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ABSTRACT: The purpose of this work is to investigate the age-related changes in body composition and their relationship with bone mineral density decreasing rates (BDR) in central south Chinese postmenopausal women. BDR is the percentage of bone mineral density (BMD) decreasing value relative to the peak bone mass. A cross-sectional study was conducted on 779 healthy postmenopausal women, aged 50-77. Lumbar spine, total hip, and femoral neck BMD and body composition were measured by dual-energy X-ray absorptiometry. In women under 65, lean mass levels showed a stable downward trend, and were significantly higher than those of the 65-70 and >70 age groups; however, the fat mass levels showed no significant difference between the age groups. After controlling for age, age at menopause, and height, both fat mass and lean mass positively correlated with BDR at the lumbar(1-4) spine, the femoral neck and the total hip. When BDR at the lumbar(1-4) spine was used as the dependent variable, a higher R (2) change and partial R (2) were seen in fat mass than the age, age at menopause or lean mass, indicating that fat mass was the most significant determinant of BDR at this site. When BDR at the femoral neck or total hip was used as the dependent variable, respectively, lean mass was a more significant determinant than that of fat mass. We found that with advancing age, lean mass begins to decrease in women aged over 65 years, but fat mass levels show no significant difference between the age groups. Both fat mass and lean mass positively correlate with BDR, with site-specific differences. Fat mass is the most significant determinant of BDR at the lumbar spine, whereas lean mass is the most significant determinant of BDR at the femoral neck and total hip.
Endocrine 11/2012; · 1.42 Impact Factor
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ABSTRACT: To assess the relationship between body composition and fracture risk as determined by the FRAX(®) model in postmenopausal women in central south China.
A cross-sectional study was conducted in 779 women. Bone mineral density (BMD) of the left femur and total body composition were measured by dual X-ray absorptiometry. All clinical information was available for incorporation into the FRAX model to assess the 10-year fracture probability.
In the FRAX model, when BMD values were included, the 10-year probability of major osteoporotic fractures and hip fractures was 3·4% and 1·0%, respectively, which was significantly higher than the probability rates of 2·7% and 0·8%, respectively, for the same events when BMD values were not included (P < 0·01). Both fat mass and lean mass were negatively correlated with the predicted 10-year probability of fracture (P < 0·01), and femoral neck BMD was the most significant determinant of the predicted 10-year fracture probability. Compared with fat mass, lean mass had more impact on the 10-year probability of both major and hip osteoporotic fractures.
In postmenopausal women in central south China, both fat mass and lean mass were negatively correlated with the predicted 10-year fracture probability. The effect of lean mass and fat mass on fracture risk may be mediated through their impact on BMD. Compared with fat mass, lean mass had more of an impact on the risk of both major osteoporotic and hip fractures, showing that physical activity is an important component in the prevention of osteoporotic fracture.
Clinical Endocrinology 04/2012; 77(4):524-30. · 3.17 Impact Factor
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ABSTRACT: To investigate the relationship between serum sclerostin level, body composition, and bone mineral density (BMD) in central south Chinese postmenopausal women.
A cross-sectional study was conducted on 260 healthy central southern Chinese postmenopausal women with vs without osteoporosis, aged 50-76 years old. Dual X-ray absorptiometry was used to measure the bone mineral content and BMD of the whole body, lumbar spine and left femur, and total body soft tissue composition. Serum sclerostin levels were measured by a quantitative sandwich enzyme-linked immunosorbent assay.
Compared with women without osteoporosis, osteoporotic women had a significantly lower level of serum sclerostin (P = 0.001). Serum sclerostin levels were positively correlated with body weight, Ponderal index and fat mass. There was a positive correlation with the BMD of both the whole body and at various sites (P < 0.05), even after controlling for age, age at menopause, height and body weight. Multiple linear stepwise regression analysis showed that serum sclerostin level was the most significant determinant of both whole-body and lumbar spine BMD, compared with age, age at menopause, fat mass and lean mass. Age had similar impact as serum sclerostin on hip BMD.
This study showed that in central south Chinese postmenopausal women, serum sclerostin is lower in women with osteoporosis than without. Serum sclerostin is positively correlated with fat mass and BMD for the whole body, lumbar spine and hip.
Clinical Endocrinology 12/2011; 76(6):797-801. · 3.17 Impact Factor
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Zhifeng Sheng,
Kang Xu,
Yangna Ou,
Ruchun Dai,
Xianghang Luo,
Shiping Liu,
Xin Su,
Xiyu Wu,
Hui Xie,
Lingqing Yuan,
Eryuan Liao
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ABSTRACT: To elucidate the relationship between body composition and bone mineral density (BMD) and the prevalence of osteoporosis in central south Chinese postmenopausal women.
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.
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.
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.
Clinical Endocrinology 03/2011; 74(3):319-24. · 3.17 Impact Factor
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ABSTRACT: We aimed at evaluating the relationship between lean mass and fat mass with age, menopausal age (MA) and years since menopause (YSM) and their effects on bone mineral density (BMD) at segmental regions in postmenopausal elderly women with and without osteoporosis. After using a dual-energy X-ray absorptiometry (DXA) methodology to measure body composition and BMD at posteroanterior spine and hip in 244 postmenopausal elderly non-osteoporotic (Non-OP) women (65.5 ± 4.3 years) and 298 postmenopausal elderly osteoporotic (OP) women (67.1 ± 4.4 years), we found that in postmenopausal elderly Non-OP women, there was no correlation between lean mass with age, MA, and YSM, as well as no correlation between fat mass with age (all, p > 0.05); leg fat (LF) mass (r = 0.187; p<0.01), whole body fat (WF) mass (r = 0.151; p < 0.05), and trunk fat (TRF) mass (r = 0.141; p < 0.05) were positively correlated with MA; LF (r = -0.131; p < 0.05) and WF (r = -0.127; p < 0.05) were negatively associated with YSM; WF and whole body lean (WL) mass were the most important body composition components influencing BMD at the third lumbar spine (L3), total first to fourth lumbar spine (L1-4) and hip, respectively; TRF was the most significant determinant of BMD at both L2 and L4. In postmenopausal elderly OP women, there was no relationship between body composition with MA (p > 0.05); Trunk lean (TRL) mass (r = -0.183; p < 0.05), leg lean (LL) mass (r = -0.136; p < 0.01), and WL mass (r = -0.162; p < 0.01) were negatively correlated with age; TRL mass (r = -0.132; p < 0.05), LL mass (r = -0.152; p < 0.01), WL mass (r = -0.170; p < 0.01) were also negative with YSM; WF was the most important factor influencing BMD at lumbar spine and hip. These data suggest in postmenopausal elderly Non-OP women, fat mass (TRF, LF, and WF) was more related with MA; WF and WL mass were the most important body composition components influencing BMD at L1-4 and hip, respectively; in postmenopausal elderly OP women, body composition was not correlated with MA; lean mass (TRL, LL, and WL) was more age-related negatively; WF mass was the most significant factor affecting BMD at lumbar spine and hip.
Archives of gerontology and geriatrics 09/2010; 53(2):e192-7. · 1.36 Impact Factor
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ABSTRACT: Using osteoprotegerin (OPG)-knockout mice, we demonstrated that in vivo the effects of both genistein and 17beta-estradiol (E2) on bone metabolism were completely abolished. In contrast, zoledronic acid could effectively suppress bone resorption and prevent bone loss.
The anti-resorptive effects of E2 on bone metabolism are considered to be mediated via modulation of the osteoblast-derived paracrine factor OPG. Recently, the phytoestrogen genistein was found to suppress bone resorption by enhancing osteoblastic production of OPG. However, the mechanism underlying the in vivo effects of E2 and genistein on bone is not entirely understood, and a central question in this regard is whether E2 regulates bone metabolism via an OPG-dependent pathway.
After mating heterozygous (OPG+/-) mice, homozygous (OPG-/-) and wild-type (WT) with a mixed C57BL/6J x 129/SV background were obtained. The study involved 6-week-old female OPG-/- (n=40) and WT mice (n=8). The OPG-/- mice were randomly divided into 5 groups (n=8 per group) as follows: (1) genistein-treated mice (Gen) that were subcutaneously injected with genistein at a maximal dose (0.8 mg/day); (2) E2-treated mice (E2) that were subcutaneously injected with E2 at a dose (0.03 microg/day); (3) DMSO control mice (DMSO) that were subcutaneously injected with a mixture of dimethylsulfoxide (DMSO) and polyethyleneglycol-300; (4) zoledronic acid-treated mice (Zol) that were subcutaneously injected with zoledronic acid at a dose of (150 microg/kg) twice per week; and (5) H2O control mice that were subcutaneously injected with sterilized water twice per week. The doses of genistein, estrogen and zoledronic acid were selected based on the results of dose-response effect of agents on bone versus uterus in OPG-/- mice. The mice were sacrificed 6 weeks after this intervention. The microarchitecture of the trabecular and cortical bone was assessed by performing microcomputed tomography (micro-CT) for the right proximal tibia. The bone mineral density (BMD) of the left femur was measured by dual-energy X-ray absorptiometry (DXA). The biomechanical parameters of the right femur were determined by a three-point bend testing. Serum levels of bone alkaline phosphatase (B-ALP), tartarate-resistant acid phosphatase-5b (TRACP-5b), and receptor activator of nuclear factor kappaB ligand (RANKL) were determined by performing ELISA.
DXA analysis revealed that the total BMD of the femur was not significantly altered in the Gen, E2, H2O, and DMSO groups. The three-point bending test revealed no significant differences in the biomechanical parameters, including ultimate loading, ultimate stress, stiff index, and elastic modulus, and micro-CT analysis revealed that the microarchitectural parameters of the trabecular bone (vBMD, tBMD, BVF, BSF, SMI, Tb.N, Conn.D, Tb.Sp, and Tb.Th) and cortical bone (Ct.Th, Mm, In.Pm, Ot.Pm, Ma.Ar, Ct.Ar, Tt.Ar, Ct.BMD, and Ct.BMC) did not differ among the groups. Genistein and E2 treatment did not alter the serum TRACP-5b, B-ALP, or RANKL levels. However, in addition to increasing the bone mass, zoledronic acid could effectively improve biomechanical parameters and could completely prevent deterioration of the bone architecture in the OPG-/- mice.
The effects of genistein and E2 on bone metabolism in vivo were lost completely in OPG-deficient mice, suggesting that the effect of these agents on bone metabolism seems to be entirely dependent on OPG. In contrast, zoledronic acid could effectively suppress bone resorption and completely prevent the bone loss in the OPG-/- mice--an effect that is likely to be independent of the OPG pathway.
Bone 06/2008; 42(5):950-9. · 4.02 Impact Factor
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ABSTRACT: Until now, the effects of phytoestrogen on bone in both women and ovarian hormone-deficient animal models of osteoporosis have remained uncertain. We have aimed here to investigate the effect of genistein (GEN) on trabecular bone quality in ovariectomized (OVX) rats. Forty 7-month-old female Sprague-Dawley rats were randomly divided into the following four groups: OVX, sham-operated (SHAM), treated with 17beta-estradiol (EST, 10 microg x kg(-1) x day(-1)), and GEN (5 mg x kg(-1) x day(-1)). At 15 weeks postoperation, the compressive test was performed on the L5 vertebral body; additionally, microcomputed tomography (micro-CT) assessment was performed to estimate the bone mineral density (BMD) and microstructure parameters of the L6 vertebral body. After fatigue damage testing, the L6 vertebral body was bulk-stained in 1% basic fuchsin and embedded in methylmethacrylate. The L4 vertebral body was embedded in methylmethacrylate for dynamic histomorphometry analysis without staining. Mounted bone slices were used to measure microcrack parameters, empty osteocyte lacuna density (e.Lc.Dn), and osteocyte density (Ot.N/T.Ar). Maximum loading (ML) and Ot.N/T.Ar were significantly lower in the OVX group than in the other groups. E.Lc.Dn was significantly decreased in GEN and EST groups compared to the OVX group. ML was significantly decreased in the GEN group compared to the SHAM group. Microcrack density, microcrack surface density, and microcrack length were significantly increased in the OVX group compared to the other groups. Mineral apposition rate was significantly decreased in the OVX group compared to the SHAM and GEN groups. Bone formation rate was significantly decreased in the OVX group compared to other groups. There were no significant differences with regard to mineralizing surface among the four groups. Volumetric BMD at organ was significantly lower in OVX, EST, and GEN groups than in the SHAM group. Bone mineral content was significantly lower in the OVX group than in the SHAM group. Bone volume fraction and trabecular number were significantly decreased in OVX, EST, and GEN groups compared to the SHAM group. Structure model index was significantly lower in the SHAM group than in OVX, EST, and GEN groups. Trabecular separation was significantly increased in the OVX group compared to SHAM and EST groups. There were no significant differences with regard to the trabecular thickness (Tb,Th) between SHAM, GEN, and OVX groups. Tb.Th was significantly lower in the EST group than in the SHAM group. Connectivity density (Conn.D) was significantly lower in the OVX group than in SHAM and GEN groups, and Conn. D was significantly lower in the EST group than in GEN. In conclusion, the present study demonstrates that GEN preserved the biomechanical quality of the trabecular bone regardless of the microstructure and BMD.
Journal of Bone and Mineral Metabolism 02/2008; 26(4):342-9. · 2.27 Impact Factor
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ABSTRACT: Myasthenia gravis (MG) is an autoimmune disease that affects the transmission signals from nerves to muscles. The basic pathology is the production of anti-acetylcholine receptor (AChR) antibodies (AChRAb) which is the consequence for the generation of autoreactive T lymphocytes responsing to AChR. However, the molecular mechanism of MG and the production of autoreactive T lymphocytes remain elusive. Recently beside its pivotal role in reproduction, the pituitary hormone prolactin (PRL) has been attributed to an immunomodulatory function. Furthermore it has been shown to be expressed in T cells and conversely it also affects the function of T cells, such as directly stimulating the proliferation and survival of T lymphocytes. In addition, elevated PRL levels frequently are described in autoimmune diseases, such as systemic lupus erythematosus (SLE) and multiple sclerosis (MS). So we hypothesized that the stimulating effect of PRL on T-cells function may be implied in the pathogenesis of MG and, perhaps, prolactin may be a promising therapeutic target for MG.
Medical Hypotheses 02/2008; 70(5):1017-20. · 1.39 Impact Factor
