Dose-response study of denosumab on bone mineral density and bone turnover markers in Japanese postmenopausal women with osteoporosis

The efficacy and safety of denosumab were evaluated in Japanese postmenopausal women with osteoporosis. Total hip and distal 1/3 radius bone mineral densities (BMDs) were increased, and lumbar spine BMD was increased in magnitude with increasing dose. Bone turnover markers significantly decreased compared with placebo. Denosumab was well tolerated in Japanese subjects.

INTRODUCTION

The efficacy and safety of three doses of denosumab were compared with a placebo over 12 months in Japanese postmenopausal women with osteoporosis.

METHODS

In this phase 2 multicenter, randomized, placebo-controlled study, 226 subjects were randomized and 212 subjects received at least 1 dose of investigational product, subcutaneously. All subjects also received daily supplements of at least 600 mg elemental calcium and 400 IU vitamin D from the beginning of screening through 12 months of treatment.

RESULTS

Compared with placebo, denosumab (14, 60, and 100 mg) showed significant increases in percent BMD values of lumbar spine (5.25, 6.27, and 7.00) and total hip (3.90, 3.69, and 4.35) from baseline in 12 months. Distal 1/3 radius BMD was also significantly increased except at the 100-mg dose (1.82, 1.35, and 1.15). Denosumab significantly decreased the serum C-terminal crosslinking telopeptide of type 1 collagen and urinary N-terminal crosslinking telopeptide of type I collagen/urinary creatinine levels in 8 days, and bone alkaline phosphatase in 3 months. No new vertebral fracture was observed on spinal radiographs in either group. The overall incidences of adverse events were similar in the denosumab groups and the placebo group. No subject developed antibodies to denosumab. These results were similar to those obtained in the US phase 2 study.

CONCLUSIONS

Denosumab 60 mg could be an effective dose for Japanese postmenopausal women with osteoporosis as was shown in the Caucasian population.

Risk factors for infantile atopic dermatitis and recurrent wheezing

BACKGROUND

The pathogenic mechanisms of atopic dermatitis (AD) and recurrent wheezing (RW) during infancy are not fully understood.

OBJECTIVE

We evaluated immunological markers associated with AD and RW during infancy.

METHODS

We followed a cohort (n = 314) from birth to 14 months of age. Some of the participants underwent a physical examination and blood test at 6 and 14 months of age. Univariate and multivariate logistic regression analysis and receiver operating characteristic curve analysis were performed to find which immunological markers could be risk factors for AD and RW.

RESULTS

Of 16 immunological markers found in cord blood, only immunoglobulin (Ig) E was associated with AD at 6 months of age (adjusted OR [aOR], 1.607). None of the markers was associated with AD or RW at 14 months of age. Of 23 immunological markers at 6 months of age, total IgE (aOR, 1.018) and sensitization to egg white (aOR, 23.246) were associated with AD at 14 months of age. Phytohemagglutinin (PHA)-induced production of interleukin (IL) 4 from peripheral blood mononuclear cells (PBMCs) (aOR, 1.043) was associated with RW at 14 months of age.

CONCLUSION

Cord blood IgE was a risk factor for AD at 6 months of age. Total IgE and sensitization to egg white at 6 months of age were risk factors for AD at 14 months of age. PHA-induced IL-4 production in PBMCs at 6 months of age was a risk factor for RW at 14 months of age.

Urinary pentosidine improves risk classification using fracture risk assessment tools for postmenopausal women

We investigated whether measurement of pentosidine, in addition to the conventional risk assessment tool, the Fracture and Immobilization Score (FRISC), improves early identification of fracture cases. A total of 765 postmenopausal Japanese women with baseline measurement of urinary pentosidine were followed in a hospital-based cohort study. Endpoints were incidence of vertebral fracture, incidence of long bone fracture, and incidence of long bone and vertebral fracture. To assess the effect of pentosidine on fracture risk, we fitted multivariate Cox regression models adjusted for age, body weight, diabetes mellitus, lumbar BMD, prior fracture, and presence of back pain. To explore potential nonlinear relationships, we fitted a multivariate generalized additive model. To assess the discriminatory power of pentosidine, we performed receiver operating characteristic analysis. The hazard ratios for a 1 SD increase in pentosidine were 1.18 (95% CI 1.05-1.33, p < 0.01) for vertebral fracture and 1.20 (95% CI 1.07-1.33, p < 0.01) for long bone and vertebral fractures. The relationship was approximately linear, and there was no indication of the presence of a threshold. The C statistics were 0.732 (95% CI 0.686-0.778) for the model with both pentosidine and the 10-year risk and 0.702 (95% CI 0.654-0.750) for the 10-year risk alone. Eighty-three subjects (11%) in the whole cohort were in the highest quartile of pentosidine, although their 10-year risks were less than 15% and included 17 incident vertebral fracture cases. Urinary pentosidine improves risk classification using conventional risk assessment tools. Optimal clinical strategies of diagnosis and treatment remain uncertain and in need of additional investigation.

A new active vitamin D3 analog, eldecalcitol, prevents the risk of osteoporotic fractures--a randomized, active comparator, double-blind study

BACKGROUND

Eldecalcitol is an analog of 1,25-dihydroxyvitamin D(3) that improves bone mineral density; however, the effect of eldecalcitol on the risk of fractures is unclear. The objective of this study is to examine whether eldecalcitol is superior to alfacalcidol in preventing osteoporotic fractures. This trial is registered with ClinicalTrials.gov, number NCT00144456.

METHODS AND RESULTS

This 3 year randomized, double-blind, active comparator, superiority trial tested the efficacy of daily oral 0.75 μg eldecalcitol versus 1.0 μg alfacalcidol for prevention of osteoporotic fractures. 1054 osteoporotic patients 46 to 92 years old were randomly assigned 1:1 to receive eldecalcitol (n=528) or alfacalcidol (n=526). Patients were stratified by study site and serum 25-hydroxyvitamin D level. Patients with low serum 25-hydroxyvitamin D levels (<50 nmol/L) were supplemented with 400 IU/day vitamin D(3). Primary end point was incident vertebral fractures. Secondary end points included any non-vertebral fractures and change in bone mineral density and bone turnover markers. Compared with the alfacalcidol group, the incidence of vertebral fractures was lower in eldecalcitol group after 36 months of treatment (13.4 vs. 17.5%; hazard ratio, 0.74; predefined 90% confidence interval [CI], 0.56-0.97). Eldecalcitol reduced turnover markers and increased bone mineral density more strongly than alfacalcidol. Eldecalcitol reduced the incidence of three major non-vertebral fractures, which was due to a marked reduction in wrist fractures by a post-hoc analysis (1.1 vs. 3.6%; hazard ratio, 0.29; 95% CI, 0.11-0.77). Among the adverse events, the incidence of increase in serum and urinary calcium was higher in the eldecalcitol group, without any difference in glomerular filtration rate between the two groups.

CONCLUSIONS

Eldecalcitol is more efficacious than alfacalcidol in preventing vertebral and wrist fractures in osteoporotic patients with vitamin D sufficiency, with a safety profile similar to alfacalcidol.

Effect of eldecalcitol, an active vitamin D analog, on hip structure and biomechanical properties: 3D assessment by clinical CT

The effects of an active vitamin D analog, eldecalcitol (ELD), on bone mineral density (BMD), bone geometry, and biomechanical properties of the proximal femur were investigated by using clinical CT. The subjects--a subgroup of a recent randomized, double-blind study comparing anti-fracture efficacy of ELD with alfacalcidol (ALF) - constituted 193 ambulatory patients with osteoporosis (189 postmenopausal women and 4 men aged 52-85 years, average ± SD: 70.9 ± 6.92 years) enrolled at 11 institutions. Multidetector-row CT data was acquired at baseline and at completion of 144 weeks' treatment. Cross-sectional densitometric and geometric parameters of the femoral neck were derived from three-dimensional CT data. Biomechanical properties including cross-sectional moment of inertia (CSMI), section modulus (SM) and buckling ratio (BR) of the femoral neck, and CSMI of the femoral shaft were also calculated. We found that, (1) with respect to the femoral neck cross-sectional parameters (total bone), in the ALF group, volumetric BMD (vBMD) decreased but bone mass was maintained and cross-sectional area (CSA) increased. In contrast, ELD maintained vBMD with a significant increase in bone mass and a trend toward increased CSA. (2) With respect to the femoral neck cross-sectional parameters (cortex), cortical thickness decreased in the ALF group, but was maintained in the ELD group. In the ALF group, vBMD and bone mass increased, and CSA was maintained. In the ELD group, vBMD, CSA, and bone mass increased. (3) With respect to the biomechanical properties of the femoral neck, ELD improved CSMI and SM to a greater extent than did ALF. BR increased in both the ALF and ELD groups. (4) With respect to the femoral shaft parameters, overall the results of bone geometry and CSMI of the femoral shaft were very consistent with the results for the femoral neck; however, cortical vBMD of the femoral shaft decreased significantly in both the ELD and ALF groups. In conclusion, our longitudinal analysis of hip geometry by clinical CT revealed the unexpected potential of ELD to increase cortical CSA, vBMD, and bone mass, and to maintain cortical thickness, probably through the more potent effect of ELD in mitigating endocortical bone resorption than ALF. By improving the biomechanical properties of the proximal femur, ELD may have the potential to reduce the risk of hip fractures.

[Doctor initiated clinical trial for obtaining evidences in treatment of osteoporosis: JOINT (Japanese Osteoporosis Intervention Trial) protocol]

Due to the recent advances in the treatment of osteoporosis, clinicians can utilize many kinds of drugs to prevent fractures. Evidence of drug supplied to clinicians was mainly obtained from the results of the developmental studies. However, the evidence is still lack for the treatment in an individual patient in the"real world". This is a reason why we build up A-TOP (Adequate Treatment of Osteoporosis) research group and why we perform JOINT (Japanese Osteoporosis Intervention Trial) protocol to obtain the evidences, which are required by the clinicians. The two protocols were aimed to investigate whether concurrent treatment with bisphosphonates and active vitamin D3 (JOINT02) or vitamin K2 (JOINT03) is effective or not comparing to the mono-therapy. The former project was finished the 2-year observation and the latter project is currently underwent. The present paper introduces the aims, rationale, and organization of JOINT studies.

Serum level of pepsinogen significantly associated with gastric distress induced by amino-bisphosphonates

To elucidate whether serum levels of pepsinogens are associated with the occurrence of gastrointestinal adverse events induced by amino-bisphosphonates (amino-BP), the serum levels of pepsinogen were measured in amino-BP users. Our results indicate that measurement of pepsinogen I is useful in predicting gastric distress induced by amino-BP in osteoporosis.

INTRODUCTION

To elucidate whether serum levels of pepsinogens are associated with the occurrence of gastrointestinal adverse events induced by amino-BP, the serum levels of pepsinogen I and II were measured in amino-BP users.

METHODS

When the patients complained of gastric distress symptoms during the first 6 months after amino-BP use resulting in discontinuation of the drug, endoscopical examinations were performed to assess whether gastric lesions were present. A total of 223 amino-BP users were enrolled in the study, of which 47 patients refused to take the drug due to gastric distress symptoms. The remaining 176 patients did not complain of any gastric distress.

RESULTS

Among 47 patients, eight patients showed obvious gastric lesions such as gastric or duodenal ulcers and acute gastric mucosal lesions in the endoscopical examination. The remaining 39 patients did not show any gastric lesions. The possible confounding factors, such as a Helicobactor pylori infection or concurrent use of ulcerogenic agents, did cause not affect gastric distress in amino-BP users. The serum pepsinogen I level was significantly associated with severity of the gastric lesion 46.8 ± 27.7, 60.8 ± 32.4, and 103.4 ± 49.2 ng/ml for patients without any gastric distress, with gastric distress accompanied no gastric lesions, and with gastric distress accompanied gastric lesions, respectively.

CONCLUSIONS

ROC analysis revealed that the cutoff value of pepsinogen I for expectation of gastric regions was 76.8 ng/ml. The results clearly indicate that measurement of pepsinogen I may be useful in predicting gastric distress induced by amino-BP in osteoporosis.

Effects of alendronate plus alfacalcidol in osteoporosis patients with a high risk of fracture: the Japanese Osteoporosis Intervention Trial (JOINT) - 02

OBJECTIVES

The authors conducted a randomized controlled trial to clarify the efficacy and safety of alendronate plus alfacalcidol versus alendronate alone in a clinical setting.

RESEARCH DESIGN AND METHODS

Eligible patients were postmenopausal women with severe osteoporosis who were aged 70 years or older and had several risk factors for incident fractures. The primary endpoint was prevention of incident fractures, and the anti-fracture efficacy was evaluated in relation to the baseline serum 25(OH)D level.

RESULTS

A total of 2164 patients were randomized to alendronate plus alfacalcidol (combination therapy) or alendronate alone (monotherapy). Although the overall difference in the incidence of vertebral fracture between the two groups was not significant, the combination therapy group had a significantly reduced risk of vertebral fractures after the first 6 months (HR, 0.53). In subgroup analyses, the combination therapy group was superior in the strata of number of prevalent vertebral fractures of ≥2 (HR, 0.51) and grade 3 of prevalent vertebral fractures (HR, 0.55). The rate of non-vertebral weight-bearing bone fractures was significantly lower in the combination therapy group than in the monotherapy group during the follow-up period (HR, 0.31). A lower baseline 25(OH)D level was associated with a higher incidence of non-vertebral weight-bearing bone fractures (HR, 3.42) despite alendronate use. Although one patient given the combination therapy had mild hypercalcemia, serious hypercalcemia and unknown adverse events were not encountered. Because of the limitations presented in this study, these results may not apply to female patients with longer than 2 years of treatments, and to male osteoporosis patients.

CONCLUSIONS

The combination therapy was no more effective for overall vertebral fracture prevention. However, subgroup analysis has shown that it was more effective for fracture prevention in patients with severe vertebral deformity, multiple prevalent vertebral fractures, and for non-vertebral weight-bearing bone fracture prevention.

Common variants in a novel gene, FONG on chromosome 2q33.1 confer risk of osteoporosis in Japanese

Osteoporosis is a common disease characterized by low bone mass, decreased bone quality and increased predisposition to fracture. Genetic factors have been implicated in its etiology; however, the specific genes related to susceptibility to osteoporosis are not entirely known. To detect susceptibility genes for osteoporosis, we conducted a genome-wide association study in Japanese using ∼270,000 SNPs in 1,747 subjects (190 cases and 1,557 controls) followed by multiple levels of replication of the association using a total of ∼5,000 subjects (2,092 cases and 3,114 controls). Through these staged association studies followed by resequencing and linkage disequilibrium mapping, we identified a single nucleotide polymorphism (SNP), rs7605378 associated with osteoporosis. (combined P = 1.51×10⁻⁸, odds ratio = 1.25). This SNP is in a previously unknown gene on chromosome 2q33.1, FONG. FONG is predicted to encode a 147 amino-acid protein with a formiminotransferase domain in its N-terminal (FTCD_N domain) and is ubiquitously expressed in various tissues including bone. Our findings would give a new insight into osteoporosis etiology and pathogenesis.

Established osteoporosis associated with high mortality after adjustment for age and co-mobidities in postmenopausal Japanese women

OBJECTIVE

Osteoporosis has been reported to increase the risk of mortality. However, these reports did not evaluate the effects of co-mobidities and the severity of osteoporosis on mortality. The aim of our study was to determine whether or not major osteoporotic fractures contribute to the increased mortality risk in Japanese women.

METHOD

We conducted a prospective observational study. Risk factors contributing to mortality were assessed by Cox's proportional hazard model.

SUBJECTS

A total of 1,429 ambulatory postmenopausal female volunteers aged over 50 years old were enrolled in the study. Information was obtained from the subjects on baseline biochemical indices, bone mineral density (BMD), prevalent fractures, and co-morbidities. Mortality was assessed and confirmed by the certificates or hospital records. The subjects were classified into three categories in accordance with or without osteoporosis. The osteoporotic group was further categorized by the basis of the presence or absence of major osteoporotic fractures.

RESULTS

Mean age and SD of the participants were 66.5±9.3 (50-90) years old. The participants were followed for a total of 4.5±3.5 years (mean ± SD) and a total of 141 participants (9.9%) died during the observation. In addition to the traditional risks for mortality, such as age (Hazard ratio, 2.817, 95% CI, 2.237-3.560, p<0.0001), BMI (HR 0.504, 0.304-0.824, p=0.0061), prevalent malignancies (HR 2.885, 1.929-4.214, p<0.0001), dementia (HR 1.602, 1.027-2.450, p=0.038) and cardio-vascular disease (HR 1.878, 1.228-2.787, p=0.0043), the serum level of creatinine (HR 2.451, 1.107-5.284, p=0.027) and severity of osteoporosis (HR 1.390, 1.129-1.719, P=0.0018) were found to be significant independent risk factors for all-cause mortality.

CONCLUSION

These results emphasize the importance of osteoporotic fracture in terms of survival.

Vitamin D insufficiency defined by serum 25-hydroxyvitamin D and parathyroid hormone before and after oral vitamin D₃ load in Japanese subjects

Vitamin D insufficiency is a risk for both skeletal and nonskeletal health. However, some ambiguity remains about threshold serum 25(OH)D for vitamin D insufficiency. To determine the threshold serum 25(OH)D to maintain normal calcium availability without elevation in serum parathyroid hormone (PTH) among Japanese subjects with various calcium intakes, we conducted a multicenter prospective open-labeled study. We recruited 107 ambulatory subjects without disorders affecting vitamin D metabolism to whom oral vitamin D₃ 800 IU/day for 4 weeks or 1,200 IU/day for 8 weeks was given. Serum 25(OH)D, PTH, calcium, phosphate, and magnesium were measured before and after vitamin D₃ supplementation. Calcium intake was assessed by questionnaires. When all the data were combined, serum 25(OH)D was negatively correlated with PTH. The cubic spline curve between serum 25(OH)D and PTH indicated PTH reached its plateau between 35 and 40 pg/ml at 25(OH)D between 25 and 30 ng/ml. Vitamin D₃ supplementation increased serum 25(OH)D and decreased PTH. Change in PTH correlated positively with baseline serum 25(OH)D. From the regression analyses, baseline serum 25(OH)D above 28 ng/ml corresponded to the threshold level without reduction in PTH after vitamin D₃ supplementation. In multivariate regression analyses, age but not calcium intake was a significant determinant of PTH. We concluded that a serum 25(OH)D level of 28 ng/ml was identified as a threshold for vitamin D insufficiency necessary to stabilize PTH to optimal levels.

Urinary pentosidine and plasma homocysteine levels at baseline predict future fractures in osteoporosis patients under bisphosphonate treatment

To clarify what kind of risk factors predict incident fractures in patients treated with bisphosphonates, the authors investigated the relationship between baseline characteristics and incident vertebral fracture in Japanese osteoporosis patients undergoing bisphosphonate treatment. This was a multi-center follow-up study conducted at three centers, in which a total of 251 Japanese patients with osteoporosis (mean age 70.5 years) from the three centers were followed for 3.2 ± 2.0 years. Baseline data, including pre-existing fractures, bone mineral density in the lumbar spine (LBMD), bone metabolic markers, urinary pentosidine, and plasma homocysteine, were evaluated. Changes in LBMD, bone turnover markers, and incident fractures after the treatment were followed. Sixty-one patients developed incident vertebral fractures; this group of patients was older and had lower LBMD, a higher prevalent vertebral fracture number, and higher homocysteine and pentosidine levels than patients who did not develop incident vertebral fractures. Changes in LBMD, urinary N-terminal telopeptides of type I collagen (NTX), and bone-derived alkaline phosphatase showed no significant association with the occurrence of vertebral fractures. Cox's proportional hazard model demonstrated that age, prevalent fracture, pentosidine, and homocysteine were independent predictors of the incident vertebral fracture rate under bisphosphonate treatment. Higher baseline levels of pentosidine and homocysteine in osteoporosis patients are potential risk factors for incident vertebral fractures when these patients are treated with bisphosphonates. Further clarification is needed to explain why such patients have higher fracture susceptibility.

Design of a pragmatic approach to evaluate the effectiveness of concurrent treatment for the prevention of osteoporotic fractures: rationale, aims and organization of a Japanese Osteoporosis Intervention Trial (JOINT) initiated by the Research Group of Adequate Treatment of Osteoporosis (A-TOP)

The aim of osteoporosis treatment is to prevent future fractures. Although concurrent treatment has been used very frequently for osteoporosis in clinical practice, there are no data on accurate and verified effectiveness of concurrent treatment for fracture prevention in patients with osteoporosis. To clarify the clinical usefulness of concurrent treatment, the Japan Osteoporosis Society has authorized the establishment of the A-TOP (Adequate Treatment of Osteoporosis) research group. The objective of this research is to establish a design for a clinical trial to prove whether concurrent treatment using both alfacalcidol (1-alpha-hydroxycholecalciferol) and alendronate is more effective as compared to treatment using alendronate alone in terms of fracture prevention. The present study was named JOINT (Japanese Osteoporosis Intervention Trial) and is based on a method using national, prospective, randomized, open-labeled, blinded endpoints focusing on postmenopausal osteoporosis with a high risk for fracture. The patients were mainly selected by practitioners and allocated randomly by a central registration system into two groups, of which one received 5 mg/day of alendronate alone, and the other received 1 μg/day of 1-alpha-hydroxycholecalciferol (alfacalcidol) in addition to the alendronate. The endpoints focused primarily on fracture prevention, and the patients' quality of life (QOL) and change in body height, as well as adherence and the adverse events of the treatments were evaluated secondarily. To obtain sufficient statistical power in the events during a 2-year observation period, the patients who are expected to have higher risk were selected to participate in this study, and it was decided that the final plan would involve 890 patients per group (two-sided alpha = 0.05, power = 0.8). Data collection began in November 2003. Correspondence regarding the registration of the investigator and the progress of the study was conducted through a web system from the Public Health Research Foundation to practitioners.

The Fracture and Immobilization Score (FRISC) for risk assessment of osteoporotic fracture and immobilization in postmenopausal women--A joint analysis of the Nagano, Miyama, and Taiji Cohorts

INTRODUCTION

We aimed to (i) explore risk factors for major osteoporotic fracture or immobilization; (ii) develop a prediction model that can be used to assess the risk of fracture and immobilization; and (iii) assess external validity of the final model.

METHODS

A total of 1787 postmenopausal Japanese women were followed in a hospital-based cohort study. Endpoints included the annual incidence of major osteoporotic fracture and immobilization. For each endpoint, multivariate Poisson regression models were fitted separately and risk factors were screened through backward variable selection. The predictive accuracy of the final model (FRISC) was evaluated in two independent community-based cohorts.

RESULTS

Over a median follow-up of 5.3 years, a total of 383 major osteoporotic fractures (279 clinical vertebral, 44 hip, 60 distal forearm) and 83 immobilizations occurred in the developmental dataset. Backward variable selection confirmed that the following are risk factors for major osteoporotic fracture: age, weight, prior fracture, back pain, and lumbar bone mineral density (BMD). Age, prior fracture and dementia were significant risk factors for immobilization. Hosmer-Lemeshow tests did not indicate any significant deviation between the observed fracture frequency and prediction from the FRISC in the independent validation dataset. The C statistic for the FRISC was 0.727 (95% confidence interval: 0.660 to 0.794) and was higher than that for BMD alone significantly (p=0.03).

CONCLUSIONS

We developed a novel prediction model for fracture and immobilization, FRISC, and the clinical risk factors in the FRISC allows better identification of populations at high risk of fracture than BMD alone. A web application is available at http://www.biostatistics.jp/prediction/frisc.

Single-nucleotide polymorphism in the hyaluronan and proteoglycan link protein 1 (HAPLN1) gene is associated with spinal osteophyte formation and disc degeneration in Japanese women

Spinal osteoarthritis including disc degeneration is a very common condition in the axial skeletons of aged people. Recently, spinal osteoarthritis has been shown to be influenced by specific genetic risk factors. Vertebral osteophytes, endplate sclerosis, and intervertebral disc narrowing are recognized as radiographic features of spinal disc degeneration. HAPLN1 is a key component of the cartilage extracellular matrix; thus, variations in this gene may affect the pathogenesis of cartilage-related diseases such as spinal degeneration. Here, we examine the association between an HAPLN1 gene polymorphism and the radiographic features of spinal degeneration. We evaluated the degree of endplate sclerosis, osteophyte formation, and disc space narrowing in 622 Japanese postmenopausal women. Four SNPs in the HAPLN1 gene-in the 5' flanking region, intron 1, intron 2, and intron 4-were analyzed using the TaqMan polymerase chain reaction method. We found that compared to subjects with the CC or CT genotype, those with the TT genotype for an SNP at intron 2 (rs179851) were significantly overrepresented among the subjects with higher scores for osteophyte formation (P = 0.0001; odds ratio 2.12; 95% confidence interval 1.45-3.11, as determined by logistic regression analysis) and disc space narrowing (P = 0.0057; odds ratio 1.83; 95% confidence interval 1.19-2.83). Consistent with the involvement of the HAPLN1 gene in cartilage metabolism, a variation in a specific HAPLN1 gene locus may be associated with spinal degeneration.

Dose effects of oral estradiol on bone mineral density in Japanese women with osteoporosis

OBJECTIVES

This 2-year study compared 0.5 and 1.0 mg oral estradiol (E(2)), with or without levonorgestrel (LNG), for the treatment of postmenopausal osteoporosis in Japanese women.

METHODS

Japanese women with osteoporosis after natural menopause or bilateral oophorectomy were randomized to receive E(2) 0.5 or 1.0 mg/day with LNG 40 microg as required, or placebo, for 52 weeks. Women treated with E(2) in the first year continued therapy at the same doses in the second year. Efficacy, safety and pharmacokinetics were assessed.

RESULTS

There were 73 women randomized to E(2) 0.5 mg, 157 to E(2) 1.0 mg and 79 to placebo. Lumbar bone mineral density at 52 weeks increased significantly more with E(2) 1.0 mg (p < 0.001) and 0.5 mg (p < 0.001) than with placebo (no change). After 2 years, a 10% increase in bone mineral density with E(2) 1.0 mg was significantly greater than with E(2) 0.5 mg (8%; p = 0.008). E(2) was associated with an acceptable safety and tolerability profile, with slightly more adverse events with E(2) 1.0 than 0.5 mg. Serum E(2) concentration increased in a dose-dependent manner.

CONCLUSION

This study showed that E(2), at both 1.0 mg and 0.5 mg doses, was effective in increasing bone mineral density with an acceptable safety and tolerability profile in Japanese postmenopausal women with osteoporosis but that the bone mineral density response was higher with the 1.0 mg dose.

Effects of bone mineral density of the lumbar spine and prevalent vertebral fractures on the risk of immobility

SUMMARY

To clarify the contribution of osteoporosis to future immobilization, a prospective observational study was carried out on Japanese postmenopausal women. The prevalence of low bone mineral density (BMD) and vertebral fracture were independent risks for future immobilization.

INTRODUCTION

Immobilization by hip fracture requires more medical care and higher costs. Osteoporosis increases the risk of hip fracture, but there is little data linking osteoporosis and immobilization in postmenopausal Japanese women.

METHODS

The study participants consisted of postmenopausal ambulatory volunteers. Baseline information such as BMD, prevalent fractures, comorbidities, pain in the body, and variables were obtained from 1993, and time course of occurrence of immobilization was observed until 2008.

RESULTS

A total of 1,312 participants were enrolled and were observed for a total of 6.7 +/- 4.1 years. A total of 75 subjects suffered immobilization. In multivariate analysis to calculate the Cox's hazard ratio of baseline parameters for immobilization, four independent variables were observed: age (hazard ratio, 1.52 [95% CI, 1.29 to 1.80], p = 0.000), pain in the body (2.54 [1.42 to 4.89, p = 0.001]), low BMD (1.83 [1.10 to 3.13, p = 0.020]), and dementia (3.58 [91.80 to 6.76, p = 0.001]). The hazard ratio of prevalent vertebral fracture was 1.98 (1.20 to 3.30, p = 0.007) instead of low BMD of above model.

CONCLUSION

These results indicate that low BMD and prevalent vertebral fracture pose an independent risk for future immobilization in postmenopausal Japanese women.

High level of serum undercarboxylated osteocalcin in patients with incident fractures during bisphosphonate treatment

To evaluate the possible interaction of metabolic effects in the mevalonate pathway between amino-bisphosphonates (amino-BP) and vitamin K, the serum level of undercarboxylated osteocalcin (ucOC) was measured in amino-BP users in relationship to incident fracture occurrence. Osteoporotic patients (mean age, 70.7 +/- 9.1 years; n = 231) treated with alendronate or risedronate were followed for 3.4 +/- 2.1 years, and observations regarding the presence or absence of incident fractures in their vertebrae were made based on vertebral X-ray films every year. During the observation period, new fractures were found in a total of 71 patients (incident vertebral fracture, n = 61; the remaining 10 patients had long bone fractures). The baseline data of the patients with incident fractures indicated that incident fractures are more likely to occur in older patients who have a higher number of prevalent vertebral fractures and lower baseline lumbar bone mineral density (LBMD) as compared to patients without incident fractures. There was no significant difference in the changes of LBMD and urinary excretion of NTX after treatment. On the other hand, the serum level of ucOC in patients with incident fractures and with amino-BP treatment was significantly higher (2.75 +/- 0.19 ng/ml) than that in patients without incident fractures and with amino-BP treatment (2.28 +/- 0.13 ng/ml) (P = 0.038). These results indicate that older age, a greater number of prevalent fractures and higher ucOC levels, and lower LBMD are risks for incident fractures despite use of amino-BP. The time-dependent incident fracture rate was higher in accordance with an increase in the number of risk items (P < 0.001 in log-rank and Wilcoxon tests). In conclusion, measurement of undercarboxylated osteocalcin may be useful for assessing fracture risk in patients receiving amino-BP treatment.

Identification of non-synonymous polymorphisms in the WDSOF1 gene as novel susceptibility markers for low bone mineral density in Japanese postmenopausal women

Genetic factors are important for the development of osteoporosis. During the search for novel markers of single-nucleotide polymorphisms (SNPs) associated with bone mineral density (BMD) by performing a large-scale SNP screen with 251 Japanese postmenopausal women utilizing 50K SNP array, we here focused on the rs1370005 in the WD repeats and SOF1 domain-containing (WDSOF1) gene because we could found common non-synonymous variants in this WDSOF1 gene. The analysis of linkage disequilibrium (LD) in the WDSOF1 gene revealed that rs1370005 and 3 other non-synonymous SNPs (Arg47Ser, Pro108Leu and Ile194Val) lie in a 30-kb region of high LD. Quantitative real-time PCR (qRT-PCR) analysis showed that WDSOF1 mRNA was expressed in mouse primary osteoblasts and osteoclasts, suggesting that WDSOF1 plays some roles in the bone metabolism. We examined the 3 non-synonymous SNPs in WDSOF1 gene in 750 Japanese postmenopausal women. A trend test showed that Arg47Ser, Pro108Leu, and Ile194Val genotypes were significant associated with total body BMD (Arg47Ser; P=0.021, Pro108Leu; P=0.022 and Ile194Val; P=0.009). We also compared Z scores for total body BMD between the subjects bearing at least one minor allele and those lacking the minor allele using unpaired t test. Subjects with the one or two minor alleles had significantly lower Z scores for total body BMD (Arg47Ser; P=0.010, Pro108Leu; P=0.019 and Ile194Val; P=0.003). The present study suggests that these non-synonymous WDSOF1 polymorphisms play a role in the genetic susceptibility to osteoporosis.

Association of HTRA1 promoter polymorphism with spinal disc degeneration in Japanese women

HTRA1 (high-temperature requirement A1) has been implicated in the modulation of various disease pathologies. HTRA1 expression is upregulated in osteoarthritic joints, suggesting that it may contribute to the development of this debilitating disease. Moreover, recent reports have shown that the rs11200638, a single nucleotide polymorphism (SNP) in the promoter region of the HTRA1 gene, is strongly associated with an increased prevalence of age-related macular degeneration (AMD). In the present study, we examined the expression of the HTRA1 in human primary chondrocytes and an association between the rs11200638 SNP and radiographic features of spinal disc degeneration in 513 postmenopausal Japanese women. HTRA1 mRNA was detected and increased by TGF-beta treatment in human primary chondrocytes. As an association study of rs11200638 SNP in the HTRA1 gene, the subjects without the G allele (AA; n = 89) had a significantly higher spinal disc space narrowing score than the subjects bearing at least one G allele (GG + GA; n = 424) (P = 0.0292). We found that subjects without the G allele (AA) were significantly overrepresented in the subjects having a higher (> or =4) disc space narrowing score (P = 0.013; odds ratio 1.97; 95% confidence interval 1.15-3.37 by logistic regression analysis). A genetic variation at the HTRA1 gene promoter locus is associated with spinal disc degeneration, suggesting an involvement of the HTRA1 gene in osteoarthritis.

Association of a single nucleotide polymorphism in the constitutive androstane receptor gene with bone mineral density

BACKGROUND

Nuclear receptors play an important role in bone metabolism. In bone cells, the vitamin D receptor (VDR) and the steroid and xenobiotic receptor (SXR) are activated by vitamin D and vitamin K2, respectively. VDR and SXR are the NR1I subfamily members of nuclear receptors. We speculated that the constitutive androstane receptor (CAR), the third member of the NR1I subfamily, also could be implicated in the regulation of bone metabolism. Therefore, we analyzed expression of CAR mRNA in osteoblasts and then examined association of a single nucleotide polymorphism (SNP) in the human CAR gene at intron 2 (IVS2-99C>T, rs2502815) with bone mineral density (BMD).

METHODS

Expression levels of CAR mRNA were analyzed during the culture course of rat primary osteoblasts. Association of an SNP in the CAR gene with BMD was examined in 548 healthy Japanese postmenopausal women.

RESULTS

CAR mRNA increased at day 16 and then increased during culture of rat primary osteoblasts. The increase of CAR mRNA was parallel with the increase of alkaline phosphatase expression, a differentiation marker of osteoblasts. As a result of association study of an SNP in the CAR gene at intron 2, subjects with the CC genotype (n = 208) had significantly higher BMD than subjects with the TT or CT genotype (n = 340) (lumbar spine BMD, P = 0.0185; total body BMD, P = 0.0416).

CONCLUSION

CAR mRNA was expressed and regulated in primary osteoblasts. A genetic variation at the CAR gene locus is associated with BMD, suggesting an involvement of the CAR gene in bone metabolism.

Validation of the Japanese Osteoporosis Quality of Life Questionnaire

The Japanese Society for Bone and Mineral Research developed the Japanese Osteoporosis Quality of Life Questionnaire (JOQOL) to evaluate the disease-specific Health-Related QOL, which is specific for osteoporosis of Japanese patients. JOQOL was revised in 2000; it consisted of 38 items with the scale graded from 0 to 4 and a total full score of 152. To elucidate the reliability and validity of the revised JOQOL, we enrolled 193 postmenopausal women as subjects and diagnosed them as having osteoporosis or osteopenia. The mean age of the subjects was 68.2 +/- 8 years; 58 subjects (30.1%) had at least one vertebral fracture. Among them, 83 patients were retested for reliability. The mean lapse from the time of test to that of retest was 23.7(+/- 9.5) days. The subjects were questioned using the JOQOL, Medical Outcomes Study Short Form 36 (SF-36), along with questions on subjects' characteristics and their ADL. The JOQOL scores at the test and the retest were significantly correlated (r = 0.973) without significant difference between their mean scores. All the JOQOL items showed significant correlations at the test and the retest (Kendall's tau = 0.599-0.947). Cronbach's alpha coefficient of JOQOL was 0.918. These results proved the high reliability of JOQOL. The JOQOL score showed negative correlation with age (r = -0.183). The subjects with vertebral fractures had significantly lower JOQOL scores than the subjects without fractures. The JOQOL showed a significant correlation with all the scores in each domain of eight of SF-36 (r = 0.350-0.839). These results were consistent with that of the preceding study. It is concluded that the reliability and the validity of JOQOL were demonstrated in this study.

Effect of daily oral minodronate on vertebral fractures in Japanese postmenopausal women with established osteoporosis: a randomized placebo-controlled double-blind study

SUMMARY; A randomized placebo-controlled trial was conducted to examine the effect of daily oral 1 mg minodronate on vertebral fractures in 704 postmenopausal women with established osteoporosis for 24 months. Minodronate treatment reduced vertebral fractures by 59% without serious adverse events. Minodronate is a safe and effective bisphosphonate for osteoporosis treatment.

INTRODUCTION

Minodronate increases bone mineral density (BMD) in postmenopausal osteoporotic patients. However, its efficacy in reducing osteoporotic fractures has not been tested.

METHODS

To examine anti-fracture efficacy and safety of daily oral minodronate in postmenopausal women with established osteoporosis, a randomized, double-blind, placebo-controlled trial was conducted in 704 postmenopausal women (55 to 80 years) with one to five vertebral fractures and low BMD. Subjects were randomly assigned to receive daily oral 1 mg minodronate (n = 359) or placebo (n = 345) for 24 months, with daily supplements of 600 mg calcium and 200 IU vitamin D(3).

RESULTS

Daily 1 mg minodronate for 24 months reduced the risk of vertebral fractures by 59% (95% CI, 36.6-73.3%). Furthermore, when fractures during the first 6 months were eliminated, the risk of vertebral fractures from 6 to 24 months was reduced by 74% in minodronate-treated group. Minodronate treatment also reduced height loss. Bone turnover markers were suppressed by about 50% after 6 months of minodronate treatment and remained suppressed thereafter. The overall safety profile including gastrointestinal safety was similar between the two groups.

CONCLUSIONS

Daily oral minodronate is safe, well-tolerated, and is effective in reducing vertebral fracture risk in postmenopausal women with established osteoporosis.