百色壮族中老年人骨密度和体成分的特点及其相关性分析

目的测量并探讨百色壮族中老年人群的骨密度、身体成分的特点以及随年龄变化的规律,为改善少数民族地区老龄人口健康状况提供科学依据。方法随机抽取620名(男性248名,女性372名)百色壮族健康中老年人作为研究对象。测量受试者的右足跟骨密度,以及身高、体重、和身体成分(身体质量指数、腰臀比、去脂体重、肌肉量、脂肪量、体脂肪率)。运用SPSS17.0软件进行统计学处理。结果百色壮族中老年骨密度与身高、体重、腰臀比、去脂体重、肌肉量均随年龄增长逐渐降低,而脂肪量、体脂肪率在各年龄组间之间无显著差异。同年龄组男性的骨密度和身高、体重、去脂体重、肌肉量均明显高于女性,而女性的脂肪量、体脂肪率则明显高于男性。结论百色壮族中老年人的骨密度与年龄呈负相关线性关系,与体重、身高、脂肪量、体脂肪率、去脂体重、肌肉量均呈正相关线性关系。     

不同骨密度老年人群的体成分、肌力及心脏功能特点

目的 分析不同骨密度老年人群的体成分、肌力和心脏功能特点。方法 选择2019年1月至2021年12月在内蒙古自治区人民医院健康管理中心行骨密度检查年龄为65~80岁的500名受试者作为研究对象。采用人体成分分析仪检测并记录受试者骨骼肌指数、体脂肪率、脂肪控制、肌肉控制、右臂肌肉量、肌力；采用超声诊断仪检查并记录受试者心脏功能（EF、EDV、ESV、FS、HR、e/a）。结果 在500例研究对象中，骨量异常人数较多，占77 %，其中骨质疏松者93人（18.6 %），骨量减少者292人（58.4 %），骨量正常者115人（23%）。在男性中，骨质疏松者21人（8.4 %），骨量减少者153人（61.2 %），骨量正常者76人（30.4 %）；在女性中，骨质疏松者72人（28.8 %），骨量减少者139人（55.6 %），骨量正常者39人（15.6 %）；女性患骨质疏松的比例高于男性。女性的体脂肪率（37.20±4.13）高于男性（28.15±5.38）；女性骨骼肌指数（8.20±0.58）低于男性（9.23±0.55）（P＜0.05）。500例研究对象中需进行肌肉控制（增肌）的比例为55.6 % (278人),需进行脂肪控制（减脂）的比例为100 %（500人）。男性、女性分别按照骨密度分为骨质疏松组、骨量减少组及骨质正常组，三组体质量指数（body mass index, BMI)、T值、 Z值、骨骼肌指数、肌肉控制、右臂肌肉量、右手握力、左手握力比较，差异有统计学意义（P＜0.05）；年龄、体脂肪率、脂肪控制比较，差异无统计学意义（P＞0.05）。组间两两比较男性组BMI、T值、 Z值、骨骼肌指数、肌肉控制、右臂肌肉量、右手握力、左手握力组间比较差异有统计学意义（P＜0.05）；女性组T值、 Z值、骨骼肌指数、肌肉控制、右臂肌肉量、右手握力、左手握力组间比较差异有统计学意义（P＜0.05）。Pearson 相关分析显示，T值与骨骼肌指数、BMI、右臂肌肉量及右手握力呈正相关；相较BMI，T值与骨骼肌指数、右臂肌肉量相关性更高；与肌肉控制（增肌）呈负相关（r值= – 0.326，P=0.000）；与体脂肪率及脂肪控制无相关性。心脏功能EDV（F=0.042,P=0.958）、ESV（F=0.008,P=0.992）、EF值（F=0.060,P=0.942）、FS值（F=0. 057,P=0.945）、HR（F=0. 032,P=0.969）组间比较差异无统计学意义（P＞0.05）；e/a（F=3.768,P=0.034）比较差异有统计学意义（P＜0.05）。结论 老年人群骨量异常比率较高，随着骨密度减低，骨骼肌指数及肌力也会下降，且骨质疏松患者易出现心脏舒张功能减低。利用生物电阻抗测定人体成分可以分析骨质疏松患者人体成分变化，能够更细化地了解其肌肉和脂肪的含量，为进一步预防、治疗骨质疏松及优化老年人人体成分提供依据。     

仫佬族绝经前与绝经后女性体成分和骨密度的相关性研究

目的研究仫佬族绝经前与绝经后女性体成分和骨密度的相关关系,探讨体成分的变化对骨密度的影响。方法随机选取广西仫佬族成年女性200名,追溯其三代均为仫佬族,应用TANITA-MC180人体成分分析仪测定其肌肉量、脂肪量等体成分指标,采用SONOT3000超声骨密度仪测定其右侧跟骨的骨硬度指数。结果 (1)绝经前女性的体重、去脂体重、肌肉量、皮下脂肪量、躯干脂肪量、四肢肌肉量、推定骨量、骨硬度指数和T值等均显著高于绝经后女性(P0.01);而绝经前女性的内脏脂肪面积、腰臀比显著低于绝经后女性(P0.01)。(2)绝经前女性和绝经后女性的骨质疏松检出率分别为6%和45%,差异具有统计学意义(P0.01)。(3)相关分析发现肌肉量、四肢肌肉量和躯干肌肉量与骨密度之间存在显著的正相关关系(P0.01或P0.05),而当控制年龄和绝经状态后体成分和骨密度之间没有相关性;根据年龄分组后发现,≥50岁组的肌肉量各指标与骨密度存在较显著的关联(P0.05),而50岁组的体成分与骨密度不存在关联性(P0.05)。(4)多重逐步回归分析发现只有绝经状态、躯干肌肉量和内脏脂肪量与骨密度相关,而躯干肌肉量对骨密度影响最大。结论仫佬族绝经后女性的骨质疏松症发生率显著高于绝经前女性;控制年龄和绝经因素后,只有躯干肌肉量与骨密度较显著相关,结果可为骨质疏松症的预防和诊断提供理论依据。     

不同锻炼水平对大学生骨密度和体成分的影响及其相关性分析

目的探讨不同锻炼水平对大学生骨密度和体成分的影响,同时分析骨密度和体成分之间的相关性。方法选取中国矿业大学在校本科大学生120名,根据参与运动情况分为缺乏运动组、普通运动组和大运动量组,每组40名,男女各20名,采用超声法和生物电阻法分别检测其跟骨密度和体成分各项指标,测试所得数据采用Spss16.0软件进行统计分析。结果普通运动组大学生的骨密度明显高于缺乏运动组和大运动量组大学生的骨密度(P0.05),与缺乏运动组相比,普通运动组和大运动量组的体脂百分比均显著降低(P0.05),而去脂体重和肌肉量却明显升高(P0.05),与缺乏运动组和大运动量组相比,普通运动组矿物质含量明显升高(P0.05),各组去脂体重/体重、肌肉量/体重、矿物质含量与骨密度呈高度正相关(P0.01)。结论适量运动使大学生骨密度增加,大强度长时间的大量运动使骨密度下降,不利于骨骼的生长,运动锻炼可以有效改善大学生身体成分,降低脂肪含量,增加去脂体重,预防肥胖。     

健康中年男性人体成分对骨密度的影响

目的探讨健康中年男性人体成分对骨密度影响,为男性骨质疏松早期防治提供理论依据。方法以上海市奉贤区128名年龄为40~60岁(平均49.10±6.40岁)的健康中年男性为研究对象,测定其身高、体重、腰围、臀围,并计算体重指数(BMI);利用问卷调查调查其文化程度、饮酒吸烟、豆制品及奶制品摄入情况、静坐时间、睡眠时间等一般情况;利用全自动生化分析仪测定血钙(Ca)、血磷(P)、肝肾功能(ALT、AST、BUN、Cr、UA)、血脂(TC、TG、HDL、LDL)、血糖(FPG、2h-PG),高压液相法测定糖化血红蛋白(HbA1c)等生化指标;采用双能X线骨密度仪测定腰椎、股骨颈、股骨干、股骨大粗隆和全身骨密度(BMD),并根据T值或Z值评分结果将所有研究对象分为骨量正常组和骨量低下组;采用人体成分分析仪测定体脂肪含量、蛋白质含量、无机盐含量、骨骼肌含量和各部位肌肉含量。结果 128名年龄为40~60岁健康中年男性中,骨质疏松患者3人,骨量减少患者44人。骨量正常组体重、BMI、腰围、臀围、睡眠时间、蛋白质含量、无机质含量、骨骼肌含量、各部位肌肉含量皆高于骨量低下组,血清尿素及吸烟人数比率低于骨量低下组,且差异具有统计学意义;两组年龄、身高、饮酒情况、文化程度、工作性质、豆制品摄入情况及奶制品摄入情况、Ca、P、Cr、UA、ALT、AST、TC、TG、HDL、LDL、FPG、2h-PG、HbA1c、体脂肪及体脂百分比皆无统计学差异。结论适当延长每天睡眠时间有利于预防骨质疏松的发生;体重、BMI、腰围、臀围是骨质疏松的保护因素,但需通过加强体育锻炼及合理饮食,增加骨骼肌、无机质及蛋白质等非脂肪含量来增加骨密度预防骨质疏松。     

兰州汉族青少年骨强度指数特点及其影响因素分析

目的调查分析兰州汉族青少年跟骨骨强度指数(bone strength index,SI)变化规律,探讨其影响因素。方法采用超声骨密度仪和生物电阻抗分析仪测量662例(男345例,女317例)兰州汉族青少年SI及体重、体质量指数(body mass index,BMI)、去脂体重、脂肪量4项体成分指标,采用Pearson相关分析法和多元逐步回归法探讨SI的影响因素。结果总体来看,随年龄增加,兰州汉族青少年SI以及身高、体重、BMI、去脂体重、脂肪量5项指标均呈上升趋势。但是,不同性别以及不同年龄段各指标的增长速度存在差异,一般在17岁组或18岁组达到峰值,其中14岁左右为骨发育速度高峰。SI仅在总体上和13岁组存在性别差异且女性大于男性。SI与性别、年龄、身高、体重、BMI、去脂体重、脂肪量均呈正相关关系。而性别、年龄和BMI是SI的主要影响因素。结论兰州汉族青少年SI在不同性别和不同年龄段间变化规律不同,主要的影响因素为性别、年龄及BMI。     

健康青年女子体成份及全身骨密度相关分析研究

目的通过分析我国健康青年女性体成份和骨密度(BMD),探讨骨密度的影响因素,为骨质疏松的预防、诊断、治疗提供科学依据。方法应用DEXA测定了176例年龄为16～24岁健康青年女性的体成份、全身及腰椎和前臂的骨密度(BMD)。结果研究对象年龄、身高、体重、体重指数(BMI)平均值分别为19.7岁、160.6cm、55.3kg和21.4kgm2;全身骨矿物含量(BMC)和BMD平均值分别为2278±299g和1.12±0.069gcm2,随年龄的增加呈增加趋势,但无统计学差异;相关分析显示,身高、总体重、BMI、瘦体重、体脂含量及体脂百分比均与BMC和BMD呈显著正相关,按其相关性大小排序为:总体重>BMI>体脂百分比>瘦体重。结论总体重可能是影响女性骨骼健康的重要因素。     

体成分对男性2型糖尿病患者骨密度的影响

目的 应用双能X线骨密度仪（DXA）探讨体成分对男性2型糖尿病患者骨密度的影响。方法 选择年龄50～60岁在我科住院的男性2型糖尿病患者107例，分为正常体重组、超重组和肥胖组，分别测定其身高、体重，计算体重指数（BMI），利用全自动生化分析仪测定血糖、血脂，高压液相色谱法测定糖化血红蛋白（HbA1c），采用双能Ｘ线骨密度仪测定腰椎、左股骨大转子骨密度（BMD）及体成分，并进行统计学分析。结果 3组男性2型糖尿病患者腰椎BMD分别为1.12±0.05，1.21±0.07，1.36±0.09，左股骨大转子BMD分别1.12±0.06，1.22±0.08，1.41±0.08，与骨密度呈正相关；全身各部位肌肉含量与骨密度成正相关，且大腿＞上肢＞躯干；不同部位脂肪含量对骨密度的影响是不同的，其中上肢脂肪和大腿脂肪与骨密度成正相关，而躯干脂肪与骨密度成负相关；年龄、糖化血红蛋白、血脂对男性2型糖尿病患者骨密度无明显影响，而体重指数、肌肉含量及脂肪含量影响明显。结论 体重指数、肌肉含量和脂肪含量对男性2型糖尿病患者骨密度有直接影响。男性2型糖尿病患者加强锻炼，减少腹部脂肪含量，增加四肢肌肉含量，可以预防骨质疏松症的发生。     

厦门市中老年人骨密度状况的研究

目的对厦门市中老年人骨密度状况进行分析,了解厦门市地区环境、生活行为、饮食习惯对骨密度的影响,为防治骨质疏松提供理论依据。方法在2007年10月至2010年10月,对在厦门居住10年以上、21岁以上共6233人,采用美国GE公司LUNAR PRODIGY型骨密度仪,测定腰椎1-4、股骨颈、Ward三角、大转子区的骨密度,并以5岁为年龄组间距进行分组,对每组的身高、体重、性别、骨密度进行分析比较。结果骨密度随年龄增高而下降,男女在36～40岁这一年龄段的骨密度相对稳定为最高值。35岁至50岁(女性),35岁至65岁(男性)相对稳定。女的从56～60岁开始下降,男的从66～70岁开始下降。身高随年龄增高而下降,36～40岁这一年龄段平均男人身高174.2cm,女人身高162.8cm;80岁以后身高都变矮,男人平均为168.4cm,女人平均为155.7cm,女人身高变矮比男人明显。体重在36～40岁,男人的体重平均达70.1kg,女人的体重平均达60.8kg。结论厦门地区的环境、气候及较长的海岸线和全年都有日照,可提供很多户外活动的空间,厦门人的生活行为、饮食习惯使厦门人骨密度随年龄增高而下降的速度较慢。年龄往后移,身高体重适宜,肥胖的人不多。     

北京市海淀区 1639 例汉族中老年男性骨密度调查分析

目的 调查北京市海淀区1639 例汉族中老年男性骨密度,探讨本地区骨质疏松发病率及影响因素? 方法 选择2012 年3 月~6 月在我院体检的1639 例汉族中老年男性为研究对象,采用韩国Osteosys公司生产的ExA-3000型骨密度仪,检测受试者非受力侧前臂尺桡骨中远端三分之一处骨密度,建立信息采集表,记录体检人群骨密度?身高?体重?体重指数(BMI)?吸烟?饮茶?喝牛奶?运动情况,将检测结果以每 10 岁为1 年龄段分组,分析每组骨密度?t评分?患病率及相关影响因素? 结果 男性40~49 岁年龄段骨质疏松发病率为 12.19%;50~59 岁年龄段男性骨质疏松发病率为 21.54%;60~69 岁年龄段骨质疏松发病率为 40.72%;70 ~79 岁年龄段骨质疏松发病率为55.56%;80 岁以上年龄段骨质疏松发病率为 69.73%? 身高?体重?BMI和规律性运动与骨密度呈正相关(r=0.18,r=0.19,r=0.12,r=0.24,P<0.05);吸烟与骨密度呈负相关(r=-0.19,P<0.05);饮茶?喝牛奶与骨密度无明显相关性(P>0.05)? 结论 随着年龄的增加,每个年龄段中老年男性骨密度均呈下降趋势,骨质疏松发病率明显上升,差异具有统计学意义(χ2=343.88,P<0.05)? 生活方式和骨密度有明显的相关性? 因此,将骨密度检测作为中老年人体检的常规检查项目,早期发现,积极干预,倡导健康生活方式,对于防治骨质疏松具有重要意义?     

Weight,body composition,and bone density in postmenopausal women

Associations of body weight and body composition with bone mineral density (BMD) were examined in 261 postmenopausal women. BMD, body fat, and body nonfat soft tissue (NFST) were measured by dual-energy X-ray absorptiometry (DXA). A height-independent BMD variable (HIBMD) was calculated to correct for differences among individuals in bone thickness, a dimension that is ignored by DXA scanners. HIBMD was calculated as BMD divided by height at the spine and femoral neck, and BMD divided by the square root of height at the total body. Weight, fat, and nonfat soft tissue were all positively correlated with both BMD and HIBMD, but the magnitudes of regression and correlation coefficients were lower when HIBMD was the dependent variable. The weight-independent associations of body composition with HIBMD were examined by including weight and % NFST together in linear models. In these analyses, weight was positively associated with HIBMD at all three skeletal sites (r=0.22–0.26, P<0.05), % NFST was not associated with HIBMD at the spine or femoral neck (r=0.01–0.02), and there was only a weak inverse correlation of % NFST with total body BMD (r=-0.12, P<0.05). These findings are consistent with those of previous studies demonstrating positive associations between body weight and BMD. In addition, they demonstrate that once bone thickness and body weight are taken into account, body composition appears to have little if any independent effect on bone density at the skeletal sites measured. This finding is consistent with the hypothesis that the protective effect of body weight is brought about predominantly through its mechanical force on the skeleton.     

Total body,lumbar spine and hip bone mineral density in overweight adolescent girls: decreased or increased?

Despite the epidemic of overweight adolescents, the effect of being overweight on bone mineral density (BMD) during this period is poorly understood. However, recent studies have suggested that overweight adolescents have lower BMD compared to normal-weighted adolescents after adjusting for body weight. The aim of this study was to determine the influence of being overweight on bone status in a group of adolescent girls. This study included 22 overweight (BMI >25 kg/m2) adolescent girls (15.4 ± 2.4 years old) and 20 maturation-matched (15.2 ± 1.9 years old) controls (BMI <25 kg/m2). Bone mineral area, bone mineral content, BMD at the whole body (WB), lumbar spine (L2–L4), femoral neck (FN), total hip (TH) and body composition (lean mass and fat mass) were assessed by dual-energy X-ray absorptiometry (DXA). Calculation of the bone mineral apparent density (BMAD) was completed for the WB and for L2–L4. Expressed as crude values, DXA measurements of BMD at all bone sites (TB, L2–L4, TH and FN) were higher in overweight adolescent girls compared to controls. After adjusting for either body weight, lean mass or fat mass, these differences disappeared. Finally, BMAD of the L2–L4 remained higher in overweight girls compared to controls after adjusting for lean mass. We conclude that overweight adolescent girls do not have lower BMD when compared with controls, even when BMD values are adjusted for weight, lean mass or fat mass.     

Changes in body composition of children with chronic renal failure during growth hormone treatment

Growth hormone (GH) has different known metabolic effects, among which are lipolysis and anabolic action. We have studied the changes in body composition of children with chronic renal failure (CRF) after 1 year of daily treatment with GH. Body fat percentage and fat body mass (FBM) were derived from four site skinfold measurements; lean body mass (LBM) from total body potassium (TBK) and mid-arm muscle circumference (MAMC); bone mineral density (BMD) was measured by dual photon absorptiometry. GH treatment had a positive effect on weight, heigt and MAMC, but no effect on LBM (as reflected by TBK), FBM and BMD. Z-scores were derived in order to compare subjects with a normal population. While no significant change in z-score was noticed for weight, height, MAMC, FBM and BMD, TBK decreased during treatment. We conclude that GH therapy does not ultimately increase LBM in CRF patients compared with other GH-treated groups.     

Relative Importance of Lean Mass and Fat Mass on Bone Mineral Density in a Group of Lebanese Postmenopausal Women

The aim of this study was to determine the relative importance of lean mass and fat mass on bone mineral density (BMD) in a group of Lebanese postmenopausal women. One hundred ten Lebanese postmenopausal women (aged 65–84 yr) participated in this study. Age and years since menopause were recorded. Body weight and height were measured and body mass index (BMI) was calculated. Body composition (lean mass, fat mass, and fat mass percentage) was assessed by dual-energy X-ray absorptiometry (DXA). Bone mineral content (BMC) of the whole body (WB) and BMD of the WB, the lumbar spine (L1–L4), the total hip (TH), the femoral neck (FN), the ultra distal (UD) Radius, and the 1/3 Radius were measured by DXA. The expressions WB BMC/height and WB BMD/height were also used. Weight, BMI, fat mass, and lean mass were positively correlated to WB BMC, WB BMC/height, WB BMD/height, and to WB, L1–L4, TH, FN, UD Radius, and 1/3 Radius BMD. However, using multiple linear regression analyses, fat mass was more strongly correlated to BMC and to BMD values than lean mass after controlling for years since menopause. This study suggests that fat mass is a stronger determinant of BMC and BMD than lean mass in Lebanese postmenopausal women.     

Whole body bone mass and body composition in a girl with achondroplasia, at ages 9 through 12.

A 9-yr-old white female with achondroplasia was one of a group of 773 children who were recruited for a study of the accumulation of whole body skeletal mass during four annual measurements. Measurements of bone, fat, and lean mass were obtained with a Hologic 1000W instrument. The following variables are used to compare the subject with the 130 healthy white girls who participated in the study: bone mineral content (BMC), bone mineral density (BMD), and bone mineral apparent density (BMAD). Ratios of BMC to weight or BMC to height, and BMD to weight or height, were also calculated. We found that the BMC of the subject was lower when compared to the reference group, but the ratios of BMC to weight or BMC to height were similar in both. BMD was also lower in the patient, but, when expressed in relation to height and weight, the ratios were similar or slightly higher in the case. BMAD was higher in the subject with achondroplasia at all ages. The subject had a lower percentage fat and higher percentage lean mass than the reference children. We conclude that the accumulation of bone mass in this subject with achondroplasia is appropriate for her reduced body size.     

Analysis of factors affecting increase in bone mineral density at lumbar spine by bisphosphonate treatment in postmenopausal osteoporosis

Bisphosphonate is an effective drug to reduce fracture risk in osteoporotic patients; however, factors affecting the efficacy of bisphosphonate treatment are not fully known, especially in Japanese patients. In the present study, we examined the relationships between an increase in lumbar spine bone mineral density (BMD) by bisphosphonates and several pretreatment parameters, including biochemical, bone/mineral, and body composition indices, in 85 postmenopausal osteoporotic patients treated with alendronate or risedronate. BMD increase was measured by dual-energy X-ray absorptiometry at the lumbar spine before and 2 years after treatment. BMD increase at the lumbar spine was observed as independent of age, height, weight, body mass index, and fat mass, although lean body mass seemed slightly related. On the other hand, fasting plasma glucose (FPG) levels were significantly and positively related to BMD increase at the lumbar spine. In multiple regression analysis, FPG levels were not significantly related to BMD increase at the lumbar spine when lean body mass was considered. As for bone/mineral parameters, BMD increase at the lumbar spine was not significantly related to serum levels of calcium, parathyroid hormone (PTH), and alkaline phosphatase or urinary levels of deoxypiridinoline and calcium excretion. As for BMD parameters, Z-scores of BMD at any site and bone geometry parameters obtained by forearm peripheral quantitative computed tomography were not significantly related to BMD increase at the lumbar spine. BMD increases at the lumbar spine were similar between groups with or without vertebral fractures. In conclusion, BMD increase at the lumbar spine by bisphosphonate treatment was not related to any pretreatment parameters, including body size, body composition, and bone/mineral metabolism in postmenopausal Japanese women with primary osteoporosis, although FPG correlated partly to BMD through lean body mass.     

Regional and total body bone mineral content,bone mineral density,and total body tissue composition in children 8–16 years of age

Summary Normative values for total body bone mineral content (TBBM) and total body bone mineral density (TBMD) were derived from measurements on 234 children 8–16 years of age. In addition, bone mineral content (BMC) and bone mineral density (BMD) values for selected regions of interest and soft tissue (bone free lean and fat) for the total body are presented. Bone mineral and soft tissue values were determined by dual energy X-ray absorptiometry (DXA) using a Hologic QDR-2000 in the array mode. Results of a stepwise multiple regression analysis revealed a significant correlation between bone-free lean tissue (BFLT) and BMD (r² = 0.80) in girls. Adding age to the equation accounted for an additional 2% of the variance (P < 0.05) and height accounted for another 1% of the variance (P < 0.05). Body weight and fat tissue (FT) did not account for any additional variance. In boys BFLT correlated significantly with BMD (r² = 0.75;P < 0.05); none of the other predictor variables accounted for additional variance. No significant differences were found in TBBM or TBMD between boys and girls at any age. There was a significant overall gender effect for only three regions of interest. Boys had greater BMC in the head region and had greater BMD in the upper limbs, but post hoc analysis revealed no significant differences for any specific age groups. Girls had greater overall BMD in the pelvis, but this difference was only significant at the 15–6-year age group. The changes in BFLT and FT over the age ranges were consistent with the growth literature.The normative values can be applied to the assessment of children and adolescents with health problems that may impact on the skeleton as well as to research studies investigating bone mineral development in children.     

Volumetric bone density of the lumbar spine is related to fat mass but not lean mass in normal postmenopausal women

We have previously found that fat mass but not lean body mass is related to bone mineral density (BMD) in women. In these and most other studies of the dependence of BMD on body composition, areal rather than volumetric bone density was measured. It is possible that the dependence of this variable on body size introduced a scale artifact that contributed to the previous findings. The present study addresses this issue by measuring thevolumetric density of the third lumbar vertebra from simultaneous anteroposterior (AP) and lateral scans using dual-energy X-ray absorptiometry in 119 normal postmenopausal women. Whole body fat and lean body mass were also measured using this technique. In the AP projection, BMD was similarly related to body weight and to fat mass (r=0.44,p<0.0001 for both) but not to lean body mass (r=0.17, NS). BMD in the lateral projection was less closely related to body composition than was AP BMD, but the greater impact of fat (r=0.25,p<0.01) than lean body mass (r=0.09, NS) was still evident. When AP or lateral BMDs were divided by height, arm span or the square root of the scan area to produce an index with the dimensions of volumetric density, the dependence of BMD on body weight and fat mass were not affected but the relationship to lean body mass was eliminated (–0.02<r<0.09). Similarly, the volumetric density of the third lumbar vertebra was related to fat mass (r=0.21,p=0.02) but not to lean body mass (r=0.01). It is concluded that BMD is related to fat mass and that previously reported associations between lean body mass and BMD are probably contributed to by a scaling factor arising from failure to measure volumetric bone density.     

Influence of age and morphological characteristics on whole body,lumbar spine,femoral neck and 1/3 radius bone mineral apparent density in a group of Lebanese adolescent boys

The purpose of this study was to analyse the relationships between age, morphological characteristics (weight, height, body mass index (BMI), fat and lean mass), daily calcium intake (DCI), physical activity and bone mineral apparent density (BMAD) of the whole body (WB), lumbar spine (L2–L4), femoral neck (FN) and 1/3 radius in a group of Lebanese adolescent boys. This study included 60 Lebanese adolescent (16.8 ± 2.1 years old) boys. Body composition and bone mineral density (BMD) were assessed by dual-energy X-ray absorptiometry (DXA). BMAD values of the WB, L2?L4, FN and 1/3 radius were calculated. Physical activity and DCI were assessed using questionnaires. Age was positively related to WB, L2–L4 and 1/3 radius BMD and BMAD. Weight, lean mass and BMI were positively related to WB, L2–L4, FN and 1/3 radius BMD. Moreover, weight, lean mass and BMI were positively associated with L2–L4 and FN BMAD but not with BMAD of the WB and the 1/3 radius, while fat mass percentage was negatively associated with WB BMAD. In conclusion, this study shows that weight, lean mass and BMI are positively associated with BMAD of the weight-bearing bones (L2?L4 and FN) but not with BMAD of the WB and the 1/3 radius in adolescent boys.