Osteoporosis In Japanese Women Research Articles

Cost effectiveness of romosozumab versus teriparatide for severe postmenopausal osteoporosis in Japan.

This study aims to assess the cost effectiveness of romosozumab versus teriparatide, both sequenced to alendronate, for the treatment of severe postmenopausal osteoporosis in Japanese women previously treated with bisphosphonates. A Markov model was used to assess the relative cost effectiveness of 1 year of romosozumab versus 2 years of teriparatide, both sequenced to alendronate for a total treatment duration of 5 years. Outcomes for a cohort of women with a mean age of 78 years, a T-score ≤-2.5 and a previous fragility fracture were simulated over a lifetime horizon. The analysis was conducted from the perspective of the Japanese healthcare system and used a discount rate of 2% per annum. To inform relative fracture incidence, the bone mineral density (BMD) advantage of romosozumab over teriparatide was translated into relative risks of fracture, using relationships provided by a meta-regression of osteoporosis therapy trials. Outcomes were assessed in terms of lifetime costs (2020 US dollars) and quality-adjusted life years (QALYs). Base case results showed that, compared with teriparatide/alendronate, romosozumab/alendronate reduced costs by $5134 per patient and yielded 0.045 additional QALYs. Scenario analyses and probabilistic sensitivity analysis confirmed that results are robust to uncertainty in model assumptions and inputs. Results show that romosozumab/alendronate produces greater health benefits at a lower total cost than teriparatide/alendronate.

Fracture risk assessment tool (FRAX) and for the diagnosis of osteoporosis in Japanese middle-aged and elderly women: Chiba bone survey.

Osteoporosis not only increases bone fracture risk but also affects survival in postmenopausal women. Although osteoporosis is diagnosed based on low bone mineral density (BMD) determined by dual energy X-ray absorptiometry (DXA), BMD measurement is sometimes difficult because DXA is not widely available in the community. The Fracture Risk Assessment tool (FRAX) can predict 10-year major osteoporotic fracture risk and hip fracture risk with or without femoral neck BMD. The FRAX has not been investigated adequately in community-dwelling Japanese women. We administered the FRAX tool in 13,421 Japanese women who underwent DXA-based forearm BMD measurement in Chiba Bone Survey, a population-based, multicenter, cross-sectional study of postmenopausal osteoporosis conducted in Chiba, Japan. Mean age was 57.77 ± 9.24 years. Mean forearm BMD was 87.94 ± 17.00% of young adult mean (YAM). Mean FRAX major osteoporotic fracture risk without femoral neck BMD was 7.06 ± 5.22%. BMD decreased and percentage of osteoporosis increased from age 55 onward. Age distribution of percentage of subjects with FRAX major osteoporotic fracture risk >15% was similar to that of percentage of osteoporosis subjects. We identified the cutoff value of FRAX major osteoporotic fracture risk for diagnosis of osteoporosis as 7.2%. With this cutoff, the positive likelihood ratio was over 1.0 at age 55 and above but accuracy was low. In conclusion, FRAX without femoral neck BMD reflects bone status, and may be useful to diagnose osteoporosis in Japanese women aged 55 and above, although the sensitivity was low for osteoporosis screening, especially in middle-aged women.

Prevalence of sarcopenia in Japanese women with osteopenia and osteoporosis

Sarcopenia and osteoporosis are both significant health burdens among postmenopausal women. This study examined associations between sarcopenia and osteopenia/osteoporosis in Japanese women and evaluated the prevalence of sarcopenia in women with osteopenia and osteoporosis. A total of 2400 Japanese women aged 40-88years underwent dual-energy x-ray absorptiometry (DXA) scans of the whole body, lumbar spine, and total hip. Osteopenia and osteoporosis were defined according to World Health Organization criteria using bone mineral density (BMD) of the lumbar spine or hip. Sarcopenia was defined as a relative skeletal muscle index (RSMI) more than 2 standard deviations below the mean for a young adult reference population, calculated as the appendicular skeletal muscle mass (ASM) obtained from whole-body DXA divided by height in meters squared (RSMI=ASM/height(2)). Significant and marginal/moderate positive correlations were observed between RSMI and lumbar spine/total hip BMDs (r=0.197 and r=0.274, respectively; p<0.0001 each). The BMDs of the lumbar spine and total hip showed significant moderate negative correlations with age (r=-0.270 and r=-0.375, respectively; p<0.0001 each), but RSMI showed no association with age in this population (r=0.056). When osteopenia/osteoporosis was defined using lumbar spine BMD, prevalences of sarcopenia in subjects with normal BMD, osteopenia and osteoporosis were 10.4, 16.8, and 20.4%, respectively. When osteopenia/osteoporosis was defined using total hip BMD, the prevalences of sarcopenia in these subjects were 9.0, 17.8, and 29.7%, respectively. A Chi-square test for independence showed a significant association between sarcopenia and osteopenia/osteoporosis (p<0.0001). These results indicate that sarcopenia is significantly associated with osteopenia and osteoporosis in Japanese women.

Nucleotide variations in genes encoding carbonic anhydrase 8 and 10 associated with femoral bone mineral density in Japanese female with osteoporosis

Osteoporosis is a multi-factorial common disease, which is caused by combination of genetic as well as environmental factors. Among several factors, osteoclast acidification pathways during bone resorption might play an important role. Carbonic anhydrases, consisting of a gene family, are essential for pH regulation by the osteoclast. Clinically, use of carbonic anhydrase inhibitors has been known to be associated with a bone-sparing effect as judged by spine bone mineral density (BMD). Here, we investigated single nucleotide polymorphisms (SNPs) in carbonic anhydrase genes that are expressed in bone tissues, i.e., CA8 and CA10, for possible association with femoral and lumbar BMD among 337 Japanese women with osteoporosis participated in BioBank Japan project. Significant correlation was observed between CA8 SNP, rs6984526, and femoral BMD (P = 0.00029); homozygous carriers of the major (C) allele (n = 166) had the highest BMD (0.754 +/- 0.006 g/cm(2), mean +/- SD), while heterozygous carriers (n = 135) were intermediate (0.741 +/- 0.07 g/cm(2)) and homozygous T-allele carriers (n = 31) had the lowest BMD (0.691 +/- 0.012 g/cm(2)). CA8 SNP as well displayed significant association with lumbar BMD in recessive model (P = 0.00017). In addition, CA10 SNP, rs2106329, also displayed strong association with femoral BMD (P = 0.00002). The results suggest that the variations of CA8 and CA10 loci may be important determinants of osteoporosis in Japanese women.

Effect of alendronate on glucocorticoid-induced osteoporosis in Japanese women with systemic autoimmune diseases: versus alfacalcidol

Glucocorticoids-induced osteoporosis is a serious problem for patients with systemic autoimmune disease requiring relatively long-term glucocorticoid treatment. Effectiveness of alendronate for the prevention of glucocorticoids-induced osteoporosis was evaluated in comparison with that of alfacalcidol in Japanese women with autoimmune disease excluding rheumatoid arthritis. Loss of bone mass was evaluated with bone mineral density (BMD) of lumber vertebrae, bone resorption was with urinary N-telopeptide for type I collagen (NTX), and bone formation was with serum bone-specific alkaline phosphatase (B-ALP). A total of 33 patients who were treated with oral glucocorticoids (≥5 mg/day of prednisolone equivalence) for more than 6 months were randomized into two groups; alendronate group (n = 17) received 5 mg/day of alendronate, and alfacalcidol group (n = 16) received 1.0 μg/day of alfacalcidol for 24 months with glucocorticoids. The dose of alendronate was the maximal dose approved in Japan. BMD had tendency to decrease with alfacalcidol, while increase with alendronate. The difference in BMD change between the two groups was significant by 4.3% at 18 months and by 4.2% at 24 months (both P < 0.05). Bone resorption was significantly reduced only with alendronate; NTX was decreased by 28 to 35% at 6 to 24 months (P < 0.05), but not changed with alfacalcidol at 24 months. The bone formation was found to be unchanged according to the B-ALP measured between the two groups. In conclusion, the treatment of 5 mg alendronate daily is more effective than alfacalcidol for preventing the glucocorticoid-induced osteoporosis by the mechanism of reducing bone resorption in Japanese women with systemic autoimmune disease.

Association of genetic variations of genes encoding thrombospondin, type 1, domain-containing 4 and 7A with low bone mineral density in Japanese women with osteoporosis

Twins and family studies have shown that genetic factors are important determinants of bone mass. Important aspects of bone mineral density (BMD) regulation are endocrine systems, notably hormonal regulation of adrenal corticoids, as indicated by clinical knowledge of glucocorticoid-induced osteoporosis. Glucocorticoid is known to negatively regulate bone mass in vivo, and glucocorticoid increases thrombospondin messenger ribonucleic acid (mRNA) levels. We studied single nucleotide polymorphisms (SNPs) in genes encoding thrombospondin, type 1, domain-containing 4 and 7A (THSD4 and THSD7A) for possible association with lumbar and femoral BMD among 337 Japanese women with osteoporosis who participated in the BioBank Japan project. Genetic variations of THSD4 and THSD7A loci displayed significant association with lumbar and femoral BMD. Most significant correlation was observed for THSD7A SNP rs12673692 with lumbar BMD (P = 0.00017). Homozygous carriers of the major (G) allele had the highest BMD [0.886 +/- 0.011 g/cm2, mean +/- standard deviation (SD)], whereas heterozygous carriers were intermediate (0.872 +/- 0.013 g/cm2) and homozygous A-allele carriers had the lowest (0.753 +/- 0.023 g/cm2). THSD4 SNP rs10851839 also displayed strong association with lumbar BMD (P = 0.0092). In addition, both THSD7A and THSD4 displayed significant association with femoral BMD in a recessive model (P = 0.036 and P = 0.0046, respectively). Results suggest that variations of THSD7A and THSD4 loci may be important determinants of osteoporosis in Japanese women.

Effect of alendronate on glucocorticoid-induced osteoporosis in Japanese women with systemic autoimmune diseases: versus alfacalcidol

Glucocorticoids-induced osteoporosis is a serious problem for patients with systemic autoimmune disease requiring relatively long-term glucocorticoid treatment. Effectiveness of alendronate for the prevention of glucocorticoids-induced osteoporosis was evaluated in comparison with that of alfacalcidol in Japanese women with autoimmune disease excluding rheumatoid arthritis. Loss of bone mass was evaluated with bone mineral density (BMD) of lumber vertebrae, bone resorption was with urinary N-telopeptide for type I collagen (NTX), and bone formation was with serum bone-specific alkaline phosphatase (B-ALP). A total of 33 patients who were treated with oral glucocorticoids (>or=5 mg/day of prednisolone equivalence) for more than 6 months were randomized into two groups; alendronate group (n = 17) received 5 mg/day of alendronate, and alfacalcidol group (n = 16) received 1.0 mug/day of alfacalcidol for 24 months with glucocorticoids. The dose of alendronate was the maximal dose approved in Japan. BMD had tendency to decrease with alfacalcidol, while increase with alendronate. The difference in BMD change between the two groups was significant by 4.3% at 18 months and by 4.2% at 24 months (both P < 0.05). Bone resorption was significantly reduced only with alendronate; NTX was decreased by 28 to 35% at 6 to 24 months (P < 0.05), but not changed with alfacalcidol at 24 months. The bone formation was found to be unchanged according to the B-ALP measured between the two groups. In conclusion, the treatment of 5 mg alendronate daily is more effective than alfacalcidol for preventing the glucocorticoid-induced osteoporosis by the mechanism of reducing bone resorption in Japanese women with systemic autoimmune disease.

A Comparison Study of the Reference Curves of Bone Mineral Density at Different Skeletal Sites in Native Chinese, Japanese, and American Caucasian Women

To understand the differences among reference curves for bone mineral density (BMD) for Chinese, Japanese, and American Caucasian women, we measured the BMD at the anteroposterior (AP) lumbar spine (L1-L4), lateral lumbar spine (L2-L4), hip (including the femoral neck, trochanter, intertrochanter, Ward's triangle, and total hip), and ultradistal forearm by the dual-energy X-ray absorptiometry (DXA) in a total of 2728 healthy Chinese women, aged 5-96 years. Documented BMD data for Japanese women and device manufacturer's BMD new reference databases (including the NHANES III dataset) for American Caucasian women were also used in this study. The cubic regression model was found to fit best in analyzing the age-associated variations of BMD at various sites in Chinese women, i.e., the equations had the largest coefficient of determination (R2). At the AP/Lat spine, trochanter, intertrochanter, and Ward's triangle, BMD reference curves for Chinese women were lower than those for Japanese or Caucasian women, while at the femoral neck, total hip, and ultradistal forearm, the reference curves for Chinese women were higher than those for Japanese women, with overlaps and crossing of the curves for some age spans in comparing the Chinese and Caucasian women. There were significant differences in the peak BMD (PBMD) at various sites among the Chinese, Japanese, and Caucasian women (P = 0.000). The PBMDs for Chinese women at the lumbar spine and various sites of the hip were 5.7% +/- 2.1% (mean +/- SD, range, 2.7-7.9%) lower than those for Japanese women and 5.1% +/- 2.7% (range, 0.5-7.2%) lower than those for Caucasian women; however, the PBMDs for Chinese women were 26.2% higher than those for Japanese women and 10% higher than those for Caucasian women at the ultradistal forearm. After the PBMD, average T-scores of Chinese women for losses at the AP lumbar spine with increasing age were nearly identical to those for Japanese women, but both were greater than those for Caucasian women. The average T-scores for BMD loss at various sites in Chinese women were higher than those for both Japanese and Caucasian women except at the femoral neck, where the T-scores of Chinese women were exceeded by those of both Japanese and Caucasian women. Estimated from the T-score curve of BMD loss, the age of osteoporosis occurrence at the femoral neck in Chinese women was about 10 years later than that in Japanese or Caucasian women; at the AP spine, Chinese women were similar to Japanese women; at the other sites, the age for occurrence of osteoporosis in Chinese women was about 5-15 years earlier than that in either Japanese or Caucasian women. There are differences in prevalence or odds ratio (OR) of osteoporosis at the same skeletal region for Chinese, Japanese, and Caucasian women aged > or = 50 years or at different skeletal regions in women of the same race. The prevalences of osteoporosis at various regions of the hip in Chinese women are 10.1-19.8% and ORs are 22.0-32.3, of which prevalence at the femoral neck is the lowest (10.1%); the prevalences of osteoporosis in Japanese women are 11.6-16.8% and ORs are 21.1-26.3, of which prevalence at the femoral neck is the lowest (11.6%); and the prevalences of osteoporosis in Caucasian women are 13.0-20.0% and ORs are 19.4-48.9, of which prevalence at the femoral neck is the highest (20%). In conclusion, racial differences in BMD reference curves, prevalences, and risks of osteoporosis at various skeletal sites exist among native Chinese, Japanese, and American Caucasian women.

Bone mineral density of the spine, hip and distal forearm in representative samples of the Japanese female population: Japanese Population-Based Osteoporosis (JPOS) Study.

Low bone mineral density (BMD) is one of the most important elements for the diagnosis of osteoporosis and screening people with higher risk of fractures. To establish the criterion value of BMD for the diagnosis of osteoporosis and to estimate the prevalence rate of osteoporosis in Japanese women, we performed a Japanese population-based osteoporosis (JPOS) study. The subjects were 4550 women aged 15 through 79 years randomly selected from seven municipalities throughout Japan. The sample size was determined to ensure that the observed mean BMD would remain within 2.5% from the real value with a probability of 0.95 in each of the 5-year age groups. The study comprised bone mass measurements by dual-energy X-ray absorptiometry at the spine (L2-4), hip and distal forearm, body size measurements and detailed interviews on medical and gynecologic history. After excluding those subjects with apparent or suggested abnormalities affecting bone mass from 3985 women (87.6%) who completed the study, 3465 women remained and served as the subjects. We present 5-year age-specific mean values of BMD and cut-off values for the diagnosis of osteoporosis according to World Health Organization (WHO) and the Japanese Society of Bone and Mineral Research (JSBMR) criteria. The cut-off levels at the spine and the distal radius proposed in this study were similar to those proposed by the JSBMR but the cut-off level at the femoral neck in this study was 4.7% higher than that of the JSBMR. The prevalence rates of osteoporosis according to WHO criteria in the present subjects aged 50 through 79 years were calculated as 38.0% at the spine, 11.6% at the femoral neck and 56.8% at the distal one-third site of the radius, and those in the Japanese female population of the same age were estimated to be 35.1%, 9.4% and 51.2%, respectively. A fivefold difference was observed among the prevalence rates at different skeletal sites, which suggests that the different definitions of osteoporosis should be established for the different skeletal sites. The prevalence rate diagnosed at the femoral neck seemed to be lower in the present study than those reported for Caucasians. This might account for a lower incidence rate of hip fracture in Japanese women.

Association of the C-509-->T polymorphism, alone of in combination with the T869-->C polymorphism, of the transforming growth factor-beta1 gene with bone mineral density and genetic susceptibility to osteoporosis in Japanese women.

Transforming growth factor-beta1 is an important local regulator of bone metabolism, acting downstream of estrogen and cooperatively with vitamin D. The possible association of a C 509-->T polymorphism in the promoter region of the transforming growth factor-beta1 gene, alone or in combination with a T869-->C (Leu10-->Pro) polymorphism, with bone mineral density and genetic susceptibility to osteoporosis was investigated in 625 postmenopausal Japanese women. The frequencies of the CC, CT, and TT genotypes of the C-509-->T polymorphism in the study population were 24%, 49%, and 27%, respectively. A significant association of C-509-->T genotype with bone mineral density was detected: lumbar spine (L2-L4) and total body bone mineral density values were 7% and 5% lower, respectively, in individuals with the TT genotype than in those with the CT or CC genotype. The serum concentration of transforming growth factor-beta1 did not vary with C-509-->T genotype. Multivariable logistic regression analysis, with adjustment for age, height, body weight, time since menopause, smoking status, body fat mass, and lean mass, revealed a significantly higher frequency of the TT genotype of the C-509-->T polymorphism in 286 individuals with osteoporosis than in 170 normal controls. Analysis of combined C-509-->T and T869-->C genotypes showed that L2-L4 bone mineral density decreases and the prevalence of osteoporosis increases with the number of T alleles. These results suggest that the C-509-->T polymorphism, alone or in combination with the T869-->C polymorphism, of the transforming growth factor-beta1 gene is a genetic determinant of bone mass, and that the number of T alleles in the combined genotype is a risk factor for the genetic susceptibility to osteoporosis in postmenopausal Japanese women.

Association of Estrogen Receptor β Gene Polymorphism with Bone Mineral Density

Chromosomal mapping of the human estrogen receptor β (ERβ) gene by fluorescence in situ hybridization (FISH) reveals that ERβ is located at human chromosome 14, region q23-24.1, where the aberration of DNA copy number in the bone disorders is frequently involved. Then, we investigated the association between dinucleotide (cytosine-adenine; CA) repeat polymorphism located in the flanking region of ERβ gene and bone mineral density (BMD) in 204 healthy postmenopausal Japanese women. The genotype was classified into “A” through “O” according to the number of the repeats, from 18 to 32. BMD was expressed in Z score (a deviation from the weight-adjusted average BMD of each age using the standard deviation as a unit). When we separate the subjects into two groups bearing at least one I allele (26 CA repeats) and those who did not, the former subjects had significantly higher Z score of L2-4 BMD (mean ± standard deviation; 0.674 ± 1.53 vs 0.128 ± 1.38; P = 0.027). These data suggest that genetic variation at the ERβ locus may be associated with some determinants for BMD and the possible involvements of this polymorphism in the cause of postmenopausal osteoporosis in Japanese women.

The soya bean: so small yet so mighty

The role of diet in contributing to the incidence of coronary heart disease, cancer and other common Western diseases is attracting increasing attention. Foods which provide different biologically active compounds, such as phyto‐oestrogens, have been extensively studied and epidemiological evidence suggests that populations consuming a diet high in phyto‐oestrogens have a lower risk of these diseases. This paper reviews some of the key studies on soy isoflavones which suggest that the incorporation of soy protein into the British diet may offer important health benefits. Non‐steroidal dietary oestrogens are found in high concentrations in the traditional diets of the Far East, and by vegans who consume large amounts of soy protein. Consumption of isoflavones across Asia varies considerably and it is estimated that between 25 to 45mg of isoflavones is consumed daily, compared to as little as 5mg daily in Western countries. It is well established that modification of dietary fat, especially saturated fat, soluble fibre and total calories have a role in coronary heart disease risk. In a meta‐analysis of 38 controlled trials on soy proteins, it was concluded that significant reductions in serum and total LDL cholesterol could be achieved. A wide range of epidemiological data shows strong correlations between a diet high in soy protein and vegetables and a reduced risk of breast cancer. The incidence of osteoporosis in Japanese women is significantly lower than in Western women and dietary factors such as soy protein intake may be important in sustaining this protection.

Association of Bone Mineral Density with a Polymorphism of the Peroxisome Proliferator-Activated Receptor γ Gene: PPARγ Expression in Osteoblasts

The peroxisome proliferator-activated receptor γ (PPARγ) protein as well as its transcript was detected in primary osteoblasts derived from rat calvariae. To analyze the possible involvement of PPARγ in the human bone metabolism, association between bone mineral density (BMD) and a polymorphism of PPARγ gene was investigated in Japanese postmenopausal women. We examined a polymorphism corresponding to a silent C → T transition located in exon 6 of the PPARγ gene, that was previously reported to be associated with plasma leptin levels in the obese. The frequencies of the C and T alleles in the population studied here were 0.851 and 0.149, respectively. When we separated the subjects into two groups, one bearing at least one T allele (CT + TT) and the other which did not (CC), the former subjects had lower BMD (Z score of total body; 0.056 ± 1.00. L2-4; −0.25 ± 1.26, mean ± standard deviation). These data suggest that there is an association between the restriction fragment length polymorphism (RFLP) of PPARγ gene and BMD and the possible involvement of this single nucleotide polymorphism (SNP) in the cause of postmenopausal osteoporosis in Japanese women.

Vitamin D receptor gene polymorphisms are associated with osteoporosis in Japanese women

Vitamin D receptor gene polymorphisms are associated with osteoporosis in Japanese women