Correlation analysis between bone mineral density and serum element contents of postmenopausal women in Xi'an urban area

Associations Between Serum Selenium and Bone Mineral Density in 8-19-year-old children and adolescents: NHANES 2013-2018

The peak bone mass (PBM) in puberty has been proven to be a critical determinant of osteoporosis and brittle fractures in the elderly. Selenium is an essential trace element that could influence bone metabolism in our bodies. However, no study has investigated the impact of selenium status on bone mineral density (BMD) among children and adolescents. This was a cross-section study from National Health and Nutrition Examination Survey (NHANES) in the USA involving participants aged 8-19 years. We conducted multiple linear regression models to assess the relationship between selenium status and BMD among children and adolescents, and then stratified analyses were performed according to genders and races. Smooth curve fits and two-piecewise linear regression models were conducted to explore their nonlinear relationship. A total of 4570 participants (2338 boys and 2232 girls) were included in the present study, with a mean age of 13.57 ± 3.41 years. In the multivariable adjustment model, serum selenium was positively associated with lumbar spine BMD (β = 0.021 95% CI: 0.008, 0.034, P = 0.001). The dose-response analyses indicated a non-linear inverted U-shaped relationship between serum selenium and lumbar spine BMD. Lower and higher selenium concentrations were related to decreased BMD, and the inflection point of serum selenium was 2.60 umol/L. The inverted U-shaped association was also observed in females (inflection point: 2.49 umol/L), males (inflection point: 2.65 umol/L), Non-Hispanic White (inflection point: 2.50 umol/L), Non-Hispanic Black (inflection point: 2.50 umol/L), and other races (Including multi-racial) (inflection point: 2.81 umol/L). Our study first shows a non-linear inversed U-shaped association between selenium status and BMD among children and adolescents. The proper selenium status will benefit bone health in children and adolescents. More research is still required to verify our findings and their potential mechanisms.

Associations of blood trace elements with bone mineral density: a population-based study in US adults

BACKGROUND

This study aimed to investigate the association between blood trace elements and bone mineral density (BMD) and to determine the association between blood trace elements and the risk of low BMD/osteoporosis among US adults.

METHODS

We performed a cross-sectional study using data from National Health and Nutrition Examination Survey (NHANES, 2011-2016). Multivariable linear regression models were employed to assess the associations of BMD in lumbar spine (LS-BMD), pelvic (PV-BMD) and total femur (TF-BMD) with blood trace elements, including Fe, Zn, Cu, Se, Mn, Cd, Pb, Hg. Additionally, the associations of low BMD/osteoporosis with blood trace elements were also evaluated using multivariable logistic regression.

RESULTS

Higher blood Pb levels were found associated with decreased LS-BMD (p for trend < 0.001), PV-BMD (p for trend = 0.007), and TF-BMD (p for trend = 0.003) in female, while higher blood Se levels were associated with increased PV-BMD in female (p for trend = 0.042); no linear association between BMD and other blood trace element was observed. Also, significant associations were found between Pb levels and the prevalence of low BMD (p for trend = 0.030) and the prevalence of osteoporosis (p for trend = 0.036), while association between other blood trace elements and low BMD/osteoporosis was not observed.

CONCLUSION

This study provides comprehensive insight into the association between blood trace elements and BMD and supports a detrimental effect of blood Pb levels on bone mass in women. Considering our analysis from a representative US general population, further study is warranted for the extreme levels of blood trace elements on bone metabolism.

Relationship of blood heavy metals and osteoporosis among the middle-aged and elderly adults: A secondary analysis from NHANES 2013 to 2014 and 2017 to 2018

Objective

This study aimed to assess the relationship between blood heavy metals and a higher prevalence of osteoporosis in middle-aged and elderly US adults using the National Health and Nutritional Examination Surveys (NHANES).

Methods

The secondary data analysis was performed using the data of NHANES 2013–2014 and 2017–2018. We used the information, including physical examination, laboratory tests, questionnaires, and interviews, provided by participants in NHANES. Logistic regression and weighted quantile sum (WQS) regression models were used to explore the relationships between levels of blood heavy metals and a higher prevalence of osteoporosis.

Results

A total of 1,777 middle-aged and elderly participants were analyzed in this study, comprising 115 participants with osteoporosis and 1,662 without osteoporosis. Adjusted model 1 showed a significant positive relationship between cadmium (Cd) levels and a higher prevalence of osteoporosis (quartile 2, OR = 7.62; 95% CI, 2.01–29.03; p = 0.003; quartile 3, OR = 12.38; 95% CI, 3.88–39.60; p &lt; 0.001; and quartile 4, OR = 15.64; 95% CI, 3.22–76.08; p = 0.001). The fourth quartile of selenium (Se) level (OR = 0.34; 95% CI, 0.14–0.39; p &lt; 0.001) led to a lower prevalence of osteoporosis and exerted a protective effect on model 1. Other models produced similar results to those of model 1. A subgroup analysis showed that Cd levels were positively related to a higher prevalence of osteoporosis in all three models in women, while this relationship was not found in men. The fourth quartile of the Se level was related to a lower prevalence of osteoporosis in both male and female analyses. A significant positive relationship was found between the blood Cd level and a higher prevalence of osteoporosis in the non-smoking subgroup. Blood Se level showed a protective effect on the fourth quartile in both the smoking and non-smoking subgroups.

Conclusion

Blood Cd level aggravated the prevalence of osteoporosis, while blood Se level could be a protective factor in osteoporosis among the US middle-aged and older populations.

Evaluation of Relationship Between SOD1 50-bp Deletion Gene Polymorphism, Cu, Zn Level, and Viscosity in Postmenopausal Osteoporosis Patients with Vertebral Fractures

Oxidative stress plays a role in the pathogenesis of bone loss, causing low bone mineral density (BMD) and associated osteoporotic fractures. In our study, we aimed to investigate the relationship of SOD1 50-bp insertion(Ins)/deletion(Del) polymorphism that is involved in oxidative stress metabolism, Cu and Zn element concentrations, and plasma viscosity level, with postmenopausal osteoporosis and related vertebral fractures. The study included 167 voluntary individuals. The 50-bp Ins/Del polymorphism of SOD1 was determined by allele-specific PCR. Plasma Cu and Zn levels were measured by atomic absorption spectrophotometry (AAS). The plasma viscosity was determined using the Harkness Capillary Viscometer device. In our study, the distribution of SOD1 promoter 50-bp Ins/Del polymorphism did not indicate a significant difference between the groups and in postmenopausal osteoporosis patients with and without fractures (p > 0.05). The Ins/Ins genotype was found to be common in individuals in both groups. The Cu and Zn levels of the study group were found to be between the normal reference values (p > 0.05). It was determined that plasma viscosity increased significantly in the group of osteoporotic patients and in patients with postmenopausal osteoporosis with fractures (p < 0.01). In addition, plasma viscosity was found to significantly increase in patients with Ins/Ins genotype and fractures (p < 0.01). Postmenopausal osteoporosis and associated vertebral fracture were found not to be directly related to SOD1 50-bp polymorphism and Cu and Zn element levels. Plasma viscosity levels were found to increase due to the increase in oxidative stress products. Further studies are needed to clarify the roles and relationships of SOD genes and trace elements in the development of postmenopausal osteoporosis and vertebral fracture.

The Effects of Lead and Cadmium Co-exposure on Serum Ions in Residents Living Near a Mining and Smelting Area in Northwest China

In this study, we investigated the associations between cadmium (Cd) and lead (Pb) co-exposure, and serum ion levels in two populations living near a mining/smelting area and a nature reserve (control area), respectively. A total of 445 participants were included in this study. Their blood cadmium (BCd), blood lead (BPb), and serum ion levels were determined, and the association between exposure levels and serum ion levels was analyzed. The exposure levels of subjects living in the polluted area were significantly higher (p < 0.001). Lower levels of potassium, inorganic phosphorus, and iron were observed in subjects from the polluted area, whereas their sodium and chloride levels were higher (p < 0.01). The anion gap in their serum was also significantly lower. We observed positive dose-effect relationships between Cd and/or Pb exposure and serum sodium and chloride, and negative dose-effect relationships between Cd and/or Pb exposure and serum inorganic phosphorus, iron, as well as the anion gap. High Cd-Pb, high Cd, and high Pb exposure led to modification effects in potassium, calcium, inorganic phosphorus, and iron levels, and the anion gap. No synergistic effects were observed in our results. In conclusion, our data demonstrate that Cd and Pb exposure, alone or in combination, can lead to serum ion imbalances.

Manganese, iron, copper, and selenium co-exposure and osteoporosis risk in Chinese adults

BACKGROUND & AIMS

Previous experimental studies demonstrated that either deficient or excessive trace elements, such as manganese (Mn), iron (Fe), copper (Cu) and selenium (Se), are detrimental to bone health. Epidemiologic evidence for the effect of the four trace elements on osteoporosis (OP) risk remains inadequate. This cross-sectional study aimed to examine their associations with the OP risk among Chinese adults.

METHODS

Concentrations of Mn, Fe, Cu, and Se were measured in plasma using an inductively coupled plasma mass spectrometer among 627 Chinese adults aged ≥ 50 years. Individual effect of the four elements on OP risk was analyzed by logistic regression and Bayesian Kernel Machine Regression (BKMR) models. The latter model was also adopted to examine the exposure-response relationships and joint effects of the four elements on OP risk.

RESULTS

The median Mn, Fe, Cu, and Se levels were 4.78, 1026.63, 904.55, and 105.39 μg/L, respectively, in all participants. Inverse associations of Fe and Se levels with OP risk were observed in the logistic regression model. BKMR analysis revealed a U-shape pattern for the Fe-OP association, and a reduced OP risk in response to co-exposure of the four elements above the 50th percentiles but an elevated one in response to that below the 50th percentiles. Sex discrepancy existed in the findings. No interactions were found for the four elements affecting OP risk.

CONCLUSIONS

Co-exposure to Mn, Fe, Cu, and Se was associated with improved bone density, where Fe contributed most to the beneficial effect. Further studies are needed to verify these findings and explore the underlying biological mechanism.

Effect of Copper and Selenium Supplementation on the Level of Elements in Rats' Femurs under Neoplastic Conditions

A study was conducted to determine the effect of long-term supplementation with selenium and copper, administered at twice the level used in the standard diet of rats, on the content of selected elements in the femoral bones of healthy rats and rats with implanted LNCaP cancer cells. After an adaptation period, the animals were randomly divided into two experimental groups. The rats in the experimental group were implanted with prostate cancer cells. The rats in the control group were kept in the same conditions as those in the experimental group and fed the same diet, but without implanted cancer cells. The cancer cells (LNCaP) were intraperitoneally implanted in the amount of 1 × 106 (in PBS 0.4 mL) at the age of 90 days. The content of elements in the samples was determined by a quadrupole mass spectrometer with inductively coupled plasma ionization (ICP-MS). In the femoral bones of rats with implanted LNCaP cells, in the case of the standard diet and the copper-enriched diet, there was a marked decreasing trend in the content of the analysed elements relative to the control rats. This may indicate slow osteolysis taking place in the bone tissue. Contrasting results were obtained for the diet enriched with selenium; there was no significant reduction in the level of these elements, and there was even an increase in the concentrations of Fe and K in the bones of rats with implanted LNCaP cells. Particularly, numerous changes in the mineral composition of the bones were generated by enriching the diet with copper. The elements that most often underwent changes (losses) in the bones were cobalt, iron, manganese and molybdenum. The changes observed, most likely induced by the implantation of LNCaP cells, may indicate a disturbance of mineral homeostasis.

The Effects of Selenium on Bone Health: From Element to Therapeutics

Osteoporosis, characterized by low bone mass and a disruption of bone microarchitecture, is traditionally treated using drugs or lifestyle modifications. Recently, several preclinical and clinical studies have investigated the effects of selenium on bone health, although the results are controversial. Selenium, an important trace element, is required for selenoprotein synthesis and acts crucially for proper growth and skeletal development. However, the intake of an optimum amount of selenium is critical, as both selenium deficiency and toxicity are hazardous for health. In this review, we have systematically analyzed the existing literature in this field to determine whether dietary or serum selenium concentrations are associated with bone health. In addition, the mode of administration of selenium as a supplement for treating bone disease is important. We have also highlighted the importance of using green-synthesized selenium nanoparticles as therapeutics for bone disease. Novel nanobiotechnology will be a bridgehead for clinical applications of trace elements and natural products.

The concentrations of bone calcium, phosphorus and trace metal elements in elderly patients with intertrochanteric hip fractures

INTRODUCTION

Trace metal elements may play a crucial role in bone mineralization and metabolism. However, the quantification of trace element concentrations in human bone tissue has received little attention.

MATERIALS AND METHODS

Bone tissue samples were collected from 55 elderly patients (15 males and 40 females) with intertrochanteric hip fractures. The calcium, phosphorus, manganese, iron, copper, and zinc concentrations in the cortical bone zone, cancellous bone zone, and junction zone between cortical and cancellous bone were determined by energy-dispersive X-ray fluorescence (EDX). The differences in trace element concentrations in the three regions were compared, and the correlation between gender and bone trace element contents of the bones was analyzed using the Kruskal-Wallis's test. The correlation between age, body mass index (BMI), and bone calcium, phosphorus concentrations, and trace elements in three bone zones was determined using Spearman correlation analysis.

RESULTS

The Kruskal-Wallis test showed no difference in bone phosphorus concentration among the three regions. In contrast, the difference in the concentrations of bone calcium and four metal elements was statistically significant (P<0.01). In addition, no statistical differences were observed in the concentrations of trace elements among the three regions in elderly male and female patients. Spearman correlation analysis showed a strong negative correlation between bone calcium and phosphorus in three bone regions (r=-0.999, -0.95, -0.998, P < 0.01) and a significant positive correlation between trace metal elements in the cancellous bone zone. In the junction zone, the BMI showed a strong positive correlation with bone calcium content (r=0.347, P=0.009) and a significant negative correlation with phosphorus content (r=-0.349, P=0.009).

CONCLUSION

Bone calcium and phosphorus were the main components of hydroxyapatite, and these two elements accounted for the majority of bone mineral salts. Trace metal elements are essential for bone metabolism and specific synergistic interactions. BMI may be associated with bone calcium and phosphorus contents in elderly patients with osteoporosis.

Causal Effect of Serum Magnesium on Osteoporosis and Cardiometabolic Diseases

Serum magnesium is associated with osteoporosis and cardiometabolic diseases, but their causal associations remain elusive. We used the two-sample Mendelian randomization (MR) study to explore the causal roles of serum magnesium on osteoporosis and cardiometabolic diseases by using the aggregated genome-wide association studies (GWASs). Six single-nucleotide polymorphisms (SNPs, p < 5 × 10^-8) associated with serum magnesium concentrations were all used as instrumental variables. A genetic predisposition to higher serum magnesium concentrations was inversely associated with lower lumbar spine bone mineral density (BMD, beta-estimate: -1.982, 95% CI: -3.328 to -0.635, SE: 0.687, p = 0.004), which was further confirmed by multiple sensitivity analyses. There was limited evidence of associations between serum magnesium and type 2 diabetes, coronary artery disease, heart failure, and atrial fibrillation. This work provided strong evidence that genetically increased serum magnesium concentrations were causally associated with low lumbar spine BMD and suggested that serum magnesium concentrations may be crucial to prevent osteoporosis.

Copper as Dietary Supplement for Bone Metabolism: A Review

While in vitro and animal studies of osteoblastic and osteoclastic activity as well as bone resistance for copper are numerous, and the results encouraging in terms of regulation, human studies are scarce. The aim of this narrative review was to investigate the correlation of blood copper, daily copper intake, and copper supplementation with bone mineral density. This review included 10 eligible studies: five studies concerned copper blood levels, one study concerned daily copper intake, and four studies concerned copper supplementation. Blood copper levels did not show statistically significant differences in four of the studies analyzed, while only one study showed differences between osteoporotic and healthy women, although only with women between 45 and 59 years of age and not between 60 and 80 years of age. The dietary copper intake among women with or without osteoporosis did not show any differences. Only one study with a small sample of subjects carried out these assessments; therefore, it is a topic that the literature must deepen with further studies. The two studies that analyzed the integration of copper (2.5-3 mg/day) only showed good results in terms of slowing down bone mineral loss and reducing resorption markers, confirming the effectiveness of copper supplementation on bone metabolism.

Do Only Calcium and Vitamin D Matter? Micronutrients in the Diet of Inflammatory Bowel Diseases Patients and the Risk of Osteoporosis

Osteoporosis is one of the most common extraintestinal complications among patients suffering from inflammatory bowel diseases. The role of vitamin D and calcium in the prevention of a decreased bone mineral density is well known, although other nutrients, including micronutrients, are also of extreme importance. Despite the fact that zinc, copper, selenium, iron, cadmium, silicon and fluorine have not been frequently discussed with regard to the prevention of osteoporosis, it is possible that a deficiency or excess of the abovementioned elements may affect bone mineralization. Additionally, the risk of malnutrition, which is common in patients with ulcerative colitis or Crohn's disease, as well as the composition of gut microbiota, may be associated with micronutrients status.

Is Zinc an Important Trace Element on Bone-Related Diseases and Complications? A Meta-analysis and Systematic Review from Serum Level, Dietary Intake, and Supplementation Aspects

Bone-related diseases are very common problems, especially in the elderly population. Zinc takes part in the growth and maintenance of healthy bones. This meta-analysis aims to evaluate the effects of zinc supplementation or dietary zinc intake on serum zinc levels and bone turnover markers. A systematical research was performed with 2899 articles in PubMed, WoS, and Scopus for relevant articles in English which have mean/standard deviation values of serum zinc levels, dietary zinc intake/zinc supplementation (mg/day), and bone turnover markers up to February 2020. In the overall analysis, serum zinc level was significantly lower in patients with osteoporosis compared with controls (p 0.0002). Dietary zinc intake decreased in the fracture group compared with controls according to subgroup analysis patients with fracture (p 0.02). Zinc supplementation was effective on the femoral neck (p < 0.0001) and lumbar spine (p 0.05) bone mineral density (BMD). In the correlation analysis of the data obtained from all of the included studies, serum osteocalcin (p 0.0106, r - 0.9148) correlated with serum zinc level. In conclusion, serum zinc level and dietary zinc intake could have an essential role in preventing osteoporosis. Zinc supplementation might improve bone turnover markers for bone formation such as serum osteocalcin and serum alkaline phosphatase and also, BMD at the site of the femoral neck.

Serum Zinc Concentrations of Adults in an Outpatient Clinic and Risk Factors Associated With Zinc Deficiency

Context

Subclinical features of zinc deficiency can be challenging to recognize. The prevalence of zinc deficiency based on blood zinc concentration in an adult outpatient clinic setting has not been well-studied.

Objective

To estimate the prevalence of low serum zinc concentrations among community-dwelling adults, and to characterize clinical features and risk factors associated with zinc deficiency.

Methods

This retrospective pilot prevalence study took place from 2014 to 2017 at an outpatient clinic in southeast Ohio. Patients aged 50 years or older with a stable health status were categorized into a case group with zinc deficiency (serum zinc concentration, <0.66 µg/mL) and a control group (serum zinc concentration, ≥0.66 µg/mL). Measurements included serum zinc concentration, nutritional biomarkers (ie, magnesium, calcium, albumin, and total 25-hydroxy vitamin D levels), patient history of fractures and events such as hospitalization, antibiotic use, and self-reported falls that occurred within 1 year prior to the date serum zinc concentration was measured (index date). Patients were excluded if they had a serum zinc measurement within 2 months after a hospitalization, severe renal insufficiency (3 patients with serum creatinine concentration above 2.5 mg/dL), or serum zinc concentration above 1.20 µg/mL.

Results

This study included 157 patients, consisting of a case group of 41 (26%) patients with zinc deficiency and a control group of 116 (74%) without zinc deficiency. Mean (SD) zinc concentrations of the case and control groups were 0.58 (0.05) µg/mL and 0.803 (0.13) µg/mL, respectively (P<.01). Patients in the case group were more likely to have had a history of hospitalization, antibiotic use, a fall within 1 year before the index date, and a history of fractures and hip fracture (P<.01 in each case). Patients taking gastric acid suppressants had increased odds of lower zinc concentrations (odds ratio, 2.24; 95% CI, 1.08-4.63). Both logistic and multivariate linear regression models revealed that past fractures, hip fractures, and hypoalbuminemia (albumin <3.5 g/dL) were associated with zinc deficiency or lower zinc concentrations.

Conclusion

This study revealed that 26% of patients in an outpatient adult clinic had zinc deficiency based on serum concentrations. Patients with fracture history and low serum albumin were at higher risk for zinc deficiency.

Selenium and bone health: a protocol for a systematic review and meta-analysis

INTRODUCTION

Bone health affects the ability of human body to stay active, and its degradation can cause considerable morbidity and mortality. The factors related to bone health play an important role in preventing osteoporosis and its adverse consequences. However, the risk factors for osteoporosis have not been fully elucidated. Deficiency in the trace element selenium may be one of the risk factors for the development of osteoporosis. Previous studies have investigated the effects of selenium on osteoporosis; however, the results are inconclusive. Therefore, the present study aimed to systematically examine the existing literature on the associations between dietary or serum selenium and bone mineral density (BMD), osteoporosis or osteoporotic fractures, and to quantify such associations through meta-analysis.

METHODS AND ANALYSIS

PubMed, Embase and Cochrane Library will be searched using a specified search strategy to identify relevant studies up to October 2019. Both interventional and observational studies in humans will be included. The outcomes will include BMD and the prevalence or incidence of osteoporosis and osteoporotic fractures. For dietary or serum selenium and BMD, osteoporosis or osteoporotic fractures pooled analyses, estimates will be expressed as the mean difference, and the pooled OR, relative risk, HR or beta coefficient, and corresponding 95% CIs. Heterogeneity of the studies and publication bias will be investigated accordingly. To assess the quality and the risk of bias of the included studies, the Newcastle-Ottawa Quality Scale or the Cochrane risk of bias assessment tool will be used where appropriate.

ETHICS AND DISSEMINATION

Since no private and confidential patient data will be included in the reporting, approval from an ethics committee is not required. The results will be published in a peer-reviewed journal. The study raises no ethical issues.

PROSPERO REGISTRATION NUMBER

CRD42019147188.

The Association Between the Concentration of Serum Magnesium and Postmenopausal Osteoporosis

Background: Osteoporosis is the most common and widespread chronic skeletal metabolic disease in the world and can lead to catastrophic fractures. Therefore, it is important to look for factors that can be modified or controlled to prevent osteoporosis. Although serum Mg is believed to be associated with osteoporosis in many individuals, there are conflicting reports on the association between serum Mg and osteoporosis. Therefore, this meta-analyses aimed to explore the association between the concentration of serum Mg and osteoporosis as well as that between the concentration of serum Mg and osteopenia.

Methods: Articles were searched in PubMed. We also reviewed the reference lists of the relevant publications and reviews as of December 2019. Finally, 11 eligible studies involving 2,776 postmenopausal women were selected. We performed subgroup analysis, and publication bias was assessed.

Results: According to the forest plot analysis, postmenopausal women with osteoporosis had a lower concentration of serum Mg than normal controls [standardized mean difference (SMD) = −0.56, 95% confidence interval (CI) = −1.02 to −0.09]. However, this result was not applicable to those with osteopenia (SMD = −0.30, 95% CI = −0.69 to 0.09). The subgroup analysis by geographical location found a similar pattern in European postmenopausal women with osteoporosis (SMD = −0.73, 95% CI = −1.322 to −0.143), but not in Asian (SMD = −0.007, 95% CI = −0.381 to 0.394). The subgroup analysis by site of bone mineral density (BMD) showed the serum Mg concentration of postmenopausal women with osteoporosis (BMD of femur) was lower than in healthy controls (SMD = −0.44, 95% CI = −0.77 to −0.12), and BMD of the spine group had the same conclusion (SMD = −0.78, 95% CI = −1.36 to −0.19). Besides, the serum Mg concentration of postmenopausal women with osteoporosis was lower than that of the normal bone mass group in the studies those included more than 50 postmenopausal women with osteoporosis (SMD = −0.57, 95% CI = −1.04 to −0.11). We also found postmenopausal women under the age of 60 with osteoporosis had a lower concentration of serum Mg than the healthy controls (SMD = −0.61, 95% CI = −1.09 to −0.13).

Conclusion: Postmenopausal women with osteoporosis have a lower concentration of serum Mg. However, the association between the concentration of serum Mg and osteopenia needs further confirmation.

Association between Bone Mineral Density and Serum Iron Indices in Premenopausal Women in South Korea

Background

Osteoporosis is characterized by a decrease in bone mineral density (BMD) and increased risk of fragility fractures. Serum iron level may interact with bone health status. This study investigated the correlations of BMD with serum iron level, hemoglobin level, and total iron-binding capacity (TIBC).

Methods

We performed a retrospective analysis of data from the medical records of premenopausal women in South Korea. The women’s BMDs and the Z scores of the BMDs were verified using dual-energy X-ray absorption. The participants were stratified into quartiles for analyses of the associations of BMD with serum iron level, TIBC, and hemoglobin level.

Results

A simple linear regression analysis revealed associations of changes in BMD with iron level (β=-0.001, standard error [SE]=0.001, P<0.001), hemoglobin level (β=0.015, SE=0.003, P<0.001), and TIBC (β=0.001, SE=0.001, P<0.001). This pattern was also observed in a multiple linear regression analysis. A multivariate logistic regression analysis of iron level and TIBC for low BMD revealed odds ratios of 1.005 (P<0.001) and 0.995 (P<0.001), respectively.

Conclusion

This study demonstrated clear relationships of changes in BMD with serum iron level and TIBC, and thus confirms the usefulness of these markers in the clinical evaluation of iron storage and BMD in younger women.

Selenium Status in Elderly People: Longevity and Age-Related Diseases

BACKGROUND

Selenium (Se) is a trace element active in selenoproteins, which can regulate oxidative stress. It is generally perceived as an import factor for maintaining health in the elderly.

METHODS

The goal of this review is to discuss selenium concentration in biological samples, primarily serum or plasma, as a function of age and its relation with longevity. The elemental level in various age-related diseases is reviewed.

CONCLUSION

Highest selenium values were observed in healthy adults, while in an elderly population significantly lower concentrations were reported. Variables responsible for contradictory findings are mentioned. Risk and benefits of Se-supplementation still remain under debate.

Effects of parathyroid hormone (1-34) on the regulation of the lysyl oxidase family in ovariectomized mice

Osteoporosis (OP) is a highly prevalent chronic disease. The anabolic agent parathyroid hormone (PTH) is often prescribed for the treatment of OP to strengthen bone quality and decrease the risk of fracture, although the specific mechanisms are still unclear. Lysyl oxidase (LOX) can stabilize the organic matrix through catalyzing the cross-linking of collagen and elastin. In this study, we established osteoporotic models via ovariectomizing C57BL/6J mice and treating them with PTH. We further aimed to determine the expression changes of the LOX family, impacted by PTH, in ovariectomized mice. We observed that bone mass was reduced and bone microstructure was deteriorative in ovariectomized mice. And PTH attenuated the microstructural damage and accelerated bone remodeling, as confirmed via μCT and HE staining. Serum levels of copper and zinc indirectly proved the results. The expression levels of five members of the LOX family all declined in ovariectomized mice compared to in sham-operated control mice (p < 0.05), and the daily injection of PTH successfully reversed the low expression of LOXs in OP. The current study examined expression changes of LOXs in osteoporotic mice and PTH-treated osteoporotic mice for the first time, and provided an important piece of evidence that the aberrant expression of LOXs had intimate associations with the occurrence and development of OP. And LOXs may act as the downstream effectors of PTH, contributing to unbalanced bone metabolism and damaged bone microstructure. Consequently, LOXs may act as promising therapeutic targets for OP.

LOX family is a potential target in ovariectomized osteoporosis (OP).

Perspective: The Case for an Evidence-Based Reference Interval for Serum Magnesium: The Time Has Come

The 2015 Dietary Guidelines Advisory Committee indicated that magnesium was a shortfall nutrient that was underconsumed relative to the Estimated Average Requirement (EAR) for many Americans. Approximately 50% of Americans consume less than the EAR for magnesium, and some age groups consume substantially less. A growing body of literature from animal, epidemiologic, and clinical studies has demonstrated a varied pathologic role for magnesium deficiency that includes electrolyte, neurologic, musculoskeletal, and inflammatory disorders; osteoporosis; hypertension; cardiovascular diseases; metabolic syndrome; and diabetes. Studies have also demonstrated that magnesium deficiency is associated with several chronic diseases and that a reduced risk of these diseases is observed with higher magnesium intake or supplementation. Subclinical magnesium deficiency can exist despite the presentation of a normal status as defined within the current serum magnesium reference interval of 0.75-0.95 mmol/L. This reference interval was derived from data from NHANES I (1974), which was based on the distribution of serum magnesium in a normal population rather than clinical outcomes. What is needed is an evidenced-based serum magnesium reference interval that reflects optimal health and the current food environment and population. We present herein data from an array of scientific studies to support the perspective that subclinical deficiencies in magnesium exist, that they contribute to several chronic diseases, and that adopting a revised serum magnesium reference interval would improve clinical care and public health.

Stanozolol Decreases Bone Turnover Markers, Increases Mineralization, and Alters Femoral Geometry in Male Rats

Stanozonol (ST) is a synthetic derivative of testosterone; it has anabolic/androgenic activity, increasing both the turnover of trabecular bone and the endocortical apposition of bone. The present study aimed to examine the effects of ST on bone status in rats by bone mineral content, markers of formation and resorption, bone density, and structural and microarchitectural parameters. Twenty male Wistar rats were randomly distributed into two experimental groups corresponding to placebo or ST administration, which consisted of weekly intramuscular injections of 10 mg/kg body weight of ST. Plasma parameters were analyzed by immunoassay. Bone mineral content was determined by spectrophotometry. Bone mineral density (BMD) and structural parameters were measured by peripheral quantitative computed tomography, and trabecular and cortical microarchitecture by micro-computed tomography. Plasma Ca, Mg, and alkaline phosphatase were higher, and urinary Ca excretion, corticosterone, and testosterone concentrations lower in the ST group. Femur Ca content was higher and P content was lower in the ST, whereas osteocalcin, aminoterminal propeptides of type I procollagen, and C-terminal telopeptides of type I collagen were lower. Total cross-sectional, trabecular, and cortical/subcortical areas were lower in the ST. No differences were observed on BMD and area parameters of the diaphysis as well as on trabecular and cortical microarchitecture. The use of ST increases bone mineralization, ash percentage, and Ca and Mg content in femur. In spite of an absence of changes in BMD, geometric metaphyseal changes were observed. We conclude that ST alters bone geometry, leads to low bone turnover, and thus may impair bone quality.

Selenium Status Is Positively Associated with Bone Mineral Density in Healthy Aging European Men

Objective

It is still a matter of debate if subtle changes in selenium (Se) status affect thyroid function tests (TFTs) and bone mineral density (BMD). This is particularly relevant for the elderly, whose nutritional status is more vulnerable.

Design and Methods

We investigated Se status in a cohort of 387 healthy elderly men (median age 77 yrs; inter quartile range 75–80 yrs) in relation to TFTs and BMD. Se status was determined by measuring both plasma selenoprotein P (SePP) and Se.

Results

The overall Se status in our population was low normal with only 0.5% (2/387) of subjects meeting the criteria for Se deficiency. SePP and Se levels were not associated with thyroid stimulating hormone (TSH), free thyroxine (FT4), thyroxine (T4), triiodothyronine (T3) or reverse triiodothyronine (rT3) levels. The T3/T4 and T3/rT3 ratios, reflecting peripheral metabolism of thyroid hormone, were not associated with Se status either. SePP and Se were positively associated with total BMD and femoral trochanter BMD. Se, but not SePP, was positively associated with femoral neck and ward's BMD. Multivariate linear analyses showed that these associations remain statistically significant in a model including TSH, FT4, body mass index, physical performance score, age, smoking, diabetes mellitus and number of medication use.

Conclusion

Our study demonstrates that Se status, within the normal European marginally supplied range, is positively associated with BMD in healthy aging men, independent of thyroid function. Thyroid function tests appear unaffected by Se status in this population.

Comparison of trace element concentration in bone and intervertebral disc tissue by atomic absorption spectrometry techniques

BACKGROUND

Trace element (TE) analysis in human tissue has the dual purpose of assessing environmental pollution and metabolism. In literature, bone TE analysis is common, but studies in intervertebral disc (IVD) tissue are lacking. The aim of the study was evaluation of the difference of TE concentration in intervertebral disc and bone in patients with degenerative changes. The comparison of the tissues differing in metabolism, blood perfusion, or separateness from adjoining tissues but playing similar biomechanical role and presenting some common morphological traits may shed new light on metabolism nuances, degenerative process, as well as accumulation potential of IVD in respect to bone.

METHODS

In the study, we analyzed two types of samples: intervertebral disc (n =30, from 22 patients operated due to degenerative disc disease) and femoral bone (n =26, separately femoral head and neck, from 26 patients, acquired in total hip arthroplasty procedure in course of idiopathic osteoarthritis of the hip joint). In the samples we analyzed, with atomic absorption spectrometry, the concentrations of Pb, Ni, Mo, Cu, Mg, and Zn.

RESULTS

The element concentrations identified in bone are comparable to those presented in the literature. In the case of Pb, Ni, Mo, Mg, and Zn, the concentration in the bone was 2 to 25.8 times higher than that observed in the disc. Only the Cu concentration was higher in disc tissue than in bone. In disc tissue, fewer samples had TE concentrations below the detection threshold. We found significant differences in TE profiles in the compared tissues.

CONCLUSIONS

The results show that the disc could serve as a more stable compartment for evaluating TE concentration, especially for TEs that are environmentally related.

Low serum levels of zinc, copper, and iron as risk factors for osteoporosis: a meta-analysis

Zinc (Zn), copper (Cu), and iron (Fe) are essential trace elements for the growth, development, and maintenance of healthy bones. However, there are conflicting reports as to the relationship between serum level of Zn, Cu, or Fe and osteoporosis (OP). The purpose of the present study is to clarify the relationship between serum Zn, Cu, or Fe and OP using a meta-analysis approach. We searched all articles indexed in PubMed published up to May 2014 concerning the association between serum level of Zn, Cu, or Fe and OP. Eight eligible articles involving 2,188 subjects were identified. Overall, pooled analysis indicated that patients with OP had a lower serum level of Zn, Cu, or Fe than the healthy controls (Zn standardized mean difference (SMD) = -1.396, 95% confidence interval (CI) = [-2.129, -0.663]; Cu SMD = -0.386, 95% CI = [-0.538, -0.234]; Fe SMD = -0.22, 95% CI = [-0.30, -0.13]). Further subgroup analysis found that geographical location and gender had an influence on the serum level of Zn in OP and healthy controls, but not on the serum level of Cu or Fe. No evidence of publication bias was observed. In conclusion, this meta-analysis suggests that low serum levels of Zn, Cu, and Fe seem to be important risk factors for OP and well-designed studies with adequate control for confounding factors are required in future investigations.

Association between serum level of magnesium and postmenopausal osteoporosis: a meta-analysis

There are conflicting reports as to the association between serum level of magnesium (Mg) and postmenopausal osteoporosis (OP). The purpose of the present study is to clarify the association between serum level of Mg and postmenopausal OP using a meta-analysis approach. We searched articles indexed in Pubmed and the Chinese Journal Full-text Database (CJFD) published as of October 2013 that met our predefined criteria. Seven eligible studies involving 1,349 postmenopausal women from 12 case-control study arms were identified. Overall, pooled analysis indicated that postmenopausal osteoporotic women had a lower serum level of Mg than the healthy controls (standardized mean difference [SMD]=-0.55, 95 % confidence interval [CI]=-0.83 to -0.26). Further subgroup analysis found a similar pattern in Turkey (SMD=-0.66, 95% CI=-0.99 to -0.32) and Belgium (SMD=-0.98, 95% CI=-1.91 to -0.05), but not in China (SMD=0.02, 95% CI=-0.21 to 0.26). And the difference of serum level of Mg between postmenopausal osteoporotic women and healthy controls below the age of 60 years (SMD=-0.61, 95% CI=-1.09 to -0.13) was similar to that among the population over 60 years (SMD=-0.49, 95% CI=-0.80 to -0.18).In conclusion, this meta-analysis suggests that the low serum level of Mg seems to be a risk factor for OP among the postmenopausal women. However, the subgroup analysis found that there was contradiction regarding races and geography, like China and Turkey. Thus, this finding needs further confirmation by trans-regional multicenter study to obtain better understanding of causal relationships between serum Mg and postmenopausal OP.

Serum calcium concentration as an indicator of intervertebral disk degeneration prognosis

This study aims to investigate the relationship between serum macro- and trace element contents and the degree of disk degeneration in patients with intervertebral disk herniation (IDH). This study was carried out on 69 subjects (30 women and 39 men) diagnosed with IDH. Blood samples of the subjects were collected, and serum concentrations of the elements that include macroelements, such as calcium, phosphorus, potassium, sodium, and magnesium, and trace elements, such as zinc, iron, copper, and selenium, were determined using inductively coupled plasma-atomic emission spectrometry. Magnetic resonance imaging (MRI) examination of the entire lumbar region of the vertebral column was conducted using a 1.5-T MRI scanner. The degree of disk degeneration was classified into three categories. Correlation analysis between the degree of disk degeneration and the serum element was performed using SPSS 16.0. In the correlation analysis between the degree of disk degeneration and the element contents, only calcium was found to be negatively correlated with the degree of disk degeneration (r = -0.332, P < 0.01). Comparison results between male and female groups showed no significant difference in the element content and in the degree of disk degeneration (P > 0.05). Moreover, the serum calcium content showed a significant correlation with the degree of disk degeneration, suggesting that the serum calcium concentration can be used as an indicator of intervertebral disk degeneration prognosis.

Comparative evaluation of serum levels of main minerals and postmenopausal osteoporosis

OBJECTIVE

The purpose of this study was to determine the relationship between serum main minerals and postmenopausal osteoporosis.

STUDY DESIGN

A total of 728 postmenopausal women were included in this study. Women were separated into two groups according to presence or absence of osteoporosis (OP). BMD was measured in total femur (TF), femoral neck (FN) and lumbar spine (L1-L4) by dual-energy X-ray absorptiometry. Risk factors for OP were recorded by using a structured questionnaire.

MAIN OUTCOME MEASURES

Women's blood were collected and serum concentrations of iron, copper, zinc, sodium, potassium, magnesium, calcium, ionized calcium, inorganic phosphorus were measured.

RESULTS

Low serum copper levels were significantly associated with OP according to BMD values for TF, FN and L1-L4. There was a significant relationship between low serum zinc levels and OP for L1-L4 spines. Low iron serum levels were also significantly associated with OP in BMD measurements of TF. Low serum magnesium levels had significant association with OP of L1-L4 spines and TF. Serum levels of calcium, ionized calcium, potassium, sodium and inorganic phosphorus were not associated with OP.

CONCLUSIONS

In postmenopausal women, the low serum levels of copper, zinc, iron and magnesium appear to be an important risk factor for OP.

Bone turnover and bone mineral density are independently related to selenium status in healthy euthyroid postmenopausal women

CONTEXT

Selenium status may have direct effects on bone and indirect effects through changes in thyroid hormone sensitivity.

OBJECTIVE

We hypothesized that variation in selenium status in healthy euthyroid postmenopausal women is associated with differences in bone turnover, bone mineral density (BMD) and fracture susceptibility.

DESIGN

The Osteoporosis and Ultrasound Study (OPUS) is a 6-yr prospective study of fracture-related factors.

SETTING

The study was comprised of a population-based cohort from five European cities.

PARTICIPANTS

A total of 2374 postmenopausal women participated. Subjects with thyroid disease and nonthyroidal illness and those receiving drugs affecting thyroid status or bone metabolism were excluded, leaving a study population of 1144.

INTERVENTIONS

There were no interventions.

MAIN OUTCOME MEASURES

We measured selenium (micrograms per liter); selenoprotein P (milligrams per liter); free T(4) (picomoles per liter); free T(3) (picomoles per liter); TSH (milliunits per liter); bone turnover markers; BMD; and vertebral, hip, and nonvertebral fractures.

RESULTS

Higher selenium levels were associated with higher hip BMD at study entry (β = 0.072, P = 0.004) and lower levels of bone formation (osteocalcin: β = -0.101, P < 0.001; procollagen type 1 N-terminal propeptide: β = -0.074, P = 0.013) and resorption markers (C-telopeptide of type 1 collagen: β = -0.058, P = 0.050; N-telopeptide of type 1 collagen: β = -0.095, P = 0.002). Higher selenoprotein P was associated with higher hip (β = 0.113, P < 0.001) and lumbar spine BMD (β = 0.088, P = 0.003) at study entry, higher hip BMD after the 6-yr follow-up (β = 0.106, P = 0.001) and lower osteocalcin (β = -0.077, P = 0.009), C-telopeptide of type 1 collagen (β = -0.075, P = 0.012), and N-telopeptide of type 1 collagen (β = -0.110, P < 0.001).

CONCLUSION

Selenium status is inversely related to bone turnover and positively correlated with BMD in healthy euthyroid postmenopausal women independent of thyroid status.

Plasma selenium, zinc, copper and lipid levels in postmenopausal Turkish women and their relation with osteoporosis

It has been shown that the trace elements and lipids play role in the growth, development and maintenance of bones. We aimed to investigate serum selenium (Se), zinc (Zn), copper (Cu) and lipid (total cholesterol, triglyceride (TG), high density lipoprotein-cholesterol, low-density lipoprotein-cholesterol) levels in postmenopausal women with osteoporosis, osteopenia and in healthy controls, and to determine the relationship between Se, Zn, Cu and lipid parameters and bone mineral density (BMD). The study included 107 postmenopausal women; 35 healthy (group 1), 37 osteopenic (group 2) and 35 osteoporotic (group 3). The women in all three groups were carefully matched for body mass index (BMI). Serum concentrations of Se, Zn and Cu were measured by atomic absorption spectrophotometry. Plasma Se, Cu, Zn and lipid levels were similar in all groups (p > 0.05). When we combined the women in each of the three groups, and considered them as one group (n = 107) we found a positive correlation between BMI and lumbar vertebra BMD, femur neck BMD, femur total BMD; a positive correlation between TG and femur neck BMD, femur total BMD; a positive correlation between Zn and lumbar vertebra BMD (total T score) (p < 0.05). There was no correlation between Se, Cu, Zn, P and lipid parameters (p > 0.05). Although BMI has a positive effect on BMD, trace elements and lipids, except Zn and TG, did not directly and correlatively influence BMD. Further studies are needed to clarify the role and relationship of trace elements and lipid parameters in postmenopausal osteoporosis.

Relative and combined effects of selenium, protein deficiency and ethanol on bone

Some observations suggest that oxidative damage may affect both osteoblastic function and osteoclastic activity in alcohol-mediated bone alterations. Selenium, a potent antioxidant, is decreased in alcoholics.

OBJECTIVE

To analyse if the supplementation with selenium may alter bone changes observed in a murine model fed ethanol and/or a 2% protein-containing diet, following the Lieber-deCarli design.

MATERIAL AND METHOD

Adult male Sprague-Dawley rats were divided into 8 groups, which received the Lieber-DeCarli control diet, an isocaloric, 36% ethanol-containing diet, an isocaloric, 2% protein-containing diet; and an isocaloric diet containing 2% protein and 36% ethanol diet, and another similar four groups to which selenomethionine (1mg/kg body weight). After sacrifice (5 weeks later), trabecular bone mass was histomorphometrically assessed, bone and serum selenium were determined by flame atomic absorption spectrophotometry, and serum osteocalcin, insulin growth factor 1 (IGF-1), PTH and telopeptide, by radioimmunoanalysis. Liver glutathione peroxidase (GPX) activity was also determined.

RESULTS

Ethanol-fed rats showed decreased TBM, IGF-1 and osteocalcin, especially when ethanol was added to a 2%-protein diet. Selenium did not modify at all bone parameters, despite a marked increase in serum selenium and a less pronounced one in bone selenium, and an increase in liver GPX.

CONCLUSION

Our results do not support the existence of a beneficial effect of selenium addition on bone changes observed in this murine model treated following the Lieber-deCarli experimental design.

Relationships between endothelial nitric oxide synthase gene polymorphisms and osteoporosis in postmenopausal women

OBJECTIVE

To investigate the relationships between endothelial nitric oxide synthases (eNOS) G894T and 27 bp-variable number tandem repeat (VNTR) gene polymorphisms and osteoporosis in the postmenopausal women of Chinese Han nationality.

METHODS

In the present study, 281 postmenopausal women from Xi'an urban area in West China were recruited, and divided into osteoporosis, osteopenia, and normal groups according to the diagnostic criteria of osteoporosis proposed by World Health Organization (WHO). The bone mineral density (BMD) values of lumbar vertebrae and left hips were determined by QDR-2000 dual energy X-ray absorptiometry. Blood samples were tested for plasma biochemical indicators including testosterone, estradiol, calcitonin, osteocalcin, and procollagen type I amino-terminal propeptide by enzyme-linked immunosorbent assay (ELISA), tartrate-resistant acid phosphatase by spectrophotometric method, and the content of nitric oxide by Griess method. Genome DNA was extracted from whole blood, and G894T polymorphism of eNOS gene was analyzed by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method and 27 bp-VNTR polymorphism of eNOS gene was genotyped by PCR method. Then the relationships between genotypes and biochemical indicators, genotypes and osteoporosis, and haplotypes and osteoporosis were analyzed.

RESULTS

The average BMD values of the femoral neck, ward's triangle and lumbar vertebrae 1-4 (L1-L4) in the subjects with T/T genotype in eNOS G894T locus were significantly higher than those in the subjects with G/T and G/G genotypes (P<0.05). The average BMD of the femoral neck in the subjects with a/a genotype of eNOS 27 bp-VNTR locus was evidently higher than that in the subjects with b/b genotype (P<0.05). The plasma testosterone and osteocalcin concentrations in the subjects of eNOS G894T G/T genotype were evidently higher than those in the subjects of other genotypes (P<0.05); the plasma estradiol concentration in the subjects of eNOS 27 bp-VNTR a/a genotype was obviously higher than that in the subjects of b/b genotype (P<0.01). eNOS G/G homozygous frequencies in osteoporosis women, osteopenia women, and normal women were 85.37%, 76.38%, and 83.87%, respectively (P>0.05). 0% osteoporosis woman, 0.79% osteopenia women, and 3.23% normal women were eNOS a/a homozygous (P<0.05). The frequencies of eNOS 27 bp-VNTR a allele were 5.33% in the osteoporosis group, 10.24% in the osteopenia group, and 16.13% in the normal group (P<0.05, odds ratio (OR)=0.29, 95% confidence interval (CI)=0.11-0.77), suggesting that a/a genotype and a allele might have protective effects on osteoporosis. The haplotype analysis showed that G-b was 87.7% (214/244) in the osteoporosis group (P<0.05, OR=2.48, 95% CI=1.18-5.18). G-a was 5.3% (13/244) in the osteoporosis group (P<0.05, OR=0.29, 95% CI=0.11-0.77). G-b was a risk factor for osteoporosis, and G-a a protective factor.

CONCLUSION

eNOS G894T G/T genotype influenced the plasma testosterone and osteocalcin concentrations, and T/T genotype influenced BMD. eNOS 27 bp-VNTR a/a genotype increased plasma estradiol concentration to have a protective effect on osteoporosis.