markers of bone turnover and bone mineral density (BMD) were measured in 40 young patients (mean age 19.8 +/- 4.5 years) with beta-thalassemia major: 20 subjects were biochemically eugonadal. since they were undergoing HRT (group A, treated patients), and 20 were hypogonadic, having suspended HRT (group B, untreated patients). We also examined 20 healthy control subjects (group C) matched for age, anthropometric features and sex to the study groups. Our study shows that young thalassemic patients exhibit a significant loss of cortical and trabecular bone [aBMD L2-L4: 0.886 +/- 0.052 g/cm2 (group A), 0.726 +/- 0.040 g/cm2 (group B), 1.083 +/- 0.090 g/cm (group C); aBMD femoral neck: 0.890 +/- 0.071 g/cm2 (group A), 0.700 +/- 0.065 g/cm2 (group B), 0.934 +/- 0.076 g/ cm2 (group C)]. Osteoporosis is only observed at the lumbar level in treated thalassemic patients, while in untreated patients it involves the femoral neck also. Bone turnover in thalassemic patients is higher in the resorptive phase, than in the neoformation phase and this is more marked in hypogonadic untreated patients. In conclusion, our data demonstrate the important role played by hypogonadism in the development and deterioration of osteopenia/osteoporosis in thalassemia major. Consequently, sex hormone replacement therapy represents an appropriate tool in the prevention and treatment of osteoporosis in thalassemics, probably together with bisphosphonates in cases with severely increased bone resorption.
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