Effects of exercise practice on the maintenance of radius bone mineral density in postmenopausal women

The effect of exercise practice on the radius bone mineral density (BMD) was investigated on 480 women at the age of perimenopause and later. The BMD at the 1/3 distal site of the radius on a non-dominant hand was measured using the Dual Energy X-ray Absorptiometry method. The subjects were divided into group E with regular exercising and group C without regular exercising. The difference of mean radius BMD values was not statistically significant between groups E and C. Each of the groups E and C was further classified into a perimenopause group and groups with stratified postmenopausal years (postmenopausal years less than 5, less than 10 and more than 10). Then, the mean radius BMD value of the perimenopause subgroup was taken as 100% for each of the groups E and C, and the relative radius BMD values of subgroups were compared between groups E and C. The relative BMD values for the subgroup of postmenopausal years more than 10 were higher in E group than those in C group, while no difference was observed in below postmenopausal 10 years between the two groups. To clarify the BMD difference among exercise events, group E was further divided into the following three subgroups: the subgroup practising events which give high-impact to arm (HI group), such as tennis, ping-pong, golf and volleyball, the subgroup practising swimming (SW group), and the subgroup practising events which give low-impact to arm (LI group), such as walking, running, aerobic dance and light gymnastics. No significant differences were observed in BMD values among the above sports event-stratified subgroups when postmenopausal years were less than 10 years, but the relative BMD values for the subgroup of postmenopausal years more than 10 were higher in HI and LI group than those in control group. These results suggest the possibility that exercise practice suppresses a postmenopausal decline in bone density for preventing osteoporosis from developing.     

Influences of Endplate Removal and Bone Mineral Density on the Biomechanical Properties of Lumbar Spine

Purpose

To investigate (1) effects of endplate removal and bone mineral density (BMD) on biomechanical properties of lumbar vertebrae (2) whether the distributions of mechanical strength and stiffness of endplate are affected by BMD.

Methods

A total of thirty-one lumbar spines (L1-L5) collected from fresh cadavers were used in this study. Bone density was measured using lateral DEXA scans and parts of samples were performed with partial or entire endplate removal. All the specimens were divided into three BMD groups. According to endplate integrity of the lumbar vertebrae, each BMD group was then divided into three subgroups: subgroup A: intact endplate; subgroup B: central region of endplate removal; subgroup C: entire endplate removal. The axial compression test was conducted with material testing system at a speed of 2mm/min. The experimental results were statistically analyzed using SPSS 17.0.

Results

(1) Significant differences of biomechanical properties occurred among normal BMD, osteoporotic and serious osteoporotic group (P<0.05). (2) Spearman analysis showed that BMD was positively correlated with the failure load and stiffness of lumbar vertebrae. (3) For each BMD group, significant differences of biomechanical properties were found between subgroup A and C, and between subgroup B and C (P<0.05). (4) For each BMD group, there was no statistical difference of biomechanical properties between subgroup A and B (P>0.05).

Conclusions

Entire endplate removal can significantly decrease the structural properties of lumbar vertebrae with little change in biomechanical properties by preservation of peripheral region of the endplate. BMD is positively correlated to the structural properties of the lumbar vertebrae.     

Study on Bone Density at Various Skeletal Sites for the Diagnosis of Primary Osteoporosis

The objective of this study was to evaluate the diagnostic value of bone density changes in lumbar vertebrae and femoral necks in patients with primary osteoporosis (OP) at various ages. Dual-energy X-ray absorptiometry (DXA) scans were performed on patients who had their primary visits between March 2008 and February 2009. The bone mineral density (BMD) of the lumbar vertebrae 1-4 (L1-L4) in anteroposterior projection and the proximal femoral neck in lateral projection were measured. If the BMD values (T score) of any site is -2.5 or less (T ≤?-2.5), the patients were diagnosed as primary OP, and the T scores were statistically analyzed. The 81 patients who had lumbar vertebrae with a T ≤?-2.5 led to a positive rate of 80.1?% in the diagnosis of primary OP; the 47 patients who had femoral neck with a T ≤?-2.5 gave a positive rate of 47.0?%. The patients with type I or type II primary OP were divided into two age groups of ≤70 and ≥71?years old. The comparison of lumbar spine T score values did not show significant statistical difference (P?>?0.05) between the age groups, while the result of the femoral necks revealed significant difference between the two groups (P?相似文献   

牙列缺损种植修复患者焦虑状况的影响因素分析

探讨牙列缺损种植修复患者发生焦虑状况的可能影响因素。2016年3月至2017年12月期间,选择我院收治的牙列缺损行种植义齿修复患者150例作为研究对象。评价患者的状态和特质焦虑量表(STAI)、修正版牙科焦虑量表(MDAS)和VAS疼痛评分之间的相关性,Logistic回归分析确定患者焦虑的影响因素。根据术前的SAI和TAI评分将牙列缺损患者分为低焦虑组、中焦虑组和高焦虑组,高焦虑组的VAS评分和MDAS评分均显著高于其他两组(p<0.05)。SAI、TAI和MDAS评分分别与VAS评分显著正相关(r=0.664,r=0.758,r=0.437,p<0.05)。性别(女)、年龄(<25岁)、付费方式(自费)、居住地(农村)和收入(<4 000元)为牙列缺损患者产生焦虑情绪的独立危险因素。牙列缺损患者行种植修复手术前的焦虑水平与术后的疼痛正相关。性别、年龄、付费方式、居住地和收入是牙列缺损患者焦虑水平升高的独立危险因素。     

Bone mineralization and physical development of children

A cross-sectional study of BMD and physical development values in children of various age-specific groups was carried out. In all, the study included 357 children (194 boys and 163 girls) aged from 5 to 16 years. The study did not include children with inherited or acquired diseases of the musculoskeletal system, chronic diseases of the liver or kidneys, diabetes, thyrotoxicosis or malabsorption syndrome or professional athletes. BMD values were estimated by dual X-ray absorbtiometry (DXA) of the lumbar part of the spine (L2-L4) using a "DPX-MD+" device equipped with a "child" software program. Out of all the examined children, 58.9% had harmonic physical development, and 13.1% had a decreased body height and body mass. It was revealed that BMC and BMD values in the lumbar part of the spine intensively increased with age. BMC closely correlates with body height (r = 0.8; p < 0.000) and body mass (r = 0.7; p < 0.000). BMD also correlates with anthropometric parameters. The lowest BMC and BMD values and Z-score as well can be found in children with a low body height and body mass (<10th percentile).     

Effect of puberty on the relationship between bone markers of turnover and bone mineral density in Turner's syndrome

It has been suggested that the appropriate timing of puberty is necessary for normal bone mineral acquisition which may not be achieved amongst patients with Turner's syndrome (TS). The aim of this study was to assess bone mineral density (BMD) and bone turnover in 34 patients with TS (age range 2.2-39.0 years). The areal BMD (aBMD) was determined by dual-energy X-ray absorptiometry, and the volumetric BMD was calculated. Blood and second voided urine samples were taken the morning after an overnight fast for evaluation of the biochemical markers of bone turnover: bone-specific alkaline phosphatase (BAP) and N-telopeptides of type I collagen (NTX), respectively. Both were determined by enzyme-linked immunosorbent assay. The patients were divided into three groups: group 1 (n = 13; prepubertal; age range 2.2-19.0 years), group 2 (n = 10; teenagers; age range 12.4-19.0 years), and group 3 (n = 11; adults; chronological age >20 years). They were also grouped by breast development according to Tanner stage into B1 (n = 12), B2-3 (n = 9), and B4-5 (n = 13). The aBMD was significantly lower in group 1 and was higher at Tanner stages 4 and 5 as compared with patients at Tanner stage 1. The bone turnover markers were significantly higher in group 1 (NTX: p = 0.002; BAP: p = 0.0005) and declined, as puberty progressed. A negative correlation was observed between aBMD and biochemical bone markers at the lumbar spine (NTX: r = -0.54, p = 0.05; BAP: r = -0.44, p = 0.01) and in the whole body (NTX: r = -0.60, p = 0.0008; BAP: r = -0.19, p = 0.002). We conclude that the negative relationships between aBMD and biochemical markers suggest a high bone turnover, mainly in prepubertal patients and that the results observed in relation to aBMD and puberty are imputed to the delayed puberty which occurs amongst TS patients.     

Bone Mineral Density of the Spine in 11,898 Chinese Infants and Young Children: A Cross-Sectional Study

Background

Bone mineral density (BMD) increases progressively during childhood and adolescence and is affected by various genetic and environmental factors. The aim of this study was to establish reference values for lumbar BMD in healthy Chinese infants and young children and investigate its influencing factors.

Methods and Findings

Healthy children aged 0 to 3 years who underwent regular physical examinations at the Child Health Care Clinic of Hubei Maternal and Child Health Hospital (N = 11,898) were recruited for this study. We also chose 379 preterm infants aged 0 to 1 years to preliminarily explore the development of BMD in this special population. BMD (g/cm²) measurements of the lumbar spine (L2–L4) were carried out with dual-energy X-ray absorptiometry and a questionnaire was administered to full-term children''s parents to gather information on various nutritional and lifestyle factors as well as mothers'' nutritional supplement use during pregnancy. Lumbar BMD significantly increased with age among both boys and girls (p<0.05), with fastest growth observed during the first postnatal year. There was no significant difference in lumbar BMD between boys and girls of similar age (p>0.05), either among healthy reference children or preterm infants. However, BMD values in preterm infants were significantly lower than those in term infants 3 to 8 months old (p<0.05) after adjustment for gestational age. Multivariable linear regression analysis indicated significant positive associations between lumbar BMD of healthy children and the child''s age and current weight, mother''s weight gain during pregnancy, birth weight, children''s outdoor activity duration and children''s physical activity duration.

Conclusion

Our study provides reference values of lumbar BMD for healthy Chinese children aged 0 to 3 years and identifies several influencing factors.     

Relationships between anthropometric, body composition and bone mineral parameters in 7-8-year-old rhythmic gymnasts compared with controls

The aim of the study was to investigate the relationships between specific anthropometric (9 skinfolds, 13 girths, 8 lengths and 8 breadths), body composition (body fat %, fat free mass [FFM], fat mass [FM]) parameters and bone mineral parameters (bone mineral density [BMD], bone mineral content [BMC) in young rhythmic gymnasts and same age controls. Eighty nine 7-8-year-old girls participated in this study and were divided to the rhythmic gymnast's (n = 46) and control (n = 43) groups. Body composition was determined by dual energy X-ray absorptiometry (FFM, FM, body fat %, BMD and BMC). Body fat % and FM were lower and BMD and BMC values at lumbar spine (L2-L4) and femoral neck were higher in rhythmic gymnasts compared with controls. All measured skinfold thicknesses were thicker in controls. In girths, lengths and widths there were only few significant differences between the groups. Stepwise multiple regression analysis indicated that skinfold thicknesses (supraspinale and medial calf) influenced L2-L4 BMD only in controls 38.2% (R2x100). Supraspinale and iliac crest skinfold thicknesses characterised L2-L4 BMC 43.9% (R2x100). Calf girths influenced BMD in L2-L4 52.3% (R2x100) in controls. BMC in L2-L4 was dependent only on mid-thigh girths 35.9% (R2x100). BMD in L2-L4 was dependent on tibiale-laterale height 30.0% (R2x100). Biiliocristal breadths together with sitting height characterised BMC in L2-L4 BMD 62.3% (R2x100). In conclusion, we found that the relationships between anthropometry, body composition and bone parameters in young rhythmic gymnasts are weak. In control group first of all lower body anthropometric parameters significantly correlated with BMD and BMC in spine.     

Prolonged increase in dietary phosphate intake alters bone mineralization in adult male rats

Excessive intake of dietary phosphate without the company of calcium causes serum parathyroid hormone (s-PTH) concentration to rise. We investigated the effect of a modest but prolonged increase in dietary intake of inorganic phosphate on the bone quantitative factors of mature male rats. Twenty Wistar rats were divided into two groups and fed a high-phosphate diet (1.2% phosphate) or a control diet (0.6% phosphate) for 8 weeks. In the beginning and at the end of the study period, femur and lumbar bone mineral density (BMD), bone mineral content and area were measured using DXA, s-PTH was analyzed from the blood sample, and after sacrifice, right femur was cut loose and processed into paraffin cuts. Bone diameter, inner diameter and cortical width was measured from the hematoxylin- and eosin-dyed femur cuts. Tibias were degraded and calcium and phosphate content was analyzed by inductively coupled plasma-mass spectrometer. Femoral BMD increased significantly more in the control group than in the phosphate group (P=.005). Lumbar BMD values decreased in both groups, and the fall was greater in the control group (P=.007). The phosphate group had significantly higher s-PTH values (P=.0135). Femoral histomorphometric values or tibial mineral contents did not differ between groups. In conclusion, increase in dietary phosphate intake caused s-PTH to rise and hindered mineral deposition into cortical bone, leading to lower BMD. The effect on trabecular bone was opposing as mineral loss was less in the lumbar spine of phosphate group animals. These results are in concurrence with the data stating that skeletal response to PTH is complex and site dependent.     

绝经后骨质疏松患者血清I型胶原氨基末端、I型胶原羧基末端及骨钙素的表达变化及临床意义

摘要 目的：探讨绝经后骨质疏松患者血清I型胶原氨基末端（NTx）、I型胶原羧基末端（CTX）及骨钙素（BGP）的表达变化及临床意义。方法：选取我院2017年8月-2022年8月收治的60例绝经后骨质疏松患者作为研究对象,将其分为观察组,另选取同期来我院体检的60名绝经后健康志愿者作为对照组。对比两组患者NTx、CTX、BGP表达水平,并建立受试者特征工作（ROC）曲线分析NTx、CTX、BGP对绝经后骨质疏松的诊断效能。3个月后对所有患者进行门诊复查随访,将症状明显明显减轻,X线检查明显改善,骨密度值明显增加的35例绝经后骨质疏松患者分为预后良好组,将其余25例未达到上述标准的患者分为预后不良组,对比两组患者临床一般情况,并应用Logistic回归分析NTx、CTX、BGP对绝经后骨质疏松的预后预测价值。结果：两组受检者NTx、CTX、BGP表达水平对比差异显著,观察组NTx、CTX高于对照组,BGP低于对照组（P＜0.05）; NTx、CTX、BGP三者联合对绝经后骨质疏松的诊断效能优于单一检测（P＜0.05）;预后良好组与预后不良组患者年龄、BMI、合并基础疾病、病程、Ca表达水平对比无明显差异（P＞0.05）,预后良好组与预后不良组患者病情严重程度、骨密度T值、雌二醇、血清NTx、CTX、BGP表达水平对比差异显著（P＜0.05）;logistic回归分析结果表明：CTX、BGP为绝经后骨质疏松的预后不良的独立影响因素（P＜0.05）。结论：绝经后骨质疏松患者血清I型胶原氨基末端、I型胶原羧基末端表达水平高于非骨质疏松群体,骨钙素低于非骨质疏松群体,三者联合可提升绝经后骨质疏松的诊断效能。另外,CTX、BGP作为绝经后骨质疏松的预后不良的独立影响因素,CTX水平越高、BGP水平越低可能预示患者预后不良,因此临床需针对此类患者及时改良治疗措施,提升其预后水平。     

Comparison between quantitative X-ray imaging,dual energy X-ray absorptiometry and microCT in the assessment of bone mineral density in disuse-induced bone loss

Objectives:

We recently introduced a new methodology called quantitative X-ray imaging (qXRI) to investigate bone mineral density in isolated rodent bones. The aims of the present study were to compare DXA and microCT with qXRI in a rat model of disuse osteoporosis.

Methods:

Fourteen Copenhagen rats were injected with a single dose of botulinum toxin (BTX - 2 UI) in the right Mus quadriceps femoris. The left hindlimb serves as control. Areal BMD and vBMD were determined with a Hologic Discovery-W device and a Skyscan 1172 microcomputed tomograph (microCT). Absorbing material density (AMD) was determined on digitized X-ray images obtained with a Faxitron M020 device.

Results:

All three methods highlighted significant lower values for aBMD, vBMD and AMD in trabecular and cortical bone in the BTX-injected side. In trabecular bone, aBMD, vBMD and AMD were significantly correlated with BV/TV. In cortical bone, only aBMD and vBMD were significantly correlated with cortical bone mass On the other hand, only AMD was significantly correlated with the mechanical parameters bending strength and bending modulus.

Conclusions:

qXRI is a rapid and cheap method to assess trabecular bone mass in isolated rodent bones and can be used as a surrogate for the densitometry of small animals.     

Effect of parity on bone mineral density in female rhesus macaques from Cayo Santiago

This cross-sectional study investigates the relationship between parity, bone mineral density, and spontaneous osteopenia/osteoporosis in a large skeletal population of female rhesus macaques (Macaca mulatta) from the free-ranging colony of Cayo Santiago, Puerto Rico. The sample consists of 119 mature female monkeys aged 4.0-22.2 years at time of death. The data consist of measurements of bone mineral content (BMC) and bone mineral density (BMD), obtained from dual-energy X-ray absorptiometry (DEXA) of the last lumbar vertebra. After controlling for age, there is a significant increase in BMD of the spine with increasing parity (P = 0.0006), up to a parity of 7 offspring. Thus, high parity initially has a positive effect on BMD in female rhesus monkeys, but this positive effect disappears with parities that are greater than 7 offspring. After controlling for parity, however, age has a negative (P = 0.015) effect on BMD, beginning several years after the attainment of peak BMD (age 9.5 years). Thus, it appears that parity initially mitigates the effects of aging, but the positive effect of parity on BMD is eventually overwhelmed by the aging process. Mean BMC and BMD values are higher in parous females compared to nulliparous females in the same age range. Similarly, females with low parity have significantly lower mean BMD values than do age-matched high-parity controls, and the frequency of osteopenia and osteoporosis is greater in low-parity females. Forty-three percent (43%) of the osteopenic/osteoporotic females in the sample are members of the low-parity group, even though it composes only 13% (16/119) of the entire sample. This study demonstrates that the free-ranging female rhesus monkeys from Cayo Santiago are a good nonhuman primate model for the study of bone mineral density, parity, osteopenia, and osteoporosis.     

Breastfeeding and Bone Mass at the Ages of 18 and 30: Prospective Analysis of Live Births from the Pelotas (Brazil) 1982 and 1993 Cohorts

Objective

To evaluate the effect of total breastfeeding, breastfeeding duration and type of breastfeeding at 3 months of age on bone mass at 18 and 30 years.

Study Design

A prospective, longitudinal study was conducted with two birth cohorts (1982 and 1993) in Pelotas, Southern Brazil. Measurements of bone mineral content (BMC) and bone mineral density (BMD) at 18 and 30 years of age were obtained by dual-energy X-ray absorptiometry (DXA). Information on breastfeeding was collected during the first 4 years of life. Analyses were performed by linear regression and stratified by sex.

Results

A total of 1109 and 3226 participants provided complete information on breastfeeding in early life and bone mass at 18 and 30 years, respectively. No association between breastfeeding and bone mass was observed in women at both ages nor among men at age 30. Among men at the age of 18, BMC and BMD were higher among those breastfed regardless of duration (p=0.032 and p=0.043, respectively).

Conclusions

Despite a very weak positive effect of breastfeeding (yes/no) on BMC and BMD at age 18 in men, most findings pointed to a lack of association between breastfeeding and bone mass until young adulthood.     

Effects of physical training on bone mineral density and bone metabolism

The purpose of this study was to examine the influences of long-term walking training and walking and jumping training on bone mineral density (BMD) and bone metabolism. Data from 28 healthy premenopausal women was assessed. The subjects were divided into the walking group (WG; 17 women mean+/-SE age 35+/-2 years), and the walking and jumping group (WJG; 11 women mean+/-SE age 39+/-1 years). BMD was measured in the lumbar spine and proximal femur using dual energy X-ray absorptiometry (DXA). As markers of bone metabolism, this study was to measure bone formation markers, bone-alkaline phosphatase (B-ALP: measured by enzyme immunoassay/EIA) and osteocalcin (BGP: by radioimmunoassay/RI) as well as bone resorption markers, parathyroid hormone (PTH: measured by/RI) and type I collagen cross-linked N-telopeptides (NTx: by EIA). Despite the significant decrease in body weight (p<0.05), no corresponding decrease in BMD was observed. Moreover, no significant difference in bone markers BGP, PTH, and NTx was observed. B-ALP was significantly increased (p<0.05) after one year, and the rate of this increase was greater in the WJG than in the WG. It is thus concluded that walking training for one year is beneficial for the promotion of bone formation, and that jumping stimulus maintain BMD effectively.     

2型糖尿病骨密度与冠状动脉钙化积分相关性研究

目的:探讨2型糖尿病患者冠脉钙化积分与骨密度的关系。方法:入选在2015年6月至2017年6月我科住院的2型糖尿病患者98例,按照性别以及糖化血红蛋白8%、低密度脂蛋白2.6 mmol/L、身高体重指数24 kg/m2为切点分为两组,进行冠脉动脉CT检查,计算冠脉动脉总钙化积分,依照钙化积分等于0为阴性组,大于0为阳性组。同时检测患者的骨密度、骨代谢指标、血钙、血磷等水平。比较冠脉钙化积分和骨代谢指标及骨密度的相关性。结果:1)男性患者中:阳性组糖化血红蛋白和颈部血管斑块形成明显高于阴性组,差异有统计学意义。女性患者中:阳性组年龄、颈部血管内膜厚度、高血压病史明显高于阴性组,差异有统计学意义。2)阳性、阴性两组之间骨代谢指标差异无统计学意义。3)男性患者中:阳性组腰椎骨密度明显高于阴性组,差异有统计学意义。女性患者中阳性组的腰椎骨密度明显低于阴性组,差异有统计学意义,在控制混杂因素以后,两组间差异无统计学意义。4)分别在男性和女性患者中按照年龄为60岁分为两组,两组间阳性组与阴性组的骨代谢指标及骨密度差异无统计学意义。结论:在2型糖尿病患者中,冠脉钙化积分和骨代谢以及骨密度之间无明显相关性。     

Bone mineral density is associated with estrogen receptor gene polymorphism in men

In order to identify genetic effects of allelic variation on bone mineral density (BMD), association studies have been performed recently. Examining the relation between PvuII and XbaI restriction fragment length polymorphism (RFLPs) at the estrogen receptor (ER alpha) gene and BMD, in women or men, have yielded conflicting results. We analyzed the association between this polymorphism and BMD Z score values of cancellous bone at the 3rd finger in 344 members of nuclear families of European population, Chuvasha, living in Russia. The population sample included 183 males, aged 18-84, and 161 females, aged 23-79. The analysis has been performed separately for both sexes and for both generations (parents and offspring). We used a novel direct haplotyping method, which determines simultaneously each of the PvuII and XbaI RFLPs and their relation to each other. The haplotypes were represented as the combination of both polymorphic sites on the same chromosome, by using P/p and X/x for PvuII and XbaI restriction sites, respectively. The subjects were classified into 3 groups of genotypes: A = PXPX (homozygote for the PX haplotype); B = PXPx, PXpx (the heterozygotes for the PX haplotype); C = PxPx, Pxpx, pxpx (genotypes that are lacking the PX haplotype). The PXPX genotype (A) was associated with higher BMD Z score values in comparison to the genotypes that are lacking the PX haplotype (C), in total males [0.618 vs. -0.133 (p = 0.004)] and for the "sons" generation [0.724 vs. -0.198 (p = 0.02)]. Similar tendency was observed for the "fathers" generation (0.539 vs. -0.085), though the difference did not approach statistical significance (p = 0.087). These findings were not found in the female samples, nor in the "mothers" or "daughters" generations. The question if there are differences in the mode of action of estrogen through its receptor on bone mass, between the genders or between the males' generations, have to be further investigated.     

Measuring and interpreting age‐related loss of vertebral bone mineral density in a medieval population

This study investigates the age‐ and sex‐related patterns in vertebral bone mineral density (BMD) and the relationship between BMD and vertebral osteophytosis (VO), using a specialized peripheral densitometer in a skeletal sample excavated from the British medieval village Wharram Percy. A total of 58 individuals were divided by sex into three broad age categories (18–29, 30–49, 50+ years.). Each fourth intact vertebral centra was scored for VO and 5‐mm thick coronal sections scanned in a specialized peripheral densitometer (GE Lunar Piximus DXA). Changes in BMD associated with age, sex, and VO severity were examined in the whole vertebral section, a strictly trabecular region, and a primarily cortical region of bone separately. Significant change in vertebral BMD was found to occur by middle age with little or no statistical change in BMD between middle and old age. Females appear to suffer greater bone loss at an earlier age with no change in BMD between middle and old age, whereas males show a more steady loss of BMD across the age groups. The bone mineral content and BMD of the cortical region is higher in individuals with pronounced/severe osteophytosis. The unusual age‐ and sex‐related patterns of change in vertebral BMD at Wharram Percy are compared with the patterns of age‐related change from recent longitudinal population‐based studies. The results emphasize the different pattern of bone loss in young adulthood seen in trabecular regions of the skeleton and highlight the importance of consideration of degenerative joint disease in BMD studies. The influence of lifestyle factors on vertebral BMD in this medieval population is also discussed. Am J Phys Anthropol 2009. © 2009 Wiley‐Liss, Inc.     

The Association between the Serum C-Peptide Level and Bone Mineral Density

Objective

Although serum C-peptide was previously considered biologically inactive, a growing number of recent studies have shown that it is an active peptide with important physiologic functions. The present study aimed to investigate the association of serum C-peptide level with bone mineral density (BMD) in residents of the United States.

Methods

The study included 6,625 participants aged 12–85 years. Total and regional BMD were measured using dual-energy X-ray absorptiometry. Stratified multiple linear regression analysis was performed to determine the association of the serum C-peptide level with BMD. Three regression models were produced for each stratum. All models were adjusted for ethnicity, height, weight, education level, physical activity, smoking status, alcohol use, triglycerides and creatinine level, and models 2 and 3 were further adjusted for the fasting plasma glucose (FPG) and alkaline phosphatase (ALP) levels, respectively.

Results

Sex-specific results showed a significant association between the serum C-peptide level and total BMD in both sexes. Stratified analyses based on age and body mass index showed that serum C-peptide levels were significantly negatively associated with most regional BMD, and most of these associations remained significant after stratification based on the serum insulin level.

Conclusion

The serum C-peptide level was significantly negatively associated with the total and most regional BMD. These findings suggest that serum C-peptide may have biological activity associated with bone metabolism and therefore serum C-peptide control is advisable in order to reduce the risk of low bone mineral density.     

BENEFICIAL EFFECTS OF JUDO TRAINING ON BONE MINERAL DENSITY OF HIGH-SCHOOL BOYS IN KOREA

Bone mineralization is strongly stimulated by weight-bearing exercise during growth and development. Judo, an Olympic combat sport, is a well-known form of strenuous and weight-bearing physical activity. Therefore, the primary goal of this study was to determine the effects of Judo practice on the bone health of male high school students in Korea. The secondary goal of this study was to measure and compare the bone mineral density (BMD) of the hands of Judo players and sedentary control subjects. Thirty Judo players (JDP) and 30 sedentary high school boys (CON) voluntarily participated in the present study, and all of the sedentary control subjects were individually matched to the Judo players by body weight. BMD was determined by using dual-energy X-ray absorptiometry (Hologic, Bedford, MA, USA). The lumbar spine, femur and forearm BMD in the JDP group were significantly greater by 22.7%, 24.5%, and 18.3%, respectively, than those in the CON group. In addition, a significant difference in the CON group was observed between the dominant hand (DH) radius (0.710 ± 0.074 g/cm²) and the non-dominant hand (NDH) radius (0.683 ± 0.072 g/cm²), but this was not observed in the JDP group (DH = 0.819 ± 0.055 g/cm²; NDH = 810 ± 0.066 g/cm²) (P < 0.05). Therefore, the results of this study suggest that Judo practice during the growth period significantly improves bone health in high school male students. In addition, it seems that Judo practice could eliminate the effect of increased BMD in the dominant hand.     

Bone mineral density is inversely related to parathyroid hormone in adolescent girls.

Preventive programs aimed at maximizing peak bone mass as a way of reducing the risk of osteoporotic fractures later in life should take into account the contribution of nutritional factors to bone mass accumulation in young age. The role of calcium and energy intakes on radial mineral density was investigated in 200 healthy girls (aged 11-15 yr) simultaneously evaluating serum changes of insulin-like growth factor-I (IGF-I), parathyroid hormone (PTH) and osteocalcin (OC). Dietary calcium and energy intakes were assessed by a 3-day food record method, bone mineral density (BMD) was performed at ultradistal (ud) and proximal (pr) radial sites using dual energy X-ray absorptiometry. Calcium consumption below the levels suggested by Dietary Reference Intakes in more than 80% of population studied was not related to BMD, which in turn markedly increased in post-compared to premenarcheal girls. Interestingly, in a multiple regression analysis PTH was inversely related to BMD after adjustment for calcium intake, bone age and menarche. Serum IGF-I was positively associated to energy intakes and bone age in girls before menarche, who exhibited the highest values of OC. Our data highlighted the role of food habits in modulating some hormonal response that might influence bone mineral apposition during adolescent age. Low calcium consumption associated to enhanced PTH values, if persisting, could be responsible for reduced rate of gain in bone mineral density. Thus, to optimize bone mineralization during the critical period of rapid body growth adequate intakes of calcium and energy should be recommended.