Establishment of BMD reference plots and determination of peak BMD at multiple skeletal regions in mainland Chinese women and the diagnosis of osteoporosis

Association of osteoporotic fractures of femoral neck and femoral neck geometric parameters in native Chinese women

BACKGROUND

Although it is generally believed that the femoral neck fracture is related to the femoral neck geometric parameters (FNGPs), the association between the risk of osteoporotic fracture of the femoral neck and FNGPs in native Chinese women is still unclear.

METHODS

A total of 374 female patients (mean age 70.2 ± 9.32 years) with osteoporotic fracture of the femoral neck, and 374 non-fracture control groups were completely matched with the case group according to the age ratio of 1:1. Using DXA bone densitometer to measured eight FNGPs: the outer diameter (OD), cross-sectional area (CSA), cortical thickness (CT), endocortical diameter (ED), buckling ratio (BR), section modulus (SM), cross-sectional moment of inertia (CSMI), and compressive strength index (CSI) at the narrowest point of the femoral neck.

RESULTS

Compared with the control group, the average values of OD (2.9%), ED (4.5%), and BR (26.1%) in the patient group significantly increased (p = 0.015 to < 0.001), while CSA (‒15.3%), CT (‒18.2%), SM (‒10.3%), CSMI (‒6.4%), and CSI (‒10.8%) significantly decreased (all p < 0.001). The prevalence of osteoporosis in the lumbar spine, femoral neck, and total hip was, respectively, 82%, 81%, and 65% in fracture patients. Cox proportional hazard model analysis showed that in the age adjusted model, the fracture hazard ratio (HR) of CSA, CT, BR, SM, and CSI significantly increased (HRs = 1.60‒8.33; 95% CI = 1.08‒16.6; all p < 0.001). In the model adjusted for age and femoral neck BMD, HRs of CT (HRs = 3.90‒8.03; 95% CI = 2.45‒15.1; all p < 0.001) and BR (HRs = 1.62‒2.60; 95% CI = 1.20‒5.44; all p < 0.001) were still significantly increased.

CONCLUSION

These results suggest that the majority of osteoporotic fractures of the femoral neck of native Chinese women occur in patients with osteoporosis. CT thinning or BR increase of FNGPs may be independent predictors of fragility fracture of femoral neck in native Chinese women unrelated to BMD.

Sex- and Age-Specific Prevalence of Osteopenia and Osteoporosis: Sampling Survey

BACKGROUND

Osteopenia and osteoporosis are posing a long-term influence on the aging population's health contributing to a higher risk of mortality, loss of autonomy, hospitalization, and huge health system costs and social burden. Therefore, more pertinent data are needed to demonstrate the current state of osteoporosis.

OBJECTIVE

This sampling survey seeks to assess the trends in the prevalence of osteopenia and osteoporosis in a Chinese Han population.

METHODS

A community-based cross-sectional study involving 16,377 participants used a multistage sampling method. Bone mineral density was measured using the quantitative ultrasonic densitometry. Student t test and Mann-Whitney U test were used to test the difference between normally and nonnormally distributed quantitative variables between male and female participants. A chi-square (χ2) test was used to compare categorized variables. Stratified analysis was conducted to describe the prevalence rates of osteoporosis (T score ≤-2.5) and osteopenia (T score -2.5 to -1.0) across age, sex, calcium intake, and menopause. A direct standardization method was used to calculate the age-standardized prevalence rates of osteoporosis and osteopenia. T-score was further categorized into quartiles (T1-T4) by age- and sex-specified groups.

RESULTS

The prevalence rates of osteopenia and osteoporosis were 40.5% (6633/16,377) and 7.93% (1299/16,377), respectively, and the age-standardized prevalence rates were 27.32% (287,877,129.4/1,053,861,940) and 3.51% (36,974,582.3/1,053,861,940), respectively. There was an increase in osteopenia and osteoporosis prevalence from 21.47% (120/559) to 56.23% (754/1341) and 0.89% (5/559) to 17.23% (231/1341), respectively, as age increased from 18 years to 75 years old. The prevalence rates of osteopenia and osteoporosis were significantly higher in female participants (4238/9645, 43.94% and 1130/9645, 11.72%) than in male participants (2395/6732, 35.58% and 169/6732, 2.51%; P<.001), and in postmenopausal female participants (3638/7493, 48.55% and 1053/7493, 14.05%) than in premenopausal female participants (538/2026, 26.55% and 53/2026, 2.62%; P<.001). In addition, female participants with a history of calcium intake had a lower osteoporosis prevalence rate than female participants without any history of calcium intake in all age groups (P=.004). From low quartile to high quartile of T-score, the prevalence of diabetes mellitus (752/4037, 18.63%; 779/4029, 19.33%; 769/3894, 19.75%; and 869/3879, 22.4%) and dyslipidemia (2228/4036, 55.2%; 2304/4027, 57.21%; 2306/3891, 59.26%; and 2379/3878, 61.35%) were linearly increased (P<.001), while the prevalence of cancer (112/4037, 2.77%; 110/4029, 2.73%; 103/3894, 2.65%; and 77/3879, 1.99%) was decreased (P=.03).

CONCLUSIONS

Our data imply that as people age, osteopenia and osteoporosis are more common in females than in males, particularly in postmenopausal females than in premenopausal females, and bone mineral density significantly affects the prevalence of chronic diseases. These findings offer information that can be applied to intervention programs meant to prevent or lessen the burden of osteoporosis in China.

Association between BMI and osteoporotic fractures at different sites in Chinese women: a case-control retrospective study in Changsha

BACKGROUND

Osteoporotic fractures are a growing problem in an aging society. The association between body mass index (BMI) and osteoporotic fractures varies by fracture site and ethnicity. Limited knowledge exists regarding this association in native Chinese, particularly utilizing local databases as reference sources.

OBJECTIVE

To investigate the association between BMI and osteoporotic fractures at different sites in Chinese women.

METHODS

Three thousand ninety-eight female patients with radiographic fractures and 3098 age- and sex-matched healthy controls without fractures were included in the study. Both of them underwent assessment using dual-energy X-ray absorptiometry (DXA), with BMD measurements calculated using our own BMD reference database. Participants were classified into underweight (BMI < 18.5 kg/m2), normal weight (18.5 ≤ BMI < 24.0 kg/m2), overweight (24 ≤ BMI < 28 kg/m2) and obese (BMI ≥ 28 kg/m2) according to the Chinese BMI classification standard.

RESULTS

There were 2296 (74.1%) vertebral fractures, 374 (12.1%) femoral neck fractures, and 428 (13.8%) other types of fractures in the case group. Bone mineral density (BMD) was almost lower in the fracture groups compared to the control groups (p = 0.048 to < 0.001). Compared with normal weight, underweight had a protective effect on total [odds ratio (OR) = 0.61; 95% confidence interval (CI), 0.49 -0.75; P< 0.001], and lumbar fractures (OR = 0.52; 95% CI, 0.41 - 0.67; P < 0.001), while obesity was associated with an increased risk for total (OR = 2.26; 95% CI, 1.85 - 2.76; P < 0.001), lumbar (OR = 2.17; 95% CI, 1.72 - 2.73; P < 0.001), and femoral neck fractures (OR = 4.08; 95% CI, 2.18 - 7.63; P < 0.001). Non-linear associations were observed between BMI and fractures: A J-curve for total, lumbar, and femoral neck fractures, and no statistical change for other types of fractures. Underweight was found to be a risk factor for other types of fracturess after adjusting for BMD (OR = 2.29; 95% CI, 1.09 - 4.80; P < 0.001). Osteoporosis and osteopenia were identified as risk factors for almost all sites of fracture when compared to normal bone mass.

CONCLUSIONS

Underweight has a protective effect on total and lumbar spine fractures in Chinese women, while obesity poses a risk factor for total, lumbar, and femoral neck fractures. The effect of BMI on fractures may be mainly mediated by BMD.

Effect of Body Surface Area on Severe Osteoporotic Fractures: A Study of Osteoporosis in Changsha China

Clinical vertebral fractures and femoral neck fractures are severe osteoporotic fractures that increase morbidity and mortality. Anthropometric variables are associated with an increased risk of osteoporotic fractures, but it is not clear whether body surface area (BSA) has an effect on clinically severe osteoporotic fractures. The study included total of 3,694 cases of clinical vertebral fractures and femoral neck fractures (2,670 females and 1,024 males) and 3,694 controls without fractures who were matched with the cases by sex and age. There was a significant positive correlation between BSA and bone mineral density (BMD) in female and male fracture patients (females: r = 0.430-0.471, P < 0.001; males: r = 0.338-0.414, P < 0.001). There was a significant systematic increase in BMD in both genders at various skeletal sites, grouped by BSA quartile. The osteoporosis rates of the lumbar spine (97.9%), femoral neck (92.4%) and total hip (87.1%) in the female Q1 group were significantly higher than those in the Q4 group (P < 0.001), which were 80.0%, 57.9% and 36.9%, respectively, in the Q4 group; the osteoporosis rates of the lumbar spine, femoral neck, and total hip were 53.9%, 59.4%, and 36.3% in the male Q1 group, and 15.2%, 21.9%, and 7.03% in the Q4 group, which were significantly lower than those in the Q1 group (P < 0.001). In age-adjusted Cox regression models, the risk of fracture in the remaining three groups (Q2, Q3, and Q4) for weight, BMI, and BSA for both genders, compared with the highest quartile (Q1 by descending quartile stratification) were significantly higher. In models adjusted for age and BMD, only men in the BSA Q3 (HR = 1.55, 95% CI = 1.09-2.19) and BSA Q4 groups (HR = 1.41, 95% CI = 1.05-1.87) had significantly higher fracture risks. In models adjusted for age, height, weight, BMI, and BSA, low BMD was the greatest fracture risks for both sexes. Our results showed that BSA was closely related to BMD, prevalence of osteoporosis, and fracture risk, and that a decline in BSA may be a new potential risk factor for osteoporotic fractures in Chinese men.

The Multi-Modal Risk Analysis and Medical Prevention of Lumbar Degeneration, Fatigue, and Injury Based on FEM/BMD for Elderly Chinese Women Who Act as Stay-Home Grandchildren Sitters

Background: An increasing number of Chinese elderly women stay at home and act as grandchildren sitters. In consequence of the frequent load-bearing, chronic lumbar fatigue probably caused a higher risk of lumbar degeneration, fatigue, and injury which has become one of the most important aging and health problems in China. In this study, a multi-mode lumbar finite element model (FEM) with specific bone mineral density (BMD) were developed and validated for further spine injury prevention and control.

Methods: The material properties of lumbar vertebra were modified according to degenerated bone mineral density, and geometry was adjusted based on intervertebral disc height. The motion of lifting children was simulated by a 76 year-old Chinese women's FEM, and the stress distribution was calculated and predicted.

Results: The pressure of L5-S intervertebral disc in the bending 3-year-old dummy lifting posture was significantly higher than the same posture without lifting, the maximum effective stress of endplate cartilage in the upright child lifting posture was 1.6 times that of the bending without lifting posture. And the fatigue risk limitation frequency of the upright with dummy posture was predicted with the functional equation of fatigue and stress which was deduced by genetic algorithm, which combined with the effective stress of lumbar vertebrae spongy bone calculated from FEM.

Conclusions: The child-lifting motion could increase the risk of lumbar degeneration, fatigue, and injury in elderly women, and they should keep below the frequency limit of the motion of lifting children in their daily life. This study could put forward scientific injury prevention guidance to Chinese elderly women who lift children in daily life frequently.

Single-cell RNA sequencing deconvolutes the in vivo heterogeneity of human bone marrow-derived mesenchymal stem cells

Bone marrow-derived mesenchymal stem cells (BM-MSCs) are multipotent stromal cells that have a critical role in the maintenance of skeletal tissues such as bone, cartilage, and the fat in bone marrow. In addition to providing microenvironmental support for hematopoietic processes, BM-MSCs can differentiate into various mesodermal lineages including osteoblast/osteocyte, chondrocyte, and adipocyte that are crucial for bone metabolism. While BM-MSCs have high cell-to-cell heterogeneity in gene expression, the cell subtypes that contribute to this heterogeneity in vivo in humans have not been characterized. To investigate the transcriptional diversity of BM-MSCs, we applied single-cell RNA sequencing (scRNA-seq) on freshly isolated CD271+ BM-derived mononuclear cells (BM-MNCs) from two human subjects. We successfully identified LEPRhiCD45low BM-MSCs within the CD271+ BM-MNC population, and further codified the BM-MSCs into distinct subpopulations corresponding to the osteogenic, chondrogenic, and adipogenic differentiation trajectories, as well as terminal-stage quiescent cells. Biological functional annotations of the transcriptomes suggest that osteoblast precursors induce angiogenesis coupled with osteogenesis, and chondrocyte precursors have the potential to differentiate into myocytes. We also discovered transcripts for several clusters of differentiation (CD) markers that were either highly expressed (e.g., CD167b, CD91, CD130 and CD118) or absent (e.g., CD74, CD217, CD148 and CD68) in BM-MSCs, representing potential novel markers for human BM-MSC purification. This study is the first systematic in vivo dissection of human BM-MSCs cell subtypes at the single-cell resolution, revealing an insight into the extent of their cellular heterogeneity and roles in maintaining bone homeostasis.

A systematic dissection of human primary osteoblasts in vivo at single-cell resolution

Human osteoblasts are multifunctional bone cells, which play essential roles in bone formation, angiogenesis regulation, as well as maintenance of hematopoiesis. However, the categorization of primary osteoblast subtypes in vivo in humans has not yet been achieved. Here, we used single-cell RNA sequencing (scRNA-seq) to perform a systematic cellular taxonomy dissection of freshly isolated human osteoblasts from one 31-year-old male with osteoarthritis and osteopenia after hip replacement. Based on the gene expression patterns and cell lineage reconstruction, we identified three distinct cell clusters including preosteoblasts, mature osteoblasts, and an undetermined rare osteoblast subpopulation. This novel subtype was found to be the major source of the nuclear receptor subfamily 4 group A member 1 and 2 (NR4A1 and NR4A2) in primary osteoblasts, and the expression of NR4A1 was confirmed by immunofluorescence staining on mouse osteoblasts in vivo. Trajectory inference analysis suggested that the undetermined cluster, together with the preosteoblasts, are involved in the regulation of osteoblastogenesis and also give rise to mature osteoblasts. Investigation of the biological processes and signaling pathways enriched in each subpopulation revealed that in addition to bone formation, preosteoblasts and undetermined osteoblasts may also regulate both angiogenesis and hemopoiesis. Finally, we demonstrated that there are systematic differences between the transcriptional profiles of human and mouse osteoblasts, highlighting the necessity for studying bone physiological processes in humans rather than solely relying on mouse models. Our findings provide novel insights into the cellular heterogeneity and potential biological functions of human primary osteoblasts at the single-cell level.

Relationship between bone mineral density and fragility fracture risk: a case-control study in Changsha, China

Background

Fragility fracture is associated with bone mineral density (BMD), and most databases used in related researches are instrument-matched. Little is known about the relationship between BMD and fragility fracture risk of native Chinese, especially using local databases as reference databases.

Objective

To investigate relationship between BMD and risk of fragility fracture in native China.

Methods

3,324 cases, including 2,423 women (67.7 ± 8.9 years) and 901 men (68.4 ± 11.6 years) having radiological fragility fractures and 3,324 age- and gender-matched controls participated in the study. We measured BMD at posteroanterior spine and hip using dual-energy X-ray absorptiometry (DXA), calculated BMD measurement parameters based on our own BMD reference database.

Results

BMDs and mean T-scores were lower in case group (with clinical fragility) than in control group (without clinical fragility). In patients with fragility fractures, prevalence of lumbar osteoporosis, low bone mass, and normal BMD were 78.9 %, 19.3 %, and 1.8 %, respectively, in women, and 49.5, 44.8 %, and 5.7 %, respectively, in men. In hip, these prevalence rates were 67.2 %, 28.4 %, and 4.4 % in females, and 43.2 %, 45.9 %, and 10.9 % in males, respectively, showing differences between females and males. Multivariate Cox regression analysis showed that after adjusting age, height, weight, and body mass index, fracture hazard ratio (HR) increased by 2.7–2.8 times (95 % CI 2.5–3.1) and 3.6–4.1 times (95 %CI 3.0–5.1) for women and men respectively with decreasing BMD parameters. In both sexes, risk of fragility fracture increased approximately 1.6–1.7 times (95 % CI 1.5–1.8) for every 1 T-score reduction in BMD.

Conclusions

Risk of clinical fragility fracture increases with decreasing BMD measurement parameters and anthropometric indicators in native China, and fracture HR varies from gender and site.

Single-cell RNA sequencing of human femoral head in vivo

The homeostasis of bone metabolism depends on the coupling and precise regulation of various types of cells in bone tissue. However, the communication and interaction between bone tissue cells at the single-cell level remains poorly understood. Thus, we performed single-cell RNA sequencing (scRNA-seq) on the primary human femoral head tissue cells (FHTCs). Nine cell types were identified in 26,574 primary human FHTCs, including granulocytes, T cells, monocytes, B cells, red blood cells, osteoblastic lineage cells, endothelial cells, endothelial progenitor cells (EPCs) and plasmacytoid dendritic cells. We identified serine protease 23 (PRSS23) and matrix remodeling associated protein 8 (MXRA8) as novel bone metabolism-related genes. Additionally, we found that several subtypes of monocytes, T cells and B cells were related to bone metabolism. Cell-cell communication analysis showed that collagen, chemokine, transforming growth factor and their ligands have significant roles in the crosstalks between FHTCs. In particular, EPCs communicated with osteoblastic lineage cells closely via the "COL2A1-ITGB1" interaction pair. Collectively, this study provided an initial characterization of the cellular composition of the human FHTCs and the complex crosstalks between them at the single-cell level. It is a unique starting resource for in-depth insights into bone metabolism.

Bone mineral density spectrum in individuals with type 1 diabetes, latent autoimmune diabetes in adults, and type 2 diabetes

OBJECTIVE

To assess bone mineral density (BMD) and associated clinical factors in patients with type 1 diabetes (T1D), latent autoimmune diabetes in adults (LADA), and type 2 diabetes (T2D) and in non-diabetic subjects.

METHODS

Total 108 age-, sex-, disease duration-, and postmenopausal ratio-matched patients with T1D, LADA, and T2D each and 216 age-, sex-, and postmenopausal ratio-matched non-diabetic controls. Anthropometric, biochemical, and BMD data were collected and analysed.

RESULTS

BMD of total hip and lumbar spine of individuals in the LADA group was lower than those in the T2D and control groups but higher than those in the T1D group. After adjusting for body mass index (BMI), a significant difference in BMD in the lumbar spine was seen between groups. After adjustment for smoking, BMI, 25-(OH) vitamin D, calcium, haemoglobin A1c, and diabetic complication scores, BMD values of patients in LADA group were not significantly different from those of patients in T1D and T2D groups. Multiple stepwise regression analysis showed that BMD was (a) positively associated with weight and C-peptide, and negatively associated with age in patients with diabetes, (b) positively associated with C-peptide in the T1D and LADA groups. The proportion of patients with osteoporosis in the T1D, LADA, T2D, and control groups was 55.6%, 45.4%, 34.3%, and 26.9%, respectively.

CONCLUSIONS

BMD values in T1D, LADA, and T2D were in an increasing order of mention. Patients with autoimmune diabetes were more susceptible to osteoporosis. A lower C-peptide level may be responsible for decreased BMD in individuals with autoimmune diabetes.

Decreased lower-extremity muscle performance is associated with decreased hip bone mineral density and increased estimated fracture risk in community-dwelling postmenopausal women

The present study demonstrated that the lower-extremity muscle performance in Chinese community-dwelling postmenopausal women with lower bone mineral density (BMD) was positively associated with hip BMD and negatively associated with estimated fracture risk.

PURPOSE

Postmenopausal women are at high risk for osteoporotic fractures. It has been shown that decreased lower-extremity muscle performance is associated with osteoporotic fractures. However, the relationship between muscle performance and bone mineral density in postmenopausal women is inconsistent in the literature. The present study was to investigate the relationship between lower-extremity muscle performance and BMD or estimated fracture risk in community-dwelling postmenopausal women.

METHODS

Two hundred forty-seven postmenopausal women aged 50-85 years were recruited in the study. The short physical performance battery (SPPB) tool including the chair stand test (CST), gait speed test (GST), and balance test (BT) was used to determine lower-extremity functioning and the CST, GST, BT, and SPPB total scores were recorded. The BMD of lumbar spine (LSBMD), femoral neck (FNBMD), and total hip (THBMD) were measured by dual-energy X-ray absorptiometry (DXA), and the vertebral fracture was confirmed by lateral spine X-rays radiographs. In addition, patients' 10-year estimated major osteoporotic fracture risk (MOFR) and hip fracture risk (HFR) were assessed by the Fracture Risk Assessment Tool (FRAX). Linear regression analysis was used to analyze the association between muscle performance and BMD.

RESULTS

The CST, GST, and SPPB total scores were positively associated with LSBMD, THBMD, and FNBMD before adjustment for age, height, and weight. The SPPB total score was positively associated with FNBMD and THBMD, but not with LSBMD after adjustment for age, height, and weight. The BT score was positively associated with FNBMD and THBMD, but not with LSBMD before and after adjustment for age, height, and weight. Moreover, the CST, GST, BT, and SPPB scores were negatively associated with the FRAX score.

CONCLUSION

The lower-extremity muscle performance in community-dwelling postmenopausal women is positively associated with FNBMD and THBMD and negatively associated with the FRAX score.

Association between renal function and bone mineral density in healthy postmenopausal Chinese women

BACKGROUND

The relationship between renal function and bone mineral density (BMD) is controversial. The aim of this study was to determine the relationship of renal function with BMD and osteoporosis risk in healthy postmenopausal Chinese women.

METHODS

A cross-sectional study was conducted in 776 healthy postmenopausal Chinese women. Dual-energy X-ray absorptiometry was used to measure BMDs. Clinical, demographic, and biochemical data were obtained at the time of image acquisition. Estimated glomerular filtration rate (eGFR) was calculated using a Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation.

RESULTS

Women with eGFR levels of at least 90 ml/min/1.73m² had a lower prevalence of osteoporosis compared with women with decreased eGFR levels (60 ml/min/1.73 m² ≤ eGFR < 90.0 ml/min/1.73 m²). BMDs at femoral neck and total hip were significantly lower in the lower eGFR class than the higher class (0.717 ± 0.106 vs 0.744 ± 0.125 g/cm², P < 0.01; 0.796 ± 0.116 vs 0.823 ± 0.129 g/cm², P < 0.01, respectively). eGFR was positively correlated with BMDs at femoral neck and total hip in unadjusted analysis (P < 0.05). After controlling for age, menopausal duration and body mass index (BMI), decreased eGFR was not associated with osteoporosis risk.

CONCLUSIONS

After adjustments for age, menopausal duration and BMI, the decline in renal function was not independently associated with osteoporosis risk in healthy postmenopausal Chinese women.

MicroRNA-410 participates in the pathological process of postmenopausal osteoporosis by downregulating bone morphogenetic protein-2

The present study aimed to investigate bone morphogenetic protein (BMP)-2 and microRNA (miR)-410 expression and the mechanism of regulation in serum and CD¹⁴⁺ peripheral blood mononuclear cells (PBMCs) from postmenopausal osteoporosis patients and model mice. A total of 26 patients with postmenopausal osteoporosis were included in the experimental group and 29 age-matched healthy subjects were included in the control group. A total of 60 mice were divided into sham and ovariectomized (OVX) groups. Following surgery, 28 mice remained in the sham and 25 mice remained in OVX group. BMP-2 protein expression in serum and CD¹⁴⁺ PBMCs from patients and model mice was determined using ELISA and western blotting, respectively. Reverse transcription-quantitative polymerase chain reaction assays were performed to determine miR-410 and BMP-2 mRNA levels in serum and CD¹⁴⁺ PBMCs from patients and model mice. Dual luciferase reporter assays were used to identify direct interactions between miR-410 and BMP-2 mRNA. Compared with the control group, BMP-2 mRNA and protein expression in serum and CD¹⁴⁺ PBMCs from patients with postmenopausal osteoporosis and model mice were significantly decreased. miR-410 levels in serum and CD¹⁴⁺ PBMCs from patients with postmenopausal osteoporosis and model mice were significantly increased when compared with the control group. Dual luciferase reporter assays revealed that BMP-2 was a target gene of miR-410. The current study demonstrated that decreased BMP-2 expression in serum and CD¹⁴⁺ PBMCs from patients with postmenopausal osteoporosis was associated with the upregulation of miR-410. These results suggest that miR-410 may participate in the pathological process of postmenopausal osteoporosis by downregulating BMP-2.

MiR-96 regulates bone metabolism by targeting osterix

MicroRNAs (miRNAs) play important roles in bone metabolism and aging. Here we show that miR-96 was markedly up-regulated in serum of elderly patients with osteoporosis by miRNA microarray analysis and qRT-PCR. Moreover miR-96 was also up-regulated in bone marrow mesenchymal stem cells (BMSCs) of aged humans and mice. Our results show that the over-expression of miR-96 reduced osteogenic differentiation of BMSCs, whereas the inhibition of miR-96 increased osteogenic differentiation of BMSCs. At the molecular level, miR-96 regulated osteogenesis by targeting osterix. Interestingly, over-expression of miR-96 in young mice by intravenous injection of agomiR-96 developed a low bone mass due to impaired osteogenesis. However, inhibition of miR-96 in aged mice attenuated the age-related bone loss. Thus, our data suggest that miR-96 regulates osteogenesis and may represent a potential diagnostic marker or therapeutic target for age-related bone loss.

Relationships between serum Omentin-1 levels and bone mineral density in older men with osteoporosis

OBJECTIVE

To investigate the correlation between serum Omentin-1 levels and the presence of osteoporosis in older men.

METHODS

Serum Omentin-1, bone turnover biochemical markers, and bone mineral density (BMD) were determined in 45 older men with osteoporosis or 45 older men without osteoporosis (65-70 years old).

RESULTS

Omentin-1 levels were increased in older men with osteoporosis, and the differences remained significant after controlling for fat mass. Omentin-1 was negatively correlated with BMD. In a multiple linear stepwise regression analysis, Omentin-1, lean mass, but not fat mass, were independent predictors of BMD for the combined group. Significant negative correlations between Omentin-1 and bone-specific alkaline phosphatase (BAP) and bone cross-linked N-telopeptides of type Ⅰ collagen (NTX) were found. Omentin-1 was also independently associated with BMD and bone turnover markers in older men with osteoporosis and control groups that were considered separately.

CONCLUSIONS

Omentin-1 is an independent predictor of BMD in older men with osteoporosis, and it is negatively correlated with bone turnover biochemical markers. It is suggested that Omentin-1 may exert a negative effect on bone mass through the regulation of the osteoblast differentiation in the older men with osteoporosis.

Relationships of serum lipid profiles and bone mineral density in postmenopausal Chinese women

OBJECTIVES

Recent studies suggest that serum lipid profiles are related to bone mineral density (BMD). But data about this relationship on Chinese population are scarce. We investigated the relationships between serum lipid and BMD in postmenopausal Chinese women.

METHODS

A cross-sectional study was conducted in 790 Chinese postmenopausal women. BMDs were measured by dual X-ray absorptiometry. Serum lipid profiles were obtained after a 12-h fasting.

RESULTS

Women with serum high-density lipoprotein cholesterol (HDL-C) levels of at least 1·55 mmol/l had a greater prevalence of osteoporosis compared with women with lower HDL-C (≤1·54 mmol/l). After controlling for age, menopausal duration, body mass index, serum creatinine levels, outdoor activity, smoking and alcohol intake, high HDL-C levels were associated with osteoporosis (OR = 1·64, 95%CI 1·16-2·33, P < 0·01). BMD at femoral neck and total hip was significantly lower in the higher HDL-C class than the lower class (0·722 ± 0·118 vs 0·744 ± 0·120 g/cm(2) , P < 0·01; 0·800 ± 0·126 vs 0·824 ± 0·125 g/cm(2) , P < 0·01, respectively). No association was found between total cholesterol (TC), triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C) with BMD.

CONCLUSIONS

In Chinese postmenopausal women, elevated levels of serum HDL-C had a greater probability of being osteoporosis than the lower HDL-C levels. Our analysis showed higher HDL-C level that is favourable for cardiovascular diseases should be regarded as a risk factor for osteoporosis.

Vitamin D status and its relationship with body composition, bone mineral density and fracture risk in urban central south Chinese postmenopausal women

AIMS

This study was designed to assess vitamin D (25(OH)D) status and its relationship with bone mineral density (BMD) and fracture risk, which was determined using the FRAX algorithm, among postmenopausal central south Chinese women, and to identify the risk factors for vitamin D deficiency and osteoporosis.

METHODS

This cross-sectional study involved 578 healthy postmenopausal central south Chinese women. Fat mass and BMD at lumbar spine (L1-L4), femur neck and total hip were measured with dual X-ray absorptiometry. Serum levels of 25(OH)D, parathyroid hormone and creatinine were measured. The 10-year probabilities of hip and major osteoporotic fracture were calculated by the FRAX model.

RESULTS

Approximately 72.1% women were vitamin D deficient (25(OH)D <50 nmol/l). Serum 25(OH)D levels did not correlate with body mass index (BMI), fat mass and weight. They positively correlated with all BMDs (p < 0.05) and negatively correlated with both 10-year fracture probabilities (p < 0.05). BMI ≤19 and age ≥65 years were risk factors for osteoporosis at all sites.

CONCLUSIONS

Vitamin D deficiency was prevalent among postmenopausal central south Chinese women. Serum 25(OH)D levels were correlated with all BMDs and negatively correlated with both 10-year fracture probabilities.

Reference intervals of bone turnover markers determined by using their curve-fitting valley for adult females in China

SUMMARY

The reference values for bone turnover markers (BTMs) have a significant role in the diagnosis, monitoring, and treatment of metabolic bone disease. This study proposes that the peak value of bone mineral density and the trough value for the BTM curve can be used to determine the reference range of BTM.

INTRODUCTION

The aim of this study is to determine the reference intervals of BTMs for adult females in China with an attempt to reference the peak bone mineral density (BMD) with the corresponding BTM valley.

METHODS

This study included 546 premenopausal and 394 postmenopausal women. The levels of several BTMs were determined, and the BMD was measured using a dual-energy X-ray absorptiometry.

RESULTS

The BTMs of postmenopausal women were 17-96 % higher than premenopausal women. The change of BTM with age presented an optimal goodness-of-fit according to the cubic regression model (R (2) = 0.074-0.346, all P = 0.000). All kinds of BTM levels were positively correlated with age in premenopausal women aged 27-56 years old (r = 0.167-0.502, P = 0.023-0.000). Except for uCTX, the BTM reference value determined using a curve-fitting valley was significantly lower than the reference values for premenopausal women. The BTM reference values determined in this study were also significantly different from the reference values given by the manufacturers of the reagents used.

CONCLUSIONS

This study found that the changes of level with age of BTMs in Chinese women present an optimal goodness-of-fit according to the cubic regression model. The fitting valley corresponds to the BMD fitting peak and may possibly be an effective means of determining the BTM reference intervals.

MiR-503 regulates osteoclastogenesis via targeting RANK

MicroRNAs (miRNAs) play important roles in osteoclastogenesis and bone resorption. However, no study has investigated the role of miRNA in postmenopausal osteoporosis. Here, we report that miR-503 was markedly reduced in circulating progenitors of osteoclasts-CD14(+) peripheral blood mononuclear cells (PBMCs) from postmenopausal osteoporosis patients compared with those from postmenopausal healthy women. Overexpression of miR-503 in CD14(+) PBMCs inhibited receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis. Conversely, silencing of miR-503 in CD14(+) PBMCs promoted osteoclastogenesis. RANK, which is activated by the binding of RANKL and inducing osteoclast differentiation, was confirmed to be a target of miR-503. In vivo, silencing of miR-503 using a specific antagomir in ovariectomy (OVX) mice increased RANK protein expression, promoted bone resorption, and decreased bone mass, whereas overexpression of miR-503 with agomir inhibited bone resorption and prevented bone loss in OVX mice. Thus, our study revealed that miR-503 plays an important role in the pathogenesis of postmenopausal osteoporosis and contributes to a new therapeutic way for osteoporosis.

Age-related bone turnover markers and osteoporotic risk in native Chinese women

BACKGROUND

The rate of bone turnover is closely related to osteoporosis risk. We investigated the correlation between bone turnover markers and BMD at various skeletal sites in healthy native Chinese women, and to study the effect of changes in the levels of bone turnover markers on the risk of osteoporosis.

METHODS

A cross-section study of 891 healthy Chinese women aged 20-80 years was conducted. The levels of serum osteocalcin (OC), bone-specific alkaline phosphatase (BAP), serum cross-linked N-terminal telopeptides of type I collagen (sNTX), cross-linked C-terminal telopeptides of type I collagen (sCTX), urinary NTX (uNTX), urinary CTX (uCTX) and total urinary deoxypyridinoline (uDPD) were determined. BMD at the posteroanterior spine and the hip was measured using DXA.

RESULTS

Pearson's correlation coefficient found significant negative correlation between bone turnover marker and BMD T-score at different skeletal sites (r = -0.08 to -0.52, all P = 0.038-0.000). After adjustments for age and body mass index, the partial correlation coefficients between the OC, BAP, sNTX, sCTX and uCTX, and the T-scores at various skeletal sites were still significant. After adjustment of height and weight, the correlation coefficients between most BTMs and PA lumbar spine BMD were also significant. Multiple linear regression analysis showed that bone turnover markers were negative determinants of T-scores. BAP and OC accounted for 33.1% and 7.8% of the variations in the T-scores of the PA spine, respectively. Serum OC, BAP, uDPD, and sNTX accounted for 0.4-21.9% of the variations in the femoral neck and total hip T-scores. The bone turnover marker levels were grouped as per quartile intervals, and the T-scores, osteoporosis prevalence and risk were found to markedly and increase with increase in bone turnover marker levels.

CONCLUSIONS

This study clarified the relationship between bone turnover markers and osteoporosis risk in native Chinese women. Bone turnover marker levels were found to be important determinants of BMD T-scores. Furthermore, osteoporotic risk significantly increased with increase in the levels of bone turnover markers.

miR-148a regulates osteoclastogenesis by targeting V-maf musculoaponeurotic fibrosarcoma oncogene homolog B

MicroRNAs (miRNAs) play crucial roles in bone metabolism. In the present study, we found that miR-148a is dramatically upregulated during osteoclastic differentiation of circulating CD14+ peripheral blood mononuclear cells (PBMCs) induced by macrophage colony stimulating factor (M-CSF) and receptor activator of nuclear factor-κB ligand (RANKL). Overexpression of miR-148a in CD14+ PBMCs promoted osteoclastogenesis, whereas inhibition of miR-148a attenuated osteoclastogenesis. V-maf musculoaponeurotic fibrosarcoma oncogene homolog B (MAFB) is a transcription factor negatively regulating RANKL-induced osteoclastogenesis. miR-148a directly targeted MAFB mRNA by binding to the 3' untranslated region (3'UTR) and repressed MAFB protein expression. In vivo, our study showed that silencing of miR-148a using a specific antagomir-inhibited bone resorption and increased bone mass in mice receiving ovariectomy (OVX) and in sham-operated control mice. Furthermore, our results showed that miR-148a levels significantly increased in CD14+ PBMCs from lupus patients and resulted in enhanced osteoclastogenesis, which contributed to the lower bone mineral density (BMD) in lupus patients compared with normal controls. Thus, our study provides a new insight into the roles of miRNAs in osteoclastogenesis, and contributes to a new therapeutic pathway for osteoporosis.

Relationship between serum omentin-1 level and bone mineral density in girls with anorexia nervosa

BACKGROUND

Adolescents with anorexia nervosa (AN) have low bone mineral density (BMD). Omentin- 1, the main circulating adipocytokine, plays an important role in bone metabolism in healthy individuals. However, their association with bone metabolism in AN is unknown.

METHODS

Serum omentin-1, bone turnover biochemical markers, and BMD were determined in 26 girls with AN and 24 healthy girls (15-18 years old).

RESULTS

Omentin-1 levels increased in AN subjects, and the differences became greater after controlling for fat mass. Omentin-1 was negatively correlated with BMD. In the multiple linear stepwise regression analysis, omentin-1, body mass index and lean mass, but not fat mass, were independent predictors of BMD for the combined group. Significant negative correlations were found between omentin-1 and bone-specific alkaline phosphatase, bone cross-linked N-telopeptides of type I collagen. Omentin-1 was also independently associated with BMD and bone turnover markers in the AN and control groups considered separately.

CONCLUSIONS

Omentin-1 was an independent predictor of BMD in adolescents with AN, and negatively correlated with bone turnover markers. This suggested that omentin-1 may exert a negative effect on bone mass by inhibiting bone formation in girls with AN.

Relationship between Serum Levels of OPG and TGF- β with Decreasing Rate of BMD in Native Chinese Women

The objective of this study was to investigate the relationship between serum levels of OPG, TGF- β 1, and TGF- β 2 and BMD decrease rate (BDR) in native Chinese women. This cross-sectional study was performed on 465 healthy native Chinese women aged 35-80 years. Serum levels of OPG, TGF- β 1, and TGF- β 2 were determined. BDR was measured by DXA at the posteroanterior spine, hip, and distal forearm. At all skeletal sites tested, there was a negative correlation between BDR and serum levels of both OPG (r = -0.122 to -0.230, all P = 0.007-0.000) and TGF- β 2 (r = -0.100 to -0.173, all P = 0.029-0.000) and a positive correlation between BDR and serum TGF- β 1 (r = 0.245 - 0.365, all P = 0.000). After adjustment for age and BMI, there were no statistically significant correlations between serum levels of OPG or TGF- β 2 and BDR. However, statistically significant correlations between serum TGF- β 1 and BDR at the lumbar spine and ultradistal forearm remained. Multiple linear regression stepwise analysis showed that serum OPG could explain 1.4-3.7% of BDR variation. Serum TGF- β 1 was a positive determinant of BDR and could explain 5.3-13.3% of BDR variation.

Early bone mineral density decrease is associated with FSH and LH, not estrogen

BACKGROUND

It remains unclear whether gonadotropins or estrogen is responsible for early bone mineral density (BMD) decrease in Chinese women.

METHODS

A cross-sectional study was conducted on 368 healthy adult women, aged 35-60 years. We measured BMD, calculated BMD decrease rates (BDRs) and assessed serum follicle-stimulating hormone (FSH), luteinizing hormone (LH) and estradiol (E(2)) levels.

RESULTS

BDR was significantly negatively correlated with serum FSH (r=-0.429 to -0.622, all p=0.000) and LH (r=-0.359 to -0.526, all p=0.000). After adjustment for age and body mass index, the negative correlations of serum FSH and LH with BDR persisted, but there was no overall correlation between serum E(2) and BDR. Multiple linear stepwise regression analysis suggested that serum FSH is a negative determinant of BDR. Serum E(2) seems to be a positive determinant of BDR in a few parts of the skeleton.

CONCLUSIONS

The decrease of BMD during the menopause is associated with FSH and LH levels, rather than E(2) in Chinese women.

Age, race, weight, and gender impact normative values of bone mineral density

BACKGROUND

Osteoporosis and fractures represent a major public health issue. Accurate normative reference bone mineral density (BMD) values are vital for diagnosing osteoporosis. The generalizability of the T-score method across gender, race, and age in clinic decision-making has been debated. Our aim was to identify the best statistical model to derive normative BMD values in both men and women in the multiethnic United States population.

METHODS

The Third National Health and Nutrition Examination Survey was used as a data source. Gender- and race/ethnicity-stratified data analyses and modeling were conducted on 9779 persons (ages 20 to 65 years) who reported no conditions or medications likely to affect bone metabolism. Sampling and design effects were addressed using STATA 10. Model comparisons were conducted by partial F tests and residual plots.

RESULTS

Polynomial regression provided a statistically significant better fit than linear regression in predicting normative BMD in both men and women. Age-centered polynomial models provided the best model for predicting normative BMD values.

CONCLUSION

The gender- and race-specific lower limit of normal values obtained created a new classification method of low BMD, which might mitigate some of the T-score limitations in men and minority populations.

The relationship between bone turnover markers and BMD decreasing rates in Chinese middle-aged women

BACKGROUND

The relationship between bone turnover markers (BTMs) and BMD decreasing rate (BDR) in Chinese women is unclear. Wu investigated the relationship between (BTMs) and BDR at various skeletal sites in Chinese middle-aged women.

METHODS

A cross-section study of 555 healthy Chinese women over 35-60years of age. BMD at posteroanterior spine, the left hip, and the left forearm were measured with a DXA. Levels of serum osteocalcin (OC), bone-specific alkaline phosphatase (BAP), cross-linked N-terminal telopeptides of type I collagen (sNTX) and total urinary deoxypyridinoline (uDPD) were determined.

RESULTS

BDR at various skeletal sites had significant negative correlation with serum OC(r=-0.395 to -0.530), BAP(r=-0.297 to -0.486), and sNTX(r=-0.207 to -0.272). After adjustment of age and weight, serum OC, BAP, and sNTX rather than total uDPD still exhibited significant correlations with BDR. Stepwise regression analyses showed that, serum OC and BAP were the significantly negative determinants of BDR. Between 4.7-27.7% and 1.2-16.1% of the changes in BDR were determined by serum OC and BAP, respectively. However, sNTX and total uDPD had no significant effect on BDR at various skeletal sites.

CONCLUSIONS

This study indicated the correlation between BTMs and early-stage BDR in Chinese middle-aged women and suggested that serum OC and BAP, rather than sNTX and total uDPD, are the key determining factors of early BMD decreases.

Relationship of body composition with prevalence of osteoporosis in central south Chinese postmenopausal women

OBJECTIVES

To elucidate the relationship between body composition and bone mineral density (BMD) and the prevalence of osteoporosis in central south Chinese postmenopausal women.

METHODS

A cross-sectional study was conducted on 954 healthy central southern Chinese postmenopausal women, aged 50-82. Total body, lumbar spine and left femur BMD and total body soft tissue composition were measured by dual X-ray absorptiometry.

RESULTS

Among the study population, 578 (60.5%) subjects were without osteoporosis and 376 (39.4%) subjects were osteoporotic. The osteoporotic women were older, shorter and thinner, had an earlier age at menopause, a lower BMD and bone mineral content (BMC) of the total body and at different sites, and had lower body mass and body mass components than the women without osteoporosis. Both fat mass and lean mass were positively correlated with age at menopause, height, weight, body mass index (BMI) and BMD at all sites. Fat mass and lean mass were also inversely correlated with age and years since menopause (P<0.05). After controlling for age, age at menopause and height, both fat mass and lean mass were positively correlated with BMD at the lumbar(1-4) spine, the femoral neck and the total hip. Fat mass was the most significant determinant of BMD at the lumbar(1-4) spine with a higher R(2) change and a partial R(2) compared with that of lean mass, while lean mass had more impact on the total hip values. Either a fat mass below 18.4 kg or a lean mass below 33.9 kg was correlated with a higher prevalence of osteoporosis at the lumbar spine or total hip.

CONCLUSIONS

In central south Chinese postmenopausal women, both fat mass and lean mass are correlated with BMD at the lumbar spine and hip. Fat mass was the most significant determinant of BMD at the lumbar spine, while lean mass had more impact on the total hip value. Both lower values of fat mass and lean mass are related to a higher prevalence of osteoporosis at either the lumbar spine or the total hip. Thus, it is important to maintain a reasonable body weight to balance bone health and other metabolic disorders.

Estrogen receptor α36 mediates a bone-sparing effect of 17β-estrodiol in postmenopausal women

Recently, a membrane-based estrogen receptor (ER), ER-α36, was identified and cloned that transduces membrane-initiated estrogen signaling such as activation of the mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signaling pathway. Here we show that the postmenopausal level of estradiol (E2) induces mitogenic, antiapoptotic, and antiosteogenic effects and proapoptotic effects in postmenopausal osteoblasts and osteoclasts with high levels of ER-α36 expression, respectively. We also found that ER-α36 mediated the effects of postmenopausal-level E(2) on proliferation, apoptosis, and differentiation of osteoblasts through transient activation of the MAPK/ERK pathway, whereas ER-α36-mediated postmenopausal-level E(2) induces apoptosis of osteoclasts through prolonged activation of the MAPK/ERK pathway with the involvement of reactive oxygen species. We also show that the levels of ER-α36 expression in bone are positively associated with bone mineral density but negatively associated with bone biochemical markers in postmenopausal women. Thus the higher levels of ER-α36 expression are required for preserving bone mass in postmenopausal and menopausal women who become osteoporotic if ER-α36-mediated activities are dysregulated.

Relationships between serum adiponectin, apelin, leptin, resistin, visfatin levels and bone mineral density, and bone biochemical markers in post-menopausal Chinese women

BACKGROUND

Adiponectin, apelin, leptin, resistin, and visfatin, as the main circulating peptides secreted by adipose tissue, are potential contributors to bone metabolism. However, their association with bone mineral density (BMD) is unclear.

AIM

The present study investigated whether these serum adipocytokines levels are associated with BMD and bone turnover markers.

METHODS

Serum adiponectin, apelin, leptin, resistin, visfatin levels, bone turnover biochemical markers, and BMD were determined in 336 post-menopausal Chinese women (41-81 yr old).

RESULTS

Adiponectin was negatively correlated with fat mass, while leptin had a positive correlation. In the multiple linear stepwise regression analysis, years since menopause, lean mass, estradiol, and adiponectin, but not fat mass, apelin, leptin, resistin, and visfatin, were independent predictors of BMD. The significant positive correlations between adiponectin and bone-specific alkaline phosphatase, bone crosslinked N-telopeptides of type I collagen were found.

CONCLUSIONS

Adiponectin was an independent predictor of BMD in post-menopausal Chinese women, and positively correlated with bone turnover biochemical markers. It suggested that adiponectin may exert a negative effect on bone mass by promoting excessive bone resorption associated with bone loss in post-menopausal women.

A survey of bone mineral density of healthy Han adults in China

A recent survey of bone mineral density (BMD) in China recruited 7,042 healthy Han Chinese aged 20 years and older. The mean BMDs were different in gender, age, and region; the proportions of men and women older than 50 years with a high risk of osteoporosis were estimated as 10.4% and 31.2%, respectively

INTRODUCTION

A survey of BMD was completed during 2002-2006 in China. By three-stage sampling, a total of 7,042 healthy Han Chinese aged 20 years and older were recruited in ten cities: 2,694 subjects from Beijing, Tianjin, Haerbin, Lanzhou, and Yantai of northern China and 4,348 from Shanghai, Changsha, Chengdu, Haikou, and Foshan of southern China.

METHODS

Two dual X-ray absorptiometry (DXA) systems (Hologic and Lunar) were used with parallel measurements of the European spine phantoms in each center. The mean BMDs in age groups older than 50 and the peak bone mineral density (pBMD) at femoral neck and that at greater trochanter were higher for men than women, and the pBMDs for northern China were higher than those for southern China, ranging from 1% to 4%.

DISCUSSION AND CONCLUSION

This work has provided two useful references for the first time: one is the estimation of the proportion and number of individuals older than 50 years with a high risk of osteoporosis, 10.4% and 12.5 million men, 31.2% and 37.2 million women, which is important for health care planning and marketing projections, and another is the conversion equations for cross-calibration among different types of DXA instruments frequently used in China.

Relationships between serum adiponectin, leptin concentrations and bone mineral density, and bone biochemical markers in Chinese women

BACKGROUND

Adiponectin and leptin, as the main circulating peptides secreted by adipose tissue, are potential contributors to bone metabolism. However, their association with bone mineral density (BMD) is unknown. We investigated whether these serum adipocytokines concentrations are associated with BMD and bone turnover markers.

METHODS

Serum adiponectin, leptin concentrations, bone turnover biochemical markers, and BMD were determined in 265 premenopausal and 336 postmenopausal Chinese women.

RESULTS

In postmenopausal Chinese women, the multiple linear stepwise regression analysis showed that year since menopause, lean mass, estradiol, and adiponectin, but not fat mass, leptin, were independent predictors of BMD in postmenopausal Chinese women. However, in premenopausal Chinese women, adiponectin was not the predictor of BMD. The significant positive correlations between adiponectin and bone-specific alkaline phosphatase (BAP), bone cross-linked N-telopeptides of type I collagen (NTX) were found only in postmenopausal women. Serum BAP, and NTX, but not adiponectin, decreased in response to alendronate therapy.

CONCLUSIONS

Adiponectin was an independent predictor of BMD, and positively correlated with bone turnover biochemical markers in postmenopausal Chinese women, but not premenopausal women. It suggested that adiponectin may exert a negative effect on bone mass by promoting excessive bone resorption associated with bone loss. However, these effects may be mediated by menopausal status.

Age-related changes in biochemical markers of bone turnover and gonadotropin levels and their relationship among Chinese adult women

The relationship between the levels of gonadotropic hormones and bone metabolism in Chinese adult women is unclear. Our research shows that a significant positive correlation exists between the levels of gonadotropic hormones and various bone turnover indicators. Follicle-stimulating hormone (FSH) has been found to have a greater influence on all types of bone turnover indicator than luteinizing hormone (LH). Further, FSH has a greater influence on bone formation indicators than on bone resorption indicators.

INTRODUCTION

The aim of this study was to investigate the relationship between serum FSH and LH and biochemical markers of bone turnover in native Chinese adult women.

METHODS

We conducted a cross-sectional study of 694 healthy Chinese women aged between 20 and 82 years. Serum FSH, LH, bone-specific alkaline phosphatase (BAP), osteocalcin (OC), N-terminal telopeptides of type I collagen, C-terminal telopeptides of type I collagen, urinary NTX, urinary CTX, and urinary deoxypyridinoline (uDPD) were determined.

RESULTS

All types of bone turnover indicator were significantly positively correlated with FSH (r = 0.164-0.626, all P = 0.000) and LH (r = 0.130-0.618, all P = 0.013-0.000). The correlation coefficient between serum FSH and BAP was the highest (r = 0.626), and that between serum FSH and uDPD was the lowest (r = 0.164). The serum gonadotropic hormone levels were higher; concentrations of bone turnover indicators were higher. The extent of the influence of FSH on various bone turnover indicators was approximately seven to 20 times greater than that of LH on these indicators. FSH could explain 43% and 22% of the changes in BAP and OC, respectively; whereas, LH could explain only 2.1% and 1.1%, respectively. FSH could explain approximately 1.9-11.8% of the changes in bone resorption indicators; however, LH had almost no effect on them.

CONCLUSIONS

Gonadotropic hormone levels are correlated with the rate of bone turnover in Chinese women: the higher the serum gonadotropic hormone levels in circulation, the higher the levels of bone turnover indicators. FSH has a greater influence on all types of bone turnover indicator than LH; moreover, it has a greater influence on bone formation indicators than on bone resorption indicators.

Age curves of bone mineral density at the distal radius and calcaneus in Koreans

This study evaluated age-related changes in bone mineral density (BMD) and identified the peak bone mineral density (PBMD) in Koreans. We recruited 2929 subjects, ranging in age from 5 to 86 years, from three regions: Seoul, Siwha, and Gwangyang. The BMD at the distal radius and calcaneus were measured with dual-energy X-ray absorptiometry, and anthropometric measures were also obtained. PBMD was calculated from the highest mean in each age group. The PBMD at the distal radius was 0.514 +/- 0.06 g/cm(2) in females and 0.598 +/- 0.07 g/cm(2) in males. Peak ages for both sexes were the thirties. For the calcaneus, PBMD was 0.509 +/- 0.09 g/cm(2) in females and 0.629 +/- 0.09 g/cm(2) in males. Peak ages were the thirties for females and the twenties for males. These results could facilitate international or interracial comparisons and be used as reference data to screen for osteoporosis in Koreans.

A novel microRNA targeting HDAC5 regulates osteoblast differentiation in mice and contributes to primary osteoporosis in humans

MicroRNAs (miRNAs) interfere with translation of specific target mRNAs and are thought to thereby regulate many cellular processes. Recent studies have suggested that miRNAs might play a role in osteoblast differentiation and bone formation. Here, we identify a new miRNA (miR-2861) in primary mouse osteoblasts that promotes osteoblast differentiation by repressing histone deacetylase 5 (HDAC5) expression at the post-transcriptional level. miR-2861 was found to be transcribed in ST2 stromal cells during bone morphogenetic protein 2-induced (BMP2-induced) osteogenesis, and overexpression of miR-2861 enhanced BMP2-induced osteoblastogenesis, whereas inhibition of miR-2861 expression attenuated it. HDAC5, an enhancer of runt-related transcription factor 2 (Runx2) degradation, was confirmed to be a target of miR-2861. In vivo silencing of miR-2861 in mice reduced Runx2 protein expression, inhibited bone formation, and decreased bone mass. Importantly, miR-2861 was found to be conserved in humans, and a homozygous mutation in pre-miR-2861 that blocked expression of miR-2861 was shown to cause primary osteoporosis in 2 related adolescents. Consistent with the mouse data, HDAC5 levels were increased and Runx2 levels decreased in bone samples from the 2 affected individuals. Thus, our studies show that miR-2861 plays an important physiological role in osteoblast differentiation and contributes to osteoporosis via its effect on osteoblasts.

Relationship of age-related concentrations of serum FSH and LH with bone mineral density, prevalence of osteoporosis in native Chinese women

BACKGROUND

Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) may play an important role in bone mass regulation in postmenopausal women.

METHODS

A cross-sectional study of 699 healthy Chinese women, aged 20 to 82 y, was conducted. Serum FSH and LH and BMD were measured at the posteroanterior (PA) spine, lateral spine, total hip, and distal forearm.

RESULTS

The geometric mean values (+/-SD) of serum FSH and LH in premenopausal women were 3.94 +/- 2.08 and 7.51 +/- 2.58 IU/l, respectively, and in postmenopausal women were 28.8 +/- 1.88 and 25.6 +/- 1.95 IU/l, respectively. The correlation of FSH to BMD at different skeletal regions (r = -0.597 - -0.492, P = 0.000) was higher than that of LH to BMD (r = -0.452 - -0.332, P = 0.000). The prevalences of osteoporosis for the quartiles of FSH at various skeletal sites were 0.57%, 0.43%, 27.1%, and 30.9%, respectively; and of LH were 2.14%, 4.43%, 19.5%, and 26.0%, respectively. The prevalence of osteoporosis in 3rd and 4th quartile was more significantly increased than the 1st and 2nd quartile.

CONCLUSIONS

These data suggest that FSH and LH levels in circulation are associated with BMD changes and osteoporosis occurrence in Chinese women.

Relationships between serum adiponectin, leptin, resistin, visfatin levels and bone mineral density, and bone biochemical markers in Chinese men

BACKGROUND

Adiponectin, leptin, resistin, and visfatin, as the main circulating peptides secreted by adipose tissue, are potential contributors to bone metabolism. We investigated whether these serum adipocytokines levels are associated with BMD and bone turnover biochemical markers in 232 Chinese men (20-80 y).

METHODS

Serum adiponectin, leptin, resistin, and visfatin levels were determined by ELISA.

RESULTS

Leptin had a positively correlation with fat mass, and remained significant after adjustment for age and BMI. There was a significant negative weak correlation between adiponectin and fat mass, and disappear after adjustment for age and BMI. Resistin and visfatin were not significantly correlated with fat mass. In the multiple linear stepwise regression analysis, lean mass and adiponectin, but not leptin, resistin and visfatin, were independent predictors of BMD. The significant positive correlations between adiponectin and bone-specific alkaline phosphatase (BAP), bone cross-linked N-telopeptides of type collagen (NTX) were found, and remained significant after adjustment for age and fat mass.

CONCLUSIONS

Adiponectin was an independent predictor of BMD in Chinese men, and positively correlated with bone turnover biochemical markers. It suggested that adiponectin exert a negative effect on bone mass in men.

Establishment of BMD reference databases for the diagnosis and evaluation of osteoporosis in central southern Chinese men

Osteoporosis in men is an increasingly important public health problem. This study was designed to establish bone mineral density (BMD) reference databases for central southern Chinese men at multiple skeletal sites. We recruited 2433 native Chinese males for BMD assessment. Of these, 1537 were healthy volunteers (age range, 15-85 years), and 896 were suspected to have osteoporosis. BMD values were measured at the posteroanterior (PA) and lateral spine, hip, and distal forearm using a Delphi A absorptiometer. The quadratic regression model provided the best fit for age-related changes in BMD in the spine and hip. The cubic regression model was the best for describing age-related BMD changes in the distal forearm. Peak BMD in the lumbar spine, femoral neck, and total hip occurred at 15-19 years. Peak BMD at the distal forearm occurred at 40-44 years. The prevalence of primary osteoporosis in subjects ranging from 50-85 years was 4.3%-27.7% at various skeletal sites. Compared to the databases established here, the Hologic databases led to significantly higher osteoporosis detection rates. The BMD reference databases established for central southern Chinese men provide the most reliable diagnostic standards for osteoporosis detection in men of central south China.

Effects of the sample size of reference population on determining BMD reference curve and peak BMD and diagnosing osteoporosis

Establishing reference databases generally requires a large sample size to achieve reliable results. Our study revealed that the varying sample size from hundreds to thousands of individuals has no decisive effect on the bone mineral density (BMD) reference curve, peak BMD, and diagnosing osteoporosis. It provides a reference point for determining the sample size while establishing local BMD reference databases.

INTRODUCTION

This study attempts to determine a suitable sample size for establishing bone mineral density (BMD) reference databases in a local laboratory.

METHODS

The total reference population consisted of 3,662 Chinese females aged 6-85 years. BMDs were measured with a dual-energy X-ray absorptiometry densitometer. The subjects were randomly divided into four different sample groups, that is, total number (Tn) = 3,662, 1/2n = 1,831, 1/4n = 916, and 1/8n = 458. We used the best regression model to determine BMD reference curve and peak BMD.

RESULTS

There was no significant difference in the full curves between the four sample groups at each skeletal site, although some discrepancy at the end of the curves was observed at the spine. Peak BMDs were very similar in the four sample groups. According to the Chinese diagnostic criteria (BMD >25% below the peak BMD as osteoporosis), no difference was observed in the osteoporosis detection rate using the reference values determined by the four different sample groups.

CONCLUSIONS

Varying the sample size from hundreds to thousands has no decisive effect on establishing BMD reference curve and determining peak BMD. It should be practical for determining the reference population while establishing local BMD databases.

Prevalence of osteoporosis and reference data for lumbar spine and hip bone mineral density in a Korean population

The aims of this study were to establish reference data for bone mineral density (BMD) at central skeletal sites using Lunar dual-energy X-ray absorptiometry (DXA), and to estimate the age-and sex-specific prevalence of osteoporosis in a Korean population. We performed a population-based, cross-sectional study. The subjects were 4148 (1810 men and 2338 women) Korean adults, aged 20-79 years. The BMD for central sites (lumbar spine, femoral neck, trochanter, and Ward's triangle) were measured by DXA. The standardized prevalence of osteoporosis among individual aged 50-79 years in lumbar spine, femoral neck, Ward's triangle, and trochanter was 40.1%, 12.4%, 28.4%, and 4.4% in women and 6.5%, 5.9%, 3.7%, and 1.6% in men, respectively. In women, peak BMD occurred in the age range 40-49 years for the femoral neck and trochanter, 30-39 years for the lumbar spine, and 20-29 years for Ward's triangle. In men, peak BMD values were observed at 20-29 years for all measured sites. This study establishes a normative database for BMD at central skeletal sites using dual-energy X-ray absorptiometry and provides more reliable information on the prevalence of osteoporosis in Korea.

Bone mineral content and bone mineral density at lumbar spine and forearm in Chinese girls aged 6-18 years

We investigated the age-related bone mineral content (BMC), bone mineral density (BMD) and the tempo of growth in BMC and BMD at lumbar spine and forearm in 455 Chinese girls aged 6-18 yr. BMC and BMD at the anteroposterior lumbar spine (LS), the left forearm (radius+ulna ultradistal, R+UUD) and one-third region (R+U1/3) were measured using a dual-energy X-ray bone densitometer (DXA). BMC and BMD exhibited different change patterns with the age changes. There were significant correlations between age, height, weight and BMC and BMD at LS, R+UUD and R+U1/3 sites. BMC and BMD increased significantly with increments in pubertal stages at LS, R+UUD and R+U1/3 sites. In conclusion, our study showed that Tanner stage had a significant positive association with BMC and BMD of the lumbar spine and forearm. The differences were found in the growth tempo of BMC and BMD within a region and between the spine and forearm. Both BMD and BMC were recommended to evaluate the bone health in children and adolescents.

Establishment of peak bone mineral density in Southern Chinese males and its comparisons with other males from different regions of China

Peak bone mineral density (PBMD) is an important determinant of osteoporotic fracture and a precondition for correct diagnosis of osteoporosis. The objective of this study was to establish the reference data of PBMD at the lumber spine and hip in Southern Chinese males. Bone mineral density (BMD) was measured at the lumbar spine and hip (femoral neck, trochanter, intertrochanter, and total) in 1155 Chinese men aged 15-39 years, using dual-energy X-ray absorptiometry (DXA). We utilized a fit curve method to determine the best age range over which to calculate PBMD. Our results indicated that the PBMD was observed at the age range of 18-25 years at the various sites. The mean value and standard deviation of PBMD was 0.753 +/- 0.117, 1.156 +/- 0.148, 0.896 +/- 0.120, 0.989 +/- 0.122, and 0.980 +/- 0.116 g/cm2 at the trochanter, intertrochanter, femoral neck, total hip, and spine, respectively. When the present PBMD reference was compared with the documented PBMD reference of males from other regions of China, we found great difference in standardized PBMD between Changsha males and those from other regions of China. The PBMD for Chinese males in Changsha at the various sites were 3.19%-11.33% lower than that for American Caucasian males. In conclusion, the PBMD at the spine and hip may be used as normal reference data for Southern Chinese males in Changsha instead of documented PBMD from other regions of China and the manufacturer's reference data.

Comparative evaluation of local and international reference databases for forearm densitometry: different impacts on diagnostic decisions

Reference databases play a key role in the management of osteoporosis. The aim of this preliminary study was to compare the diagnostic consequences of using either an international or a local reference database in peripheral densitometry. For this purpose, standard curves for bone mineral density (measured by dual-energy X-ray absorptiometry at the distal and proximal forearm) were generated for healthy Hungarian men and women. In total, 303 healthy volunteers of both sexes (age range: 20-94 yr) were recruited from four osteoporosis centers. Subjects with medical conditions or taking medication affecting the bone metabolism were excluded. Bone densitometry was performed with pDEXA (Norland-Stratec, Fort Atkinson, WI) devices in each center after cross-calibration of the machines. The precision error of the forearm measurement was also determined (<1% in vitro, and 1.2-2.5% in vivo). In females, the peak forearm density was detected in the 30-39-yr group. The density decreased by 8% per 5 yr in early postmenopausal females, and by 10% per 10 yr in late postmenopausal females. In males, the highest bone mineral density was found in the 30-39-yr group for the distal forearm, but 1 decade later for the proximal site. Subsequently, a 5% decrease in density occurred per 10 yr, except in the 8th decade, in which a 20% decrease was demonstrated. One thousand four hundred thirty-four patients with suspected osteoporosis were classified according to the forearm density T-scores using both the new Hungarian reference database and the international database provided by the manufacturer. Comparison of the results measured at the distal forearm with the two different databases led to similar outcomes. However, at the proximal site, one fifth of the female patients were reclassified from the low-density group to the normal group using the domestic normative database. An opposite difference was observed for the males: use of the Hungarian reference data resulted in 40% more men being categorized in the low-density group than when the international normal database was applied. Our results suggest that not only geographic differences, but also the reference database used, can influence the prevalence of the diagnosis of osteoporosis. Further data are currently being collected to increase the statistical power of the study.

Serum concentrations of MMP-1, MMP-2, and TIMP-1 in Chinese women: Age-related changes, and the relationships with bone biochemical markers, bone mineral density

BACKGROUND

Osteoblast-derived matrix metalloproteinse-1 (MMP-1), MMP-2 and tissue inhibitor of metalloproteinase-1 (TIMP-1) play a role in bone metabolism by degrading bone matrix.

METHODS

We measured MMP-1, MMMP-2, TIMP-1 and associated results with age and bone metabolism in 591 Chinese women aged 20-80 y.

RESULTS

Serum MMP-1, MMP-2, and TIMP-1 concentrations exhibited positive correlation with age. Serum concentrations of MMP-1 were higher in 40-69 y old women. The concentrations of MMP-2 were significantly increased in the 50-69 y olds. Serum TIMP-1 concentrations were significantly lower in women aged 30-59 y, and then these were followed by an increase at >60 y olds. We found a significant negative weaker correlation between MMP-2 and BMD. But multiple linear stepwise regression analysis showed that MMP-2 was not a determinant factor for BMD. There were significant positive correlations between MMP-2 and bone alkaline phosphatase (BAP), osteocalcin (OC), and cross-linked N-telopeptides of type I collagen (NTX).

CONCLUSIONS

The serum concentrations of MMP-1, MMP-2, and TIMP-1 exhibit age-related changes, and circulating MMP-2 and bone turnover are related.

Peak bone mass of Iranian population: the Iranian Multicenter Osteoporosis Study

Osteoporosis is a major public health problem in the Western countries and is projected to have a similar impact in the Middle East. It has been suggested that peak bone mineral density (BMD), a major determinant of osteoporotic fractures later in life, may be lower in this part of the world compared with the Western world. The purpose of the Iranian Multicenter Osteoporosis Study was to determine peak bone mass in a randomly chosen sample of healthy Iranian subjects. A total of 5201 participants (2340 males, mean age 42.7+/-13.8) were recruited based on randomized clustered sampling from all regions of five major cities across the country. In women, peak lumbar BMD (1.182+/-0.127 g/cm2) occurred in the 29- to 33-yr age group, whereas peak total femur BMD (1.006+/-0.126 g/cm2) occurred in the 32- to 36-yr age group. In men, peak lumbar BMD (1.181+/-0.153 g/cm2) and femoral BMD (1.096+/-0.159 g/cm2) both occurred in the 20- to 24-yr age group. When standardized to mg/cm2 units using established formulas, Iranian peak bone mass values are comparable with that of Western countries and are generally higher than that of Eastern Asian and Middle Eastern countries.

Age-related changes of serum bone alkaline phosphatase and cross-linked C-telopeptides of type I collagen and the relationship with bone mineral density in Chinese women

BACKGROUND

Previous studies have shown that bone turnover rate changes with age. At the same time, there is no definitive research regarding age-related changes of bone turnover level and its association with bone mineral density (BMD) in Chinese mainland women.

METHODS

In a cohort of 663 Chinese mainland women aged 20-70 years, serum bone alkaline phosphatase (BAP) and serum cross-linked C-telopeptides of type I collagen (sCTX) were measured to evaluate the state of bone formation and resorption, respectively. BMD was measured in the posteroanterior spine, supine lateral spine, hip and forearm using a dual-energy X-ray absorptiometry.

RESULTS

The cubic polynomial regression model best fit age-related changes in serum BAP (R2=0.398, p<0.001) and sCTX concentrations (R2=0.148, p<0.001) with largest R2 from comparison 8 different regression models. Their values reached a minimal level in the 30-39 years age group, and increased dramatically in the 40-59 years groups. There was a decreasing trend of BAP in women >60 years. The levels of BAP and sCTX were inversely correlated to BMD in various skeletal regions over the entire population (r=-0.096 to -0.357, p<0.05). sCTX was a significant predictor of a T-score< or =-2.5 of BMD in postmenopausal women with sCTX levels above mean+2 SD of women aged 30-39 years compared with other postmenopausal women, which indicated by odds ratios 1.9-3.7 (p<0.05) for various skeletal regions, especially for the lateral lumbar spine (2.2, p<0.01), Ward's triangle (3.7, p<0.01), and ultradistal end of radius + ulna (2.8, p<0.001).

CONCLUSIONS

Age-dependent serum BAP and sCTX were inversely correlated to BMD, and sCTX was a useful parameter for the prediction of a low T-score of BMD at skeletal sites with abundant cancellous bone in postmenopausal women.

Relationship of circulating MMP-2, MMP-1, and TIMP-1 levels with bone biochemical markers and bone mineral density in postmenopausal Chinese women

INTRODUCTION

Osteoblast-derived matrix metalloproteinase (MMP)-2, MMP-1 and tissue inhibitor of metalloproteinase (TIMP)-1 have been shown to play a role in bone metabolism by degrading the bone matrix.

METHODS

The present study was performed to investigate the relationships between serum MMP-2, MMP-1, or TIMP-1 levels and bone mineral density (BMD), as well as bone biochemical markers, in 297 Chinese postmenopausal women aged 42-80 years.

RESULTS

We found a significant negative weak correlation between MMP-2 and BMD at various skeletal regions. After adjustment for age and BMI, the correlation with BMD at the femoral neck and total hip disappeared. Multiple linear stepwise regression analysis showed that MMP-2 was not a determinant factor for BMD. The significant positive correlations between MMP-2 and bone cross-linked N-telopeptides of type I collagen (NTX), alkaline phosphatase (BAP), and osteocalcin (OC) and were found, and remained significant after adjustment for age and BMI. Moreover, serum MMP-2 concentrations were significantly higher in postmenopausal women with osteoporosis than in age-matched normal controls. There were no significant correlations between MMP-1, TIMP-1 and BMD. There were no significant relationships between MMP-1 and BAP, OC, and NTX. The associations between TIMP-1 and BAP and OC were not specific and constant.

CONCLUSIONS

In conclusion, our results suggest that circulating MMP-2 and markers of bone turnover are correlated, and serum MMP-2 levels may rise with increase in bone turnover.

Cross-calibration and minimum precision standards for dual-energy X-ray absorptiometry: the 2005 ISCD Official Positions

The International Society for Clinical Densitometry (ISCD) Committee on Standards of Bone Measurement (CSBM) consists of experts in technical aspects of bone densitometry. The CSBM recently reviewed the scientific literature on cross-calibration and precision assessment. A report with recommendations was presented at the 2005 ISCD Position Development Conference (PDC). Based on a thorough review of the data by the ISCD Expert Panel during the conference, the ISCD adopted Official Positions with respect to (1) cross-calibration when changing or replacing hardware; (2) the approach to cross-calibration when an entire system is changed to one made by either the same or a different manufacturer; (3) when no cross-calibration study or bone mineral density (BMD) comparison is done between facilities; and (4) the minimum acceptable precision for an individual technologist. We present here the ISCD Official Positions on these topics that were established as a result of the 2005 PDC, together with the associated rationales and supportive evidence.