Study of twice-weekly injections of Teriparatide by comparing efficacy with once-weekly injections in osteoporosis patients: the TWICE study.

A 48-week, multicenter, randomized, double-blind, double-dummy, active-controlled, non-inferiority trial (the TWICE study) conducted in Japanese primary osteoporosis patients with a high risk of fractures demonstrated that a 28.2-µg twice-weekly regimen of teriparatide can provide comparable efficacy to a 56.5-µg once-weekly regimen of teriparatide, while also improving safety. INTRODUCTION: While a 56.5-µg once-weekly regimen of teriparatide has high efficacy for osteoporosis, treatment continuation rates are low, with one of the major causes being adverse drug reactions such as nausea or vomiting. The TWICE study was therefore conducted to investigate whether a twice-weekly regimen with 28.2-µg teriparatide can provide comparable efficacy to the 56.5-µg once-weekly regimen while improving safety. METHODS: A 48-week, multicenter, randomized, double-blind, double-dummy, active-controlled, non-inferiority trial was conducted in Japan. Patients with primary osteoporosis aged ≥ 65 years at high risk of fractures (n = 553) were randomly allocated to the 28.2-µg twice-weekly group (n = 277) or the 56.5-µg once-weekly group (n = 276). The primary endpoint was the percentage change in lumbar spine (L2-L4) bone mineral density (BMD) at final follow-up. RESULTS: The percentage changes in lumbar spine (L2-L4) BMD at final follow-up in the 28.2-µg twice-weekly and 56.5-µg once-weekly groups were 7.3% and 5.9%, respectively; the difference (95% confidence interval [CI]) in percentage change was 1.3% (0.400-2.283%). Since the lower limit of the 95% CI was above the pre-specified non-inferiority margin (- 1.6%), non-inferiority of the 28.2-µg twice-weekly group was demonstrated. Adverse drug reactions were significantly less frequent in the 28.2-µg twice-weekly group (39.7% vs 56.2%; p < 0.01); the incidence of major adverse drug reactions was lower, and the number of subjects who discontinued due to adverse drug reactions was less in the 28.2-µg twice-weekly group. CONCLUSIONS: A 28.2-µg twice-weekly regimen of teriparatide can provide comparable efficacy to a 56.5-µg once-weekly regimen while improving safety. CLINICAL TRIAL REGISTRATION: JapicCTI-163477 .

Multiple vitamin deficiencies additively increase the risk of incident fractures in Japanese postmenopausal women.

The associations of multiple vitamin deficiencies on incident fractures were uncertain, the relationships between serum vitamin markers and incident bone fractures were investigated in Japanese postmenopausal women. The number of deficiencies was additively associated with incident fracture after adjustment for possible confounding factors including the treatment of osteoporosis. INTRODUCTION: To evaluate the associations of multiple vitamin deficiencies on incident fractures, the relationships between serum vitamin markers and incident bone fractures were investigated in Japanese postmenopausal women. METHODS: This analysis used a subset of the ongoing cohort maintained by a primary care institution. Inclusion criteria of the present study were postmenopausal women aged ≥ 50 years, without vitamin supplementation and secondary osteoporosis. Baseline serum concentrations of 25-hydroxyvitamin D (25(OH)D), undercarboxylated osteocalcin (ucOC), and homocysteine (Hcy) were measured to assess vitamin D, vitamin K, and vitamin B, respectively. Since 25(OH) D positively relates to vitamin D, ucOC and Hcy negatively relate to vitamin K and vitamin B nutrients, respectively, the subjects with lower (25(OH)D) or higher (ucOC or Hcy) values than each median value was defined as subjects with the corresponding vitamin deficiency. Subjects were divided into four groups according to the number of deficiency: no deficiency, single deficiency, double deficiencies, and triple deficiencies. Relationships between the vitamin deficiencies and incident fractures were evaluated by Cox regression analysis. RESULTS: A total of 889 subjects were included in this analysis; their mean and SD age was 68.3 ± 9.5 years, and the follow-up period was 6.3 ± 5.1 years. The numbers of subjects in the four groups were 139 (15.6%), 304 (34.2%), 316 (35.5%), and 130 (14.6%) for the groups with no, single, double, and triple deficiencies, respectively. Incident fractures were observed in 264 subjects (29.7%) during the observation period. The number of deficiencies was significantly associated with incident fracture (hazard ratio 1.25, 95% confidence interval 1.04-1.50, P = 0.018) after adjustment for possible confounding factors including the treatment of osteoporosis. CONCLUSION: Accumulation of vitamin deficiencies was related to incident fractures.

Correction to: Stimulation of intestinal calcium absorption by orally administrated vitamin D3 compounds: a prospective open-label randomized trial in osteoporosis.

There were two errors in this article. 1. In the section "Ethical considerations", the registration number of the study was incorrectly given as UMIN000024492. The correct number is UMIN0000 20267. 2. The Acknowledgments paragraph was incomplete.

Modeling and simulation of bone mineral density in Japanese osteoporosis patients treated with zoledronic acid using tartrate-resistant acid phosphatase 5b, a bone resorption marker.

Annual intravenous administration of zoledronic acid is used in the treatment of osteoporosis. A mathematical model was developed to predict bone mineral density up to 2 years after two annual doses of zoledronic acid from the early values of a bone resorption marker in osteoporosis patients. INTRODUCTION: The measurement of bone mineral density (BMD) has been used as a surrogate marker instead of the observation of incident fractures to detect the efficacy of treatment. However, this method requires a long time to obtain significant changes. On the other hand, bone resorption markers respond to bone resorption inhibitors within a few weeks. Therefore, the aim of this study was to develop a mathematical model predicting long-term BMD after two annual doses of zoledronic acid (ZOL) using the early response of a bone resorption marker in osteoporosis patients. METHODS: The model was constructed using 3410 tartrate-resistant acid phosphatase 5b (TRACP-5b) serum concentrations and 1146 lumbar spine (L2-L4) BMD values from 306 patients with primary osteoporosis. A mathematical model was developed to describe the time-dependent profiles of TRACP-5b and BMD. RESULTS: The percentage changes from baseline of the BMD (%BMD) at up to 2 years were predicted from patients' baseline BMD and baseline and 12-week TRACP-5b values by the model obtained. The simulated 90% prediction interval almost covered the observed %BMD distribution at each time point, and the predictions were comparable to the observed %BMD. CONCLUSIONS: This is the first model to predict BMD for up to 2 years following two annual doses of ZOL using patients' background characteristics and the early response of TRACP-5b. This model allows us to inform patients at the initial stage of ZOL treatment of their predicted response to treatment.

Stimulation of intestinal calcium absorption by orally administrated vitamin D3 compounds: a prospective open-label randomized trial in osteoporosis.

Intestinal fractional calcium absorption (FCA) was assessed before and after vitamin D3 treatment. Serum 1,25(OH)2D concentration was significantly increased by plain vitamin D3 and reduced by eldecalcitol. The 1α hydroxyl calcidiol and eldecalcitol treatments increased FCA, which may be induced through direct stimulation of vitamin D receptors in the intestine. INTRODUCTION: To assess the effects of vitamin D3 compounds on intestinal FCA and calcium-regulating hormones in post-menopausal osteoporosis, a randomized open-label prospective study was conducted. METHODS: Forty eligible patients were allocated randomly into four groups: eldecalcitol (ELD; 0.75 µg/day), 1α hydroxyl calcidiol (ALF; 1 µg/day), plain vitamin D3 (800 IU/day), and control. Before and after the 4-week treatment, intestinal FCA was estimated by using a double isotope method, and serum concentrations of calcium-regulating hormones and a bone turnover marker were measured. RESULTS: The baseline FCA value of the participants was 21.5 ± 7.9% (mean ± SD) and was significantly correlated with serum 1,25(OH)2D (calcitriol) concentration. After the treatment, the FCA significantly increased by 59.5% (95% CI, 41.6 to 77.4%) in the ELD group and by 45.9% (27.9 to 63.8%) in the ALF group, whereas no significant change in the plain vitamin D3 group was found. Unlike the baseline FCA, post-treatment FCA exhibited no significant correlation with serum calcitriol concentration. Parathyroid hormone levels were suppressed by ALF and plain vitamin D3 but were sustained in the ELD and control groups. Serum calcitriol tended to be suppressed by ELD, whereas plain vitamin D3 treatment increased both serum 25(OH)D and calcitriol concentrations. CONCLUSION: These findings suggest that oral administration of vitamin D3 analogues (ALF and ELD) stimulates FCA but plain vitamin D3 does not. Those effects of vitamin D3 compounds on FCA were independent of serum calcitriol concentration, suggesting that ALF and ELD may directly stimulate intestinal vitamin D receptors.

Restrictive pulmonary dysfunction is associated with vertebral fractures and bone loss in elderly postmenopausal women.

Association between lung function and bone metabolism remains controversial. We found that impaired lung function was associated with vertebral fractures and bone loss in Japanese postmenopausal women. While vertebral deformities would impair lung function, respiratory dysfunction might in turn increase fracture risk, suggesting a complex bidirectional interaction. INTRODUCTION: Association between bone metabolism and pulmonary function in the general population is controversial. The aim of this study was to investigate relationship between lung and bone parameters in elderly postmenopausal women. METHODS: One hundred and six postmenopausal women (75.6 ± 8.0 years old) who underwent spirometric tests were examined for prevalent vertebral fractures, bone mineral density (BMD), bone metabolic markers, and other metabolic indices such as urinary pentosidine. RESULTS: Multivariable logistic regression analyses revealed that forced vital capacity (FVC) (OR = 0.063, 95% CI: 0.011-0.352, p = 0.002) and urinary pentosidine (OR = 1.067, 95% CI: 1.020-1.117, p = 0.005) were associated with the presence of vertebral fractures after adjustment for height loss, age, and BMD at femoral neck. Moreover, vital capacity (VC) or FVC as well as body mass index and age was among independent determinants of BMD after adjustment for height loss and the number and grade of vertebral fractures in forced multiple linear regression analysis (VC: ß = 0.212, p = 0.021, FVC: ß = 0.217, p = 0.031). Urinary pentosidine was negatively correlated with pulmonary function parameters such as FVC and forced expiratory volume in 1 s (FEV1.0), although these correlations appeared dependent on age. CONCLUSIONS: Diminished FVC was associated with prevalent vertebral fractures and decreased BMD in Japanese postmenopausal women without apparent pulmonary diseases. Mechanism of such association between pulmonary function and bone status remains to be determined.

Intake of omega-3 fatty acids contributes to bone mineral density at the hip in a younger Japanese female population.

This study investigated the relationships between intakes of polyunsaturated fatty acids, omega-3 fatty acids, and omega-6 fatty acids and bone mineral density in Japanese women aged 19 to 25 years. Intakes of omega-3 fatty acids (n-3) were positively associated with peak bone mass at the hip. INTRODUCTION: Lifestyle factors such as physical activity and nutrition intake are known to optimize the peak bone mass (PBM). Recently, intake of polyunsaturated fatty acids (PUFAs) has been reported to contribute to bone metabolism. In this study, the relationships of intakes of n-3 and omega-6 (n-6) fatty acids with PBM were evaluated in Japanese female subjects. METHODS: A total of 275 healthy female subjects (19-25 years) having PBM were enrolled, and lumbar and total hip bone mineral density (BMD) and bone metabolic parameters were measured. Dietary intakes of total energy, total n-3 fatty acids, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and total n-6 fatty acids were assessed by a self-administered questionnaire. Physical activity information was also assessed. RESULTS: The mean ± SD age was 20.6 ± 1.4 years, and BMI was 21.2 ± 2.7 kg/m2. BMI and serum bone alkaline phosphatase contributed significantly to lumbar BMD on multiple regression analysis. Intake of n-3 fatty acids and physical activity were also significantly related to total hip BMD. Using EPA or DHA instead of total n-3 fatty acids in the model did not result in a significant result. CONCLUSION: Adequate total n-3 fatty acid intake may help maximize PBM at the hip.

Health state utility values and patient-reported outcomes before and after vertebral and non-vertebral fractures in an osteoporosis clinical trial.

We assessed the health state utility value (HSUV) reductions associated with vertebral fractures using data collected in the Japanese Osteoporosis Intervention Trial-03 (JOINT-03). Our analysis revealed that assessment of HSUVs after morphometric vertebral fracture is important to capture the burden of vertebral fractures. INTRODUCTION: Evaluation of the HSUV after fracture is important to calculate the quality-adjusted life years (QALYs) of osteoporosis patients, which is essential information in the context of health economic evaluation. METHODS: JOINT-03 study patients were aged ≥65 years and treated with risedronate and vitamin K2 or risedronate alone. Radiographic information and patient-reported outcomes measured by EQ-5D and a visual analogue scale (VAS) were assessed at registration and followed up after 6, 12, and 24 months. According to differences among the dates of these assessments and the radiographic information, we classified the follow-up HSUVs calculated based on EQ-5D results into before or after fracture categories regardless of clinical symptoms. RESULTS: Among 2922 follow-up HSUVs, 201 HSUVs were categorized as HSUVs that were observed after incident vertebral fractures on X-ray films. The median time from the detection of an incident vertebral fracture until the EQ-5D assessment was 53 days (25th percentile, 0 day; 75th percentile, 357 days). The impact of incident vertebral fractures on HSUVs was quantified as -0.03. Among the five health profile domains on the EQ-5D, an incident vertebral fracture had significant effects on anxiety/depression, self-care, and usual activities. CONCLUSIONS: The results suggest that incident morphometric vertebral fracture was associated with impairment of the HSUV for patients with osteoporosis not only immediately but also several months after the fracture.

Efficacy and safety of once-yearly zoledronic acid in Japanese patients with primary osteoporosis: two-year results from a randomized placebo-controlled double-blind study (ZOledroNate treatment in Efficacy to osteoporosis; ZONE study).

In a 2-year randomized, placebo-controlled study of 665 Japanese patients with primary osteoporosis, once-yearly administration of zoledronic acid (5 mg) reduced the risk of new morphometric vertebral fractures. INTRODUCTION: The purpose of this study was to determine the efficacy and safety of once-yearly intravenous infusion of ZOL in Japanese patients with primary osteoporosis. METHODS: This was a two-year multicenter, randomized, placebo-controlled, double-blind, parallel-group comparative study (ZONE Study). Subjects were 665 Japanese patients between the ages of 65 and 89 years who had prevalent vertebral fracture. Subjects were randomly assigned to receive once-yearly intravenous infusion of 5 mg of ZOL or placebo at baseline and 12 months. RESULTS: The 2-year incidence of new morphometric vertebral fracture was 3.0 % (10/330 subjects) in the ZOL group and 8.9 % (29/327) in the placebo group (p = 0.0016). The 24-month cumulative incidence of new morphometric vertebral fracture was 3.3 % in the ZOL group versus 9.7 % in the placebo group (log-rank test: p = 0.0029; hazard ratio: 0.35; 95 % confidence interval: 0.17-0.72). The cumulative incidence of any clinical fracture, clinical vertebral fracture, and non-vertebral fracture was significantly reduced in the ZOL group by 54, 70, and 45 %, respectively, compared to the placebo group. At 24 months, ZOL administration increased bone mineral density in the lumbar spine, femoral neck, and total hip (t test: p < 0.0001). No new adverse events or osteonecrosis of the jaw were observed in this study. CONCLUSIONS: Once-yearly administration of ZOL 5 mg to Japanese patients with primary osteoporosis reduced the risk of new morphometric vertebral fractures and was found to be safe.

Treatment responses with once-weekly teriparatide therapy for osteoporosis.

UNLABELLED: Monitoring bone mineral density is useful to assess treatment response for osteoporosis, but it does not always reflect fracture prevention. Two types of bone mineral density thresholds were used to analyze data from a once-weekly teriparatide trial, and they appear to be useful indicators of treatment success for osteoporosis. INTRODUCTION: This study aimed to clarify whether the criteria of treatment response could be used to evaluate treatment success with once-weekly teriparatide. METHODS: The data of subjects whose lumbar or femoral neck bone mineral density (BMD) was measured in the TOWER study were included. The least significant change (LSC) and the absolute change were used as the criteria for judgment of treatment success. The correlation between the incidence of fractures and the treatment response was also assessed. RESULTS: There was no significant difference in baseline characteristics between the placebo and teriparatide groups. Once-weekly teriparatide therapy for 72 weeks showed treatment success in 79.2 % of the subjects for lumbar BMD and 44.1 % for femoral neck BMD by LSC and in 50.5 and 39.6 % by absolute change, respectively. A lower incidence of vertebral fracture was observed in patients who achieved treatment success for lumbar BMD. With the LSC, some treatment success was observed in the early phase of treatment, and it increased with treatment duration. CONCLUSIONS: It appears that the LSC could be used as a surrogate efficacy indicator at an earlier stage of treatment, and the absolute criterion of -2.5SD was confirmed as a useful marker of long-term treatment success.

Efficacy of weekly teriparatide does not vary by baseline fracture probability calculated using FRAX.

UNLABELLED: The aim of this study was to determine the efficacy of once-weekly teriparatide as a function of baseline fracture risk. Treatment with once-weekly teriparatide was associated with a statistically significant 79 % decrease in vertebral fractures, and in the cohort as a whole, efficacy was not related to baseline fracture risk. INTRODUCTION: Previous studies have suggested that the efficacy of some interventions may be greater in the segment of the population at highest fracture risk as assessed by the FRAX® algorithms. The aim of the present study was to determine whether the antifracture efficacy of weekly teriparatide was dependent on the magnitude of fracture risk. METHODS: Baseline fracture probabilities (using FRAX) were computed from the primary data of a phase 3 study (TOWER) of the effects of weekly teriparatide in 542 men and postmenopausal women with osteoporosis. The outcome variable comprised morphometric vertebral fractures. Interactions between fracture probability and efficacy were explored by Poisson regression. RESULTS: The 10-year probability of major osteoporotic fractures (without BMD) ranged from 7.2 to 42.2 %. FRAX-based hip fracture probabilities ranged from 0.9 to 29.3 %. Treatment with teriparatide was associated with a 79 % (95 % CI 52-91 %) decrease in vertebral fractures assessed by semiquantitative morphometry. Relative risk reductions for the effect of teriparatide on the fracture outcome did not change significantly across the range of fracture probabilities (p = 0.28). In a subgroup analysis of 346 (64 %) participants who had FRAX probabilities calculated with the inclusion of BMD, there was a small but significant interaction (p = 0.028) between efficacy and baseline fracture probability such that high fracture probabilities were associated with lower efficacy. CONCLUSION: Weekly teriparatide significantly decreased the risk of morphometric vertebral fractures in men and postmenopausal women with osteoporosis. Overall, the efficacy of teriparatide was not dependent on the level of fracture risk assessed by FRAX in the cohort as a whole.

Three-year denosumab treatment in postmenopausal Japanese women and men with osteoporosis: results from a 1-year open-label extension of the Denosumab Fracture Intervention Randomized Placebo Controlled Trial (DIRECT).

SUMMARY: A 12-month extension phase of DIRECT in Japanese subjects with osteoporosis showed that total 3 years of denosumab treatment in Japanese postmenopausal women and men with osteoporosis was associated with low fracture rates, persistent bone turnover marker (BTM) reductions, continuous bone mineral density (BMD) increases, and a favorable overall benefit/risk profile. INTRODUCTION: The DIRECT trial demonstrated that 2 years of treatment with denosumab 60 mg subcutaneously every 6 months significantly reduced the incidence of vertebral fracture compared to placebo in Japanese postmenopausal women and men with osteoporosis. The purpose of this study is to evaluate the efficacy and safety of denosumab treatment for up to 3 years. METHODS: This study includes a 2-year randomized, double-blind, placebo-controlled phase and a 1-year open-label extension phase in which all subjects received denosumab. The data correspond to 3 years of denosumab treatment in subjects who received denosumab (long-term group) and 1 year of denosumab treatment in subjects who received placebo (cross-over group) in the double-blind phase. RESULTS: Eight hundred and ten subjects who completed the double-blind phase enrolled into the extension phase, and 775 subjects completed the study. All subjects received denosumab with daily supplements of calcium and vitamin D. The cumulative 36-month incidences of new or worsening vertebral fractures and new vertebral fractures were 3.8 and 2.5 %, respectively, in the long-term group. In this group, the BMD continued to increase, and the reduction in BTMs was maintained. In the cross-over group, comparable BMD increases and BTMs reductions to those of in their first year of the long-term group were confirmed. Adverse events did not show a notable increase with long-term denosumab administration. One event of osteonecrosis of the jaw occurred in the cross-over group. CONCLUSIONS: Three-year denosumab treatment in Japanese subjects with osteoporosis showed a favorable benefit/risk profile.

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.

UNLABELLED: 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.

Profile of changes in bone turnover markers during once-weekly teriparatide administration for 24 weeks in postmenopausal women with osteoporosis.

SUMMARY: Changes in bone turnover markers with weekly 56.5 µg teriparatide injections for 24 weeks were investigated in women with osteoporosis. Changes in bone turnover markers 24 h after each injection of teriparatide were constant. During the 24 week period, bone formation markers increased and baseline bone resorption marker levels were maintained. INTRODUCTION: This study aimed to clarify the changes in bone turnover markers during 24 weeks of once-weekly teriparatide injections in postmenopausal women with osteoporosis. METHODS: The 24 h changes in pharmacokinetics (PK), calcium metabolism, and bone turnover markers (serum osteocalcin, procollagen type I N-terminal propeptide (P1NP), urinary cross-linked N-telopeptide of type I collagen (NTX), deoxypiridinoline (DPD)) after each injection of 56.5 µg teriparatide at the data collection weeks (0, 4, 12, and 24 weeks) were investigated. The changes were evaluated by comparison with the data at 0 h in each data collection week. RESULTS: Similar 24 h changes in each parameter after injection of teriparatide were observed in each data collection week. Serum calcium increased transiently, and intact PTH decreased 4-8 h after injection; serum calcium subsequently returned to baseline levels. Calcium and intact PTH levels decreased for 24 weeks. Although serum osteocalcin decreased at 24 h, it was significantly increased at 4 weeks. P1NP decreased transiently and then increased significantly at 24 h. P1NP was significantly increased at 4 weeks. Urinary NTX and DPD were significantly increased transiently and then decreased at 24 h. The urinary DPD level decreased significantly at 4 weeks. CONCLUSIONS: Twenty-four hour changes in PK, calcium metabolism, and bone turnover markers showed the same direction and level after once-weekly teriparatide injections for 24 weeks, with no attenuation of the effect over time. After 24 weeks, the bone formation marker, serum osteocalcin, increased significantly, but the serum P1NP, did not. Bone resorption markers decreased or remained the same.

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.

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

UNLABELLED: 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.

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

UNLABELLED: 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.