The effects of once-weekly teriparatide on hip structure and biomechanical properties assessed by CT

SUMMARY

Once-weekly administration of 56.5 μg teriparatide improved cortical bone parameters and biomechanical parameters at the proximal femur by CT geometry analysis.

INTRODUCTION

The aim of this study was to evaluate the effects of weekly administration of teriparatide [human PTH (1-34)] on bone geometry, volumetric bone mineral density (vBMD), and parameters of bone strength at the proximal femur which were longitudinally investigated using computed tomography (CT).

METHODS

The subjects were a subgroup of a recent, randomly assigned, double-blind study (578 subjects) comparing the anti-fracture efficacy of a once-weekly subcutaneous injection of 56.5 μg teriparatide with placebo (TOWER trial).

RESULTS

Sixty-six ambulatory postmenopausal women with osteoporosis were enrolled at 15 study sites having multi-detector row CT, and included women injected with teriparatide (n = 29, 74.2 ± 5.1 years) or with placebo (n = 37, 74.8 ± 5.3 years). CT data were obtained at baseline and follow-up scans were performed at 48 and 72 weeks. The data were analyzed to obtain cross-sectional densitometric, geometric, and biomechanical parameters including the section modulus (SM) and buckling ratio (BR) of the femoral neck, inter-trochanter, and femoral shaft. We found that once-weekly teriparatide increased cortical thickness/cross-sectional area (CSA) and total area, and improved biomechanical properties (i.e., decreasing BR) at the femoral neck and shaft. Teriparatide did not change the cortical perimeter.

CONCLUSIONS

Our longitudinal analysis of proximal femur geometry by CT revealed that once-weekly administration of 56.5 μg teriparatide improved cortical bone parameters at the femoral neck and shaft and also improved biomechanical parameters.

Serum 25-hydroxyvitamin D level as an independent determinant of quality of life in osteoporosis with a high risk for fracture

BACKGROUND

Deteriorated quality of life (QOL) is a major problem in osteoporotic women. However, little is known regarding the determinants of QOL in patients with osteoporosis.

OBJECTIVE

Our aim was to explore the role of vitamin D status on QOL score in osteoporosis with high fracture risk.

METHODS

Patients were osteoporotic women aged ≥70 years and with ≥1 risk factor for incident fracture, namely prevalent osteoporotic fracture, bone mineral density (BMD) >-3.0 SD of young adult mean, or high bone turnover marker. Health-related QOL was assessed using the Japanese Osteoporosis Quality of Life Questionnaire (JOQOL). When patients were classified into quartiles by total QOL score). Serum 25-hydroxyvitamin D (25[OH]D) level was measured by immunoassay.

RESULTS

A total of 1585 osteoporotic women were included in the study (age range, 70-95 years). Age, body mass index, serum 25(OH)D status (low, normal, or high), bone mineral density, number of prevalent vertebral fractures, presence of hypertension, presence of osteoarthritis, and history of falls were significantly correlated with QOL quartile. Multivariate liner regression analysis indicated that low serum 25(OH)D level (<20 ng/mL) was an independent determinant of total QOL score quartile (P = 0.0055). The conventional determinants of QOL-age (P < 0.0001), body mass index (P = 0.0060), number of prevalent vertebral fractures (P < 0.0001), presence of osteoarthritis (P = 0.0074), and history of fall (P = 0.0098)-were also independent determinants of total QOL score.

CONCLUSIONS

These results strongly suggest that low serum 25(OH)D level was a significant determinant of QOL in these osteoporotic women, independently of the conventional factors that reduce QOL. Maintenance of serum 25(OH)D levels >20 ng/mL may be required to maintain patients' QOL in osteoporosis.

Effect of the cathepsin K inhibitor odanacatib administered once weekly on bone mineral density in Japanese patients with osteoporosis--a double-blind, randomized, dose-finding study

The efficacy and safety of oral placebo or odanacatib 10, 25, or 50 mg once weekly for 52 weeks were evaluated in a double-blind, randomized, multi-center study in Japanese female and male patients with osteoporosis.

INTRODUCTION

Odanacatib is a selective and reversible cathepsin K inhibitor that decreases bone resorption and increases bone mineral density (BMD).

METHODS

The primary efficacy endpoint was percent change from baseline to week 52 in lumbar spine BMD. Secondary endpoints included percent change in total hip, femoral neck, and trochanter BMD and in bone biomarkers after treatment for 52 weeks.

RESULTS

In this study, 286 patients [94% female, mean age (SD) 68.2 (7.1) years] were included in the analysis. The least-squares mean percent changes from baseline to week 52 in the groups receiving placebo, 10, 25 and 50 mg of odanacatib for lumbar spine (L1~L4) BMD were 0.5, 4.1, 5.7, and 5.9% and for total hip BMD were -0.4, 1.3, 1.8, and 2.7%, respectively. The changes in femoral neck and trochanter BMD were similar to those at the total hip. Bone turnover markers were reduced in a dose-dependent manner. However, the effects of odanacatib on bone formation markers were less compared with the effects on bone resorption markers. Tolerability and safety profiles were similar among all treatment groups with no dose-related trends in any adverse events.

CONCLUSIONS

Weekly odanacatib treatment for 52 weeks increased BMD at the lumbar spine and at all hip sites in a dose-dependent manner and was well tolerated in Japanese patients with osteoporosis.

Polymorphism of SLC25A32, the folate transporter gene, is associated with plasma folate levels and bone fractures in Japanese postmenopausal women

AIM

Elevation of homocysteine is associated with an increased risk for bone fractures. We previously reported that the methylenetetrahydrofolate reductase (MTHFR) gene polymorphism is associated with homocysteine levels and fracture. The association between the fracture and folate levels or their related gene polymorphisms is not completely clear. We speculated that the SLC25A32 gene, the mitochondrial inner membrane folate transporter, also could be implicated in the regulation of folate metabolism and fracture.

METHODS

A total of 851 Japanese postmenopausal women participated in the association study between the single nucleotide polymorphism genotype and plasma homocysteine or folate. We also tested the association between the candidate single nucleotide polymorphism and 663 postmenopausal women.

RESULTS

The AA genotype of rs2241777 single nucleotide polymorphism at the 3'UTR region in the SLC25A32 gene was associated with lower plasma folate concentration compared with the other genotypes in 851 postmenopausal women. A total of 674 postmenopausal ambulatory Japanese women were followed up for 5.5 ± 0.1 years (mean ± SE). The AA genotype groups also showed an apparently higher rate and earlier onset of incident fractures than the other genotypes. A total of 407 participants had >70% young-adult mean bone mineral density at the start of the observation.

CONCLUSIONS

These results show that the SLC25A32 gene polymorphism could be a risk factor for lower folate concentration and future fracture.

Plasma level of homocysteine associated with severe vertebral fracture in postmenopausal women

The aim of this cross-sectional cohort study was to clarify risk factors for severe vertebral fractures in postmenopausal Japanese women. Subjects were ambulatory volunteers age over 50 years who were recruited from a population of outpatients at a primary care institute. At registration, age, body mass index (BMI), bone mineral density (BMD), and present illness were investigated. Biochemical parameters including urinary levels of type I collagen cross-linked N-telopeptides (NTXs), and pentosidine and plasma levels of homocysteine were measured. Values were compared with different fracture grades (grade 0-3). A total of 1,475 postmenopausal women (66.6 ± 9.0 years) were included in the present study. Distributions of vertebral fracture grades were grade 1, 137 cases (9.3 %); grade 2, 124 cases (8.4 %); and grade 3, 162 cases (11.0 %). Age, BMI, BMD, NTX, pentosidine, and homocysteine were significantly associated with vertebral fracture in unadjusted analysis. In addition, a higher prevalence of hypertension was observed in patients with severe fracture. When comparing vertebral fracture grade 0 versus grade 2-3 by multiple regression analysis, pentosidine and homocysteine levels were a significant risk for moderate/severe vertebral fracture (odds ratio [OR] = 1.17, 95 % confidence interval [CI] 1.00-1.38, p = 0.049; OR = 1.22, 95 % CI 1.03-1.46, p = 0.013). Homocysteine levels were also a significant risk when comparing vertebral fracture grade 0 versus grade 3 (OR = 1.27, 95 % CI 1.04-1.58, p = 0.021). Plasma level of homocysteine was an independent risk for severe vertebral fractures.

Number and severity of prevalent vertebral fractures and the risk of subsequent vertebral fractures in Japanese women with osteoporosis: results from the minodronate trial

The aim was to evaluate the risk of new vertebral fractures with the increasing number and severity of prevalent vertebral fractures in women who received placebo or minodronate in a post hoc analysis of a 2-year randomized, double-blind, placebo-controlled study. The subjects were women aged 55-80 years old with 1-5 fragility fractures between the T4 and L4 vertebrae and bone mineral density <80 % of the young adult mean. A total of 704 subjects were randomized to take minodronate 1 mg (n = 359) or placebo (n = 345) once a day for 24 months. In the placebo group, the risk of incident vertebral fractures during the 2-year observational period was significantly related to the number and severity of prevalent vertebral fractures at baseline. The number of prevalent vertebral fractures was an independent risk factor for incident vertebral fracture in multivariate analysis. The relative risk reductions of vertebral fractures by minodronate treatment were 45.2, 61.1, and 64.2 % for patients with 1, 2, and ≥3 prevalent vertebral fractures, respectively, and 87.8, 64.6, and 50.1 % for patients with mild, moderate, and severe prevalent vertebral fractures, respectively. In conclusion, the number of prevalent vertebral fractures is an independent risk factor for incident vertebral fracture and minodronate reduces the fracture risk even in patients at a higher risk for fracture.

Eldecalcitol is more effective for the prevention of osteoporotic fractures than alfacalcidol

Eldecalcitol, a vitamin D3 analogue, significantly reduces the risk of new vertebral fractures and increases bone mineral density (BMD) more than does alfacalcidol. To determine the effect of eldecalcitol on the incidence of all fragility fractures caused by osteoporosis, we conducted post hoc analyses of the phase III clinical trial to evaluate the incidence of the osteoporotic fractures defined in the World Health Organization (WHO) Technical Report, and, also, the incidence of the major osteoporotic fractures utilized in the WHO Fracture Risk Assessment Tool (FRAX), and compared those in the eldecalcitol group with those in the alfacalcidol group. We also analyzed the incidence of osteoporotic fractures stratified by prespecified risk factors for fractures. Eldecalcitol treatment reduced the incidence of osteoporotic fractures defined by the WHO more than alfacalcidol treatment (18.6 % vs. 25.2 %; hazard ratio, 0.70; 95 % CI, 0.54-0.93). Prevalent vertebral fractures, two or more prevalent vertebral fractures, and total hip BMD T score less than -2.5 were the risk factors for new osteoporotic fractures with significant differences between the two treatments. Eldecalcitol also decreased the incidence of major osteoporotic fractures in the FRAX more than alfacalcidol (11.1 % vs. 16.3 %; hazard ratio, 0.66; 95 % CI, 0.46-0.94). In conclusion, treatment with eldecalcitol reduced the risk of fragility fractures caused by osteoporosis compared with alfacalcidol administration, which may result from a potent effect of eldecalcitol on BMD, bone structure, and bone turnover.

Diagnostic criteria for primary osteoporosis: year 2012 revision

In 1995, the Japanese Society for Bone and Mineral Metabolism (now the Japanese Society for Bone and Mineral Research) established the Osteoporosis Diagnostic Criteria Review Committee. Following discussion held at the 13th scientific meeting of the Society in 1996, the Committee, with the consensus of its members, proposed diagnostic criteria for primary osteoporosis. The Committee revised those criteria in 1998 and again in 2000. The Japanese Society for Bone and Mineral Research and Japan Osteoporosis Society Joint Review Committee for the Revision of the Diagnostic Criteria for Primary Osteoporosis aimed at obtaining international consistency and made a revised edition based on the new findings in 2012.

Vertebral fracture risk after once-weekly teriparatide injections: follow-up study of Teriparatide Once-Weekly Efficacy Research (TOWER) trial

OBJECTIVE

To evaluate fracture risk and bone mineral density (BMD) in patients with primary osteoporosis, 1 year after completing 72 weeks of weekly teriparatide injections.

RESEARCH DESIGN AND METHODS

After 72 weeks of teriparatide injections or placebo (original trial), treatment was unblinded and subjects were subsequently treated with bisphosphonates or other therapeutic regimens at the discretion of their physicians and followed for 1 year. Spine radiographs and BMD measurements at the lumbar spine, femoral neck, and total hip by dual energy X-ray absorptiometry were performed.

MAIN OUTCOME MEASURE

Incident vertebral fracture rate.

RESULTS

A total of 465 patients were enrolled and 447 (96.1%) completed the study. In the 1 year follow-up period, new morphometric vertebral fractures occurred in 7/203 (3.4%) in the post-teriparatide group and 33/241 (13.7%) in the post-placebo group (relative risk [RR]: 0.23, 95% confidence interval [CI]: 0.10 to 0.52, P < 0.05). The cumulative incidences from the start of the original trial were 4.9% and 22.8%, respectively (RR: 0.18, 95% CI: 0.09 to 0.36, P < 0.05). There were no significant differences in incidences of vertebral fractures between subsequent therapeutic regimens in the post-teriparatide group. In subjects treated with bisphosphonates, mean BMD values further significantly increased by 9.6%, 2.9%, and 4.1% at the lumbar spine, femoral neck, and total hip, respectively (P < 0.05).

CONCLUSIONS

The reduced risk of vertebral fracture was sustained for 1 year after completion of 72 weeks of weekly teriparatide injections. The effects did not differ between subsequent therapeutic regimens. BMD gains continued with sequential bisphosphonate treatment, but not with the other sequential therapeutic regimens. Bisphosphonates seem to be a useful choice as a subsequent treatment to weekly teriparatide.

LIMITATION

This study was an observational follow-up study and the regimens of subsequent medication after discontinuation of the original TOWER trial were not randomly allocated.

Eldecalcitol reduces the risk of severe vertebral fractures and improves the health-related quality of life in patients with osteoporosis

Eldecalcitol reduces the risk of vertebral fractures in comparison to alfacalcidol in osteoporotic patients under vitamin D repletion. The aim of this study was to evaluate the effects of eldecalcitol on the spinal location of incident vertebral fractures, the severity of the fractures, and the changes in health-related quality of life (HRQOL) compared with those of alfacalcidol. The post hoc analysis has been performed on the data from the three-year, double-blind, randomized, head-to-head clinical trial of eldecalcitol versus alfacalcidol conducted in Japan. A total of 1054 patients were enrolled and randomized to take 0.75 μg eldecalcitol or 1.0 μg alfacalcidol daily for 3 years. The incidence of vertebral fractures was re-evaluated based on the location on the spine (upper T4-T10; lower T11-L4). The severity of vertebral fractures was determined by the semi-quantitative method, and the change in HRQOL was analyzed by using the Medical Outcomes Study Short Form 36-item questionnaire. The incidence of vertebral fracture at the lower spine was less in the eldecalcitol group than in the alfacalcidol group (p = 0.029). The incidence of severe vertebral fracture (Grade 3) was 3.8 % in the eldecalcitol group and 6.7 % in the alfacalcidol group, demonstrated a significant difference between the 2 groups (p = 0.036). Both eldecalcitol and alfacalcidol improved HRQOL in osteoporotic patients. Although no significant differences in each HRQOL scores were observed between eldecalcitol and alfacalcidol during the observational period, overall improvement from baseline of HRQOL scores were clearly observed in the eldecalcitol group. In conclusion, the incidences of lower spinal vertebral fractures and severe vertebral fractures were reduced further by eldecalcitol compared to alfacalcidol in the 3-year clinical trial. Daily treatment with eldecalcitol is effective in improving HRQOL, possibly owing to the reduced risk of lower spinal vertebral fractures and/or severe vertebral fractures.

Overweight/obesity and underweight are both risk factors for osteoporotic fractures at different sites in Japanese postmenopausal women

This cohort study of 1,614 postmenopausal Japanese women followed for 6.7 years showed that overweight/obesity and underweight are both risk factors for fractures at different sites. Fracture risk assessment may be improved if fracture sites are taken into account and BMI is categorized.

INTRODUCTION

The effect of body mass index (BMI) on fracture at a given level of bone mineral density (BMD) is controversial, since varying associations between BMI and fracture sites have been reported.

METHODS

A total of 1,614 postmenopausal Japanese women were followed for 6.7 years in a hospital-based cohort study. Endpoints included incident vertebral, femoral neck, and long-bone fractures. Rate ratios were estimated by Poisson regression models adjusted for age, diabetes mellitus, BMD, prior fracture, back pain, and treatment by estrogen.

RESULTS

Over a mean follow-up period of 6.7 years, a total of 254 clinical and 335 morphometric vertebral fractures, 48 femoral neck fractures, and 159 long-bone fractures were observed. Incidence rates of vertebral fracture in underweight and normal weight women were significantly lower than overweight or obese women by 0.45 (95 % confidence interval: 0.32 to 0.63) and 0.61 (0.50 to 0.74), respectively, if BMD and other risk factors were adjusted, and by 0.66 (0.48 to 0.90) and 0.70 (0.58 to 0.84) if only BMD was not adjusted. Incidence rates of femoral neck and long-bone fractures in the underweight group were higher than the overweight/obese group by 2.15 (0.73 to 6.34) and 1.51 (0.82 to 2.77) and were similar between normal weight and overweight/obesity.

CONCLUSIONS

Overweight/obesity and underweight are both risk factors for fractures at different sites. Fracture risk assessment may be improved if fracture sites are taken into account and BMI is categorized.

Effects of a single injection of teriparatide on bone turnover markers in postmenopausal women

This study investigated the effects of a single administration of teriparatide on bone turnover markers in postmenopausal women. Teriparatide caused a transient increase in bone resorption and inhibition of bone formation followed by a subsequent increase in bone formation and a decrease in resorption that lasted at least 1 week.

INTRODUCTION

This study aims to investigate the effects of a single subcutaneous administration of teriparatide on bone turnover markers to elucidate why once weekly intermittent administration of teriparatide is effective on osteoporosis.

METHODS

Pharmacokinetics and calcium metabolism and bone turnover parameters were measured in 30 postmenopausal women after two doses of teriparatide (28.2 or 56.5 μg injection) or placebo in a randomized, double-blind, placebo-controlled study.

RESULTS

Teriparatide plasma concentration increased in a dose-dependent manner, and the maximum concentration was achieved 1 h after injection. Serum levels of calcium and phosphorus were transiently increased and decreased after teriparatide injection, respectively. Calcium metabolism returned to baseline levels 24 h later. Two days after injection, the serum level of 1,25-dihydroxy vitamin D was increased by ~80 % from baseline for both doses of teriparatide. Serum levels of osteocalcin and procollagen type I N-terminal propeptide decreased during the first 24 h followed by a ~10 % increase for 14 days. The serum level of cross-linked N-telopeptide (NTX) of type I collagen increased during the first 24 h followed by a 10 to 12 % dose-dependent suppression from baseline for 14 days. Urinary cross-linked C-telopeptide of type I collagen changes occurred in the same direction as serum NTX, but not dose dependently.

CONCLUSION

A single administration of teriparatide caused an immediate, transient increase in bone resorption and inhibited bone formation followed by an increase in bone formation and decrease in resorption for ≥1 week. These findings may provide proof for the effect of a once-weekly regimen of teriparatide on bone turnover.

Guidelines for the use of bone metabolic markers in the diagnosis and treatment of osteoporosis (2012 edition)

Recently the clinical application of bone metabolic markers has achieved significant progress and the measurements of these indices give us a better understanding of the pathogenesis of osteoporosis. Bone metabolic markers were adapted to select drug treatment for osteoporosis and to evaluate drug efficacy. Therefore, the proper application and assessment of bone metabolic markers in clinical practice is very important. To achieve these aims, the committee on the guidelines for the use of biochemical markers of bone turnover in osteoporosis authorized by the Japan Osteoporosis Society has summarized recent progress in bone markers and proposed the proper utilization of bone markers. Although the use of bone metabolic markers now has an important role in the daily management of osteoporosis, their use in Japan is still insufficient because of insurance coverage limitations. Since the Japan Osteoporosis Society first created the 2001 guidelines, new bone metabolic markers have been introduced into clinical practice. The availability of new osteoporosis treatments that promote bone formation has changed the clinical application of bone metabolic markers in current practice. Therefore, revisions to the current clinical practice are needed which led to the proposal to create these new 2012 guidelines.

The importance of absolute bone mineral density in the assessment of antiresorptive agents used for the prevention of osteoporotic fractures

The usefulness of bone mineral density (BMD) monitoring during antiresorptive treatment is still controversial. This study aimed to determine which factors of change (absolute value or the percent change from the baseline) in BMD are associated with the risk of future fractures. A total of 565 postmenopausal osteoporosis who were treated antiresorptive drugs were included in this prospective observational study. Lumbar BMD (LBMD) was measured at baseline and 1-yr after the initial and subsequent incident fracture was observed. The percent changes in LBMD at 1 yr were 5.4 ± 6.4% and 118 (20.9%) achieved increased LBMD with change of classification to >-2.5 standard deviation (SD). After the initial 1-yr examination, incident fractures developed in 152 (26.9%). The incident fracture risk was significantly associated with the absolute value in LBMD, but not with the percent change. A Cox proportional hazard model demonstrated that increased LBMD with change of classification to >-2.5 SD was a significant predictor for a reduction in incident fractures (hazard ratio: 0.41, 95% confidence interval: 0.21-0.71). In conclusion, these results suggest that monitoring of the antifracture efficacy of antiresorptive treatments should be based on the absolute value of BMD. In particular, increased change to >-2.5 SD is important for reducing the future fracture risk.

Randomized Teriparatide [human parathyroid hormone (PTH) 1-34] Once-Weekly Efficacy Research (TOWER) trial for examining the reduction in new vertebral fractures in subjects with primary osteoporosis and high fracture risk

CONTEXT

Weekly teriparatide injection at a dose of 56.5 μg has been shown to increase bone mineral density.

OBJECTIVE

A phase 3 study was conducted to determine the efficacy of once-weekly teriparatide injection for reducing the incidence of vertebral fractures in patients with osteoporosis.

DESIGN AND SETTING

In this randomized, multicenter, double-blind, placebo-controlled trial conducted in Japan, the incidence of morphological vertebral fractures by radiographs was assessed.

PATIENTS

Subjects were 578 Japanese patients between the ages of 65 and 95 yr who had prevalent vertebral fracture.

INTERVENTION

Subjects were randomly assigned to receive once-weekly s.c. injections of teriparatide (56.5 μg) or placebo for 72 wk.

MAIN OUTCOME MEASURE

The primary endpoint was the incidence of new vertebral fracture.

RESULTS

Once-weekly injections of teriparatide reduced the risk of new vertebral fracture with a cumulative incidence of 3.1% in the teriparatide group, compared with 14.5% in the placebo group (P < 0.01), and a relative risk of 0.20 (95% confidence interval, 0.09 to 0.45). At 72 wk, teriparatide administration increased bone mineral density by 6.4, 3.0, and 2.3% at the lumbar spine, the total hip, and the femoral neck, respectively, compared with the placebo (P < 0.01). Adverse events (AE) and the dropout rates by AE were more frequently experienced in the teriparatide group, but AE were generally mild and tolerable.

CONCLUSION

Weekly s.c. administration of teriparatide at a dose of 56.5 μg may provide another option of anabolic treatments in patients with osteoporosis at higher fracture risk.

Eldecalcitol normalizes bone turnover markers regardless of their pre-treatment levels

BACKGROUND

Three-year treatment with eldecalcitol has been shown to improve lumbar and total hip bone mineral density (BMD), decrease bone turnover markers, and lower the incidences of vertebral and wrist fractures in patients with osteoporosis more than with treatment with alfacalcidol under vitamin D repletion. The purpose of this study was to determine whether there was a risk of eldecalcitol causing severely suppressed bone turnover in osteoporosis patients with low pre-treatment levels of bone turnover markers.

METHODS AND RESULTS

Post-hoc analysis was conducted on the data from a 3-year, randomized, double-blind, active-comparator, clinical trial of eldecalcitol versus alfacalcidol under vitamin D repletion conducted in Japan. Enrolled patients with baseline measurements of bone turnover markers were stratified into tertiles according to their pre-treatment levels of serum bone-specific alkaline phosphatase, serum procollagen type I N-terminal propeptide, or urinary collagen-N-telopeptide. Eldecalcitol treatment rapidly reduced bone turnover markers, and kept them within the normal range. However, in the patients whose baseline values for bone turnover were low, eldecalcitol treatment did not further reduce bone turnover markers during the 3-year treatment period. Further long-term observation may be required to reach the conclusion. CLINICALTRIALS.GOV NUMBER: NCT00144456.

CONCLUSIONS

Eldecalcitol normalizes, but does not overly suppress, bone turnover regardless of baseline levels of bone turnover markers. Thus, it is unlikely that eldecalcitol treatment will increase the risk of severely suppressed bone turnover and therefore deterioration of bone quality, at least for a treatment duration of 3 years.

Association of circulating sclerostin levels with fat mass and metabolic disease--related markers in Japanese postmenopausal women

CONTEXT

Wnt/β-catenin signaling is related to the pathogenesis of osteoporosis, diabetes, and metabolic diseases. Sclerostin is an inhibitor of Wnt/β-catenin signaling. However, there are few data regarding the relationship between sclerostin levels and metabolic disease.

OBJECTIVE

This study aimed to identify the relationship between serum sclerostin levels, body composition markers, and the markers of metabolic disease.

DESIGN, SETTING, AND PATIENTS

The present study is a cross-sectional study. We measured serum sclerostin levels in 352 Japanese postmenopausal women and analyzed the relationship of these levels with bone mineral density, abdominal fat mass, and biochemical markers. The mean (sd) age of the subjects was 65.5 (9.3) yr.

RESULTS

Serum sclerostin levels were positively correlated with percentages of abdominal and gynoid fat. We also analyzed the association between serum sclerostin levels and biochemical markers related to metabolic diseases. Multivariate analysis revealed that the serum sclerostin levels were significantly correlated with the levels of low-density lipoprotein cholesterol and homocysteine.

CONCLUSIONS

The circulating sclerostin levels were associated with fat mass. The circulating sclerostin levels were also correlated with low-density lipoprotein cholesterol and homocysteine.

A multicenter randomized double-masked comparative study of different preparations of alendronate in osteoporosis - monthly (four weeks) intravenous versus once weekly oral administrations

OBJECTIVE

The aim of this study was to evaluate the efficacy and safety of intravenous alendronate (ALN) 900 µg every 4 weeks compared to oral ALN 35 mg once weekly.

METHODS

A 52-week, multicenter, randomized, double-masked, active-controlled, parallel-group, non-inferiority study was conducted in a total of 325 Japanese patients aged 48-87 years with osteoporosis. Patients were randomly assigned to an intravenous ALN (iv, n = 162) group or oral ALN (po, n = 163) group. The efficacy of the both formulations was assessed primarily by bone mineral density (BMD) measurement.

RESULTS

The percentage BMD change from baseline in lumbar spine (L2-L4) after 52 weeks of treatment was 6.4 ± 0.3% in the iv group and 6.0 ± 0.3% in the po group (least-squares mean ± SE). The inter-group difference in least-squares mean of percentage change from baseline in BMD was 0.37%, and its 95% confidence interval was -0.47% to 1.20%. The non-inferiority of the iv group was established against the po group with a prespecified non-inferiority margin (Δ) of 1.5%. In addition, the four bone turnover markers were reduced to a similar level by either treatment throughout the treatment period. The safety profile was also similar between the two treatment groups. Because of the limitations presented in this study, the results of the iv group may not apply to non-Japanese patients with osteoporosis.

CONCLUSIONS

The efficacy and safety of the intravenous ALN 900 µg once every 4 weeks were similar to those of the oral ALN 35 mg once weekly, indicating that intravenous administration of ALN is an effective treatment for osteoporosis and will provide a useful alternative to oral dosing.

Three years of treatment with minodronate in patients with postmenopausal osteoporosis

The objective of this study was to determine the safety and efficacy of long-term minodronate treatment in women with postmenopausal osteoporosis based on re-analysis of a phase III 2-year clinical trial with a 1-year extension. Women aged 55-80 years old with fragility fractures were enrolled and randomized to take 1 mg minodronate or placebo once a day in the original 2-year study. The subjects who completed the 2-year study were invited to participate in an additional 1-year extension in which all subjects were to receive minodronate. Finally, a total 380 subjects completed the extension study (186 from the placebo group and 194 from the minodronate group). Fracture results observed in the extension study were consistent with those observed in the first 2 years in minodronate group. In contrast, the placebo/minodronate group showed a decreased incidence of new vertebral fractures during year 3 compared to that in year 2. In the patients who received minodronate in the original 2-year study, lumbar bone mineral density (BMD) increased consistently during year 3 and bone turnover markers decreased within the first 6 months and remained constant thereafter over 3 years. Similar positive effects of minodronate on BMD and bone turnover markers occurred when therapy was initiated in the placebo/minodronate group. No new safety concerns observed during the extension period compared to the safety observations made during the 2-year study. It was concluded that daily administration of 1 mg oral minodronate is safe and well tolerated, and that the efficacy of this dose in reducing vertebral fracture risk in postmenopausal women over 2 years is sustained with continuing treatment.

Efficacy and safety of monthly oral minodronate in patients with involutional osteoporosis

Monthly minodronate at 30 or 50 mg had similar efficacy as 1 mg daily in terms of change in bone mineral density (BMD) and bone turnover markers with similar safety profiles. This new regimen provides patients with a new option for taking minodronate.

INTRODUCTION

Minodronate at a daily oral dose of 1 mg has been proven to have antivertebral fracture efficacy. In the present study, the efficacy and safety of oral minodronate at monthly doses of either 30 mg or 50 mg were compared with a daily dose of 1 mg.

METHODS

A total of 692 patients with involutional osteoporosis were randomized to receive minodronate at either 30 or 50 mg monthly or a daily dose of 1 mg. The primary endpoint was the percent change from baseline in lumbar spine (LS) BMD at 12 months. Total hip BMD, bone turnover markers, serum calcium (Ca), and parathyroid hormone (PTH) levels were also evaluated.

RESULTS

Minodronate at monthly doses of 30 or 50 mg were noninferior to the 1 mg daily dose in terms of change in LS-BMD. Changes in total hip BMD were also comparable. Although a transient decrease in serum Ca and increase in PTH levels were observed in all three groups at slightly different magnitudes and time courses, changes in bone turnover markers were comparable among the different dosage groups with a similar time course. Safety profiles were also comparable.

CONCLUSION

Minodronate at monthly doses of 30 or 50 mg has similar efficacy to the daily 1 mg dose in terms of BMD and bone turnover markers with similar tolerability.

GPR98/Gpr98 gene is involved in the regulation of human and mouse bone mineral density

CONTEXT

Genetic factors are important in the development of osteoporosis.

OBJECTIVE

The aim of this study was to search for novel genes that regulate bone mineral density (BMD).

DESIGN

We performed a search for 57,244 single-nucleotide polymorphisms (SNP) associated with BMD using SNP arrays and a replication study.

SETTING AND PATIENTS

Baseline examinations were conducted in Japanese postmenopausal women. The mean (sd) age of the subjects was 66.5 (8.4) yr. We chose five SNP associated with BMD as those having lower combined P values between the first-stage (n = 251) and the second-stage (n = 499) analyses than the value determined by Bonferroni's correction. We also analyzed the bone-related phenotypes in knockout mice of a candidate gene.

RESULTS

We focused on an SNP of G protein-coupled receptor 98 (GPR98) gene that showed a significant P value after the multiple-comparison tests in Japanese postmenopausal women. The subjects with one or two risk SNP (GG and AG genotype groups) had an increased risk of fractures (AA vs. GG + AG; P = 0.043). Femoral BMD was significantly lower in 12-wk-old Gpr98-knockout mice than in wild-type mice. A three-point bending test revealed that this morphological phenotype did in fact correlate with mechanical fragility in Gpr98-knockout mice. Compared with primary wild-type osteoblasts, primary Gpr98-deficient osteoblasts had increased Rankl expression and induced activity for osteoclastogenesis and osteoclastic function.

CONCLUSIONS

Genetic analyses in both human and mouse models uncovered the importance of the GPR98 gene in the regulation of bone metabolism.