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Glucocorticoid (GC)-induced osteoporosis (GIO) is a serious problem for patients taking GC therapy. GC increases risk for fracture. However, there are controversies regarding the threshold of bone mineral density (BMD) in patients with GIO. The present study aimed to examine the relationship between the presence or absence of vertebral fracture and various indices including BMD in 136 female Japanese patients treated with oral GC (102 patients with autoimmune diseases). Moreover, we analyzed the cut-off values of BMD for incidence of vertebral fracture in patients with oral GC use and compared these values with those in control subjects. BMD was measured by dual-energy X-ray absorptiometry of the lumbar spine, femoral neck, and distal one third of radius. We compared various indices between patients taking oral GC with and without vertebral fracture. Age, body height, and body weight were significantly greater, shorter, and lower in the group with vertebral fracture, respectively. As for BMD, age-matched BMD seemed lower in the fracture group, although the differences were significant between both groups only at the femoral neck. Duration of GC treatment was longer in the fracture group. Cut-off values of BMD at lumbar spine, femoral neck, and distal radius were higher in patients with GC treatment compared with those of control group [GC vs control (g/cm(2)): 0.807 vs 0.716 at lumbar spine; 0.611 vs 0.581 at femoral; 0.592 vs 0.477 at radius]. The sensitivity and specificity were lower in patients with GC treatment compared with those of control group. The present study demonstrated that the thresholds of BMD for vertebral fracture were higher in Japanese female patients with oral GC treatment at any site compared with postmenopausal subjects. The factors other than BMD were considered to affect bone strength and vertebral fracture risk.

Here we report the case of a 65-year-old woman with acromegaly complicated with monoclonal gammopathy of undetermined significance (MGUS). The patient visited Shimane University Hospital for treatment of spinal canal stenosis, and was diagnosed as acromegaly with GH 43.1 ng/ml, insulin-like growth factor (IGF)-I 510 ng/ml and the detection of a pituitary adenoma by MRI. She was also diagnosed as MGUS with IgG 2208 mg/dl, the existence of IgG-kappa type monoclonal protein, and 5.6% plasma cells in bone marrow. After a pituitary adenoma was operatively removed by transsphenoidal approach, IgG levels, as well as GH and IGF-I levels, decreased spontaneously and simultaneously. We suspect a pathogenetic link between acromegaly and MGUS in this case, because both GH and IGF-I are known to directly promote immunoglobulin production from plasma cells, thus inducing the proliferation of the cells in vitro.

Background and objective: Primary hyperparathyroidism (pHPT) is one of the causal diseases that induce secondary osteoporosis. Although patients with pHPT have reduced bone mineral density (BMD) especially at the cortical bone, there have been controversies about risk of fracture. Moreover, no reports have been available about the threshold of BMD for fractures in pHPT patients. Methods: BMD values were measured by dual-energy x-ray absorptiometry at lumbar spine, femoral neck and distal one third of radius. Various indices were compared in 116 female pHPT patients and 716 control subjects. Moreover, we analyzed relationship between the cut-off values of BMD and the prevalence of vertebral fractures in pHPT and control subjects. Results: The prevalence of subjects with vertebral fractures was lower in pHPT patients, compared with that of control subjects. Age and body height were significantly higher and lower in pHPT women with vertebral fractures, respectively. Lumbar spine BMD was significantly lower in pHPT women with vertebral fractures, presumably due to their increased age. There were no differences in femoral neck and radius BMD or in bone metabolic indices between pHPT women with and without vertebral fractures. On the other hand, age-matched BMD was not significantly different between both groups at any measured site. Cut-off values of BMD at lumbar spine and femoral neck were lower in postmenopausal pHPT patients, compared with those of the postmenopausal control group. Moreover, cut-off values of BMD at radius was much lower in postmenopausal pHPT patients, compared with those of the postmenopausal control group (pHPT vs control (g/cm2): 0.670 vs 0.706 at lumbar spine; 0.549 vs 0.570 at femoral; 0.394 vs 0.474 at radius). Sensitivity and specificity of vertebral fractures was lower in pHPT patients, compared with those in control group. Conclusions: The present cross-sectional study demonstrated that thresholds of BMD for vertebral fractures were lower especially at radial bone in female patients with pHPT, compared with those in the control group.

Central in the pathogenesis of glucocorticoid (GC)-induced osteoporosis is the effects of GC on bone formation. However, the mechanism of GC-inhibited bone formation is not well known. Transforming growth factor (TGF)-β is most abundant in bone matrix compared with other tissues, and we have recently proposed that Smad3, a TGF-β signaling molecule, is important for promoting bone formation. However, no reports have been available about the effects of GC on Smad3 in osteoblasts. In the present study, we investigated whether dexamethasone (Dex), an active GC analog, would affect the expression and activity of Smad3 in mouse osteoblastic MC3T3-E1 and rat osteoblastic UMR-106 cells. Dex significantly suppressed Smad3-stimulated alkaline phosphatase (ALP) activity, although it did not affect TGF-β-inhibited ALP activity in MC3T3-E1 cells. Moreover, pretreatment with Dex suppressed TGF-β-enhanced expression of type I collagen in MC3T3-E1 and UMR-106 cells. In the luciferase assay using p3TP-Lux with a Smad3-specific response element, Dex significantly suppressed the transcriptional activity induced by TGF-β as well as Smad3. However, Dex did not affect the expression of Smad3 in these cells at both mRNA and protein levels. In conclusion, the present study indicates that Dex inhibits ALP activity and type I collagen expression, presumably by suppressing Smad3-induced transcriptional activity but not by modulating Smad3 expression in osteoblastic cells.

We examined the frequency of multiple vertebral fractures (MVFs) and esophageal hiatal hernia (HH) in 18 Japanese postmenopausal women (74.1 +/- 9.9 years, mean +/- SD), with refractory reflux esophagitis (RRE) that had needed a proton pump inhibitor for more than 6 months to suppress symptoms such as heartburn and acid regurgitation, as well as in 57 control subjects without RE (71.4 +/- 5.9 years). MVFs (two or more VFs), HH, and both features were found in 11 (61%), 16 (89%), and 11 (61%) subjects, respectively, in the RRE group. All 11 patients with MVFs also had HH, suggesting their strong association. On the other hand, MVFs, HH, and both were found in 15 (26%), 23 (40%), and 8 (14%) subjects, respectively, in those without RE. The differences in frequencies of MVFs, HH, and both between the two groups were significant (chi2 = 7.3, 12.9, and 16.0; P = 0.015, 0.0009, and 0.0002, respectively). When univariate logistic regression analysis was performed with the presence of RRE as a dependent variable and the presence of MVFs, HH, and both as independent variables, MVFs, HH, and both were selected as indices affecting the presence of RRE (age-adjusted odds ratios: 4.34, 11.07, and 10.30; 95% confidential intervals: 1.40-13.45, 2.30-53.22, and 2.96-35.86; P = 0.0109, 0.0027, and 0.0002, respectively). These results show that the presence of MVFs is associated with the presence of RRE in Japanese postmenopausal women, and this association becomes more significant when HH is present. Thus, a kyphotic lumbar spine with MVFs may cause HH and RE by raising the intraabdominal pressure. As recent therapeutic agents for osteoporosis, alendronate and risedronate, are known to be very effective for suppressing the occurrence of new VFs, these agents may also prevent gastrointestinal disorders such as HH and RRE in osteoporotic women when administered to subjects without VFs.

Menin, the product of the multiple endocrine neoplasia type 1 (MEN1) gene, is required for commitment of multipotential mesenchymal stem cells to the osteoblast lineage, however, it inhibits their later differentiation (Sowa, H., Kaji, H., Canaff, L., Hendy, G.N., Tsukamoto, T., Yamaguchi, T., Miyazono, K., Sugimoto, T., and Chihara, K. (2003) J. Biol. Chem. 278, 21058-21069). Here, we have examined the mechanism of action of menin in regulating osteoblast differentiation using the mouse bone marrow stromal ST2 and osteoblast MC3T3-E1 cell lines. In ST2 cells, reduced menin expression achieved by transfection of menin antisense DNA (AS) antagonized bone morphogenetic protein (BMP)-2-induced alkaline phosphatase activity and osteocalcin and Runx2 mRNA expression. Menin was co-immunoprecipitated with Smad1/5 in ST2 and MC3T3-E1 cells, and inactivation of menin antagonized BMP-2-induced transcriptional activity of Smad1/5 in ST2 cells, but not MC3T3-E1 cells. Menin was co-immunoprecipitated with the key osteoblast regulator, Runx2, and AS antagonized Runx2 transcriptional activity and the ability of Runx2 to stimulate alkaline phosphatase activity only in ST2 cells but not in MC3T3-E1 cells. In the osteoblast MC3T3-E1 cells, transforming growth factor-beta and its signaling molecule, Smad3, negatively regulated Runx2 transcriptional activity. Menin and Smad3 were co-immunoprecipitated, and combined menin and Smad3 overexpression antagonized, whereas menin and the dominant-negative Smad3DeltaC together enhanced BMP-2-induced transcriptional activity of Smad1/5 and Runx2. Smad3 alone had no effect. Therefore, menin interacts physically and functionally with Runx2 in uncommitted mesenchymal stem cells, but not in well differentiated osteoblasts. In osteoblasts the interaction of menin and the transforming growth factor-beta/Smad3 pathway negatively regulates the BMP-2/Smad1/5- and Runx2-induced transcriptional activities leading to inhibition of late-stage differentiation.

Although several studies indicated that parathyroid hormone (PTH) exerted anabolic action on bone, its precise mechanisms have been unknown. On the other hand, transforming growth factor beta (TGF-beta), abundantly stored in bone matrix, stimulates bone formation with a local injection in rodents. Although our previous study suggested that Smad3 is an important molecule for the stimulation of bone formation, no reports have been available about the effects of PTH on Smad3. In this present study, we examined the effects of PTH on Smad3 and the physiological significance in mouse osteoblastic cells. PTH promoted the expression of Smad3 mRNA within 10 min and the protein level in a dose-dependent manner in MC3T3-E1 and rat osteoblastic UMR-106 cells. Protein kinase A (PKA) activator as well as protein kinase C (PKC) activators increased Smad3 protein level, and both PKA and PKC inhibitors antagonized PTH-induced Smad3, indicating that PTH promotes the production of Smad3 through both PKA and PKC pathways. Next, we examined anti-apoptotic effects of PTH and Smad3 in these cells, employing trypan blue, transferase-mediated nick end labeling, and Hoechst staining. Pretreatment with PTH or overexpression of Smad3 decreased the number of apoptotic cells induced by dexamethasone and etoposide. Moreover, a dominant negative mutant, Smad3DeltaC, abrogated PTH-induced anti-apoptotic effects. On the other hand, PTH augmented TGF-beta-induced transcriptional activity. Furthermore, PTH enhanced TGF-beta-induced production of type I collagen, whereas it did not affect TGF-beta-reduced proliferation in MC3T3-E1 cells. These observations indicated that PTH amplified the anabolic effects of TGF-beta by accelerating the transcriptional activity of Smad3. In conclusion, we first demonstrated that PTH-Smad3 axis exerts anti-apoptotic effects in osteoblasts and reinforces the anabolic action by TGF-beta in osteoblasts. Hence, PTH-Smad3 axis might be involved in the bone anabolic action of PTH.

Mutations in fibroblast growth factor 23 (FGF-23) cause autosomal dominant hypophosphatemic rickets. Clinical and laboratory findings in this disorder are similar to those in oncogenic osteomalacia, in which tumors abundantly express FGF-23 messenger RNA, and to those in X-linked hypophosphatemia, which is caused by inactivating mutations in a phosphate-regulating endopeptidase called PHEX. Recombinant FGF-23 induces phosphaturia and hypophosphatemia in vivo, suggesting that it has a role in phosphate regulation. To determine whether FGF-23 circulates in healthy persons and whether it is elevated in those with oncogenic osteomalacia or X-linked hypophosphatemia, an immunometric assay was developed to measure it.Using affinity-purified, polyclonal antibodies against [Tyr223]FGF-23(206-222)amide and [Tyr224]FGF-23(225-244)amide, we developed a two-site enzyme-linked immunosorbent assay that detects equivalently recombinant human FGF-23, the mutant form in which glutamine is substituted for arginine at position 179 (R179Q), and synthetic human FGF-23(207-244)amide. Plasma or serum samples from 147 healthy adults (mean [+/-SD] age, 48.4+/-19.6 years) and 26 healthy children (mean age, 10.9+/-5.5 years) and from 17 patients with oncogenic osteomalacia (mean age, 43.0+/-13.3 years) and 21 patients with X-linked hypophosphatemia (mean age, 34.9+/-17.2 years) were studied.Mean FGF-23 concentrations in the healthy adults and children were 55+/-50 and 69+/-36 reference units (RU) per milliliter, respectively. Four patients with oncogenic osteomalacia had concentrations ranging from 426 to 7970 RU per milliliter, which normalized after tumor resection. FGF-23 concentrations were 481+/-528 RU per milliliter in those with suspected oncogenic osteomalacia and 353+/-510 RU per milliliter (range, 31 to 2335) in those with X-linked hypophosphatemia.FGF-23 is readily detectable in the plasma or serum of healthy persons and can be markedly elevated in those with oncogenic osteomalacia or X-linked hypophosphatemia, suggesting that this growth factor has a role in phosphate homeostasis. FGF-23 measurements might improve the management of phosphate-wasting disorders.

To examine longitudinal changes of bone mineral density (BMD) after parathyroidectomy (PTx) in patients undergoing maintenance hemodialysis (HD) with severe secondary hyperparathyroidism (HPT) to determine which factor contributes most to bone changes.Fifteen Japanese HD patients who had been refractory to medical therapy were subject to PTx with autotransplantation. We measured BMD by dual energy X-ray absorptiometry (DXA) at the lumbar spine (L2 - 4 BMD) and the distal 1/3 region of the radius (1/3R BMD) at 1, 3, 6, 12, 24, and 36 months after PTx.Baseline Z-score of BMD was markedly low at 1/3R (- 3.07) and slightly low at L2 - 4 (-0.59) in this group. A significant increase in L2 - 4 BMD was observed as early as one month after PTx, which was sustained afterwards. Annual percent changes in L2 - 4 and 1/3R BMD were + 15.6 % and + 6.4 %, respectively. The annual percent changes in BMD at both sites were positively associated with preoperative intact PTH levels (L2 - 4; r = 0.642, p = 0.010, 1/3R; r = 0.884, p0.001) and total alkaline phosphatase (ALP) levels (L2 - 4; r = 0.663, p = 0.007, 1/3R; r = 0.858, p0.001). Stepwise multiple regression analysis revealed that serum levels of intact PTH and ALP were the best predictors of both percentage and net changes in radial BMD with high determination coefficients (r 20.8).Successful PTx following appropriate supplementation with vitamin D and calcium provides a marked increase in lumbar BMD and a modest increase in radial BMD in HD patients with secondary HPT. Preoperative levels of PTH and ALP are useful for predicting postoperative changes in bone mass.

OBJECTIVE: A significant decrease in vitamin D receptor (VDR) and calcium-sensing receptor (CaSR) protein expression has been demonstrated recently in parathyroid (PT) adenomas. In this study, we investigated the relationships between the proliferative activity of parathyroid glands (PTGs) and the expression of VDR as well as CaSR, and compared it with the clinical severity in patients with primary hyperparathyroidism (1 degrees HPT). DESIGN: Seven patients with 1 degrees HPT were included in this study. Four patients with thyroid carcinoma served as controls. METHODS: Immunohistochemical staining was performed on serial sections of PTGs with specific antibodies against CaSR, VDR, and Ki67. Areas examined in each section were selected at random in relation to the gland size. The number of Ki67-positive cells was expressed as a labeling index (LI; positive cells per 1000 PT cells). The expression of CaSR and VDR was semi-quantitatively analyzed based on the intensity of staining. After averages of the scores from all areas were calculated, CaSR and VDR scores, and Ki67 LI were assigned to each gland for use in statistical analyses. RESULTS: In PT adenomas, scores of VDR and CaSR were markedly lower than in normal PTGs (P

This study presents a tsunami human damage prediction method employing numerical calculation and GIS (Geographical Information System) for Usa town, Tosa City, Shikoku Island, Japan. Sometime near the end of the first half of the twenty-first century, a huge earthquake is predicted to occur along the Nankai trough and costal areas facing the Pacific ocean of Shikoku Island. Much damage due to the resultant tsunamis will be caused, therefore, it is necessary to predict the extent of human damage for every town in high-risk areas. The number of tsunami victims was estimated by population in areas of maximum inundation. The number of deaths as a result of tsunami was estimated by a method which employed accumulated death toll of every area in terms of time and space, taking into account consideration of time necessary to begin to seek refuge after an earthquake, tsunami inundation depth on land, flow velocity and evacuation speed. As a result of this study a rapid decrease in death toll by early evacuation was shown quantitatively for the first time. Thus, with the method presented here, it is possible to estimate the extent of tsunami human damage on coastal regions, and may be useful as a tsunami human damage countermeasure. Language: en

Transforming growth factor (TGF) beta inhibits alkaline phosphatase (ALP) activity and mineralization in mouse osteoblastic MC3T3-E1 cells, whereas local administration of TGF-beta stimulates bone formation in vivo. We recently demonstrated that Smad3, a TGF-beta signaling molecule, promotes ALP activity and mineralization in MC3T3-E1 cells. Moreover, the target disruption of Smad3 in mouse is reported to cause a decrease in bone mineral density. These findings indicate that Smad3 plays an important role in the regulation of bone formation. However, why the effects of TGF-beta and Smad3 on ALP activity and mineralization are different remains unknown. The purpose of the present study is to clarify the role of mitogen-activated protein kinase (MAPK) in TGF-beta and Smad3 pathways in osteoblast. TGF-beta activated extracellular signal-regulated kinases/p42/p44 (ERK1/2), p38 MAPK, and c-Jun N-terminal kinase (JNK) in mouse osteoblastic MC3T3-E1 cells. The expression of dominant negative type Smad3, Smad3DeltaC, affected neither TGF-beta-activated MAPKs nor TGF-beta-inhibited ALP activity. Specific inhibitors of ERK1/2 activation (PD98059 and U0126), as well as JNK inhibitors (curcumin and dicumarol) antagonized the inhibitory effects of TGF-beta on ALP activity and mineralization, whereas the specific inhibitor of p38 MAPK (SB203580) did not affect them. PD98059 and curcumin enhanced Smad3-induced ALP activity and mineralization, whereas SB203580 inhibited them. In the luciferase reporter assay using 3TP-lux with the specific Smad3-responsive element, PD98059, and curcumin enhanced TGF-beta- and Smad3-induced transcriptional activity in MC3T3-E1 cells. On the other hand, TGF-beta-induced production of type I collagen was antagonized by curcumin but not by PD98059. The present study indicated that TGF-beta-responsive ERK1/2 and JNK cascades negatively regulate Smad3-induced transcriptional activity as well as ALP activity and mineralization in osteoblasts.

Transforming growth factor (TGF) beta is abundantly stored in bone matrix and appears to regulate bone metabolism. Although the Smad family proteins are critical components of the TGF-beta signaling pathways, the roles of Smad3 in the expression of osteoblastic phenotypes remain poorly understood. Therefore, this study was performed to clarify the roles of Smad3 in the regulation of proliferation, expression of bone matrix proteins, and mineralization in osteoblasts by using mouse osteoblastic cell line MC3T3-E1 cells stably transfected with Smad3. Smad3 significantly inhibited [3H]thymidine incorporation and fluorescent intensity of the MTT-dye assay, compared with empty vector. Moreover, Smad3 increased the levels of type I procollagen, osteopontin (OPN), and matrix Gla protein (MGP) mRNA in Northern blotting. These effects of Smad3 mimicked the effects of TGF-beta on the same cells. On the other hand, Smad3 greatly enhanced ALP activity and mineralization of MC3T3-E1 cells compared with empty vector, although TGF-beta inhibited ALP activity and mineralization of wild-type MC3T3-E1 cells. A type I collagen synthesis inhibitor L-azetidine-2-carboxylic acid, as well as osteocalcin (OCN), significantly antagonized Smad3-stimulated ALP activity and mineralization of MC3T3-E1 cells. In conclusion, this study showed that in mouse osteoblastic cells, Smad3 inhibited proliferation, but it also enhanced ALP activity, mineralization, and the levels of bone matrix proteins such as type I collagen (COLI), OPN, and MGP. We propose that Smad3 plays an important role in osteoblastic bone formation and might help to elucidate the transcriptional mechanism of bone formation and possibly lead to the development of bone-forming drugs.

Many clinical studies have shown that osteoporosis is associated with atherosclerosis and cardiovascular death. Although both high plasma levels of low density lipoprotein cholesterol (LDL-C) and low plasma levels of high density lipoprotein cholesterol (HDL-C) are known to be risk factors for atherosclerosis, it is unclear whether such lipid derangements are also associated with the pathogenesis of osteoporosis. In this study, we evaluated the relationships between plasma levels of total C, LDL-C, HDL-C, or triglyceride (TG) versus bone mineral density (BMD) at the lumbar spine, femoral neck, radius, or total body as well as the presence of vertebral fractures in 214 Japanese postmenopausal women (age range, 47-86 years, mean 62.7). Multiple regression analysis was performed between BMD at each skeletal site versus each lipid level adjusted for age, years after menopause, body mass index (BMI), and %fat. Plasma LDL-C levels were significantly and inversely correlated with the absolute values of both one-third radial (1/3R) and distal radial (UDR) BMD (p0.01), and tended to be inversely correlated with the absolute values of L-BMD (p=0.051). In contrast, plasma HDL-C levels were significantly and positively correlated with the absolute values of L, 1/3R and UDR BMD (p0.05). On the other hand, plasma TG levels were significantly lower in women with vertebral fractures than in those without fractures (97.0+/-36.5 vs. 126.4+/-65.8 mg/dl, mean+/-SD, p0.05). When multivariate logistic regression analysis was performed with the presence of vertebral fractures as a dependent variable and each lipid level adjusted for age, years after menopause, BMI, and %fat as independent variables, TG alone was selected as an index affecting the presence of vertebral fractures (odds ratio: 0.51, 95% confidential interval: 0.29-0.89 per SD increase, p0.05). Our study showed that plasma LDL-C and HDL-C levels were inversely and positively correlated with both R- and L-BMD values, respectively, while low plasma TG levels were associated with the presence of vertebral fractures in postmenopausal women. Thus, plasma lipids might be related to bone mass and bone fragility, and might be the common factor underlying both osteoporosis and atherosclerosis.

Antiresorptive agent-related osteonecrosis of the jaw (ARONJ) is an intractable, though rare, complication in cancer patients with bone metastases and patients with osteoporosis who are treated with antiresorptive agents, including bisphosphonates and denosumab. Despite the more than 10 years that have passed since the first cases of bisphosphonate-related osteonecrosis of the jaw (BRONJ) were reported, our understanding of the epidemiology and pathophysiology of ARONJ remains limited, and data supported by evidence-based medicine are still sparse. However, the diagnosis and staging of ARONJ, identification of risk factors, and development of preventive and therapeutic approaches have advanced significantly over the past decade. The Position Paper 2017 is an updated version of the Position Paper 2010 of the Japanese Allied Committee on Osteonecrosis of the Jaw, which now comprises six Japanese academic societies. The Position Paper 2017 describes a new diagnostic definition for ARONJ, as proposed by the American Association of Oral and Maxillofacial Surgeons (AAOMS), summarizes our current understanding of the pathophysiology of ARONJ based on a literature search, and suggests methods for physicians and dentists/oral surgeons to manage the disease. In addition, the appropriateness of discontinuing antiresorptive medications (drug holiday) before, during, and after invasive dental treatments is discussed extensively. More importantly, the manuscript also proposes, for the first time, the importance of interactive communication and cooperation between physicians and dentists/oral surgeons for the successful treatment of ARONJ. The Position Paper 2017 is intended to serve as a guide for improving the management of ARONJ patients in Japan.

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.

Background The prevalence of both lifestyle-related metabolic disorders and osteoporosis is increasing in Asia. Objectives To conduct a systematic review of the published literature to identify studies examining disorders of glucose and lipid metabolism (type 2 diabetes, hyperglycemia, hypercholesterolemia, hyperlipidemia, dyslipidemia, metabolic syndrome [MetS], and atherosclerosis) as risk factors for osteoporosis and fracture in Asian populations. Studies examining the relationship between metabolic disorders and bone mineral density (BMD) were also included. Methods EMBASE (including MEDLINE) and the Cochrane Library were searched. Studies conducted only within Asia, which reported multivariate analysis with a sample size of 200 or more subjects, were included. Results A total of 32 studies were included. All six studies examining diabetes and fracture found that subjects with diabetes had a significantly higher risk of fracture than did subjects without diabetes (risk estimate range 1.26–4.73). Two studies found that subjects with atherosclerosis had a significantly higher risk of fracture (risk estimate range 1.10–2.52). Studies consistently reported that MetS is likely associated with osteoporosis or decreased BMD in men but not women. No consistent association was found for diabetes and BMD, with studies reporting contrasting results. There was limited evidence investigating lipid metabolism and hyperglycemia and risk of fracture or bone loss in Asian populations. Conclusions These findings suggest that diabetes is a risk factor for fracture in Asian populations. MetS may be associated with bone loss in Asian men and atherosclerosis associated with increased fractures; however, caution is needed interpreting these findings given limitations in study design.

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. 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. 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. 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. Three-year denosumab treatment in Japanese subjects with osteoporosis showed a favorable benefit/risk profile.

Internal tandem duplication mutations in the Flt3 gene (ITD-FLT3) enhance cell migration toward the chemokine Cxcl12, which is highly expressed in the therapy-protective bone marrow niche, providing a potential mechanism underlying the poor prognosis of ITD-FLT3(+) acute myeloid leukemia. We aimed to investigate the mechanisms linking ITD-FLT3 to increased cell migration toward Cxcl12. Classification of the expression of Cxcl12-regulated genes in ITD-FLT3(+) cells demonstrated that the enhanced migration of ITD-FLT3(+) cells toward Cxcl12 was associated with the differential expression of genes downstream of Cxcl12/Cxcr4, which are functionally distinct from those expressed in ITD-FLT3(-) cells but are independent of the Cxcr4 expression levels. Among these differentially regulated genes, the expression of Rock1 in the ITD-FLT3(+) cells that migrated toward Cxcl12 was significantly higher than in ITD-FLT3(-) cells that migrated toward Cxcl12. In ITD-FLT3(-) cells, Rock1 expression and Mypt1 phosphorylation were transiently up-regulated but were subsequently down-regulated by Cxcl12. In contrast, the presence of ITD-FLT3 blocked the Cxcl12-induced down-regulation of Rock1 and early Mypt1 dephosphorylation. Likewise, the FLT3 ligand counteracted the Cxcl12-induced down-regulation of Rock1 in ITD-FLT3(-) cells, which coincided with enhanced cell migration toward Cxcl12. Rock1 antagonists or Rock1 shRNA abolished the enhanced migration of ITD-FLT3(+) cells toward Cxcl12. Our findings demonstrate that ITD-FLT3 increases cell migration toward Cxcl12 by antagonizing the down-regulation of Rock1 expression. These findings suggest that the aberrant modulation of Rock1 expression and activity induced by ITD-FLT3 may enhance acute myeloid leukemia cell chemotaxis to the therapy-protective bone marrow niche, where Cxcl12 is abundantly expressed.

Background Dipeptidyl peptidase-4 (DPP-4) inhibitors might have pleiotropic effects because receptors for incretin exist in various tissues, including liver. We examined whether DPP-4 inhibitors affect liver function in patients with type 2 diabetes. Material/Methods A retrospective review of 459 patients with type 2 diabetes who were prescribed DPP-4 inhibitors was performed. After exclusion of patients with hepatitis B or C, steroid use, and other diseases that might affect liver function and diabetes status, 224 patients were included in the analysis. Results Forty-four patients (19.6%) with liver injury defined by aspartate transaminase (AST) or alanine transaminase (ALT) over the normal level of 40 U/L. In the patients with liver injury, AST and ALT were significantly decreased after 6 months from the first date of DPP-4 prescription, with mean changes of −6.2 U/L [95% confidence interval (CI) −10.9 to −1.4, p=0.012] and of −11.9 U/L (95%CI −19.5 to −4.2, p=0.003), respectively. Percent changes in AST were significantly and negatively correlated with baseline AST and ALT (r=−0.27, p

Bone metablism of glucocorticoid-induced osteopororsis (GIO) is characterised by transient increase in bone resorption and persistent suppression of bone formation caused by glucocorticoid. Teriparatide is an ideal drug for GIO, because of antagonistic effect against that pathophysiological conditions. Based on new findings of treatment for GIO around the world, teriparatide was selected as one of alternative drugs of the first line agents for GIO in revised version of the guidelines on the management and treatment of GIO of the Japanese Society for Bone and Mineral Research : 2014 update.

Objective: To clarify the relationship between serum hyaluronan levels and vascular function in type 2 diabetic patients., Methods: A cross-sectional cohort study., Results: In multivariate regression analysis, endothelium-dependent flow-mediated dilation was associated with age and duration of diabetes, but not with serum hyaluronan level, while endothelium-independent nitroglycerine-mediated dilation (NMD) was only associated with serum hyaluronan level (standardized estimate = -0.401, p = 0.003). NMD in the lowest tertile of hyaluronan level was significantly higher than the other tertiles (15.9% versus 12.5% and 10.4%, p = 0.047 and p = 0.002, respectively)., Conclusions: Serum hyaluronan level may be useful as a surrogate marker for early changes in the vascular function, which often occurs in patients with diabetes mellitus.

Growth hormone (GH) as well as insulin like growth factor-1 (IGF-1) are essential hormones to maintain homeostasis of bone turnover by activating osteoblastogenesis and osteoclastogenesis. Results from GH replacement therapy for primary osteoporosis and adult-onset GH deficiency (AGHD) suggest that one year or more treatment period by this agent is required to gain bone mineral density (BMD) over the basal level after compensating BMD loss caused by dominant increase in bone resorption which was observed at early phase of GH treatment. A recent meta-analysis demonstrates the efficacy of GH replacement therapy on increases in BMD in male patients with AGHD. Additional analyses are needed to draw firm conclusions in female patients with AGHD, because insufficient amounts of GH might be administrated to them without considerations of influence of estrogen replacement therapy on IGF-1 production. Further observational studies are needed to clarify whether GH replacement therapy prevent fracture risk in these patients.

Vitamin D deficiency and advanced glycation end products (AGEs) are suggested to be involved in the pathogenesis of osteoporosis and sarcopenia. However, the effects of vitamin D and AGEs on myogenesis and the interaction between muscle and bone remains still unclear. We previously showed that osteoglycin (OGN) is secreted from myoblasts and stimulates osteoblastic differentiation, suggesting that it plays important roles in the interaction between muscle and bone. The aim of this study is thus to examine the effects of vitamin D and AGEs on myoblastic differentiation of C2C12 cells and osteoblastic differentiation of osteoblastic MC3T3-E1 cells through OGN expression. 1α,25-dihydroxyvitamin D3 (1,25D) and eldecalcitol, an active vitamin D analog, induced the expression of MyoD, myogenin and OGN, and these effects were abolished by vitamin D receptor (VDR) suppression by siRNA in C2C12 cells. Moreover, conditioned medium from 1,25D-pretreated C2C12 cells stimulated the expression of type 1 collagen and alkaline phosphatase in MC3T3-E1 cells, compared to control medium from 1,25D-untreated C2C12 cells. In contrast, conditioned medium from VDR-suppressed and 1,25D-pretreated C2C12 cells showed no effects. AGE2 and AGE3 suppressed the expression of MyoD, myogenin and OGN in C2C12 cells. Moreover, 1,25D blunted the AGEs' effects. In conclusion, these findings showed for the first time that active vitamin D plays important roles in myogenesis and muscle-induced osteoblastogenesis through OGN expression. Active vitamin D treatment may rescue the AGEs-induced sarcopenia as well as - suppressed osteoblastic differentiation via OGN expression in myoblasts.

In diabetic patients, advanced glycation end products (AGEs) cause bone fragility because of deterioration of bone quality. We previously showed that AGEs suppressed the mineralization of mouse stromal ST2 cells. TGF-β is abundant in bone, and enhancement of its signal causes bone quality deterioration. However, whether TGF-β signaling is involved in the AGE-induced suppression of mineralization during the osteoblast lineage remains unknown. We therefore examined the roles of TGF-β in the AGE-induced suppression of mineralization of ST2 cells and human mesenchymal stem cells. AGE3 significantly (P < .001) inhibited mineralization in both cell types, whereas transfection with small interfering RNA for the receptor for AGEs (RAGEs) significantly (P < .05) recovered this process in ST2 cells. AGE3 increased (P < .001) the expression of TGF-β mRNA and protein, which was partially antagonized by transfection with RAGE small interfering RNA. Treatment with a TGF-β type I receptor kinase inhibitor, SD208, recovered AGE3-induced decreases in osterix (P < .001) and osteocalcin (P < .05) and antagonized the AGE3-induced increase in Runx2 mRNA expression in ST2 cells (P < .001). Moreover, SD208 completely and dose dependently rescued AGE3-induced suppression of mineralization in both cell types. In contrast, SD208 intensified AGE3-induced suppression of cell proliferation as well as AGE3-induced apoptosis in proliferating ST2 cells. These findings indicate that, after cells become confluent, AGE3 partially inhibits the differentiation and mineralization of osteoblastic cells by binding to RAGE and increasing TGF-β expression and secretion. They also suggest that TGF-β adversely affects bone quality not only in primary osteoporosis but also in diabetes-related bone disorder.

Accumulating evidence shows that type 2 diabetes and chronic kidney disease (CKD) enhance fracture risk mainly by deteriorating bone quality. Vertebral fracture on X-ray films and hip fracture in past history in subjects of 50 years old or more are hallmarks to start medication for osteoporosis. Patients with diabetes or CKD who have no fracture could undergo drug treatments if their bone mineral density is osteopenic, considering the established link between these disorders and fracture risk.

Postprandial hyperglycemia is considered as a risk factor of cardiovascular disease. We hypothesized that early post-load hyperglycemia might be more useful surrogate marker to assess atherosclerosis than plasma glucose (PG) level at 120 minutes because the peak of post-load glucose by 75gOGTT is usually shown at 60 minutes. 75gOGTT and carotid echography were investigated in 108 subjects who visited our hospital to examine impaired glucose tolerance. The association of post-load plasma glucose and insulin levels with intima-media thickness (IMT) was examined. Simple correlation analyses showed that fasting PG (FPG) (r=0.26, p=0.013), PG60 (r=0.40, p0.001), PG90 (r=0.29, p=0.008), area under curve for PG (AUC-PG) (r=0.33, p=0.003), HbA1c (r=0.30, p=0.005), amount of PG increase at 60 minutes (PGΔ60) (r=0.39, p=0.002), and PGΔ90 (r=0.27, p=0.016), were significantly correlated with IMT. Multiple regression analysis using IMT as a dependent variable and PG60, FPG, HbA1c, and AUC-PG as independent variables showed that PG60 was only significantly and positively correlated with IMT (β=0.59, p=0.042). Moreover, PG60 and PGΔ60 were significantly and positively associated with IMT even after additional adjustment for classical atherosclerosis risk factors (β=0.30, p=0.005 and β=0.50, p=0.037, respectively). The cut-off values of PG60 and PGΔ60 to detect atherosclerosis (IMT1.1mm) were 188 and 101 mg/dL, respectively (p0.01). These findings show that early post-load hyperglycemia, particularly PG60 is a novel risk factor of atherosclerosis and useful to assess it.

Malnutrition is a common feature seen in chronic dialysis patients, and the survival rate of obese patients receiving such treatment is higher than that of lean patients. Irrespective of obesity or diabetes, dialysis patients commonly have insulin resistance, and the leading cause of death is cardiovascular (CV) disease. It has been reported that the concentration of p-cresol, a uremic toxin, is highly associated with CV events. As uremic toxin levels are high in dialysis patients, they may be involved in the pathogenesis of insulin resistance and CV disease in this population. However, little is known so far. Thus, we focused on this uremic toxin to examine its effects on adipocytes and their precursors. 3T3-L1 cells, a mouse preadipocyte cell line, were cultured until 90% confluency. The cells were then differentiated with 500 μM 3-isobutyl-methylxanthine, 250 nM dexamethasone, and 10 μg/mL insulin. Cell proliferation was evaluated by cell counting and bromodeoxyuridine (Brd-U) incorporation assay. Glucose uptake was estimated using radiolabeled 2-deoxyglucose. The range of concentrations of p-cresol used in the experiments was from 2 to 200 μM. The investigation of cell proliferation by cell counting revealed that, compared with control, 3T3-L1 cells treated with 100 and 200 μM p-cresol were significantly decreased in number at day 3 and day 7 of culture. The Brd-U incorporation assay also demonstrated similar inhibitory effects on cell proliferation, suggesting that p-cresol affected the normal cell cycle. Oil Red O staining at day 7 showed that the number of mature adipocytes was decreased by treatment with 200 μM p-cresol. Consistent with that finding, the number of apoptotic cells at day 7 was increased by treatment with 100 and 200 μM p-cresol. Peroxisome proliferator-activated receptor γ (PPARγ) mRNA expression increased time-dependently during the differentiation process of 3T3-L1 cells. p-Cresol dose-dependently decreased differentiation-induced mRNA expression of PPARγ. Uptake of 3H-labeled 2-deoxyglucose was markedly decreased by 200 μM p-cresol in the presence or in the absence of insulin, mainly because of the decreased number of mature adipocytes. High concentrations of p-cresol disturbed the cell cycle, induced apoptosis, inhibited the differentiation of preadipocytes into mature adipocytes, and decreased glucose uptake at baseline and after insulin stimulation. These findings indicate that accumulated p-cresol may induce reduction in adipose tissue, insulin resistance, and malnutrition, eventually leading to poor outcomes in chronic dialysis patients.

OBJECTIVE Primary hyperparathyroidism (pHPT) is a heterogeneous disease in its clinical course and severity. Previous studies have suggested an association between the clinical severity of pHPT and the genotypes of vitamin D receptor, oestrogen receptors and PTH molecules. The Ca-sensing receptor (CaR) is activated by an extracellular calcium ion and controls PTH secretion, and thus polymorphisms of CaR might be associated with the magnitude of PTH secretion and the clinical severity of pHPT. In this study, we examined the relationship between CaR polymorphisms and biochemical markers in pHPT patients. METHODS We analysed 105 Japanese pHPT patients (85 females and 20 males; mean age 55·6 ± 14·0 years). We determined the CaR genotypes of G990R and intron 5 polymorphisms with genomic DNA extracted from peripheral lymphocytes. The intron 5 polymorphism was defined as T/T, T/C and C/C. RESULTS In the G990R polymorphism, serum levels of both intact PTH and alkaline phosphatase (ALP) were significantly higher and the serum level of phosphorus was significantly lower in the RR group than in the GG group. In the intron 5 polymorphism, the T/T group showed significantly lower serum levels of intact PTH and Ca. Furthermore, patients with both the codon 990 RR and the intron 5 C allele (the RRC+ group) had significantly higher serum levels of intact PTH and ALP than did the other patients. CONCLUSIONS The present study is the first to show that CaR polymorphisms of G990R and intron 5 were closely associated with the magnitude of PTH secretion and/or PTH degradation as well as the clinical severity in pHPT patients.

OBJECTIVE Although total fat body mass (FM) is considered to be one of the major determinants of bone mass, the mechanism by which FM and bone mass are positively correlated remains unclear. Leptin, the product of the obese (ob) gene, is secreted from adipocytes and its plasma levels are known to be positively correlated with %fat (FM divided by total body weight). There is recent evidence suggesting that leptin directly stimulates osteoblastic differentiation. Thus it is possible that the anabolic action of this hormone on bone may participate in the positive correlation between FM and bone mass. In this study, we analysed the relationships between either plasma leptin levels or %fat vs. bone mineral density (BMD) values as well as the presence of vertebral compression fractures, and evaluated whether or not plasma leptin levels were associated with BMD or bone fragility in a manner independent of FM. PATIENTS One hundred and thirty-nine postmenopausal women (age 48–78 years, mean 62·5), who visited our outpatient clinic for the evaluation of osteoporosis. DESIGN and MEASUREMENTS Plasma concentrations of leptin after an overnight fast were measured by radioimmunoassay. BMD values were measured by dual-energy X-ray absorptiometry (DXA) at the lumbar spine, femoral neck and whole body. Distal one-third of radius BMD was measured by single photon absorptiometry (SPA). Vertebral fractures were assessed by lateral thoracic and lumbar spine radiographs. RESULTS Although neither plasma leptin levels nor %fat correlated with age, there was a significant positive correlation between plasma leptin levels and %fat (r = 0·563, P

Objective Skeletal involvement is a common clinical feature in acromegalic patients. Although several recent reports are available concerning bone mineral density (BMD) in acromegaly, the controversy still exists as to whether BMD of acromegalic patients is increased or not. The present study was performed to examine biochemical bone metabolic indices and BMD as well as body composition in 26 Japanese patients with active acromegaly and 26 control subjects matched for age, sex, race and height in a cross-sectional study. Measurements BMD of the lumbar spine and femoral neck, as well as body composition, was measured by dual-energy X-ray absorptiometry. Mid-radial BMD was measured by single-photon absorptiometry. We also determined serum levels of IGF-I, IGFBP-3 and osteocalcin (OC) as well as urinary levels of deoxy-pyridinoline (D-Pyr) and CrossLaps. Results Percent lean body mass was increased and percent fat mass was decreased in the acromegalic patients compared to control subjects. Serum levels of OC, as well as urinary levels of D-Pyr and CrossLaps, were significantly higher in acromegalic patients compared to control subjects (9.8 +/- 1.2 vs. 5.7 +/- 0.77 for OC; 11.8 +/- 1.66 vs. 5.0 +/- 0.49 for D-Pyr; 437.6 +/- 68.4 vs. 156.5 +/- 39.6 for CrossLaps). Z scores of BMD at mid-radius as well as lumbar spine and femoral neck were significantly higher in acromegalic patients compared to control subjects (1.086 +/- 0.311 vs. -0.060 +/- 0.274 for mid-radius; 1.022 +/- 0.280 vs. 0.319 +/- 0.165 for lumbar spine; 1.292 +/- 0.347 vs. 0.232 +/- 0.264 for femoral neck). Conclusions The present study revealed that a decrease in percent fat mass and an increase in percent lean body mass were observed in Japanese patients with active acromegaly. Bone mineral density at all sites and bone metabolic markers were also increased in acromegaly. The present findings provide additional evidence that the GH/IGF-I axis might play an important role in the maintenance of bone mass as well as the regulation of body composition in Japanese adults.

BACKGROUND: Although there have been some case reports suggesting that bone in patients with pseudohypoparathyroidism (PHP) might respond to parathyroid hormone (PTH), no information is available as to whether serum PTH concentration is related to bone metabolic markers or to bone mineral density (BMD) in PHP. OBJECTIVE: To address these relationships, by comparing intact serum PTH, bone metabolic markers and BMD in patients with PHP with those in patients with idiopathic hypoparathyroidism (IHP) and postoperative hypoparathyroidism (OHP). METHODS: Intact serum PTH, bone metabolic markers (osteocalcin, tartrate-resistant acid phosphatase, pyridinoline, deoxypyridinoline) and BMD by dual-energy X-ray absorptiometry or single-photon absorptiometry were measured in patients with PHP Ia (n=2) and PHP Ib (n=8). The results were compared with those in patients with IHP (n=5) and OHP (n=14). RESULTS: All bone metabolic markers measured were present in significantly greater amounts in patients with PHP Ib than in those with IHP+OHP. The Z score (standard deviation of average BMD at each age) of the BMD of femoral neck was significantly lower in patients with PHP Ib than in those with IHP+OHP. The Z scores of BMD of lumbar spine and radius were also lower in patients with PHP Ib than in those with IHP+OHP, but the difference was not significant. Moreover, the intact serum PTH concentrations were significantly and positively related to bone metabolic marker levels in all patients, and the intact serum PTH concentrations were significantly and negatively related to BMD of lumbar spine in PHP patients. CONCLUSIONS: These results suggest that PTH stimulates bone turnover in PHP Ib patients, resulting in a relatively lower BMD in PHP Ib patients than in IHP+OHP patients. The present study indicates that bones of most cases of PHP could respond to PTH.

There is accumulating evidence that interleukin-1 (IL-1) levels are increased locally at the site of active bone resorption in a variety of diseases including osteoporosis, periodontal disease and rheumatoid arthritis. However, the pathogenic role of IL-1 in bone loss remains to be fully elucidated. We present here additional evidence that IL-1beta enhances endothelial activation and thereby stimulates mobilization of peripheral blood mononuclear cells (PBMCs) from luminal to abluminal spaces across the endothelium. Furthermore, IL-1beta stimulates the differentiation of PBMCs into osteoclast-like cells with bone-resorbing activity in the presence of human osteoblastic SaOS-2 cells without systemic hormones. These findings provide circumstantial evidence for the hypothesis that IL-1beta generated in the bone microenviroment plays a stimulatory role in PBMC mobilization from the peripheral circulation and their subsequent differentiation into osteoclast-like cells in the bone tissue. In addition, the present study supports the notion that osteoclast progenitor cells might be derived from the peripheral circulating blood mononuclear cells in human.

Although there is clinical evidence showing that combined therapy with parathyroid hormone (PTH) and estrogen is additively effective in increasing the bone mass of patients with osteoporosis, the mechanism of the interaction between these hormones remains unclear. The present study was performed to determine whether estrogen would affect osteoblast proliferation and function modulated by PTH in human osteoblastic SaOS-2 cells. Human PTH-(1-34) significantly inhibited [(3)H]thymidine (TdR) incorporation, which was attenuated by 24 h pretreatment with 10(-10) to 10(-7) M 17 beta-estradiol (17 beta-E(2)) in a concentration-dependent manner. PTH significantly stimulated alkaline phosphatase (ALP) activity, collagen synthesis and type-1 procollagen mRNA expression after pretreatment with 17 beta-E(2 )in these cells. Tamoxifen, an anti-estrogen, antagonized these 17 beta-E(2)-induced effects. Pretreatment with insulin-like growth factor-I (IGF-I) mimicked estrogen action, and coincubation of 3 microg/ml anti-IGF-I antibody antagonized the effects of 17 beta-E(2 )as well as those of IGF-I. In the presence of 17 beta-E(2 )pretreatment, PTH strongly stimulated IGF-binding protein (IGFBP)-5 mRNA expression in these cells, and recombinant IGFBP-5 increased type-1 procollagen mRNA expression and ALP activity. In conclusion, estrogen attenuates PTH-induced inhibition of osteoblast proliferation and PTH stimulates osteoblast function in the presence of estrogen pretreatment. IGF-I and/or IGFBP-5 seemed to be involved in the estrogen-induced modulation of PTH action on osteoblast proliferation and function.

We examined the relationships between serum levels of intact parathyroid hormone (PTH) and alkaline phosphatase (ALP) versus bone mineral density (BMD) at the lumbar spine and radius in terms of their preoperative values and of their annual percentage and net changes after parathyroidectomy (PTX) in 44 Japanese patients (14 men and 30 women) with primary hyperparathyroidism (pHPT). Lumbar and radial BMD values were measured by dual energy X-ray absorptiometry and single photon absorptiometry and were used for evaluating the cancellous and cortical bone mass, respectively. Age- and sex-adjusted value (Z-score) of the radial BMD was significantly lower than that of the lumbar BMD before and after PTX (P < 0.05). In preoperative patients, serum levels of both intact PTH and ALP were significantly and negatively correlated with Z-score of the radial BMD (P < 0.05 and P < 0.001, respectively), but not with that of the lumbar BMD. After PTX, serum levels of calcium, phosphorus, ALP, and PTH became normal, and both lumbar and radial BMD values markedly increased over 1 year, with percentage changes of 12.2+/-1.4% and 11.6+/-1.6%, respectively, which were larger than those in any other Caucasian study previously documented. Even in patients without osteopenia (Z-score of BMD 20), lumbar and radial BMD values increased considerably after the operation (9.6+/-1.9% and 6.7+/-1.4%, respectively). Annual percentage and net changes in lumbar BMD were significantly and negatively correlated with those in ALP with high correlation coefficients, but those in radial BMD were correlated only with the annual net change in ALP but not with the percentage change. No significant correlations were observed between annual changes in either lumbar or radial BMD and those in intact PTH. Taken together, this study shows that PTX causes dramatic improvements in both the cancellous and cortical bone mass in Japanese pHPT patients regardless of the severity of their osteopenia, and suggests that the cancellous and cortical bones react differently to a preoperative endogenous PTH excess and a high bone turnover rate as well as to the postoperative normalization of a bone turnover rate in the patients.

カルシウム感知受容体 (CaSR) は副甲状腺ホルモン (PTH) 分泌調節に重要な役割を果たしているが, 近年, 副甲状腺の細胞増殖にも関与することが示唆されている. 我々はビタミンD受容体 (VDR) およびCaSRの細胞増殖への関与を検討するため, 重度の二次性副甲状腺機能亢進症症例から得られた副甲状腺切片を用い免疫組織化学的検討を行った.症例は34歳男性, 慢性糸球体腎炎による腎不全のため平成3年より維持血液透析中であったが, 極めて重度の二次性副甲状腺機能亢進症のため当院紹介となった. 血中補正Ca 10.9mg/dl, intact PTH 3500pg/ml, ALP 13729IU/L, osteocalcin 3140ng/ml, TRAP 44.0IU/Lと血中PTHおよび骨代謝回転の異常高値を呈した. ビタミンD経口パルス療法が無効であったため, 平成9年5月parathyroidectomy (PTx) を施行したところ, 骨痛, 貧血, Xp所見および骨代謝マーカー等検査値の著明な改善が認められた.切除された副甲状腺は4腺で合計2.5g, 一部結節形成を伴うびまん性増殖を示していた. 組織標本を用いVDR, CaSRおよび増殖マーカーであるKi 67抗原に対する抗体を用いて免疫染色を行った. その結果, 結節内にはKi 67陽性細胞が多数認められ増殖能の高いことが示された. また, びまん性増殖を示す腺においても増殖能の高い部位でのVDR, CaSR発現は増殖能の低い部位に比し著明に低下していた.PTH異常高値の病態は副甲状腺におけるVDR発現の低下のみならずCaSR発現の低下やこれらに起因する副甲状腺増殖能の亢進により説明されると考えられた.

OBJECTIVE Bone mineral density and growth hormone (GH) secretion rate both decline during normal human ageing. We evaluated the effects of recombinant human GH on markers of body composition and bone turnover in an open study in 8 elderly osteoporotic women aged 68–75 years (mean age 71 years). DESIGN Subjects were treated with GH as a single daily subcutaneous injection (0.125 IU/kg/week for the first 4 weeks and subsequently 0.25 IU/kg/week) for 48 weeks. RESULTS GH treatment caused a rapid (within 2 weeks) increase in serum levels of IGF-I and IGF-binding protein-3 (IGFBP-3) which was sustained throughout the study. Markers of bone formation and resorption were both gradually increased up to 24 weeks of GH treatment. The bone formation markers, osteocalcin (OC) and bone alkaline phosphatase, remained high during GH treatment, while the bone resorption marker, deoxypyridinoline (D-Pyr), tended to return to baseline levels after 24 weeks of GH therapy. GH treatment for 48 weeks caused a significant increase in hand grip and a decrease in waist/hip ratio. The mean percentage changes in bone mineral density (BMD) of mid-radius and lumbar spine were + 2.1% and + 1.2%, respectively, although they were not statistically significant. GH treatment was well tolerated and no major side-effects except mild oedema and joint pain were found. Since GH treatment produced durable increases in bone formation markers, BMD continued to be monitored after discontinuation of GH treatment for another 48 weeks, during which significant increases in radial and lumbar BMD (8.1 ± 2.1 and 3.8 ± 1.4% above pre- treatment values, respectively) were recorded. CONCLUSION These results indicate that GH attenuates the decrease in muscle strength and bone mass as well as the gain of abdominal fat with ageing in elderly women. The present data provide useful information about the application of GH treatment in elderly women.

OBJECTIVE Genetic contributions to bone mineral density (BMD) and bone turnover are well known. In the present study, we analysed the relationship between restriction fragment length polymorphisms of the PTH gene and the development of primary hyperparathyroidism (pHPT) as well as its severity. PATIENTS Seventy-nine pHPT patients and 104 age-matched healthy controls were analysed. DESIGN AND MEASUREMENTS PTH genotypes were determined by polymerase chain reaction and BstB I or Dra II restriction fragment length polymorphisms. The presence and absence of BstB I or Dra II restriction sites of the PTH gene were indicated by B and b or D and d, respectively. BMD levels at the lumbar spine and at the radius were measured in all subjects. Serum levels of calcium, phosphorus, alkaline phosphatase and intact PTH were measured in pHPT patients. RESULTS There were no differences in the frequencies of these PTH genotypes between pHPT patients and controls. In control subjects, lumbar BMD was significantly higher in BB genotype than in Bb/bb genotypes. In pHPT patients, there was no difference of BMD between BB and Bb/bb genotypes. In pHPT patients, serum calcium level was significantly higher in those with the BB genotype than Bb/bb genotypes. On the other hand, there was no association between DraII polymorphism and BMD in both controls and pHPT patients, but serum intact PTH level was significantly higher in DD genotype than Dd/dd genotype in pHPT patients. Moreover, serum levels of ALP and intact PTH were significantly higher in the PTH BBDD haplotype, compared to those in haplotypes other than BBDD. CONCLUSIONS The present study suggests that the BstB I polymorphism of PTH gene is closely related to bone mineral density and that PTH gene polymorphisms do not seem to affect the development of primary hyperparathyroidism but may relate to the severity of primary hyperparathyroidism.

原発性副甲状腺機能亢進症の発症機構や病態の重症度と遺伝的素因との関連などについて多くの知見が集積されつつある.一方血清カルシウム測定のルーチン化に伴い,本疾患が無症候性で発見される頻度が急増してきている.本疾患の唯一の根治的治療法は病的副甲状腺の摘除であるが,無症候例に対する対応が問題となってきている.最近カルシウム感知受容体作働薬が開発され,保存的治療への道が開かれる可能性がある.

The present study was performed to investigate the age-dependent changes in body composition and the possible role of growth hormone (GH), insulin-like growth factor (IGF)-I and IGF-binding protein-3 (IGFBP-3) in these changes in postmenopausal Japanese women. A total of 161 Japanese women aged 45-88 years (mean 62) were enrolled in the cross-sectional study. Body composition (bone mineral content (BMC), lean body mass (LBM) and fat) was measured by dual-energy X-ray absorptiometry, and the percentage of BMC, LBM and fat was calculated by dividing each absolute value of body composition by total body mass. Urinary GH concentration divided by creatinine in nocturnal urine samples collected just after waking was used as an index of endogenous GH secretion. Serum levels of IGF-I and IGFBP-3 were measured by RIA. Urinary GH levels as well as serum levels of IGF-I and IGFBP-3 declined with age. BMC, %BMC and LBM also declined with age, while fat mass and %fat did not obviously change with age. Urinary GH levels as well as serum levels of IGF-I and IGFBP-3 correlated positively with BMC, even if age was taken into account. On the other hand, urinary GH correlated negatively with fat and %fat. In contrast, serum levels of IGF-I and IGFBP-3 correlated positively with fat and %fat. LBM did not correlate with either urinary GH or serum IGFBP-3 levels but exhibited a weakly positive correlation with serum IGF-I level. The present study suggests that the GH-IGF-I-IGFBP-3 axis positively regulates bone mass, and that GH and IGF-I-IGFBP-3 inversely regulate fat mass, i.e. GH negatively and IGF-I-IGFBP-3 positively regulates it.

Several lines of evidence indicate that estrogen inhibits parathyroid hormone (PTH)-induced bone resorption in vivo and in vitro. However, its precise mechanism remains unknown. The present study was performed to investigate whether osteoclast precursor cells possess the receptors for PTH/PTH-related protein (PTHrP) and/or estrogen and to clarify the mechanism by which estrogen affects PTH-induced osteoclast-like cell (Ocl) formation. The polymerase chain reaction (PCR) product corresponding in size to the mouse PTH/PTHrP receptor cDNA was detected in mouse hemopoietic blast cells supported by granulocyte-macrophage colony-stimulating factor (GM-CSF) as well as in osteoblastic MC3T3-E1 cells. The nucleotide sequence of the PTH/PTHrP receptor PCR product of hemopoietic blast cells was found to be 95.4% identical to that of PTH/PTHrP receptor cDNA of rat osteoblastic ROS cells. The PCR product corresponding in size to the mouse estrogen receptor cDNA was detected in mouse hemopoietic blast cells supported by GM-CSF as well as in MC3T3-E1 cells. The nucleotide sequence of the estrogen receptor PCR product of hemopoietic blast cells was completely identical to that of mouse estrogen receptor cDNA. 17Beta-estradiol (17beta-E2) but not 17alpha-E2 dose dependently antagonized Ocl formation stimulated by human (h) PTH(1-34) at a minimal effective concentration of 10(-10) M in the hemopoietic blast cell culture. 17Beta-E2 also significantly inhibited Ocl formation stimulated by 10(-8) M hPTHrP(1-34), while it did not affect 1,25-dihydroxyvitamin D3-induced Ocl formation. However, 10(-8) M 17beta-E2 significantly inhibited Ocl formation stimulated by dibutyryladenosine cAMP (10(-4) M) and Sp-cAMPS (10(-4) M), an activator of cAMP-dependent protein kinase (PKA) as well as forskolin (10(-5) M). In contrast, 17beta-E2 did not affect Ocl formation by either phorbol myristate acetate (10(-7) M), an activator of protein kinase C (PKC), or A23187 (10(-7) M), a calcium ionophore. The pretreatment with 17beta-E2 significantly inhibited Ocl formation induced by the combined treatment with PTH and PKC inhibitors (H7 or staurosporine), while it did not affect Ocl formation stimulated by the combined treatment with PTH and Rp-cAMPS, a PKA inhibitor. The present data indicate that estrogen inhibits PTH-stimulated Ocl formation by directly acting on hemopoietic blast cells, possibly through blocking a PKA pathway but not a calcium/PKC pathway.

The effects of carboxyl-terminal (C-) PTH fragments, (35-84), (53-84) and (69-84), on the proliferation and function of osteoblastic UMR-106 cells were compared with those of amino-terminal (N-) (1-34) and intact (I-) (1-84) PTH. I-PTH as well as N-PTH at 10(-8)M significantly inhibited [3H] thymidine incorporation and stimulated alkaline phosphatase activity in UMR-106 cells. No C-PTH fragments affected them. In contrast, the expression of type-1 procollagen mRNA in these cells was stimulated by all C-PTH fragments, inhibited by N-PTH and not affected by I-PTH. All C-PTH fragments except (69-84) as well as N-PTH and I-PTH stimulated IGFBP-5 mRNA expression. The present study suggests that the C-portion of the PTH molecule exercises biological activities in mRNA expression of type-1 procollagen as well as IGFBP-5 in osteoblasts, and that it might be involved in the anabolic action of PTH on bone in vivo.

The present study was performed to investigate the role of insulin-like growth factor I (IGF-I), IGF-binding protein-2 (IGFBP-2), and IGFBP-3 in age-dependent bone loss in postmenopausal Japanese women. One hundred and sixty-five Japanese women aged 43-88 years (mean age, 62) were enrolled in the cross-sectional study. Bone mineral density (BMD) was measured at the lumbar spine, femoral neck, and midradius by dual-energy X-ray absorptiometry or single-photon absorptiometry. Serum levels of IGF-I, IGFBP-2, and IGFBP-3 were measured by radioimmunoassay. BMD at all sites as well as serum levels of IGF-I and IGFBP-3 declined with age, while the serum IGFBP-2 level increased with age. Serum IGFBP-3 and -2 levels were positively and negatively correlated with the serum IGF-I level, respectively. Serum IGF-I and IGFBP-3 levels showed positive correlationship with BMD at any site, particularly at the midradius, while the serum IGFBP-2 level showed negative correlation with BMD. Multiple regression analyses showed age-independent positive correlation between the serum IGF-I level and BMD at all sites as well as age-independent positive correlation between the serum IGFBP-3 level and midradius BMD. The relationship between susceptibility to osteoporotic spinal fracture and serum IGF-I, IGFBP-3, or -2 levels was examined by decade to exclude the influence of aging. Serum levels of IGF-I and IGFBP-3 were significantly lower in subjects with spinal fractures than those without fractures at any decade. No significant difference of serum IGFBP-2 level was observed between subjects with and without fractures. The present findings suggest that IGF-I and IGFBP-3 are important to maintaining bone mass quantitatively as well as qualitatively, and that the determination of serum IGF-I and IGFBP-3 levels could be clinically useful to predict the severity of osteoporosis, particularly the risk of bone fracture associated with osteoporosis.