Relationship between bone mineral density and insulin resistance in polycystic ovary syndrome

The aim of the present study was to evaluate whether there is a relationship between bone mineral density (BMD) and insulin resistance and hyperinsulinemia in women with polycystic ovary syndrome (PCOS). The study consisted of 28 amenorrheic women with PCOS and 11 amenorrheic women without PCOS. Fifteen healthy women with normal ovulatory function, matched for age and body mass index (BMI), served as controls. BMD was measured at the lumbar spine and left femoral neck with dual-energy X-ray absorptiometry. Blood samples were obtained to measure serum levels of insulin, follicle-stimulating hormone, luteinizing hormone, sex hormone-binding globulin (SHBG), total and free testosterone, androstenedione and estradiol by radioimmunassay. Insulin resistance was estimated by the insulin tolerance test (ITT), and K_ITT was taken as the insulin sensitivity index. In the PCOS group, K_ITT was significantly lower and insulin levels were higher than in either of the control groups (P < 0.001). BMD in the PCOS group was lower than in the healthy group and higher than in the amenorrheic control group (P < 0.05). In the PCOS group, there were positive correlations of BMD of the lumbar spine with insulin (r = 0.42; P < 0.05) and negative correlations of BMD with K_ITT (r = −0.58; P < 0.001) and SHBG (r = −0.38; P < 0.05). The inverse association of BMD and K_ITT was independent of BMI, insulin, SHBG, androstenedione, and free testosterone. In conclusion, insulin resistance and hyperinsulinemia in women with PCOS may be a relative protective factor against bone mineral loss. Received: November 13, 2000 / Accepted: December 28, 2000     

Relationship between bone mineral density, leptin and insulin concentration in Brazilian obese adolescents

Despite the epidemic of adolescent obesity, the effect of obesity and hormones on bone mineral accrual during growth is poorly understood. Studies using dual-energy X-ray to examine the effect of obesity on bone mass in children and adolescents have yielded conflicting results. The aim of this study was to explore the combined and independent contributions of body mass index, body composition, leptin, insulin, glucose levels and Homeostasis Model Assessment Insulin Resistance (HOMA-IR) to bone mineral density (BMD) and bone mineral content in a group of Brazilian obese adolescents. This study included 109 post-pubescent obese adolescents. A whole-body dual-energy X-ray absorptiometry scan was performed,using a HOLOGIC QDR4200, to determine whole-body BMD and body composition. Blood samples were collected in the outpatient clinic after an overnight fast, and evaluated for fasting blood glucose and immunoreactive insulin. Leptin levels were assessed with a radioimmunoassay kit. Insulin resistance was assessed by HOMA-IR and the quantitative insulin sensitivity check index. Our results showed that insulin levels and HOMA-IR correlated negatively with BMD and a linear regression analysis showed that serum leptin is inversely associated to BMD adjusted for body mass. In conclusion, our data support the hypothesis that leptin, insulin and HOMA-IR are inversely associated with BMD and play a significant direct role in bone metabolism.     

Dietary protein intake and bone mineral content in adolescents—The Copenhagen Cohort Study

Summary Data indicate that various protein sources may exhibit a differential effect on bone metabolism. We investigated associations of milk and meat protein intake with bone mineral content (BMC) in adolescents. Milk, but not meat, protein intake was positively associated with size-adjusted BMC. Milk-derived protein may be beneficial for bone mineralization. Introduction Milk and meat protein intake has been reported to exhibit a differential effect on serum insulin-like growth factor-I (IGF-I). IGF-I plays a key role in bone metabolism. Therefore, we investigated associations of different protein sources with BMC and bone area (BA) in adolescents. Methods This was a cross-sectional study of 17-year-old girls (n = 63) and boys (n = 46) participating in the second follow-up of The Copenhagen Cohort Study. We measured dietary intake (7-day food record), BMC and BA (dual-energy X-ray absorptiometry), serum markers for bone turnover and serum IGF-I (immunoassays). Results The mean total protein intake (∼1.2 g/kg) was modestly higher than that recommended. Total and milk (∼0.3 g/kg) protein intake, but not meat protein intake (∼0.4 g/kg), was positively associated with size-adjusted BMC (P ≤ 0.05). The positive association between milk protein intake and size-adjusted BMC remained significant after correction for energy, calcium, and physical activity (P ≤ 0.01) and did not seem to be mediated via current serum IGF-I. None of the analyzed protein sources was significantly associated with size-adjusted BA. Conclusions Our results suggest that some components of milk protein may promote bone mineralization. Further studies are needed to elucidate this phenomenon.     

老年男性骨密度与脂质过氧化相关性研究

对９８例男性老年人的骨密度、血清超氧化物歧化酶（ＳＯＤ）、过氧化脂质（ＬＰＯ）、丙二醛（ＭＤＡ）、谷光甘肽（ＧＳＨ）进行测定，旨在研究老年人骨密度值变化与衰老的关系。结果：老年人ＢＭＤ、ＳＯＤ、ＧＳＨ随年龄增长逐渐减少，ＢＭＤ与ＳＯＤ、ＧＳＨ水平呈正相关，与ＬＰＯ、ＭＤＡ水平呈负相关。表明老年人骨密度与其衰老生化指标呈显著相关。老年人骨密度的丢失可作为衰老的重要指标之一。     

The relationship between body fat and bone mineral density in Korean men and women

Previous studies of the effects of body fat on bone mineral density (BMD) have shown conflicting results depending on the age, sex, and menopausal status of the subjects. The purpose of the present study was to investigate the effects of body fat on BMD using data from the Fifth Korea National Health and Nutrition Examination Survey, which was conducted in 2010. Our data were drawn from a relevant population within the survey’s range of participants, yielding a total of 4,138 subjects aged 20–93 years (1,133 men <50 years, 946 men ≥50 years, 1,332 premenopausal women, and 727 postmenopausal women). Percent body fat, fat mass (FM), lean mass (LM), and BMD of the total hip, lumbar spine, and arm were measured in the original survey using dual-energy X-ray absorptiometry. Relationships between FM and BMD were evaluated using multiple linear regression analyses. LM was the strongest determinant of BMD. Although FM also showed a significant positive correlation, even after adjusting for LM, with total hip and lumbar spine BMD in men ≥50 years and pre- and postmenopausal women, this positive correlation was not observed in the arm. In an analysis of obese and non-obese subgroups, the positive correlation between FM and BMD disappeared in obese subjects. Furthermore, FM and BMD exhibited a negative correlation in premenopausal obese women. These results suggest that FM contributes to BMD primarily through mechanical loading. FM, then, is not beneficial and may be detrimental to bone health in obese people.     

Relationship between grip strength and bone mineral density in healthy Hong Kong adolescents

Summary  This study evaluated the magnitude of the correlations among grip strength, bone mineral density (BMD) and bone mineral content (BMC), after controlling for weight, height, pubertal development, weight-bearing activities and calcium intake. The results lead to the conclusion that grip strength is an independent predictor of bone mass in both sexes. The relationship between muscle strength and bone mass is systemic. Introduction  Previous studies had shown a site-specific relationship between muscle strength and bone in pubertal children. This study evaluated the magnitude of the correlations among grip strength, bone mineral density (BMD) and bone mineral content (BMC) at distant bone. Methods  Cross-sectional data of 169 11- to 12-year-old boys and 173 10- to 11-year-old girls came from the baseline result of a cohort study. Grip strength, BMD, BMC, weight, height, pubertal development, weight-bearing activities and calcium intake were measured. Pearson correlations and multiple regressions were used to calculate univariate and adjusted associations among grip strength and bone mass at distant bone. Results  Significant correlations were shown between grip strength and bone mass at hip, spine and whole body (boys: BMC:0.72–0.74, BMD:0.38–0.60; girls: BMC:0.71–0.72, BMD:0.44–0.63; p<0.0001). Multiple regressions with all covariates showed that about 70% and 50%, respectively, of the variations in BMC and BMD could be explained but not for whole body BMD. Grip strength was an independent predictor of bone mass, except hip BMD in boys and whole body BMD in girls. Stepwise regression showed that grip strength was a robust predictor in both sexes. Prediction models by grip strength and weight explained about 60% and 40% of the variations in BMC of different sites and in BMD of hip and spine, respectively. Conclusions  We found that grip strength is an independent predictor of bone mass in both sexes. The relationship between muscle strength and bone mass is systemic.     

Mechanical strength of bone in canine osteoporosis model: Relationship between bone mineral content and bone fragility

The purpose of this study was to clarify the relationship between bone mineral content (BMC) and mechanical strength in beagle dog models, and to find whether the mechanical strength changed with changes in BMC. We used 17 beagle dogs to create an experimental osteoporotic model, dividing them into six groups, based on age and experimental period. Presence and absence of ovariectomy (OVX); and calcium content of the diet. BMC was determined by dual-energy quantitative computed tomography in the lumbar vertebrae, and the mechanical strength of cancellous bone harvested from the lumbar vertebral body and femoral neck was measured. OVX alone did not affect either BMC or mechanical strength. However, when the dogs were ovariectomized, and then given a reduced calcium diet, the mechanical strength of the femoral neck decreased in parallel with the cortical BMC of the lumbar vertebrae. The mechanical strength of the vertebral cancellous bone was not decreased when the BMC was reduced by 20%, but was decreased when BMC was reduced by 30%.     

25(OH)D等因素与45~85岁冈比亚妇女骨矿含量的关系

近年来有人多次提出，与年龄有关的维生素D内分泌系统的变化可能与骨丢失和骨质疏抡症有关。本文对108名45～85岁阿比亚妇女维生素D水平与骨矿含量(BMC)关系进行了研究。研究对象选自于一项钙与骨代谢的课题。除维生素D水平与BMC的关系，对维生素D与肌肉强度，膳食钙对BMC的影响也做了探讨。结果表明：(1)与其他同类人群比较，冈比亚妇女血浆25(OH)D的水平较高，但随着年龄的增长及季节的变冷(12月～2月)而降低。(2)前臂，手腕及腰椎BMC随着年龄的增长而下降。（3)没有发现维生素D水平与BMC或肌肉强度有关，这种无关性不受骨与身体大小及血样采取季节的影响。(4)冈比亚妇女食用富含钙食物频率很低；叶菜类食用量可能与手腕部BMC减少有关。这样，在冈比亚人群中，本次研究不能证明维生素D在与年龄有关的骨丢失中起重要作用。     

The relationship between spinal trabecular bone mineral content and iliac crest trabecular bone volume

Summary The relationship between spinal trabecular bone mineral density and iliac crest trabecular bone volume has been studied in 84 patients, 23 with primary osteoporosis, 19 with osteoporosis secondary to inflammatory bowel disease, and 42 with nonsteroid-treated rheumatoid arthritis. Spinal trabecular bone mineral density was measured in the first three lumbar vertebrae by quantitative computed tomography, and iliac crest trabecular bone volume was assessed histomorphometrically in sections from trans-iliac biopsies using computerized techniques. In all 84 patients, there was a significant positive correlation between the two measurements (r=0.60,P<0.001). However, when the three patient groups were analyzed separately, a significant correlation was found in the group with secondary osteoporosis (r=0.65,P<0.01) but not in the patients with primary osteoporosis (r=0.07) or rheumatoid arthritis (r=0.19). These results indicate that the relationship between spinal trabecular bone mineral density and iliac crest trabecular bone volume differs according to the underlying disease process, these differences possibly reflecting variations in skeletal patterns of bone loss in different types of osteoporosis.     

Reference values for bone mineral density according to age with body size adjustment in Korean children and adolescents

Bone acquisition failure during growth or low bone mineral density (BMD) in childhood and adolescence might increase future osteoporosis risk. To identify these children and adolescents, appropriate reference values are necessary. The robust reference values must be community based as well as sex-, age-, and ethnicity specific. In addition, body size adjustment is necessary because individuals demonstrate different body sizes and different tempos of growth, which affect measured BMD. We aimed to provide reference data with body size adjustment of Korean children and adolescents. We used dual-energy X-ray absorptiometry data of 1,650 subjects (aged 10–20 years; 788 female) from the Korea National Health and Nutrition Examination Survey (2009–2010). The BMD of each region of interest (ROI), including the lumbar spine, total body less head, total body, and femoral neck, were obtained. We calculated the mean and percentiles for each ROI. Because height and weight variations were high and correlated independently with BMD within the same age group, we developed equations to calculate the “predicted BMD Z score.” Although 12.8–17.9 % of subjects with short stature showed a low measured BMD Z score depending on the measured site, only 2.6 % of those of short stature had a low adjusted BMD Z score after applying the predicted BMD Z score. We also compared the BMD of children and adolescents of other ethnicities using the same device. This study provided robust reference values for the assessment and monitoring of bone health in Korean children and adolescents. Additionally, it extended the knowledge of bone acquisition in Asian children and adolescents.     

Familial aggregation of bone mineral density and bone mineral content in a Chinese population

Familial aggregation of bone mineral density (BMD) and bone mineral content (BMC) has been shown in twin and familial studies, but most sample sizes were small. We here report a large familial aggregation study in a Chinese population. A total of 13,973 siblings aged 25–64 years from 3,882 families were enrolled from Anhui, China. We assessed the whole-body, hip and lumbar spine BMD and BMC by dual-energy X-ray absorptiometry (DXA). Intra-class correlation coefficients of BMD and BMC between siblings varied among different skeletal sites and between different age groups of male sib-pairs and premenopausal and postmenopausal female sib-pairs, with a range of 0.228 to 0.397. The sibling recurrence risk ratio (s) of osteoporosis was 2.6 in our population. We also evaluated the joint association of the BMD values of the first siblings and the second siblings with the risk of low BMD (defined as less than the 10th percentile of the same group population) of their younger siblings. If both the first and second siblings BMDs were in the lowest tertile, the odd ratios (ORs) of low BMD in their subsequent siblings were 8.32 [95% confidence interval (CI) 5.59–12.39)], 8.71 (95% CI 5.74–13.22) and 5.90 (95% CI 3.57–9.76) for total body, total hip and lumbar spine, respectively. This study demonstrates a significant familial aggregation of BMD and BMC in a large sample of rural Chinese adults.     

Individualized evaluation of lumbar bone mineral density and bone mineral apparent density in children and adolescents

Summary

Lumbar spine bone mineral density (LS-BMD) assessed by dual-energy X-ray absorptiometry (DXA) is used in children to evaluate bone health. LS-BMD results in children are influenced significantly by height and BMI. An adjustment for these parameters may improve the clinical use of the method.

Purpose/Introduction

DXA evaluation is considered useful in children to assess bone health. For this purpose, lumbar spine bone mineral density (LS-BMD) and bone mineral apparent density (LS-BMAD) are often used. The aim of the study was to estimate the effect of height and BMI on LS-BMD and LS-BMAD in children and adolescents and to develop a method to adjust individual results for these factors.

Methods

As part of the National Health and Nutrition Examination Survey (NHANES) study, between the years 2005 and 2010 lumbar DXA scans on randomly selected Americans from 8 to 20 years of age were carried out. From all eligible DXA scans, three major US ethnic groups were evaluated (Non-Hispanic Whites, Non-Hispanic Blacks, and Mexican Americans) for further statistical analysis. The relationship between height as well as BMI for age Z-scores and age-adjusted LS-BMD and LS-BMAD Z-scores was analyzed.

Results

For the statistical analysis, the DXA scans of 1799 non-Hispanic White children (823 females), of 1696 non-Hispanic Black children (817 females), and of 1839 Mexican American children (884 females) were eligible. The statistical analysis showed that taller and heavier children had significantly (p?<?0.001) higher age-adjusted LS-BMD Z-scores than shorter and lighter children. But on LS-BMAD, only BMI and not height had a significant influence.

Conclusions

LS-BMD results in children were influenced significantly by their height and BMI, the LS-BMAD results were only influenced by their BMI. For the first time, the proposed method adjusts LS-BMD and LS-BMAD to BMI. An adjustment of the LS-BMD and LS-BMAD results to these factors might improve the clinical significance of an individual result.

     

Osteopontin deficiency increases mineral content and mineral crystallinity in mouse bone

Fourier transform infrared microspectroscopy (FTIRM) and infrared imaging (FTIRI) were used to characterize the mineral in bones of two different lines of Opn-deficient (Opn-/-) mice and their background-matched wild-type controls (Opn+/+). Sections of tibia and femur from 12-week-old and 16-week-old mice were evaluated with a spatial resolution between 10 microm (FTIRM) and 7 microm (FTIRI). FTIRI was used to examine 400 microm x 400 microm areas in cortical bone and trabecular bone and FTIRM examined selected 20 microm x 20 microm areas at sites within these anatomically defined areas. Despite the absence of an obvious phenotype in Opn-deficient mice, being undetectable by radiographic and histological methods, FTIRM analyses revealed that the relative amount of mineral in the more mature areas of the bone (central cortical bone) of Opn-knockout mice was significantly increased. Moreover, mineral maturity (mineral crystal size and perfection) throughout all anatomic regions of the Opn-deficient bone was significantly increased. The 2-dimensional, color-coded data (images) produced by FTIRI showed similar increases in mineral maturity in the Opn-/- bone, however, the crystallinity parameters were less sensitive, and significance was not achieved in all areas analyzed. Nonetheless, the findings of increased mineral content and increased crystal size/perfection in both lines of Opn-deficient mice at both ages are consistent with in vitro data indicating that Opn is a potent inhibitor of mineral formation and mineral crystal growth and proliferation, and also support a role for Opn in osteoclast recruitment and function.     

褪黑素受体1B基因多态性与青少年骨密度的相关性

目的探讨褪黑素受体1B基因(MTNR1B)多态性与骨密度之间的相关性。方法选取140名16~20岁之间的正常女性,采用双能X线骨密度吸收仪测量双侧近端股骨的骨密度。同时,采取外周静脉血,采用试剂盒提取DNA。根据人类单倍体图计划(HapMap)提供的汉族人数据,我们在MTNR1B基因上选取了6个标签SNP(tagSNPs)。通过PCR-RFLP的方法检测褪黑素受体1B基因上6个标签SNP的基因型。采用ANOVA的统计学方法比较不同基因型对应骨密度大小。结果MTNR1B基因6个多态性位点各基因型所对应的骨密度,没有明显差异(P>0.05)。结论褪黑素受体1B基因多态性与骨密度之间没有相关性。     

Dietary habit and bone mineral density in Korean postmenopausal women

Summary  

Postmenopausal women were assessed to determine the association between dietary intake of various food groups and low bone mineral density. Among dietary factors, high consumption of protein-containing food and dairy products was associated with a reduced risk for low bone mineral density.     

The association between bone mineral density and metabolic syndrome: a Korean population-based study

This study was conducted to investigate the association between the metabolic syndrome (MS), which includes a cluster of major risk factors for cardiovascular diseases, and bone mineral density (BMD) from a population-based study. This cross-sectional study was based on a nationwide representative survey data from the Korean National Health and Nutrition Examination Survey (KNHANES) 2008. A total of 3,207 subjects were included from the KNHANES 2008 and composed of men (mean age 48.4 years), premenopausal women (mean age 36.5 years) and postmenopausal women (mean age 64.8 years). The MS was identified according to the new criteria from a joint scientific statement endorsed by major organizations including the National Heart, Lung, and Blood Institute. The mean age of study participants was significantly different according to MS status (58.2 years in the MS group vs. 45.7 years in the non-MS group, P < 0.001). The association between MS and BMD at the lumbar spine and proximal femur was analyzed with adjustment for potential confounders. Although the adjusted BMD at all skeletal sites was not significantly different between participants with and without MS, an increased number of MS components was associated with low adjusted femoral neck (FN) BMD only in men (P = 0.01). After adjusting confounding factors, the triglyceride component of MS was related to low FN BMD in men, but to high BMD at all of the skeletal sites measured in postmenopausal women. The glucose component of MS showed an association with high adjusted BMD at total hip in men. Men with MS had significantly higher odds for pooled osteopenia and osteoporosis (odds ratio: 1.49, 95 % confidence interval: 1.04–2.14). In conclusion, low BMD is associated with MS in Korean men, and the association between the MS component and the BMD is different according to gender.     

Vertebral bone mineral content in osteogenesis imperfecta

Summary Quantitative computed tomography of the lumbar spine was carried out in 28 patients with osteogenesis imperfecta (OI) in order to measure vertebral trabecular bone mineral concentration (BMC). The patients ranged in age from 6–73 years, and included 3 of the 4 major clinical subtypes of the disease. The findings underscore the heterogeneity of osteogenesis imperfecta even among family members with the same disease type. In addition, cross-sectional analysis of Type I OI patients suggests that BMC during young adulthood averages about 70% of normal, and subsequently falls more rapidly than in normal patients. BMC tends to be lower in the more severe forms of OI. Decreased BMC was not found in a few otherwise normal relatives with scoliosis or joint laxity.     

Assessment of bone mineral content in children

Quantitative digital radiography (QDR) is a new technique for measuring bone mineral content that offers improved precision, shorter study times, and less radiation exposure than single-photon absorptiometry (SPA), dual-photon absorptiometry (DPA), and quantitative computed tomography (CT) scanning. To evaluate application of QDR to a pediatric population, the bone mineral density (BMD) of both proximal femurs and lumbar spine was determined in 20 normal children aged 4-15 years. Duplicate measures indicated a precision less than 2%. A small left side/right side difference was sometimes found in the BMD of the proximal femurs. This difference was not related to age, sex, or handedness, and there was no history of significant injury to, or problems with, either lower extremity. QDR will greatly enhance early evaluation and treatment of many conditions that adversely affect the immature skeleton.