Preventive effects of raloxifene treatment on agerelated weight loss in postmenopausal women

Decline of body weight and body mass index (BMI) with aging is a major risk factor for osteoporosis and fracture, suggesting that treatment for osteoporosis may affect body composition. However, the effects of treatment for osteoporosis on body composition are not well known. The present study aimed to identify the relationship between raloxifene treatment and body composition markers. We measured bone mineral density (BMD), body composition, and bone remodeling markers in 236 Japanese postmenopausal women with raloxifene treatment (N = 50) and without treatment by any osteoporosis drug (N = 186) for 5 years and analyzed the relationship of these with BMD, BMI, body weight, and biochemical markers. The mean (SD) age of the participants was 65.5 (9.3) years. Percent-changes in body weight and BMI were significantly different between women taking raloxifene and those not taking any osteoporosis drugs (P = 0.03 and 0.048, respectively). Raloxifene treatment was a significant independent determinant of body weight and BMI. Long-term treatment with raloxifene prevents age-related weight loss.

Recent nutritional trends of calcium and vitamin D in East Asia

Calcium intake may play an important role on bone health. The recent national nutritional survey in Japan revealed the gradual decrease in calcium intake to around 480 mg/day. In addition, the patients with low level of vitamin D become too large in proportion. The present perspective proposes to increase calcium intake in Asian population.

Treatment responses with once-weekly teriparatide therapy for osteoporosis

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.

Lack of cooperation between physicians and dentists during osteoporosis treatment may increase fractures and osteonecrosis of the jaw

OBJECTIVE

Our previous questionnaire-based survey suggested that discontinuation of antiresorptive agents before tooth extraction may increase adverse events and disturb osteoporosis treatment without completely preventing osteonecrosis of the jaw (O.N.J.). We also found little cooperation between physicians and dentists in Japan. However, limitations of our previous study included a survey of doctors belonging to small clinics and a small sample size. Our current study aimed to confirm the results of our previous survey in doctors mainly belonging to academia.

METHODS

A structured questionnaire including 14 key clinical queries was sent to 1812 physicians of the Japan Osteoporosis Society, and 629 responses were received.

RESULTS

Dentists requested discontinuation of many medications that were not associated with the incidence of O.N.J. A total of 523 respondents had received discontinuation requests from dentists. Of these, 97 respondents experienced 119 adverse events including 25 fractures and seven incidences of O.N.J. The ratios of valid responses for fractures were 3.6% and 5.3% in patients with a discontinuation of <3 and ≥3 months, respectively. Those for O.N.J. were 0.7% and 1.6%, respectively. Respondents who refused discontinuation requests reported no cases of O.N.J. Approximately 17% of respondents had patients who discontinued osteoporosis treatment following a requested drug discontinuation after tooth extraction. Approximately 62% of respondents did not request oral health care by a dentist before antiresorptive therapy, and 72% reported no cooperation between physicians and dentists in their region.

CONCLUSIONS

This study reconfirms the results of our previous survey. Discontinuation of antiresorptive treatment may increase both fractures and O.N.J. Immediate development of a strategy for sharing information about O.N.J. among physicians, dentists, and patients is required to reduce the incidence of both O.N.J. and skeletal events in osteoporosis treatment. Study limitations were selection bias due to low response rate and possible inaccurate responses to the questionnaire.

Renal Phosphate Reabsorption is Correlated with the Increase in Lumbar Bone Mineral Density in Patients Receiving Once-Weekly Teriparatide

In order to assess the changes in serum calcium and phosphate and the changes in renal tubular phosphate reabsorption (TmP/GFR) and to evaluate the association between these indices and the increase in bone mineral density (BMD) with once-weekly intermittent administration of teriparatide (TPTD), the results from the teriparatide once-weekly efficacy research (TOWER) trial were re-analyzed. The TOWER trial studied postmenopausal women and older men with osteoporosis. Patients were randomly assigned to receive TPTD 56.5 μg or placebo for 72 weeks. Of these patients, the present study investigated those whose calcium and phosphate levels and lumbar BMD (L-BMD) were measured (TPTD group, n = 153 and Placebo group, n = 137). The TPTD group had significantly lower serum phosphate, calcium-phosphate product, and TmP/GFR at weeks 4, 24, 48, and 72 and urinary fractional calcium excretion (FECa) at weeks 12, 48, and 72 (p < 0.05). In the TPTD group, the serum phosphate and TmP/GFR during early treatment (4, and 12 weeks) showed a significant positive correlation with the percent change in L-BMD at weeks 48 and 72. Based on multivariate analysis corrected for age, BMI, and L-BMD at the start of treatment, serum phosphate and TmP/GFR at week 4 showed a significant correlation with the percent change in L-BMD. This study suggests that the L-BMD response to once-weekly long-term TPTD treatment is associated with circulating phosphate or with the status of its renal reabsorption. Preventing decrease in serum phosphate levels may be important in acquiring greater L-BMD with once-weekly TPTD.

Impact of Osteonecrosis of the Jaw on Osteoporosis Treatment in Japan: Results of a Questionnaire-Based Survey by the Adequate Treatment of Osteoporosis (A-TOP) Research Group

Dentists request a discontinuation of antiresorptive agents, such as bisphosphonate, before and after tooth extractions to prevent osteonecrosis of the jaw (ONJ). However, little is known about how this affects ONJ and osteoporosis treatment and how medical professionals and dentists cooperate to treat ONJ in patients with osteoporosis. This study aimed to clarify the impact of ONJ on osteoporosis treatment in Japan. A structured questionnaire including 14 key clinical queries was sent to 488 medical professionals as part of the Japanese Osteoporosis Intervention Trial (JOINT)-04, and 206 responses were received. A total of 173 respondents had received discontinuation requests from dentists. Of these, 28 respondents experienced 30 adverse events including ten fractures and one incidence of ONJ. The respondents who refused discontinuation requests observed no cases of ONJ. Approximately 16 % of respondents had patients who discontinued osteoporosis treatment, following a requested drug discontinuation, after tooth extraction. Dentists requested discontinuations for many medications that were not associated with the incidence of ONJ. Approximately 76 % of respondents had never requested oral health care from dentists before osteoporosis treatment and 72 % reported no cooperation between dentists and medical professionals in their region. Our results suggest that drug discontinuation may increase adverse events and disturb osteoporosis treatment without completely preventing ONJ. Currently, both medical professionals and dentists in Japan still continue to recommend their own treatment position. A forum to share information about ONJ among medical professionals, dentists, and patients is required.

Comparison of expert and nonexpert physicians in the assessment of vertebral fractures using the semiquantitative method in Japan

Assessment of vertebral fracture is critically important for the diagnosis and treatment of osteoporosis. This study aimed to clarify the effectiveness of the semiquantitative (SQ) method in the assessment of vertebral fractures in Japanese clinical practice. Forty-four physicians (seven experts and 37 nonexperts) assessed the spinal radiographs of 40 patients participating in the Adequate Treatment of Osteoporosis (A-TOP) Japanese Osteoporosis Intervention Trial (JOINT)-02 at the baseline, 12 months, and 24 months using the SQ method. The proportion of diagnosed fracture cases per spine was higher in the nonexpert group than in the expert group at each time point, and was especially high in the upper thoracic spine (T4-T6). The least mean squares spinal fracture index was significantly higher in the nonexpert group than in the expert group for all time points. The kappa statistics were also higher in the expert group than in the nonexpert group for all vertebral levels at all time points. Assessment of vertebral fractures using the SQ method tended to be overestimated by nonexpert physicians compared with the experts, with poor nonexpert interobserver reliability and well-matched expert interobserver reliability. Conscious efforts to avoid overestimation and to obtain higher reliability with the SQ method should be made to achieve more precise diagnoses and treatment of osteoporosis in Japanese clinical practice.

[Health benefits and demerits of calcium nutrition or supplementation in older people]

The benefit of calcium nutrition for health has been believed for a long time. In fact, higher calcium intake is associated with reduction of blood pressure, rate of bone loss after menopause and mild risk reduction of fracture. Since calcium intake from food has not been achieved to be the recommended level, calcium supplementation is widely used especially in the US. However, calcium supplementation has been reported to increase in vascular events, recently. On the other hand, calcium nutrition from foods have not been reported any harmful effect on health. Therefore, calcium effects on health seemed to be composite effects of other nutrients taking together with calcium.

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

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.

SLC25A24 as a novel susceptibility gene for low fat mass in humans and mice

CONTEXT

Genetic factors contribute to the development of obesity.

OBJECTIVE

The aim of this study was to identify novel genes that regulate body fat mass.

DESIGN

We performed a search for single nucleotide polymorphisms (SNPs) associated with body fat percentage using SNP arrays and undertook a replication study and animal study.

SETTING AND PATIENTS

Baseline examinations were conducted in 251 (first-stage analysis), 499 (second-stage analysis), and 732 (additional analyses) Japanese postmenopausal women. The mean age (mean ± SD) of the subjects was 66.5 ± 9.4 years. We also analyzed the fat-related phenotypes of a candidate gene in knockout mice.

RESULTS

In the analysis of total body fat, we focused on an SNP of SLC25A24 that showed the lowest significant P value obtained from multiple comparison tests among Japanese postmenopausal women. A significant association was also found between SLC25A24 SNPs and body mass index in the 1482 Japanese postmenopausal women examined in the study. The SLC25A24 SNPs affected the mRNA expression of SLC25A24 in human preadipocytes. Compared with wild-type mice, Slc25a24-KO mice had significantly lower body weights and white adipose tissue weights. Adipocyte differentiation was inhibited in Slc25a24-KO adipose tissues and Slc25a24-knockdown adipocytes.

CONCLUSIONS

Genetic analyses in human and mouse models revealed the importance of SLC25A24/Slc25a24 in the regulation of body fat mass and adipogenesis.

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.

New simulation model for bone formation markers in osteoporosis patients treated with once-weekly teriparatide

Daily 20-μg and once-weekly 56.5-μg teriparatide (parathyroid hormone 1–34) treatment regimens increase bone mineral density (BMD) and prevent fractures, but changes in bone turnover markers differ between the two regimens. The aim of the present study was to explain changes in bone turnover markers using once-weekly teriparatide with a simulation model. Temporary increases in bone formation markers and subsequent decreases were observed during once-weekly teriparatide treatment for 72 weeks. These observations support the hypothesis that repeated weekly teriparatide administration stimulates bone remodeling, replacing old bone with new bone and leading to a reduction in the active remodeling surface. A simulation model was developed based on the iterative remodeling cycle that occurs on residual old bone. An increase in bone formation and a subsequent decrease were observed in the preliminary simulation. For each fitted time point, the predicted value was compared to the absolute values of the bone formation and resorption markers and lumbar BMD. The simulation model strongly matched actual changes in bone turnover markers and BMD. This simulation model indicates increased bone formation marker levels in the early stage and a subsequent decrease. It is therefore concluded that remodeling-based bone formation persisted during the entire treatment period with once-weekly teriparatide.

Serum 25-hydroxyvitamin D below 25 ng/mL is a risk factor for long bone fracture comparable to bone mineral density in Japanese postmenopausal women

There is emergent evidence for divergent associations between 25(OH)D levels and fractures by race and ethnicity, but data on Asian populations are sparse. We investigated this association in a primary care cohort of 1470 postmenopausal Japanese women followed for a mean period of 7.2 years and explored a potential threshold of 25(OH)D. Endpoints were incident vertebral, proximal femur, and long bone fractures. Rate ratios were estimated using multivariate Poisson regression adjusted for lumbar or femur bone mineral density (BMD) less than -2.5 SD of the young adult mean (YAM), age, weight, presence of diabetes mellitus, parathyroid hormone, estimated glomerular filtration rate, prior fracture, back pain, present medications and past medical history. Mean age was 63.7 ± 10.7 years and osteoporosis patients were 41.3 %. The background data of the present participants were almost identical to the subjects participating in the National Health and Nutrition Survey of 2003. Overall, 49.6 % of the subjects had a 25(OH)D value <20 ng/mL and 27.8 % had a 25(OH)D value from 20 to 24 ng/mL. The propensity score for exposure to 25(OH)D < 25 ng/mL in the present and independent community dwelling populations, namely the Miyama and Taiji cohorts, were not significantly different, suggesting no evidence for selection bias. The generalized additive models showed clear decreasing trends in incidence rates of proximal femur and long bone fractures at higher levels of 25(OH)D, and the annual incidence rate of proximal femur fracture was around 0.0005 in women with 25(OH)D > 25 ng/mL, probably leading to the decreasing trend in long bone fracture. Multivariate-adjusted rate ratios of 25(OH)D < 25 ng/mL were 1.01 (95 % confidence interval [CI], 0.84-1.22, p = 0.88) for vertebral fracture, 2.71 (95 % CI 0.94-7.83, p = 0.07) for proximal femur fracture, and 2.20 (95 % CI 1.37-3.53, p < 0.01) for long bone fracture. The respective rate ratios of a BMD level lower than -2.5 SD of the YAM were 1.61 (95 % CI 1.33-1.94, p < 0.01), 1.52 (95 % CI 0.67-3.45, p = 0.32), and 1.54 (95 % CI 1.02-2.33, p = 0.04). In conclusion, 25(OH)D is a leading risk factor for long bone fracture comparable to BMD in Japanese postmenopausal women. The contribution of 25(OH)D to fracture risks is substantial even below 25 ng/mL and is possibly site-specific. We recommend measuring the serum 25(OH)D level in primary care settings.

Large-scale analysis reveals a functional single-nucleotide polymorphism in the 5'-flanking region of PRDM16 gene associated with lean body mass

Genetic factors are important for the development of sarcopenia, a geriatric disorder characterized by low lean body mass. The aim of this study was to search for novel genes that regulate lean body mass in humans. We performed a large-scale search for 250K single-nucleotide polymorphisms (SNPs) associated with bone mineral density (BMD) using SNP arrays in 1081 Japanese postmenopausal women. We focused on an SNP (rs12409277) located in the 5′-flanking region of the PRDM16 (PRD1-BF-1-RIZ1 homologous domain containing protein 16) gene that showed a significant P value in our screening. We demonstrated that PRDM16 gene polymorphisms were significantly associated with total body BMD in 1081 postmenopausal Japanese women. The rs12409277 SNP affected the transcriptional activity of PRDM16. The subjects with one or two minor allele(s) had a higher lean body mass than the subjects with two major alleles. Genetic analyses uncovered the importance of the PRDM16 gene in the regulation of lean body mass.

The effects of once-weekly teriparatide on hip geometry assessed by hip structural analysis in postmenopausal osteoporotic women with high fracture risk

Weekly administration of teriparatide has been shown to reduce the risk of vertebral and non-vertebral fractures in patients with osteoporosis at higher fracture risk in Japan. However, its efficacy for hip fracture has not been established. To gain insight into the effect of weekly teriparatide on the hip, hip structural analysis (HSA) based on dual-energy X-ray absorptiometry (DXA) was performed using the data of 209 postmenopausal osteoporotic women who had participated in the original randomized, multicenter, double-blind, placebo-controlled trial assessing the effects of once-weekly 56.5 μg teriparatide for 72 weeks. The DXA scans, obtained at baseline, 48 weeks and 72 weeks, were analyzed to extract bone mineral density (BMD) and cross-sectional geometrical indices at the narrowest point on the neck (NN), the intertrochanteric region (IT), and the proximal shaft. Compared with placebo after 72 weeks, the teriparatide group showed significantly higher BMD, average cortical thickness, bone cross-sectional area, and section modulus, and lower buckling ratio at both the NN and IT regions. No significant expansion of periosteal diameter was observed at these regions. There were no significant differences in BMD and HSA indices at the shaft region. The results indicate that overall structural strength in the proximal femur increased compared to placebo, suggesting that once-weekly teriparatide effectively reverses changes in hip geometry and strength with aging.

Once-weekly teriparatide reduces the risk of vertebral fracture in patients with various fracture risks: subgroup analysis of the Teriparatide Once-Weekly Efficacy Research (TOWER) trial

Once-weekly teriparatide (human parathyroid hormone [1-34]) (56.5 μg for 72 weeks) injections provided a vertebral fracture risk reduction in Japanese osteoporotic patients evaluated in the Teriparatide Once-Weekly Efficacy Research (TOWER) trial. Using data from the TOWER trial, a subgroup analysis was performed to study the efficacy of once-weekly teriparatide for a variety of baseline clinical risk factors in placebo (n = 281) and teriparatide (n = 261) groups. Significant fracture risk reductions were observed in the subgroups of individuals aged <75 years [relative risk (RR) 0.06, p = 0.007] and ≥75 years (RR 0.32, p = 0.015). A significant risk reduction was observed among patients with prevalent vertebral fracture in the subgroup with 1 (RR 0.08, p = 0.015) or ≥2 (RR 0.29, p = 0.009) prevalent vertebral fractures, and in those with grade 3 deformity (RR 0.26, p = 0.003). Significant risk reduction was observed in the subgroup with lumbar bone mineral density (BMD) < -2.5 SD (RR 0.25, p = 0.035). In the teriparatide group, no incident fracture was observed in the subgroups with a prevalent vertebral fracture number of 0, with grade 0-2 vertebral deformity, or with lumbar BMD ≥2.5 SD. Significant risk reduction was observed in all of the bone turnover marker and estimated glomerular filtration rate subgroups. In conclusion, once-weekly 56.5 μg teriparatide injection reduced the vertebral fracture risk in patients with varying degrees of fracture risk, age, vertebral fracture number and grade, bone turnover level, and renal function.

Clinical Trials Express: fracture risk reduction with denosumab in Japanese postmenopausal women and men with osteoporosis: denosumab fracture intervention randomized placebo controlled trial (DIRECT)

CONTEXT

Denosumab 60 mg sc injection every 6 months for 36 months was well tolerated and effective in reducing the incidence of vertebral, nonvertebral, and hip fracture in predominantly Caucasian postmenopausal women with osteoporosis.

OBJECTIVE

The objective of this phase 3 fracture study was to examine the antifracture efficacy and safety of denosumab 60 mg in Japanese women and men with osteoporosis compared with placebo.

DESIGN AND SETTING

A randomized, double-blind, placebo-controlled trial with an open-label active comparator as a referential arm was conducted.

PATIENTS

Subjects were 1262 Japanese patients with osteoporosis aged 50 years or older, who had one to four prevalent vertebral fractures.

INTERVENTION

Subjects were randomly assigned to receive denosumab 60 mg sc every 6 months (n = 500), placebo for denosumab (n = 511), or oral alendronate 35 mg weekly (n = 251). All subjects received daily supplements of calcium and vitamin D.

MAIN OUTCOME MEASURE

The primary endpoint was the 24-month incidence of new or worsening vertebral fracture for denosumab vs placebo.

RESULTS

Denosumab significantly reduced the risk of new or worsening vertebral fracture by 65.7%, with incidences of 3.6% in denosumab and 10.3% in placebo at 24 months (hazard ratio 0.343; 95% confidence interval 0.194-0.606, P = .0001). No apparent difference in adverse events was found between denosumab and placebo during the first 24 months of the study.

CONCLUSION

These results provide evidence of the efficacy and safety of denosumab 60 mg sc every 6 months in Japanese subjects with osteoporosis.

Design of a randomized clinical trial of concurrent treatment with vitamin K2 and risedronate compared to risedronate alone in osteoporotic patients: Japanese Osteoporosis Intervention Trial-03 (JOINT-03)

Concurrent treatments with bisphosphonates and vitamin K are promising given that bisphosphonates possibly interfere with vitamin K activation. This is a prospective, multi-center, open-labeled, randomized trial of the efficacy of concurrent treatment with vitamin K2 and risedronate compared with risedronate alone and to explore subsets of patients for which concurrent treatment is particularly efficacious (trial identification number UMIN000000991). Inclusion criteria are women who meet the criteria for pharmacological therapy for osteoporosis, aged ≥65 years, have any of pre-specified risk factors, can walk unassisted, and are able to answer questionnaires. Exclusion criteria are prior warfarin use, secondary osteoporosis or non-osteoporotic metabolic bone diseases, contraindication for vitamin K2 and risedronate, hyper- or hypoparathyroidism, mental disorders, prevalent vertebral fracture at ≥6 sites, severe degenerative spinal deformation between T4 and L4, serious heart, liver, or kidney disease, or bisphosphonate use within the previous 6 months. Patients were recruited from 123 institutes between January 2008 and February 2010, and allocated to vitamin K2 (45 mg/day) and risedronate (2.5 mg/day or 17.5 mg/week) or risedronate alone (2.5 mg/day or 17.5 mg/week) groups. Primary endpoint is a vertebral or non-vertebral fracture. Secondary endpoints are bone mineral density, height, undercarboxylated osteocalcin, JOQOL, EQ-5D and safety. A sample size of 910 subjects per group and 2-year follow-up will provide 80 % power to detect 35 % risk reduction for fracture, with a two-sided significance level of 5 %. Subgroup analysis stratified to adjustment factors for random allocation, body mass index, 25-hydroxyvitamin D, estimated glomerular filtration rate, grade of vertebral fracture, JOQOL, EQ-5D, and co-morbidity is pre-specified.

Changes in bone mineral density, bone turnover markers, and vertebral fracture risk reduction with once weekly teriparatide

OBJECTIVE

We aimed to evaluate the surrogacy of bone mineral density and bone turnover markers for incident vertebral fracture using data from 237 patients treated with once weekly 56.5 μg teriparatide or placebo.

METHODS

This analysis was conducted using data from the Teriparatide Once-Weekly Efficacy Research trial, a randomized, double-blind, placebo-controlled trial for patients with severe osteoporosis in Japan. A total of 237 subjects (placebo group, n = 130; teriparatide group, n = 107) were assessed at baseline and at 72 weeks. Main outcome measures included estimation of the treatment effects of once weekly teriparatide on vertebral fracture risk reduction using percentage changes in lumbar bone mineral density and bone turnover markers.

RESULTS

The percentage change in lumbar bone mineral density was 6.69% in the teriparatide group compared with 0.28% in the placebo group (p < 0.01). One incident vertebral fracture occurred in the teriparatide group compared with 16 in the placebo group. The unadjusted and adjusted hazard ratios of the teriparatide group compared with the placebo group were 0.07 (95% confidence interval: 0.01 to 0.56) and 0.64 (95% confidence interval: 0.06 to 6.36), respectively. The proportion of treatment effect explained by changes in lumbar bone mineral density was 83% (Freedman's method) and 66% (Chen's method). There were no notable changes in hazard ratios if we adjusted for bone turnover markers.

CONCLUSIONS

Most of the vertebral fracture risk reduction with once weekly 56.5 μg teriparatide is explained by changes in lumbar bone mineral density rather than changes in bone turnover markers.

Low calcium intake is associated with high plasma homocysteine levels in postmenopausal women

Nutritional interventions targeting homocysteine remain controversial, and further nutritional research is warranted. We thus sought to explore the determinants of plasma homocysteine other than B-group vitamins. This cross-sectional study surveyed the nutritional status of 713 Japanese postmenopausal women using a semiquantitative food frequency questionnaire. Associations between total energy, protein, fat, carbohydrate, and vitamin A and K intakes and homocysteine were insignificant. Mean homocysteine in the second (536.1 ± 34.7 mg/day) and third (712.9 ± 115.6 mg/day) tertiles of calcium intake were lower than in the first tertile (379.6 ± 76.6 mg/day) by -0.57 nmol/mL (95 % confidence interval, -1.10 to-0.04, p = 0.04) and -1.18 nmol/mL (-1.76 to -0.60, p<0.01), respectively, after adjustment for lifestyle and clinical factors (trend p\0.01). Mean homocysteine in those with dietary calcium intake above the median (>536 mg/day) were lower regardless of the folic acid concentration; the differences were -1.59 nmol/mL (-2.33 to -0.85, p = 0.02) and -0.75 nmol/mL (-1.37 to-0.12, p<0.01) for the high (<7.8 ng/mL) and low folic acid groups, respectively. There was no significant association between calcium and folic acid (p = 0.08). In conclusion, further prospective research to confirm our findings is needed for the development of nutritional inventions targeting homocysteine.

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.