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 (BMD) in postmenopausal women. Participants were 90 healthy ambulatory women who were 47–57 years of age, with a BMD at the femoral neck of <0.795 g/cm². After a 4‐week stabilization on a standard fat‐reduced diet, participants of the study were randomly assigned to receive continuous HRT for 1 year (n = 30; 1 mg of 17β‐estradiol [E₂] combined with 0.5 mg of norethisterone acetate), the phytoestrogen genistein (n = 30; 54 mg/day), or placebo (n = 30). Urinary excretion of pyridinoline (PYR) and deoxypyridinoline (DPYR) was not significantly modified by placebo administration either at 6 months or at 12 months. Genistein treatment significantly reduced the excretion of pyridinium cross‐links at 6 months (PYR = −54 ± 10%; DPYR = −55 ± 13%; p < 0.001) and 12 months (PYR = −42 ± 12%; DPYR = −44 ± 16%; p < 0.001). A similar and not statistically different decrease in excretion of pyridinium cross‐links was also observed in the postmenopausal women randomized to receive HRT. Placebo administration did not change the serum levels of the bone‐specific ALP (B‐ALP) and osteocalcin (bone Gla protein [BGP]). In contrast, administration of genistein markedly increased serum B‐ALP and BGP either at 6 months (B‐ALP = 23 ± 4%; BGP = 29 ± 11%; p < 0.005) or at 12 months (B‐ALP = 25 ± 7%; BGP = 37 ± 16%; p < 0.05). Postmenopausal women treated with HRT had, in contrast, decreased serum B‐ALP and BGP levels either at 6 months (B‐ALP = −17 ± 6%; BGP = −20 ± 9%; p < 0.001) or 12 months (B‐ALP = −20 ± 5%; BGP = −22 ± 10%; p < 0.001). Furthermore, at the end of the experimental period, genistein and HRT significantly increased BMD in the femur (femoral neck: genistein = 3.6 ± 3%, HRT = 2.4 ± 2%, placebo = −0.65 ± 0.1%, and p < 0.001) and lumbar spine (genistein = 3 ± 2%, HRT = 3.8 ± 2.7%, placebo = −1.6 ± 0.3%, and p < 0.001). This study confirms the genistein‐positive effects on bone loss already observed in the experimental models of osteoporosis and indicates that the phytoestrogen reduces bone resorption and increases bone formation in postmenopausal women.

Context: Sclerostin, a Wnt signaling antagonist on the osteoblasts produced by osteocytes, is regulated by mechanical strain and is implicated in the pathogenesis of disuse bone loss. There are no data on sclerostin in humans. Objective: The aim of the study was to evaluate sclerostin in patients immobilized after stroke, compared with control subjects, and to analyze its relationship with markers of bone formation and resorption. Design: This was a cross-sectional study. Setting and patients: We studied 40 postmenopausal women immobilized after a single episode of stroke 6 months or longer after onset, and 40 postmenopausal women from the general community. Bone status was assessed by quantitative ultrasound measurements at the calcaneus. Bone alkaline phosphatase (b-AP), carboxy-terminal telopeptide of type I collagen (CrossLaps), and sclerostin were evaluated by ELISA. We also used ELISA to measure serum levels of Dickkopf-1, another soluble inhibitor of Wnt/β-catenin signaling, highly expressed by osteocytes. Results: Immobilized patients had higher sclerostin serum levels (median 0.975 ng/ml; 25th to 75th percentiles 0.662–1.490) than controls (median 0.300 ng/ml; 25th to 75th percentiles 0.165–0.400: P < 0.0001) and an increased bone turnover with a more significant rise in bone resorption (CrossLaps) than formation (b-AP) markers. Sclerostin correlated negatively with b-AP (r = −0.911; P < 0.0001) and positively with CrossLaps (r = 0.391; P = 0.012). Dickkopf-1 did not significantly differ between the groups. Patients also had quantitative ultrasound measurements index lower than controls (P < 0.001). Conclusions: 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.

Patients with type 2 diabetes (T2DM) have low bone turnover, poor bone quality, and circulating levels of sclerostin significantly higher than non-T2DM controls. There are no data on the possible association of sclerostin with β-catenin, a key component of the Wnt/β-catenin canonical signaling. The aim of the study was to evaluate the circulating β-catenin levels in T2DM patients and to analyze their relationship with sclerostin and bone turnover markers. This was a cross-sectional study. The study was conducted at a clinical research center. Forty T2DM postmenopausal women were studied and compared with 40 healthy controls. Bone status was assessed by dual-energy x-ray absorptiometry measurements (bone mineral density) and by measuring bone alkaline phosphatase and carboxy-terminal telopeptide of type 1 collagen. Sclerostin and β-catenin were evaluated by an immunoenzymetric assay. Consistent with previous reports in T2DM subjects, we found sclerostin levels higher and bone turnover markers lower than controls. In our cohort of T2DM patients, β-catenin levels are significantly lower than in controls (median 1.22 pg/ml, 25th to 75th percentiles 0.50-2.80; and median 4.25 pg/ml, 25th to 75th percentiles 2.20-7.62, respectively; P=0.0002). β-Catenin correlated negatively with sclerostin (P<0.0001) and positively with bone alkaline phosphatase (P=0.0030) only in T2DM patients and negatively with age in both groups. Eight of the 40 T2DM patients had vertebral fractures. 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.

Context: Genistein, a soy isoflavone, has received wide attention over the last few years because of its potential preventive role for cardiovascular disease. Objective: Our objective was to assess the effects of genistein administration (54 mg/d) on some predictors of cardiovascular risk in osteopenic, postmenopausal women. Design and Setting: We conducted a randomized, double-blind, placebo-controlled trial at three Italian university medical centers. Intervention: After a 4-wk stabilization on a standard isocaloric, fat-reduced diet, participants were randomly assigned to receive genistein (n = 198) or placebo (n = 191) daily for 24 months. Both intervention and placebo contained calcium and vitamin D₃. Outcome Measures: Blood lipid profiles, fasting glucose and insulin, homeostasis model assessment for insulin resistance, fibrinogen, soluble intercellular adhesion molecule-1, soluble vascular cellular adhesion molecule-1, F2-isoprostanes, and osteoprotegerin at baseline and after 12 and 24 months of treatment were measured. Results: Compared with placebo, genistein significantly reduced fasting glucose and insulin as well as homeostasis model assessment for insulin resistance after both 12 and 24 months of treatment. By contrast, genistein administration did not affect blood lipid levels although fibrinogen, F2-isoprostanes, soluble intercellular adhesion molecule-1, and soluble vascular cellular adhesion molecule-1 decreased significantly compared with placebo after 24 months. Serum osteoprotegerin was higher in the genistein group compared with placebo. At 24 months, the genistein group showed no change in endometrial thickness compared with placebo. Most treatment-related adverse events were moderate and composed of gastrointestinal side effects [genistein, n = 37 (19%); placebo, n = 15 (8%)]. Conclusions: These results suggest that 54 mg genistein plus calcium, vitamin D₃, 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.

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 (n=90) were enrolled in a double-blind, randomized, placebo-controlled, 6-month trial. Women were randomly assigned to receive continuous HRT (1 mg 17β-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 26.5±10.7 μmol/L and increased to 36.3±11.4 μmol/L after 6 months of treatment with raloxifene. The mean baseline plasma endothelin level was 17.3±8.9 pg/mL and decreased to 11.5±2.1 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 8.3±2.1% at baseline and increased to 12.3±2.1% 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.

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.