Associations between organophosphate esters and bone mineral density in adults in the United States: 2011-2018 NHANES.

BACKGROUND: Organophosphate esters (OPEs) are used extensively as flame retardants and plasticizers. Laboratory studies have shown that OPEs exhibit osteotoxicity by inhibiting osteoblast differentiation; however, little is known about how OPEs exposure is associated with bone health in humans. OBJECTIVES: We conducted a cross-sectional study to investigate the association between OPEs exposure and bone mineral density (BMD) in adults in the United States using data from the 2011-2018 National Health and Nutrition Examination Survey (NHANES). METHODS: Multivariate linear regression models were used to assess the association between concentrations of individual OPE metabolites and BMDs. We also used the Bayesian kernel machine regression (BKMR) and quantile g-computation (qgcomp) models to estimate joint associations between OPE mixture exposure and BMDs. All the analyses were stratified according to gender. RESULTS: A total of 3546 participants (median age, 40 years [IQR, 30-50 years]; 50.11% male) were included in this study. Five urinary OPE metabolites with a detection rate of > 50% were analyzed. After adjusting for the potential confounders, OPE metabolite concentrations were associated with decreased total-body BMD and lumbar spine BMD in males, although some associations only reached significance for bis(1-chloro-2-propyl) phosphate (BCPP), dibutyl phosphate (DBUP), and bis(2-chloroethyl) phosphate (BCEP) (ß = -0.013, 95% CI: -0.026, -0.001 for BCPP and total-body BMD; ß = -0.022, 95% CI: -0.043, -0.0001 for DBUP and lumbar spine BMD; ß=-0.018, 95% CI: -0.034, -0.002 for BCEP and lumbar spine BMD). OPE mixture exposure was also inversely associated with BMD in males, as demonstrated in the BMKR and qgcomp models. CONCLUSIONS: This study provides preliminary evidence that urinary OPE metabolite concentrations are inversely associated with BMD. The results also suggested that males were more vulnerable than females. However, further studies are required to confirm these findings.

A phase III randomized, double-blind, placebo-controlled trial of the denosumab biosimilar QL1206 in postmenopausal Chinese women with osteoporosis and high fracture risk.

The current study evaluated the efficacy and safety of a denosumab biosimilar, QL1206 (60 mg), compared to placebo in postmenopausal Chinese women with osteoporosis and high fracture risk. At 31 study centers in China, a total of 455 postmenopausal women with osteoporosis and high fracture risk were randomly assigned to receive QL1206 (60 mg subcutaneously every 6 months) or placebo. From baseline to the 12-month follow-up, the participants who received QL1206 showed significantly increased bone mineral density (BMD) values (mean difference and 95% CI) in the lumbar spine: 4.780% (3.880%, 5.681%), total hip :3.930% (3.136%, 4.725%), femoral neck 2.733% (1.877%, 3.589%) and trochanter: 4.058% (2.791%, 5.325%) compared with the participants who received the placebo. In addition, QL1206 injection significantly decreased the serum levels of C-terminal crosslinked telopeptides of type 1 collagen (CTX): -77.352% (-87.080%, -66.844%), and N-terminal procollagen of type l collagen (P1NP): -50.867% (-57.184%, -45.217%) compared with the placebo over the period from baseline to 12 months. No new or unexpected adverse events were observed. We concluded that compared with placebo, QL1206 effectively increased the BMD of the lumbar spine, total hip, femoral neck and trochanter in postmenopausal Chinese women with osteoporosis and rapidly decreased bone turnover markers. This study demonstrated that QL1206 has beneficial effects on postmenopausal Chinese women with osteoporosis and high fracture risk.

[Systematic review and Meta-analysis of Gusongbao preparation in treatment of primary osteoporosis].

This study aims to provide evidence for clinical practice by systematically reviewing the efficacy and safety of Gusongbao preparation in the treatment of primary osteoporosis(POP). The relevant papers were retrieved from four Chinese academic journal databases and four English academic journal databases(from inception to May 31, 2022). The randomized controlled trial(RCT) of Gusongbao preparation in the treatment of POP was included after screening according to the inclusion and exclusion criteria. The quality of articles was evaluated using risk assessment tools, and the extracted data were subjected to Meta-analysis in RevMan 5.3. A total of 657 articles were retrieved, in which 15 articles were included in this study, which involved 16 RCTs. A total of 3 292 patients(1 071 in the observation group and 2 221 in the control group) were included in this study. In the treatment of POP, Gusongbao preparation+conventional treatment was superior to conventional treatment alone in terms of increasing lumbar spine(L2-L4) bone mineral density(MD=0.03, 95%CI[0.02, 0.04], P<0.000 01) and femoral neck bone mineral density, reducing low back pain(MD=-1.69, 95%CI[-2.46,-0.92], P<0.000 1) and improving clinical efficacy(RR=1.36, 95%CI[1.21, 1.53], P<0.000 01). Gusongbao preparation was comparable to similar Chinese patent medicines in terms of improving clinical efficacy(RR=0.95, 95%CI[0.86, 1.04], P=0.23). Gusongbao preparation was inferior to similar Chinese patent medicines in reducing traditional Chinese medicine syndrome scores(MD=1.08, 95%CI[0.44, 1.71], P=0.000 9) and improving Chinese medicine syndrome efficacy(RR=0.89, 95%CI[0.83, 0.95], P=0.000 4). The incidence of adverse reactions of Gusongbao preparation alone or combined with conventio-nal treatment was comparable to that of similar Chinese patent medicines(RR=0.98, 95%CI[0.57, 1.69], P=0.94) or conventio-nal treatment(RR=0.73, 95%CI[0.38, 1.42], P=0.35), and the adverse reactions were mainly gastrointestinal discomforts. According to the available data, Gusongbao preparation combined with conventional treatment is more effective than conventional treatment alone in increasing lumbar spine(L2-L4) bone mineral density and femoral neck bone mineral density, reducing low back pain, and improving clinical efficacy. The adverse reactions of Gusongbao preparation were mainly gastrointestinal discomforts, which were mild.

Clinical and genetic analysis in 185 Chinese probands of osteogenesis imperfecta.

INTRODUCTION: Osteogenesis imperfecta (OI) is a well-known heritable disorder of connective tissue characterized by skeletal fragility and low bone mass. Nearly 90% of patients with OI have disease variants in COL1A1 and COL1A2 that encode for the α1 and α2 chains of type I collagen. MATERIALS AND METHODS: A retrospective analysis of 185 probands who were diagnosed with OI in Shanghai Jiao Tong University Affiliated Sixth People's Hospital from March 2005 to December 2019 was performed. RESULTS: A total of 140 mutations in COL1A1 and 45 mutations in COL1A2 were identified, of which 18 variations were novel. In the phenotype analysis, there were more sporadic cases than familial OI cases in China (54.6% vs. 45.4%, P < 0.001). A total of 98.9% of patients presented with a fracture history. The most common fracture sites were extremity long bones (femur, tibia-fibula and radius-ulna accounted for 36.6%, 17.1% and 11.7%, respectively). Patients with OI types III and IV, especially type III, had a higher proportion of dentinogenesis imperfecta (DI) than patients with OI type I (55% vs. 28%, P < 0.001). Interestingly, G767S and D1219N in COL1A1 and G337S in COL1A2 were the most frequent (3.52%, 2.11% and 8.89%, respectively), which seem to be hotspot mutations in the COL1A1 and COL1A2 genes in Chinese patients. CONCLUSIONS: This study describes the mutations in the main pathogenic genes, COL1A1 and COL1A2, and the clinical characteristics of osteogenesis imperfecta in China. Furthermore, these findings help reveal the genetic basis of Asian OI patients and contribute to genetic counselling.

Association between LGR4 polymorphisms and peak bone mineral density and body composition.

INTRODUCTION: Leucine-rich repeat-containing G protein-coupled receptor 4 (LGR4) could affect differentiation of osteoblasts and bone mass through potentiating Wnt/ß-catenin signaling. LGR4 is also relevant to glycolipid metabolism. The present study aims to explore the relationship between genetic variations in LGR4 gene and peak bone mineral density (peak BMD) and body composition phenotypes in Chinese nuclear families. MATERIALS AND METHODS: 22 single-nucleotide polymorphisms (SNPs) were selected and five blocks were constructed in LGR4. Body composition (lean mass and fat mass) and peak BMD were measured by dual-energy X-ray absorptiometry (DXA). Quantitative transmission disequilibrium test (QTDT) analysis was used to explore the relationship between LGR4 genotypes and the mentioned phenotypes. RESULTS: For QTDT analysis after 1000 permutations, significant within-family associations were observed between rs11029986 and total fat mass (TFM) and percentage of TFM (PFM) (P = 0.014 and 0.011, respectively), rs12787344, rs4128868, rs4923445, and rs7936621 and body mass index (BMI) (P = 0.008, 0.003, 0.046, and 0.003, respectively), rs11029986 and total hip BMD (P = 0.026), and rs12796247, rs2219783, and lumbar spine BMD (P = 0.013 and 0.027, respectively). Haplotypes GCGT and AAGC (both in block 3) were observed in significant within-family association with BMI (P = 0.003 and 0.002, respectively). CONCLUSION: It is the first family-based association analysis to explore and demonstrate significant associations between LGR4 genotypes and variations of peak BMD and body composition in young Chinese men. The results are consistent with the findings that recent studies revealed, and confirm the critical relationship between LGR4 gene and both BMD and body composition.

Genetic variants in the PLS3 gene are associated with osteoporotic fractures in postmenopausal Chinese women.

Plastin 3 (PLS3) has been identified as a candidate gene for bone fragility in the Rotterdam study (RS) population. So far, however, whether PLS3 polymorphisms are genetic risk factors for osteoporosis in Asian population remains unclear. In order to investigate the association between genetic variants in PLS3 and the risk of fragility fracture and/or bone mineral density (BMD) in postmenopausal Chinese women, we conducted a case-control association study. A total of 1083 postmenopausal patients with osteoporotic fractures and 2578 unrelated non-fracture controls in Shanghai were enrolled. Seven SNPs, including six tagSNPs in PLS3 and one identified genetic risk factor (rs140121121) for osteoporosis in the RS population, were genotyped in all the participants. BMD at lumbar spine and hip sites were measured in 2578 controls. Association between SNPs and the risk of osteoporotic fractures and/or BMD were analyzed. The GC genotype of rs757124 and AC genotype of rs10521693 were associated with lumbar vertebral fracture (P = 0.020 and 0.046, respectively). The association between tagSNPs and BMD were analyzed only in 2546 controls to avoid biased conclusion. rs757124 was significantly associated with BMD at lumbar spine and hip sites. GG genotype had the highest BMD at lumbar spine (L1-4), while CC genotype had the highest BMD at hip sites. Our results suggest that polymorphisms in PLS3 are genetic loci for osteoporosis in postmenopausal Chinese women.

NOVEL MUTATIONS IN THE WNT1, TMEM38B, P4HB, AND PLS3 GENES IN FOUR UNRELATED CHINESE FAMILIES WITH OSTEOGENESIS IMPERFECTA.

OBJECTIVE: Osteogenesis imperfecta (OI) is a group of heritable fragile bone diseases, and the majority are caused by pathogenic variants in the COL1A1 and COL1A2 genes. We sought to identify the genetic causes and phenotypes of OI in Chinese patients without COL1A1 or COL1A2 mutations. METHODS: Twenty-three patients who were diagnosed with sporadic OI but did not carry COL1A1/2 mutations were recruited, and their genomic DNA was analyzed using targeted next-generation sequencing of rare OI-related genes. The resulting damaging mutations in the probands and their parents were verified using Sanger sequencing. Moreover, the efficacy of long-term bisphosphonate treatment was evaluated in proband 1. RESULTS: Compound heterozygous variants in the WNT1 and TMEM38B genes were identified in proband 1 and proband 2, respectively. A heterozygous mutation in the P4HB gene was identified in proband 3, and a hemizygous mutation in PLS3 was identified in proband 4. The unaffected parents of the probands (except the father of proband 4) with mutations in the WNT1, TMEM38B, and PLS3 genes were heterozygous carriers of each of the variants, respectively. Notably, proband 3 had the characteristic exophthalmos, flat nasal bridge and flat, wide forehead. None of the patients presented with dentinogenesis imperfecta or hearing loss. Furthermore, bisphosphonates exerted beneficial effects on proband 1, who carried the WNT1 mutations, by increasing bone mineral density Z-score, reshaping the compressed vertebrae and decreasing the fracture risk. CONCLUSION: We identified novel mutations and expanded the spectrum of phenotypes and genotypes of the extremely rare disorder OI. ABBREVIATIONS: BMD = bone mineral density; MIM = Mendelian Inheritance in Man; OI = osteogenesis imperfecta; PDI = protein disulfide isomerase.

Association of serum uric acid levels with osteoporosis and bone turnover markers in a Chinese population.

Recent evidence shows that uric acid is protective against some neurological diseases, but can be detrimental in many metabolic and cardiovascular disorders. In this study, we examined the association between serum uric acid levels and bone metabolism in Chinese males and postmenopausal females. A total of 943 males and 4256 postmenopausal females were recruited in Shanghai. The levels of serum uric acid and bone turnover markers (BTMs) were detected along with other biochemical traits. In addition, the fat distribution was calculated through MRI and image analysis software, and bone mineral density (BMD) was determined using dual-energy X-ray absorptiometry. For postmenopausal females, the prevalence of osteoporosis was significantly lower in the hyperuricemia group compared with the normouricemic group (P=4.65E-06). In females, serum uric acid level was significantly associated with osteoporosis, with odds ratio (OR) and 95% confidence interval (95% CI) of 0.844 [0.763; 0.933] (P=0.0009) after adjusting for age, body mass index, HbA1c, lean mass, visceral and subcutaneous fat areas, albumin, 25-hydroxyvitamin D3 [25(OH)D3], and parathyroid hormone (PTH). In females, serum uric acid level was positively correlated with the BMD of the femoral neck (ß±SE: 0.0463±0.0161; P=0.0042), total hip (ß±SE: 0.0433±0.0149; P=0.0038) and L1-4 (ß±SE: 0.0628±0.0165; P=0.0001) after further adjusting for age, BMI, HbA1c, lean mass, VFA, SFA, albumin, 25(OH)D3 and PTH. Regarding BTMs, serum uric acid level was negatively correlated with N-terminal procollagen of type I collagen (PINP) in females (ß±SE: -0.1311±0.0508; P=0.0100). In summary, our results suggest that uric acid has a protective effect on bone metabolism independent of body composition in Chinese postmenopausal females.

Calcifediol (25-hydroxyvitamin D) improvement and calcium-phosphate metabolism of alendronate sodium/vitamin D3 combination in Chinese women with postmenopausal osteoporosis: a post hoc efficacy analysis and safety reappraisal.

BACKGROUND: Vitamin D (VD) insufficiency or deficiency is a frequent comorbidity in Chinese women with postmenopausal osteoporosis (PMO). The present study aimed to investigate 25-hydroxyvitamin D [25(OH) D] improvement and calcium-phosphate metabolism in Chinese PMO patients treated with 70 mg of alendronate sodium and 5600 IU of vitamin D3 (ALN/D5600). METHODS: Chinese PMO women (n = 219) were treated with 12-month ALN/D5600 (n = 111) or calcitriol (n = 108). Changes in 25(OH) D at month 12 were post hoc analyzed by the baseline 25 (OH) D status using the longitudinal analysis. The main safety outcome measures included serum calcium and phosphate and 24-h urine calcium, and the repeated measures mixed model was used to assess the frequencies of the calcium-phosphate metabolic disorders. RESULTS: Absolute change in mean serum 25(OH) D level was the greatest in VD-deficient patients and least in VD-sufficient patients at months six and 12 (both, P < 0.01). Serum calcium level remained significantly lower in the ALN/D5600 treatment group than in the calcitriol treatment group throughout the 12 months. Mean 24-h urine calcium slightly increased in the ALN/D5600 treatment group and significantly increased in the calcitriol treatment group (+ 1.1 and + 0.9 mmol/L at months six and 12; both, P < 0.05). Calcitriol treatment was associated with more frequent hypercalciuria at month six (9.4% vs. 18.5%, P = 0.05), but not at month 12 (12.3% vs. 13.0%). CONCLUSION: Baseline VD status predicted 25(OH) D improvement in PMO patients on 12-month ALN/D5600 treatment. The daily use of 0.25 µg of calcitriol was associated with more frequent hypercalciuria at month six, compared to ALN/5600 treatment, necessitating the safety re-evaluation of calcitriol at a higher dosage.

Reports of 17 Chinese patients with tumor-induced osteomalacia.

Tumor-induced osteomalacia (TIO) is a rare acquired form of hypophosphatemic osteomalacia, which is usually attributed to the overproduction of fibroblast growth factor 23 (FGF-23) by benign mesenchymal neoplasms. Localization and thereafter surgical resection of tumors lead to a cure. The present study aimed to investigate the clinical data, diagnostic methods, and follow-up after tumor resection at one medical center in Shanghai to characterize the profile of this rare disorder and to share our successful experience in diagnosis and treatment. Twenty-three patients with adult-onset hypophosphatemia osteomalacia seen in Shanghai Sixth People's Hospital from 2009 to 2014 and 95 normal individuals were enrolled. After taking a medical history and performing a physical examination, we analyzed the laboratory results (including the serum FGF-23 levels) and localized the tumors by 18F-fluorodeoxyglucose positron emission tomography and computed tomography (18F-FDG PET/CT), 99mTc-octreotide (99mTc-OCT) scintigraphy, and magnetic resonance imaging (MRI). On the basis of the results of laboratory tests and imaging findings, tumor resection was conducted in 17 patients with a certain diagnosis of TIO. The results demonstrated that the 17 patients (nine men and eight women, average age 46.6 ± 12.9 years) had TIO. FGF-23 level was elevated in 94.1 % of patients (16 of 17 patients) . Serum phosphorus level decreased in 100 % of patients. 18F-FDG PET/CT revealed five tumors, 99mTc-OCT scintigraphy revealed two tumors, physical examination revealed nine tumors, and MRI revealed one tumor, among which 58.8 % of the causative tumors (10 of 17 tumors) were located in the lower extremities. After tumor resection, serum phosphorus levels normalized in 100 % of patients (all 17 patients) in 4-21 days and FGF-23 levels decreased in 90 % of patients (nine of ten patients). We found 64.7 % of the tumors (11 of 17 tumors) were phosphaturic mesenchymal tumors or a phosphaturic mesenchymal tumor mixed connective tissue variant. Measurement of serum phosphorus and FGF-23 levels in patients with suspected TIO is of paramount importance for diagnosing of TIO. 18F-FDG PET/CT, 99mTc-OCT scintigraphy, and physical examination play a considerable role in revealing TIO-associated tumors. TIO-associated tumors were more frequently located in the lower extremities than in other places; thus, the lower extremities need to be carefully checked. Complete surgical resection results in normalization of parameters in laboratory tests and relief of symptoms of TIO patients.

Association between SNPs and haplotypes in the METTL21C gene and peak bone mineral density and body composition in Chinese male nuclear families.

The methyltransferase-like 21C gene (METTL21C), which is mainly expressed in muscle, can promote the differentiation of myoblasts to myotubes and reduce glucocorticoid-induced apoptosis of osteocytes. The purpose of this study was to explore the association between single nucleotide polymorphisms of METTL21C and peak bone mineral density (BMD), body mass index, total fat mass (TFM), and total lean mass (TLM) in Chinese young men. Fifteen tagging single nucleotide polymorphisms were genotyped, and haplotype blocks were derived in 400 Chinese male nuclear families. The peak BMD of the lumbar and hip, TFM, and TLM were measured by dual-energy X-ray absorptiometry. The association analyses were performed by a quantitative transmission disequilibrium test. Both TLM and TFM had a significant positive effect on peak BMD, but the positive regulation of TLM was stronger than that of TFM. After 1000 permutations, significant within-family associations were found between rs9585961 and lumbar spine BMD and femoral neck BMD, rs9518810 and femoral neck BMD, and rs599976 and body mass index, TFM, and percentage fat mass (all P < 0.05). The association analyses with haplotypes showed that haplotype AG in block 1 was significantly associated with TFM (P = 0.031) and haplotype CAG in block 2 was significantly associated with lumbar spine BMD (P = 0.020). Our study, for the first time, demonstrates that the polymorphisms and haplotypes of METTL21C contribute to the peak BMD and TFM in Chinese males, which suggests that as a quantitative trait locus with potential pleiotropy it may have an influence on osteoporosis and obesity.

Novel mutations of TCIRG1 cause a malignant and mild phenotype of autosomal recessive osteopetrosis (ARO) in four Chinese families.

Human autosomal recessive osteopetrosis (ARO), also known as infantile malignant osteopetrosis, is a rare genetic bone disorder that often causes death. Mutations in T-cell immune regulator 1 (TCIRG1) are a frequent cause of human ARO. Six additional genes (TNFSF11, TNFRSF11A, CLCN7, OSTM1, SNX10, PLEKHM1) were also found to be associated with human ARO. In order to expand the mutation spectrum and clinical diversity for a better understanding of the ARO phenotype and to further investigate the clinical characteristics of benign subjects with ARO, we here report five individuals with ARO from four unrelated Chinese families. X-ray examination was conducted and bone turnover markers were assayed. The gene of T-cell immune regulator 1 (TCIRG1) was screened and analyzed. Monocyte-induced osteoclasts were prepared and their resorption ability was studied in vitro. We identified five novel mutations (c.66delC, c.1020+1_1020+5dup, c.2181C>A, c.2236+6T>G, c.692delA) in these patients. Four patients displayed a malignant phenotype, three of them died, and one who received bone marrow transplantation survived. The remaining one, a 24-year-old male from a consanguineous family, was diagnosed based on radiological findings but presented no neurological or hematological defects. He was homozygous for c.2236+6T>G in intron 18; this mutation influenced the splicing process. An in vitro functional study of this novel splicing defect showed no resorption pits on dentine slices. TCIRG1-dependent osteopetrosis with a mild clinical course was observed for the first time in Chinese population. The present findings add to the wide range of phenotypes of Chinese patients with TCIRG1-dependent ARO and enrich the database of TCIRG1 mutations.

Association of bone turnover markers with glucose metabolism in Chinese population.

The association between type 2 diabetes (T2DM) and bone metabolism has been discussed previously but is controversial. In this study we aimed to evaluate the association of bone turnover markers with glucose metabolism in Chinese population, in which 919 males and 4171 postmenopausal females in a region of Shanghai were recruited. Anthropometric and biochemical traits related to glucose and bone metabolism were analyzed. Participants were classified according to their glucose tolerance as normal glucose tolerance (NGT), impaired glucose regulation (IGR) or T2DM. Males and females were analyzed separately, and then associations between bone turnover markers (BTMs) and glucose metabolism were evaluated. The results showed that in females, the serum levels of N-terminal osteocalcin (N-MID), N-terminal procollagen of type I collagen (PINP) and ß-cross-linked C-telopeptide of type I collagen (ß-CTX) were significantly decreased in the T2DM group compared to the NGT group (P<0.01). When age, body mass index, serum lipids, fat percentage, visceral fat area, subcutaneous fat area, anti-diabetic medicines, PINP, N-MID and ß-CTX were included in one logistic model, N-MID (OR [95% CI]: 0.954 [0.932; 0.976]; P=0.0001) was significantly associated with T2DM in females. In females, N-MID was associated with insulin sensitivity and HOMA-ß. PINP was significantly associated with HOMA-ß, GUTT-ISI, Stumvoll first-phase insulin secretion index (STU-1) and Stumvoll second-phase insulin secretion index (STU-2), but ß-CTX was associated only with HOMA-ß (ß±SE: 0.1331±0.0311; P=1.95×10-5) and GUTT-ISI (ß±SE: 0.0727±0.0229; P=0.0015). In males, N-MID was significantly correlated with HOMA-ß (ß±SE: 0.3439±0.0633; P=7.75×10-8), GUTT-ISI (ß±SE: 0.1601±0.0531; P=0.0027) and STU-1 (ß±SE: 0.2529±0.1033; P=0.0146). Significant associations were also detected between ß-CTX and HOMA-ß (ß±SE: 0.2736±0.0812; P=0.0009). This study reveals that BTMs are highly associated with T2DM, insulin sensitivity and beta cell function in both Chinese males and postmenopausal females.

OPG, RANKL, and RANK gene polymorphisms and the bone mineral density response to alendronate therapy in postmenopausal Chinese women with osteoporosis or osteopenia.

OBJECTIVE: The aim of the study was to explore the association between OPG, RANKL, and RANK gene variations and the bone mineral density (BMD) response to alendronate therapy in postmenopausal Chinese women with osteoporosis or osteopenia. MATERIALS AND METHODS: In the present study, 40 single-nucleotide polymorphisms (SNPs) in the OPG, RANKL, and RANK genes were genotyped in 501 postmenopausal Chinese women with osteoporosis or osteopenia who were given alendronate (70 mg weekly) orally for 1 year. The BMD at the lumbar spine 1-4 (L1-L4), femoral neck, and total hip was measured. RESULTS: A total of 442 patients completed 1 year of alendronate therapy. The rs7239261 SNP of the RANK gene was significantly associated with baseline L1-L4 BMD (P=0.0004) after correction for age and BMI. Participants with the SNP A allele (C/A and A/A) had a higher BMD than those with the C/C genotype (C/A vs. C/C, P=0.001; A/A vs. C/C, P=0.025). Haplotypes AG of rs7239261-rs12969154, GG of rs3826619-rs11877530, and CACG of rs1805034-rs8083511-rs17069895-rs7231887 in the RANK gene were genetic protective factors toward a higher baseline L1-L4 BMD. No association was observed between any SNP or haplotype of the OPG, RANKL, and RANK genes and the response of BMD to alendronate therapy. CONCLUSION: The RANK gene might contribute to genetic variability in L1-L4 BMD in postmenopausal Chinese women with osteoporosis or osteopenia. No evidence of an association between any SNP or haplotype of the OPG, RANKL, and RANK genes and the response of BMD to alendronate therapy was found in postmenopausal Chinese women with osteoporosis or osteopenia.

Two novel mutations of CLCN7 gene in Chinese families with autosomal dominant osteopetrosis (type II).

Autosomal dominant osteopetrosis type II (ADO-II) is a heritable bone disorder characterized by osteosclerosis, predominantly involving the spine (vertebral end-plate thickening, or rugger-jersey spine), the pelvis ("bone-within-bone" structures) and the skull base. Chloride channel 7 (CLCN7) has been reported to be the causative gene. In this study, we aimed to identify the pathogenic mutation in four Chinese families with ADO-II. All 25 exons of the CLCN7 gene, including the exon-intron boundaries, were amplified and sequenced directly in four probands from the Chinese families with ADO-II. The mutation site was then identified in other family members and 250 healthy controls. In family 1, a known missense mutation c.296A>G in exon 4 of CLCN7 was identified in the proband, resulting in a tyrosine (UAU) to cysteine (UGU) substitution at p.99 (Y99C); the mutation was also identified in his affected father. In family 2, a novel missense mutation c.865G>C in exon 10 was identified in the proband, resulting in a valine (GUC) to leucine (CUC) substitution at p.289 (V289L); the mutation was also identified in her healthy mother and sister. In family 3, a novel missense mutation c.1625C>T in exon 17 of CLCN7 was identified in the proband, resulting in an alanine (GCG) to valine (GUG) substitution at p.542 (A542V); the mutation was also identified in her father. In family 4, a hot spot, R767W (c.2299C>T, CGG>TGG), in exon 24 was found in the proband which once again proved the susceptibility of the site or the similar genetic background in different races. Moreover, two novel mutations, V289L and A542V, occurred at a highly conserved position, found by a comparison of the protein sequences from eight vertebrates, and were predicted to have a pathogenic effect by PolyPhen-2 software, which showed "probably damaging" with a score of approximately 1. These mutation sites were not identified in 250 healthy controls. Our present findings suggest that the novel missense mutations V289L and A542V in the CLCN7 gene were responsible for ADO-II in the two Chinese families.

BMP7 gene polymorphisms are not associated with bone mineral density or osteoporotic fractures in postmenopausal Chinese women.

AIM: A previous study shows that bone morphogenetic protein 7 (BMP7) gene polymorphisms are associated with bone mineral density (BMD) in 920 European Americans. To determine the association of BMP7 polymorphisms and BMD and osteoporotic fracture susceptibility, we performed a case-control association study in postmenopausal Chinese women with or without osteoporotic fracture. METHODS: A total of 3815 unrelated postmenopausal Chinese women (1238 with osteoporotic fracture and 2577 healthy controls) were recruited. BMDs of the lumbar spine 1-4 (L1-4) and proximal femur (including total hip and femoral neck) were measured using dual-energy X-ray absorptiometry. Eight tagging single nucleotide polymorphisms (SNPs) in BMP7 gene, including rs11086598, rs4811822, rs12481628, rs6025447, rs230205, rs17404303, rs162316 and rs6127980, were genotyped. RESULTS: Among the 8 SNPs, rs6025447 and rs230205 were associated with total hip BMD (P=0.013 and 0.045, respectively). However, the associations became statistically insignificant after adjusting for age, height and weight. The TGTG haplotype of BMP7 gene was associated with total hip BMD (P=0.032), even after adjusting for age, height and weight (P=0.048); but the association was insignificant after performing the Bonferroni multiple-significance-test correction. Moreover, the 8 SNPs and 9 haplotypes of BMP7 gene were not associated with L1-4 or femoral neck BMD or osteoporotic fracture. CONCLUSION: This large-sample case-control association study suggests that the common genetic polymorphisms of BMP7 gene are not major contributors to variations in BMD or osteoporotic fracture in postmenopausal Chinese women.

Calcification of joints and arteries: second report with novel NT5E mutations and expansion of the phenotype.

Calcification of joints and arteries (CALJA; MIM 211800) is an extremely rare mendelian disorder of isolated calcification that is characterized by late onset calcification of the extremity arteries and hand and foot joint capsules. Mutations of NT5E, encoding cluster of differentiation 73, have been implicated in CALJA. Here we report on a Chinese family with CALJA and novel compound heterozygous mutations (c.1360G>A (p.Gly454Arg) and c.1387C>T (p.Arg463X)) in NT5E. Our study represents the second report on patients with CALJA associated with NT5E mutations. The clinical features expand the previously reported phenotype of NT5E mutations. The propositus has calcification of the lower extremity arteries and hand and foot joint capsules similar to those previously reported patients. However, he also has calcification of the upper extremity arteries. By protein structural modeling, we found the mutation p.Gly454Arg may disrupt the folding of ß-pleated sheet and destabilize the protein structure. Our findings will provide clues to the phenotype-genotype relations and may assist not only in the clinical diagnosis but also in the interpretation of genetic information used for prenatal diagnosis and genetic counseling.

Nuclear-Spin-Induced Circular Dichroism in the Infrared Region for Liquids.

Recently, the nuclear-spin-induced optical rotation (NSOR) and circular dichroism (NSCD) for liquids were discovered and extensively studied and developed. However, so far, nuclear-spin-induced magnetic circular dichroism in the IR region (IR-NSCD) has not been explored, even though all polyatomic molecules exhibit extensive IR spectra. Herein, IR-NSCD is proposed and discussed theoretically. The results indicate that in favorable conditions the IR-NSCD angle may be much larger than the NSOR angle in the UV/Vis region due to a vibrational resonance effect and can be measurable by using the NSOR experiment scheme. IR-NSCD can automatically combine and give NMR spectra and IRCD spectra of the nuclear spin prepolarized samples in liquids, which, in principle, could be developed to become a unique, novel analytical tool.

Physical performance and life quality in postmenopausal women supplemented with vitamin D: a two-year prospective study.

AIM: To investigate the effects of calcium and vitamin D supplementation on bone turnover marker levels, muscle strength and quality of life in postmenopausal Chinese women. METHODS: A total of 485 healthy postmenopausal Chinese women (63.44±5.04 years) were enrolled in this open-label, 2-year, prospective, community-based trial. The participants were divided into group A, B, C, which were treated with calcium (600 mg/d) alone, calcium (600 mg/d) and cholecalciferol (800 IU/d) or calcium (600 mg/d) and calcitriol (0.25 µg/d), respectively, for 2 years. Serum levels of 25-hydroxyvitamin D, parathyroid hormone, ß-CTX and P1NP were measured, and the muscle strength and quality of life were assessed at baseline and at 12- and 24-month follow-ups. RESULTS: Four hundred and sixty one participants completed this study. Serum levels of 25-hydroxyvitamin D were significantly increased in group C, but not changed in groups A and B at 24-month follow-up. Serum levels of parathyroid hormone, bone turnover marker ß-CTX and bone formation marker P1NP were significantly decreased in group C, while serum levels of ß-CTX were increased in group A at 24-month follow-up. The participants in group C maintained the grip strength, while those in groups A and B exhibited decreased grip strength at 24-month follow-up. The quality of life for the participants in groups B and C remained consistent, but that in group A was deteriorated at 24-month follow-up. CONCLUSION: Supplementation with calcitriol and calcium modifies the bone turnover marker levels, and maintains muscle strength and quality of life in postmenopausal Chinese women, whereas supplementation with cholecalciferol and calcium prevents aging-mediated deterioration in quality of life.

The efficacy and safety of weekly 35-mg risedronate dosing regimen for Chinese postmenopausal women with osteoporosis or osteopenia: 1-year data.

AIM: Oral risedronate is effective in the treatment of postmenopausal osteoporosis when administered daily, weekly, or monthly. In this 1-year, randomized, double-blind, multicenter study we compared the weekly 35-mg and daily 5-mg risedronate dosing regimens in the treatment of Chinese postmenopausal women with osteoporosis or osteopenia. METHODS: Postmenopausal women with primary osteoporosis or osteopenia were randomly assigned to the weekly group or daily group (n=145 for each) that received oral risedronate 35 mg once a week or 5 mg daily, respectively, for 1 year. The subjects' bone mineral densities (BMDs), bone turnover markers (P1NP and ß-CTX), new vertebral fractures, and adverse events were assessed at baseline and during the treatments. RESULTS: All subjects in the weekly group and 144 subjects in the daily group completed the study. The primary efficacy endpoint after 1 year, ie the mean percent changes in the lumbar spine BMD (95% CI) were 4.87% (3.92% to 5.81%) for the weekly group and 4.35% (3.31% to 5.39%) for the daily group. The incidences of clinical adverse events were 48.3% in the weekly group and 54.2% in the daily group. CONCLUSION: The weekly 35-mg and daily 5-mg risedronate dosing regimens during 1 year of follow-up show similar efficacy in improving BMDs and biochemical markers of bone turnover in Chinese postmenopausal women with osteoporosis or osteopenia. Moreover, the two dosing regimens exhibit similar safety and tolerability.