A Placebo-Controlled Study of Raloxifene Added to Risperidone in Men with Chronic Schizophrenia

Selective estrogen receptor modulators (SERMs) such as raloxifene have already shown beneficial effects on negative, positive and general psychopathology symptoms in postmenopausal women with schizophrenia. The purpose of the present investigation was to assess the efficacy of raloxifene as an adjuvant agent in the treatment of men with chronic schizophrenia in an 8-week double-blind and placebo-controlled trial. In a randomized, double-blind and placebo-controlled study, forty-six male patients diagnosed with schizophrenia (DSM-IV-TR), were randomized to either raloxifene (120 mg/day) or placebo in addition to risperidone (6 mg/day) for eight weeks. The assessment was performed using the positive and negative symptom scale (PANSS) at baseline, and at weeks 2, 4, 6 and 8. Extrapyramidal symptom rating scale (ESRS) at baseline, weeks 1, 2, 4, 6, 8 and Hamilton depression rating scale (HDRS) at baseline and week 8 were also used to assess extrapyramidal symptoms and depression simultaneously. Forty-two patients completed the trial. The raloxifene group showed significantly greater improvement on the negative subscale (P<0.001), the general psychopathology subscale (P=0.002) and total PANSS score (P<0.001) in comparison to the placebo group at the endpoint. There was no significant difference in the reduction of positive symptoms score between the two group (P=0.525). Extrapyramidal symptom rating scale and Hamilton depression rating scale and frequency of other adverse effects were comparable between two groups.This study indicates raloxifene as a potential adjunctive treatment strategy for chronic schizophrenia in men.

Efficacy and safety of currently marketed anti-osteoporosis medications

During the past 2 decades, many interventions were proven effective in the management of postmenopausal osteoporosis. The objective of an anti-osteoporosis treatment is to reduce fracture rates, ideally at all skeletal sites (i.e. spine, hip, and other non-spine). The armamentarium against osteoporosis includes anti-resorptive agents (i.e. bisphosphonates, selective estrogen receptor modulators and denosumab), bone-forming agents (i.e. peptides from the parathyroid hormone family) and one agent with a dual mechanism of action (i.e. strontium ranelate). All these medications combine antifracture efficacy with a reasonable benefit/risk profile. However, the choice of a particular chemical entity, in one individual patient is based on the knowledge and expertise of the physician. Prioritization of drugs should be based on the individual profile of the patient, the severity of osteoporosis and the specific contraindications, warnings and precautions of use of the various available medications.

Effect of raloxifene on parathyroid hormone in osteopenic and osteoporotic postmenopausal women with chronic kidney disease stage 5

INTRODUCTION

This study was aimed to investigate the effects of raloxifene on intact parathyroid hormone (PTH) level and bone mineral density (BMD) for 8 months in women on hemodialysis and women with chronic kidney disease stage 5 not dependent on dialysis to determine its effect on secondary hyperparathyroidism and osteoporosis.

MATERIALS AND METHODS

Fifty-one women on hemodialysis and 9 with chronic kidney disease stage 5 were randomly assigned to receive oral raloxifene, 60 mg/d, or placebo for 8 months. Baseline blood determinations and BMD were done and repeated after 8 months. Serum levels of total calcium, phosphorus, alkaline phosphatase, and intact PTH were measured.

RESULTS

Serum levels of intact PTH significantly decreased in both groups, and there was no difference between the two groups after 8 months (P = .37). Serum phosphorus levels also decreased by 1.8% in the two groups. After 8 months of treatment, the BMD of the lumbar spine and femural neck decreased by 1.9% in the control group, while an increase in BMD was observed in the raloxifene group,with an average increase in both BMDs of the lumbar spine and the femural neck by 2% (significant in the lumbar spine; P = .01).

CONCLUSIONS

Raloxifene has proven to be an effective medication in terms of improving BMD, with no adverse effects. However, it had no effect on controlling hyperparathyroidism in our patients. Long-term studies should be done to investigate the effects of raloxifene in chronic kidney disease and dialysis patients.

The risk of osteonecrosis of the jaws in Taiwanese osteoporotic patients treated with oral alendronate or raloxifene

BACKGROUND

This study aimed to explore the possible association between osteonecrosis of the jaws (ONJ) and oral alendronate or raloxifene used for osteoporosis and to estimate its absolute and attributable risks in the Taiwanese population.

METHODS

Using an electronic medical records system and manual confirmation of ONJ, we identified patients who began taking alendronate or raloxifene for osteoporosis and developed ONJ between January 2000 and April 2012.

RESULTS

The incidence of ONJ associated with oral alendronate for the management of osteoporosis began after 1 year of drug exposure and progressively increased with longer durations of therapy, specifically from 0.23% to 0.92% as the duration of treatment went from 2 years to 10 years. The overall frequency of ONJ related to oral alendronate over a 12-year period was 0.55%. The incidence rate of ONJ attributed to alendronate exposure was 283 per 100 000 persons per year. On multivariate Cox proportional analysis, adjusting for the potential confounders, alendronate remains an independent predictor for ONJ occurrence [hazard ratio 7.42 (1.02-54.09)] compared with raloxifene. Advanced age, drug duration, and coexisting diabetes and rheumatoid arthritis are contributing factors to the development of oral alendronate-related ONJ.

CONCLUSION

We provided the evidence to support the association of ONJ with oral alendronate used in the treatment or prevention of osteoporosis.

Evaluation of oral bioavailability and anticancer potential of raloxifene solid lipid nanoparticles

The objective of the present investigation was formulation of raloxifene loaded solid lipid nanoparticles (R-SLN) for oral administration and evaluation of its anticancer potential in 7,12- dimethylbenzanthracene (DMBA)-induced breast cancer in Sprague-Dawley rats. Optimized R-SLN formulation prepared by modified micro-emulsion method resulted in R-SLN of 288.0±28.5 nm size and 95.56% entrapment efficiency. R-SLN exhibited in vitro prolonged release of raloxifene for 72 h in phosphate buffered saline. R-SLN was stable in simulated gastro-intestinal (GIT) fluids consisting of pH 1.2, pH 7.4, simulated gastric fluid and simulated intestinal fluid. A two-fold increase was observed in raloxifene oral bioavailability from R-SLN. R-SLN exhibited enhanced efficacy and chemopreventive activity over pure raloxifene as indicated by evaluation of tumor burden (P < 0.001) and tumor incidence (P < 0.001). The results indicate the potential of raloxifene solid lipid nanoparticles in optimizing chemoprevention of breast cancer by R-SLN.

Formulation and optimization of raloxifene-loaded solid lipid nanoparticles to enhance oral bioavailability

The main aim of this study was to improve the oral bioavailability of raloxifene (RXF), a selective estrogen receptor modulator, by incorporation into solid lipid nanoparticles (SLN). RXF-loaded SLN was prepared by homogenization-sonication technique and characterized through physicochemical, pharmacokinetic, and cytotoxicity studies. The optimized SLN formulation exhibited a spherical shape with average size around 140 nm, easing its transport across the lymphatic system. Augmentation in the profiles of C(max) (308%) and AUC (270%) indicated a significant enhancement in the rate and extent of bioavailability by SLN formulations compared to free drug. In vitro cytotoxicity study performed in NIH-3T3 cells revealed that RXF-SLN was cytocompatible, and SLN remained unchanged during the freeze-drying process. Furthermore, the optimized formulation was quite stable at room temperature for more than two months, exemplifying its superior performance. In conclusion, SLN provides a promising platform for the pronounced enhancement of RXF bioavailability.

[Anti-osteoporosis drugs based on the guidelines for the Prevention and Treatment of Osteoporosis (2011 edition) ]

The aim of osteoporosis treatment is to reduce fracture risk. Many kinds of anti-osteoporosis drugs are available in these days, and most of them increase bone mineral density and reduce the risk of fractures. Japanese 2011 guidelines for prevention and treatment of osteoporosis documents the recommendation level of each osteoporosis drugs. It is important to select drugs appropriate for each osteoporosis patient considering the mechanisms of drug action and their clinical efficiency.

[Effects of raloxifene combined with conjugated equine estrogen on prothrombotic state in ovariectomized rats]

OBJECTIVE

To study effects of raloxifene (RLX) with different doses of conjugated equine estrogen(CEE) on prothrombotic profiles in the ovariectomized rats model.

METHODS

Total of 32 healthy female SD rats at age of 9 to 10 months were equally divided into every 8 rats at 4 groups randomly. One week after ovariectomized, they were treated by drugs, including control group with placebo(0.9% Nacl intragastric administration), RLX group with RLX 6 mg/(kg·d), RLX and low CEE group with RLX 6 mg/(kg·d) + CEE 0.07 mg/ (kg·d) and RLX and high CEE group with RLX 6 mg/ (kg·d) + CEE 0.5 mg/ (kg·d) for 10 weeks before death. Thrombin turbidimetry method was used to evaluate the plasma fibrinogen(FIB), transmitting substrate method for antithrombin III(ATIII) activity, double-antibody sandwich ELISA for plasminogen activator inhibitor 1 (PAI-1), D-dimer (D-D) and von Willebrand factor (vWF) and nitrate reductase method for nitric oxide(NO).

RESULTS

(1) Coagulation and anticoagulation indicators: it was observed (1.62 ± 0.22) g/L FIB at control group, (2.02 ± 0.54) g/L at RLX group, (1.97 ± 0.16) g/L at RLX and low CEE group, (2.00 ± 0.18) g/L at RLX and high CEE group. There was a statistically significant difference between control group and any one of treatment groups (P < 0.05) and no statistical significance among those three treatment groups (P > 0.05). No significant change was observed in plasma ATIII activity among groups (P > 0.05). (2) Fibrinolytic and anti-fibrinolytic indicators: it was observed (14.1 ± 2.8) µg/L PAI-1 at control group, (20.0 ± 3.3) µg/L at RLX group, (41.5 ± 5.5) µg/L at RLX and low CEE group, (38.9 ± 6.0) µg/L at RLX and high CEE group. A remarkable increase was observed between control group and any one of treatment groups (P < 0.05) . But there was no significant difference of D-D among groups (P > 0.05) . (3) Endothelial function: it was (43 ± 7) % vWF at control group, (49 ± 5) % at RLX group, (46 ± 6) % at RLX and low CEE group, (36 ± 5) % at RLX and high CEE group. The vWF of RLX and high CEE group was the lowest among all groups (P < 0.05) . There was no difference of NO among groups (P > 0.05).

CONCLUSIONS

In the different links of thrombosis, RLX gives different function and may increase the risk. CEE plays a synergism role in the matter of fibrinolysis and anti-fibrinolysis with RLX, further giving rise to thrombosis effect of RLX. And it also has a protective role in the function of vascular endothelium to some extent. But this only works with high dose.

Proliposome powders for enhanced intestinal absorption and bioavailability of raloxifene hydrochloride: effect of surface charge

The primary goal of the present study was to investigate the combined prospective of proliposomes and surface charge for the improved oral delivery of raloxifene hydrochloride (RXH). Keeping this objective, the present systematic study was focused to formulate proliposomes by varying the ratio of hydrogenated soyphosphatidylcholine and cholesterol. Furthermore, to assess the role of surface charge on improved absorption of RXH, anionic and cationic vesicles were prepared using dicetyl phosphate and stearylamine, respectively. The formulations were characterized for size, zeta potential and entrapment efficiency. The improved dissolution characteristics assessed from dissolution efficiency, mean dissolution rate were higher for proliposome formulations. The solid state characterization studies indicate the transformation of native crystalline form of the drug to amorphous and/or molecular state. The higher effective permeability coefficient and fraction absorbed in humans extrapolated from in situ single-pass intestinal absorption study data in rats provide an insight on the potential of proliposomes and cationic surface charge for augment in absorption across gastro intestinal barrier. To draw the conclusions, in vivo pharmacokinetic study carried out in rats indicate a threefold enhancement in the rate and extent of absorption of RXH from cationic proliposome formulation which unfurl the potential of proliposomes and role of cationic charge for improved oral delivery of RXH.

Adherence to raloxifene therapy: assessment methods and relationship with efficacy

Response to therapy depends on patient compliance but accurate assessment is difficult and adequate levels of adherence are uncertain. Adherence to raloxifene treatment may be assessed more accurately by electronic monitoring than by counting returned tablets. The level of adherence is positively associated with the degree of bone response.

INTRODUCTION

Adherence to study medication is usually estimated by counting returned tablets. This method relies on subjects' honesty and may be inaccurate. We aimed to assess adherence more accurately, and examine its effect on measures of bone response, by using electronic monitoring.

METHODS

Osteopenic women, ages 50 to 80, were prescribed daily raloxifene for 2 years. Electronic bottle caps (Medication Event Monitoring System (MEMS), Aardex) recorded the date and time on opening. Returned tablets were also counted. We measured bone mineral density (BMD) in duplicate at the spine and hip at baseline and 2 years. We also measured urinary N-terminal cross-linked telopeptide of type I collagen (NTX) at baseline, 1 and 2 years. We calculated the percentage changes in BMD and NTX from mean baseline to mean follow up measurements. Percentage adherence was assessed by both methods for 71 subjects that completed the study.

RESULTS

The two methods correlated significantly (p <0.001, Spearman's rho = 0.73) but the tablet count showed a higher median adherence than the MEMS caps (95.7 vs. 85.0%, p <0.001), with greater divergence at lower adherence levels. MEMS adherence in 65 subjects with complete data correlated with NTX response (p <0.01, rho = -0.33) but with BMD response only at the femoral neck. However, adherence in the lowest quartile was associated with poorer BMD response at all sites (p <0.05).

CONCLUSION

Tablet counts may give similar results overall but conceal substantial individual non-adherence. Monitoring caps may assess adherence more accurately than tablet counts and would be the preferred method in clinical trials. The degree of adherence is associated with both bone turnover and BMD responses to anti-resorptive therapy.

Raloxifene modifies the insulin sensitivity and lipid profile of postmenopausal insulin resistant women

OBJECTIVE

To investigate the effects of raloxifene on the insulin sensitivity and lipid profile in insulin-sensitive and insulin-resistant postmenopausal women.

STUDY DESIGN

This placebo-controlled, double-blind, randomized study involved 64 postmenopausal women aged between 45 and 55 years. All subjects were screened with the insulin resistance homeostasis model assessment (IR-HOMA) and those patients in the lowest quartile (n = 16) were assigned as insulin sensitive and those in the highest quartile as insulin resistant (n = 16). Patients in both groups received either raloxifene hydrochloride (60 mg/day) or a placebo for a period of 12 weeks. Insulin sensitivity, the serum lipid profile and anthropometric measurements were established before and after therapy.

RESULTS

Women with the highest IR-HOMA scores were associated with a significantly higher weight, body mass index, waist and waist-to-hip ratio (p < 0.05). Raloxifene significantly reduced the IR-HOMA scores from 5.76 ± 2.91 to 1.93 ± 0.96 (p = 0.02) and modified the lipid profile in insulin-resistant patients when compared with the placebo group and those patients receiving raloxifene in the insulin-sensitive group.

CONCLUSION

Raloxifene reduced insulin resistance and modified the lipid profile in insulin-resistant postmenopausal women.

Preventive therapy for breast cancer

Trials with tamoxifen have clearly shown that the risk of developing oestrogen receptor-positive breast cancer can be reduced by at least 50 % with prophylactic agents. The current challenge is to find new agents which achieve this or better efficacy, but with fewer side effects. Recent results indicate that the selective estrogen-receptor modulator (SERM) raloxifene has fewer endometrial cancers, gynaecologic symptoms, and thromboembolic side effects, but is also slightly less efficacious. Results for contralateral tumours in adjuvant trials suggest that aromatase inhibitors may be able to prevent up to 70-80 % of ER-positive breast cancers, and the MAP3 trial has shown to reduce all invasive breast cancer by 65 % in the preventive setting. The IBIS-II trial is currently investigating anastrozole in healthy postmenopausal women. New agents are needed for receptor negative breast cancer and premenopausal women, and several possibilities are currently under investigation.

Combination treatment with eldecalcitol (ED-71) and raloxifene improves bone mechanical strength by suppressing bone turnover and increasing bone mineral density in ovariectomized rats

The aim of this study was to investigate the effect of combination treatment with eldecalcitol (ELD) and raloxifene (RAL) on bone turnover, bone mineral density (BMD), and bone strength. Eight-month-old rats were ovariectomized (OVX) or sham operated, and divided into five groups (Sham, OVX+vehicle, OVX+RAL, OVX+ELD and OVX+ELD+RAL). ELD (7.5 ng/kg) and RAL (0.3mg/kg) were orally administered alone or in combination daily. Urinary deoxypyridinoline (DPD) levels were measured after 4, 8, and 12 weeks of treatment. After 12 weeks of treatment, BMD and mechanical properties of the lumbar spine and femur were assessed, and bone histomorphometry was performed. Urinary DPD levels in all the treatment groups were significantly decreased compared with the OVX+vehicle group. At 4 weeks of treatment, urinary DPD level of the combination group was significantly lower than that of either monotherapy group. The reduction in the BMD of the lumbar spine and femur by OVX was significantly prevented in all the treatment groups, and the BMD in the combination group was significantly higher than that in either monotherapy group. The ultimate load and work to failure of the fifth lumbar vertebra were significantly improved only by the combination treatment. The femoral midshaft ultimate load was significantly increased in the OVX+ELD group and the combination group, and the femoral midshaft work to failure was increased only in the combination group. Bone histomorphometric analysis using the third lumbar vertebra revealed that osteoblast surface (Ob.S/BS), osteoclast surface (Oc.S/BS) and osteoclast number (N.Oc/BS) significantly decreased in all treatment groups, and osteoid surface (OS/BS) and bone formation rate (BFR/BS) significantly decreased in the ELD-treated and combination groups. The values of Ob.S/BS and OS/BS in the combination group were lower than those in either of the monotherapy groups. The bone formation parameters in the combination group were not reduced to below levels of the sham-operated control, suggesting that the combination therapy with ELD and RAL may not cause oversuppression of bone turnover. These results indicated that the combination treatment with ELD and RAL might be a beneficial therapy with respect to their combined effects of enhancing the mechanical properties of trabecular and cortical bone by suppressing bone turnover and increasing BMD more than either monotherapy.

MENOPOST--calcium and vitamin D supplementation in postmenopausal osteoporosis treatment: a descriptive cohort study

SUMMARY

Adequate vitamin D/calcium supplementation during osteoporosis (OP) treatments seems insufficient. This cohort study within a national claims database evaluated calcium/vitamin D co-prescription in postmenopausal women initiating an OP treatment. A high co-prescription rate was observed with three quarters of women supplemented with calcium and/or vitamin D in agreement with current recommendations.

INTRODUCTION

Adequate calcium/vitamin D supplementation should be taken in combination with antiresorptive drugs in OP treatment. Despite guidelines, supplementation appears to be insufficient. The objective of this study was to describe and estimate co-prescription rates of calcium/vitamin D among postmenopausal women initiating an OP treatment.

METHODS

All women over 50 years with a first claim for a bisphosphonates, raloxifene, or strontium prescription filled between May and August 2010 were included in a retrospective cohort study. Data source was the health insurance claims database of the Rhône-Alpes area.

RESULTS

Among 4,415 women, 77.0 % had co-prescription of calcium or vitamin D with initial OP treatment, of which 2,150 (49.7 %) had both calcium and vitamin D. The proportion of women with calcium and/or vitamin D (81.7 %) was significantly higher when OP treatment was a bisphosphonate compared to strontium (70.9 %) or raloxifene (67.0 %) (p < 0.05). Among women prescribed both calcium and vitamin D, 7.6 % received a bisphosphonate and vitamin D ± calcium fixed-combination pack. General practitioners prescribed two thirds of initial supplementation treatment (66.9 %). Patients were twice as likely to be prescribed supplementation when the prescriber was a rheumatologist (OR = 2; 95 % CI = 1.57-2.54).

CONCLUSION

Three quarters of women initiating OP treatment were supplemented with calcium and/or vitamin D in agreement with current recommendations. This represents a high co-prescription rate.

Effects of raloxifene on lipid and bone metabolism in postmenopausal women with type 2 diabetes

Evidence suggests that bone quality is poorer and fracture risk is higher in patients with diabetes, even those with normal bone mineral density. The aim of this study was to determine the effects of raloxifene on lipid, bone, and glucose metabolism in postmenopausal women with type 2 diabetes. The study subjects (144 postmenopausal women aged less than 80 years with type 2 diabetes) were randomly assigned into three groups: no medication, alfacalcidol 1 μg/day, or raloxifene hydrochloride 60 mg/day. The primary endpoint was the change in LDL-C at 6 months. Raloxifene significantly decreased the levels of bone metabolism markers NTX and BAP at 6 months in patients with diabetes. The primary endpoint, LDL-C at 6 months, was significantly lower in the raloxifene group than in the other two groups. However, percent changes in HDL-C were not significantly different among the three groups. Although glucose metabolism was unaffected, homocysteine, a bone quality marker, was significantly decreased at 6 months in the raloxifene group. The percent improvement in LDL-C did not correlate with percent improvement in any bone metabolism or bone quality markers. Raloxifene, unlike estrogen, improved LDL-C and decreased homocysteine, indicating that raloxifene can potentially improve LDL-C as well as bone quality in postmenopausal women with type 2 diabetes.

Positive and negative affect, depression, and cognitive processes in the Cognition in the Study of Tamoxifen and Raloxifene (Co-STAR) Trial

OBJECTIVES

This study examined the relationship between positive and negative affect, depressive symptoms, and cognitive performance.

METHODS

The sample consisted of 1479 non-demented, postmenopausal women (mean age = 67 years) at increased risk of breast cancer enrolled in the National Surgical Adjuvant Breast and Bowel Project's Study of Tamoxifen and Raloxifene. At each annual visit, women completed a standardized neuropsychological battery and self-report measures of affect and depression. Data from three visits were used in linear mixed models for repeated measures using likelihood ratio tests. Separate analyses were performed to relate positive/negative affect and depression to each cognitive measure.

RESULTS

Higher positive affect was associated with better letter fluency (p = .006) and category fluency (p < .0001). Higher negative affect was associated with worse global cognitive function (p < .0001), verbal memory (CVLT List B; p = .002), and spatial ability (p < .0001). Depressive symptoms were negatively associated with verbal knowledge (p = .004), figural memory (p < .0001), and verbal memory (p's ≤ .0001).

DISCUSSION

Findings are consistent with some prior research demonstrating a link between positive affect and increased verbal fluency and between depressive symptoms and decreased memory. The most novel finding shows that negative affect is related to decreased global cognition and visuospatial ability. Overall, this research in a large, longitudinal sample supports the notion that positive affect is related to increases and negative affect to decreases in performance on distinct cognitive measures.

Baseline mammographic breast density and the risk of invasive breast cancer in postmenopausal women participating in the NSABP study of tamoxifen and raloxifene (STAR)

Mammographic breast density is an established risk factor for breast cancer. However, results are inconclusive regarding its use in risk prediction models. The current study evaluated 13,409 postmenopausal participants in the NSABP Study of Tamoxifen and Raloxifene. A measure of breast density as reported on the entry mammogram report was extracted and categorized according to The American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) classifications. An increased risk of invasive breast cancer was associated with higher mammographic breast density (P < 0.001). The association remained significant after adjusting for age, treatment, and smoking history [HR 1.35, 95% confidence interval (CI): 1.16-1.58], as well as when added to a model including the Gail score (HR 1.33, 95% CI: 1.14-1.55). At five years after random assignment, time-dependent area under the curve (AUC) improved from 0.63 for a model with Gail score alone to 0.64 when considering breast density and Gail score. Breast density was also significant when added to an abbreviated model tailored for estrogen receptor-positive breast cancers (P = 0.02). In this study, high BI-RADS breast density was significantly associated with increased breast cancer risk when considered in conjunction with Gail score but provided only slight improvement to the Gail score for predicting the incidence of invasive breast cancer. The BI-RADS breast composition classification system is a quick and readily available method for assessing breast density for risk prediction evaluations; however, its addition to the Gail model does not seem to provide substantial predictability improvements in this population of postmenopausal healthy women at increased risk for breast cancer.

The effects of conjugated estrogen, raloxifene and soy extract on collagen in rat bones

OBJECTIVE

To evaluate the action of conjugated equine estrogen, raloxifene and isolated or combined genistein-rich soy extracts on collagen fibers in the bones of oophorectomized rats.

MATERIALS AND METHODS

Seventy female rats received testosterone propionate (0.1 µg/g) on the 9th day after birth. At 6 months of age, the rats were administered the vehicle (propylene glycol, 0.5 ml/day), and ten of the rats were randomly chosen to comprise the non-oophorectomized control group (GI). The other 60 rats were ovariectomized and randomized into six groups of ten as follows: GII, vehicle; GIII, conjugated equine estrogen (CEE), 50 µg/kg/day; GIV, raloxifene (RAL), 0.75 mg/kg/day; GV, genistein-rich soy extract (GSE), 300 mg/kg/day; GVI, CEE + GSE, 50 µg/kg/day + 300 mg/kg/day; and GVII, CEE + RAL, 50 µg/kg/day + 0.75 mg/kg/day. Three months after surgery, the drugs were administered for 60 consecutive days. All rats were euthanized, and their left tibiae were removed for histological routine. The histological sections were stained with hematoxylin-eosin, and picrosirius for evaluating bone microarchitecture. Types I and II collagen fibers were analyzed by immunofluorescence. Data analysis was carried out with ANOVA and Tukey's test.

RESULTS

Collagen reduction was significant in the GIII animals when compared to the other groups (p < 0.05). There was no significant difference in the thickness of collagen fibers among the groups. There was a greater quantity of type III collagen in GVI than in the other groups.

CONCLUSION

Our data indicate that conjugated equine estrogen improves bone quality because it increases the quantity of type I collagen while reducing the quantity of thin collagen fibers. In addition, the combination of CEE and raloxifene or genistein-rich soy extract is not as efficient as CEE itself to improve bone quality.

Gender difference in the neuroendocrine regulation of growth hormone axis by selective estrogen receptor modulators

CONTEXT

In men, GH secretion is stimulated by estradiol derived locally from aromatization of testosterone. Recently, we showed that local estrogen also plays a major role in the central regulation of GH secretion in women. Tamoxifen and raloxifene are selective estrogen receptor modulators (SERMs), drugs that block central estrogen action but exert estrogen-like effects in the liver, inhibiting hepatic IGF-I production. The relative impact of SERMs on the GH-IGF-I axis in men and women has not been investigated.

OBJECTIVE

The aim of the study was to determine whether there is a gender difference in the impact of SERMs on the GH-IGF-I axis.

DESIGN

We conducted a comparative, randomized, open-label, crossover study of tamoxifen and raloxifene.

PATIENTS AND INTERVENTION

Ten healthy postmenopausal women and ten healthy men were randomized to 2-wk sequential treatment with tamoxifen (10 and 20 mg/d) and raloxifene (60 and 120 mg/d) with a washout of 2 wk between treatments.

MAIN OUTCOME MEASURES

The GH response to arginine, IGF-I, testosterone, and SHBG was measured.

RESULTS

In women, but not in men, tamoxifen significantly attenuated the GH response to arginine. The GH response was not significantly blunted by raloxifene in both sexes. Both SERMs significantly reduced mean IGF-I levels to a similar degree in men and women. In men, both SERMs significantly increased LH and testosterone levels.

CONCLUSIONS

In summary, GH secretion was blunted by tamoxifen in women in the face of reduced IGF-I feedback inhibition but not in men in whom the gonadal axis was stimulated. We conclude that potential blunting of GH secretion in men by SERMs was counteracted by concomitant central stimulation of GH secretion by testosterone. In therapeutic doses, tamoxifen may induce detrimental metabolic effects in women, but not men.

Long-term treatment with raloxifene, but not bisphosphonates, reduces circulating sclerostin levels in postmenopausal women

We determined whether suppression of sclerostin levels by estrogen treatment was mediated by anti-resorptive effect. Raloxifene, but not bisphosphonates, suppressed circulating sclerostin concentration, suggesting that sclerostin may mediate the action of estrogen on bone metabolism, independently of their anti-resorptive effects.

INTRODUCTION

Circulating sclerostin concentrations are higher in postmenopausal than in premenopausal women, and estrogen treatment suppresses sclerostin levels in both men and women. We determined whether anti-resorptives may suppress the circulating sclerostin levels.

METHODS

We conducted a retrospective observational study. Eighty postmenopausal women were treated with raloxifene for 19.4 ± 7.7 months (n = 16), bisphosphonates for 19.2 ± 6.7 months (n = 32), or were untreated (n = 32) for 17.1 ± 4.6 months. Plasma sclerostin concentrations were measured before and after treatment.

RESULTS

Plasma sclerostin levels after treatment were significantly lower in the raloxifene than in the control group (55.8 ± 23.4 pmol/l vs. 92.1 ± 50.4 pmol/l, p = 0.046), but were similar between the bisphosphonate and control groups. Relative to baseline, raloxifene treatment markedly reduced plasma sclerostin concentration (-40.7 ± 22.8%, p < 0.001), with respect to both control (-7.5 ± 29.1%) and bisphosphonate (-3.1 ± 35.2%) groups. Changes in bone-specific alkaline phosphatase and osteocalcin levels showed reverse associations with sclerostin concentration changes in the raloxifene (γ = -0.505, p = 0.017) and control (γ = -0.410, p = 0.020) groups.

CONCLUSIONS

Raloxifene, but not bisphosphonates, significantly suppressed circulating sclerostin concentration, suggesting that sclerostin may mediate the action of estrogen on bone metabolism, independently of their anti-resorptive effects.

Effects of tamoxifen and raloxifene on body and uterine weights of rats in persistent estrus

PURPOSE

To evaluate the change in body and uterine weights of rats in persistent estrus, a model developed to mimic polycystic ovary syndrome treated with selective estrogen receptor modulators (SERMs) tamoxifen and raloxifene.

METHODS

Sixty Wistar-Hannover rats induced by a single subcutaneous dose of 1.25 mg testosterone propionate were divided into three groups of 20 animals: Group I (placebo); Group II (tamoxifen, 250 microg/day) and Group III (raloxifene, 750 microg/day). At 90 days of life, the treatment began for 30 consecutive days, in which the animals were weighed weekly. On the 31st day, the animals were sacrificed and the uterus removed. Data were analyzed statistically by analysis of variance and by the Tukey-Kramer multiple comparisons test (p<0.05).

RESULTS

Means of body and uterine weights (g) after treatment were: 227.3+/-2.20 and 0.40+/-0.01; 185.3+/-2.45 and 0.25+/-0.01; 186.4+/-2.20 and 0.27+/-0.01 in Groups I, II and III, respectively (p<0.001). There was no statistical difference between groups II and III for body and uterine weight (p=0.727 and p=0.646, respectively).

CONCLUSION

The present results indicate that, at the doses and during the time of treatment used, both tamoxifen and raloxifene reduce in a similar way the body and uterine weights of rats in persistent estrus showing a possible antiestrogenic effect of SERMs under high levels of estrogens.