体重、身高对成都地区青壮年腰椎、髋部骨量的影响

目的　研究体重、身高对青壮年腰椎、髋部骨量的影响。方法　随机抽取成都地区年龄在 2 0～ 39岁 ,排除心肝肺肾、内分泌等慢性病、骨代谢疾病及脊椎畸形者 2 37名 (其中男性 10 8名 ,女性 12 9名 ) ,采用美国Lunar公司生产DPX L型双能X线骨密度仪测定受试者腰椎和髋部的骨矿含量 (BMC)、面积 (AREA)、骨密度 (BMD)。全部资料输入微机 ,用SPSS软件进行统计学处理。结果　体重、身高、体重指数 (BMI)与腰椎、髋部的BMC、Area、BMD呈正相关 ,其中体重与腰椎、髋部的BMC、Area中等程度相关 (r=0 39～ 0 5 5 ,P <0 0 1) ,身高与腰椎 (L2 - 4)AREA相关性最好 (r=0 75 8,P <0 0 1) ,体重、身高与BMD相关性差 (r=0 15 2～ 0 2 2 5 ,P <0 0 5 )。男性腰椎及髋部的BMC、AREA均明显高于同年龄组女性 (P <0 0 1) ,男、女L2 - 4BMD无显著性差异 (P >0 0 5 ) ,男性略低于女性。L2 - 4BMC与体重比值及L2 - 4AREA与体重比值 ,男、女无显著性差异 (P >0 0 5 )。L2 - 4Area与身高比值男性明显高于女性 (P <0 0 1)。结论　体重对青壮年BMC的影响大于身高 ,身高对L2 - 4AREA影响最大 ,男、女体重、身高的差异决定了峰值骨量的差异。BMC、Area、BMD 3项指标中 ,BMC更能反映体重、身高的差异 ,用BMC诊断骨质疏松     

腰椎各椎体骨密度的分析

目的分析腰椎各椎体骨密度（ＢＭＤ）的差异。方法对１２１４例在我科进行骨密度检查的２０～８９岁人群,男性３９０例,女性８２４例,除外各种器质性内分泌、消化系统及肿瘤等疾病,用双能Ｘ线骨密度仪（ＤＥＸＡ）测量腰椎ＢＭＤ,通过计算机分析比较各椎体ＢＭＤ值的差异与相互关系,用ＥＸＣＥＬ软件做统计学分析,计数资料进行配对ｔ检验。结果ＢＭＤ值以Ｌ１最低,Ｌ４最高,Ｌ１－２与Ｌ２－４ＢＭＤ女性在４０岁以上有显著差异（Ｐ＜０．００１）,男性在６０岁以上（Ｐ＜０．０５）,８０岁以后无明显差异,女性５０岁以后骨丢失明显快于男性。结论腰椎各椎体ＢＭＤ存在差异,尤以女性明显,其差异与增龄造成的腰椎退行性变的干扰有关     

Effect of nutrition and body composition on bone density after liver transplantation

We investigated the relationship between nutrition, body composition, and bone mineral density (BMD) in young adults after liver transplantation. METHOD: A cross-sectional study involving bone densitometry, anthropometry, and detailed food and lifestyle questionnaires. RESULTS: Of 37 patients recruited, 26 were male. The mean age was 38.8 (+/-12.3) years, and the posttransplant period was 7.5 (+/-5.1) years (range 1.3-16.4). A significant proportion of patients (23 [62%]) were overweight (BMI 25-29.9) or obese (BMI>or=30). A total of 20 (54%) patients were osteopenic, and four (11%) had osteoporosis (lumbar spine or total body BMD). Lean mass showed a statistically significant correlation with lumbar spine and total body BMD in men and women, the most significant being bone mineral content, r=0.66, P=.01. The correlation was stronger in females (r=0.81, P<.01) than in males (r=0.56, P<.01). The average daily intake of vitamin D, total protein, and phosphorus was greater than 100% of the American Dietary Reference recommendations, calcium was 90%, and magnesium 56%. There was no significant relationship between any nutritional parameter and BMD nor history of fractures, steroid use, or length of time from transplantation. CONCLUSION: Osteopenia determined by lumbar spine BMD underestimates poor BMD in our population of young adults after liver transplant. Maintaining muscle mass may be helpful in preserving BMD. The effect of a limited intake of magnesium needs further investigation.     

A Comparison of Calcaneus Ultrasound and Dual X-Ray Absorptiometry in Healthy North American Youths and Young Adults

Quantitative ultrasound is the newest noninvasive method to be accepted for assessing bone mineral in adults. Heel ultrasound measurements correlate with bone density measurements by dual X-ray absorptiometry (DXA) and predict fracture risk in adults. Far less is known about the value of calcaneus ultrasound (CUS) in children. We determine spine, femoral neck, and whole-body bone mineral by DXA and heel bone mass by CUS in 125 youths (69 females, 56 males) ages 9-25 yr. CUS and DXA measurements of bone mass increased with age and pubertal development during adolescence in a parallel fashion. Among females, Tanner stage was a stronger predictor than age for all CUS and DXA measurements, and among males, pubertal stage was a stronger predictor for spine bone mineral apparent density (BMAD) and femoral bone mineral density (BMD). CUS measurements correlated moderately well with DXA measurements of the spine, femoral neck, and whole-body BMD and spine BMAD (r = 0.23-0.58, p < 0. 008). CUS warrants further study as a tool for assessing bone mineral acquisition in children.     

扬州地区健康人群骨密度分析及研究

目的 探讨扬州地区健康人群腰椎骨密度(BMD)的年龄变化规律，确定各年龄段的正常骨密度值标准，为本地区骨质疏松症的诊断提供参考依据。方法 采用美国GE公司Lightspeed UI-tra型多层螺旋CT(MSCT)机对扬州地区300名(男145例，女155例)20-89岁健康人群进行腰椎(L1-3)骨密度测量。结果 男、女腰椎骨密度峰值年龄均在20-29岁，峰值后随年龄增加而骨密度下降，女性在50岁，特别在绝经以后出现明显下降，男性下降速度比较平稳。结论 扬州地区女性腰椎骨密度值在50岁以前高于男性约15-20mg／cm^3，50-59岁年龄段有一加速下降过程，骨密度值开始低于男性约7-35mg／em^3。     

应用双能CT与定量CT对椎体骨密度测量的对照研究

目的应用双能CT(DECT)及定量CT(QCT)测量腰椎骨密度,评价利用双能CT测量骨密度(BMD)的可行性。方法对56名志愿者采用DECT检查,获得钙值图,测量骨钙CT值及骨髓CT值,同时应用QCT测量骨密度(BMD),分析骨钙CT值及骨髓CT值与BMD值的相关性。结果腰椎椎体骨钙CT值与BMD值呈显著正相关(L1-5椎体Pearson相关系数分别为:r=0.715,0.692,0.739,0.673,0.686,P0.01);骨髓CT值与BMD值呈正相关(L1-5椎体Pearson相关系数分别为r=0.343、0.315、0.439、0.440、0.456,L5椎体P0.05,其余椎体P0.01)。结论 DECT所测量腰椎骨钙CT值及骨髓CT值与QCT所测BMD值密切相关,可定量反映腰椎BMD变化。     

Influence of age and body weight on spine and femur bone mineral density in U.S. white men

Bone mineral density (BMD) was measured in normal white males using 153 Gd dual-photon absorptiometry. Measurements were made on the lumbar spine (n = 315) and on the proximal femur (n = 282) utilizing three regions of interest. There was a small but significant age-related decrease in spinal BMD (r = -0.11; -0.001 g/cm2 per year) and trochanteric BMD (r = 0.27; -0.002 g/cm2 per year). The BMD of the other femoral sites decreased more rapidly; the femoral neck (r = -0.58; -0.005 g/cm2 per year) and Ward's triangle (r = -0.69; -0.007 g/cm2 per year) declined by about 21 and 34%, respectively, from age 20 to age 70. These femoral BMD decreases were three to four times greater than those usually seen in the peripheral skeleton in males but less than the decreases of 25-30 and 40% in the femoral neck and Ward's triangle of white females. This pattern of aging bone loss may partially explain the paucity of spine fractures and the lower incidence of hip fractures in males versus females.     

Validation of Thoracic Quantitative Computed Tomography as a Method to Measure Bone Mineral Density

The purpose of this study was to measure precision of thoracic quantitative computed tomography (QCT) bone mineral density (BMD) and correlation to lumbar spine QCT bone density.We measured the reproducibility of thoracic QCT; two consecutive thoracic QCT scans of the T9, T10, and T11 vertebrae were performed on 95 subjects (49 females, 46 males; mean age, 62.5 years) undergoing coronary scanning. In order to correlate the thoracic to standard lumbar measurement, the subjects also underwent a lumbar QCT scan of the L1, L2, and L3 vertebrae as part of an abdominal aortic scanning study. The variation of thoracic BMD was assessed in different ethnic subgroups. Consecutive thoracic QCT measurements showed good agreement (r=0.98; RMS CV=5.78%). Thoracic bone density was significantly higher than lumbar bone density results (paired t-test, P=0.003), but the two methods correlated well (r=0.86). The regression equation for the relationship between lumbar (X) and thoracic (Y) QCT was Y=0.87X + 22.97. The standard error of estimate was 19.0 mg/cm3. Thoracic QCT from coronary calcium thoracic scans is able to measure BMD with rescan precision and regression errors that are small compared to the biologic variability in the population. Given the relatively small precision error and the reasonable correlation to lumbar BMD, an ancillary assessment of thoracic BMD in a cardiac scan is likely to be a useful assessment of bone mineral status in the general population.     

老年2型糖尿病患者血尿酸水平与骨代谢、骨密度及骨质疏松的关系

目的探讨老年2型糖尿病患者血尿酸水平与骨代谢标志物、骨密度及骨质疏松的相关关系。方法选取2018-2019年于北京大学国际医院内分泌科门诊就诊及住院的年龄60岁以上的老年2型糖尿病患者,共计577人,其中男性289人,女性288人(均为绝经后女性)。对所有研究对象进行一般临床资料调查、生化指标及甲状旁腺素(PTH)、25羟维生素D[25(OH)D]、骨钙素(OC)、血清I型前胶原N-末端前肽(P1NP)、I型胶原交联C-末端肽(β-CTX)测定,计算估算肾小球滤过率(eGFR),双能X线吸收法(DXA)测定股骨颈(FN)及腰椎(L1~4)骨密度(bone mineral density,BMD)。将血尿酸(SUA)四分位法分层比较分析股骨颈及腰椎总BMD变化趋势,Pearson和Spearman相关分析SUA与血钙(Ca)、PTH及OC、P1NP、CTX、25(OH)D、腰椎及股骨颈BMD的关系,多因素Logistic回归分析SUA与骨质疏松的关系。结果SUA第4分组BMI、肌酐(Cr)、股骨颈及总腰椎BMD水平明显高于第1分位组,SUA第4分组eGFR水平明显低于第1分位组,差异具有统计学意义(P<0.05);Pearson相关分析显示SUA与股骨颈BMD(r=0.082,P=0.002)、糖尿病病程(r=0.129,P=0.005)、BMI(r=0.201,P=0.000)正相关,与eGFR负相关(r=-0.434,P=0.000),Spearman相关分析显示SUA与腰椎总BMD(r=0.168,P=0.003)、Ca(r=0.147,P=0.001)正相关,与β-CTX负相关(r=-0.157,P=0.001),与PTH、25(OH)D、OC、P1NP无相关性(P>0.05)。以老年2型糖尿病合并骨质疏松为因变量,多因素Logistic回归显示,调整年龄、eGFR、BMI、HbA1c后,SUA是老年2型糖尿病患者发生骨质疏松的保护因素(P=0.039,OR=0.452,95%CI:0.212~0.962)。结论在老年2型糖尿病患者中,正常偏高的血尿酸水平可能减少骨质疏松的发生风险。     

Calibration and standardization of bone mineral densitometers

Measurements of bone mineral density (BMD) by four 153Gd and two x-ray bone densitometers were compared utilizing spine phantoms that simulated the human lumbar spine. The six instruments provided BMD values that differed by as much as 16%, due to differences as large as 8% in bone mineral content and as large as 7% in bone area. Instrument calibration curves, determined by measuring thin, medium, and thick hydroxyapatite blocks, were linear (r = 0.99) but had different (p less than 0.0001) slopes and intercepts. Serial measurements of spine and total body phantoms were employed to evaluate the long-term stability of 153Gd bone densitometry. These measurements of spine phantom BMD increased 1.0-2.6% (p less than 0.0001) following a software change, and measurements of total body bone density increased 4-6% after 153Gd source replacement. The changes occurred at a time when serial measurements of cylindrical calibration standards were stable, indicating that such simple standards are unable to detect and correct for changes in instrumental response. We conclude that investigators, manufacturers, and government regulatory agencies must develop and implement the following: (1) effective calibration procedures that would assure comparability among instruments, and (2) appropriate quality control phantoms that would allow the confident interpretation of serial patient measurements.     

Omentin-1, visfatin and adiponectin levels in relation to bone mineral density in Iranian postmenopausal women

The bone and fat interface is implicated in the pathogenesis of postmenopausal osteoporosis. The association between circulating omentin-1 levels and bone mineral density (BMD) in postmenopausal women has never been assessed. A total of 382 healthy postmenopausal women were randomly selected. Omentin-1, visfatin, adiponectin, the receptor activator of nuclear factor-κB ligand (RANKL), osteoprotegerin, high sensitivity C-reactive protein, degradation products of C-terminal telopeptides of type I collagen, and osteocalcin were measured by highly specific enzyme-linked immunosorbent assay methods. BMD was determined for the lumbar spine (L2-L4) and the proximal femur using dual-energy X-ray absorptiometry. In multivariable-adjusted linear regression, serum omentin-1 levels were inversely correlated with BMD at the lumbar spine (β=-0.11, p=0.020). In multiple regression analyses, serum visfatin and adiponectin levels were not significantly correlated with BMD at different skeletal sites after controlling for age, body mass index, and bone-related markers. However, the highest quartile of adiponectin compared to the lowest quartile, after adjusting for potential confounders, revealed an inverse association with BMD in the lumbar spine (β=-0.19, p=0.010). In conclusion, circulating omentin-1 levels had an inverse correlation with BMD at the lumbar spine in Iranian postmenopausal women. To further understand the role of omentin-1 in bone and mineral metabolism, large-scale longitudinal studies focusing on BMD and osteoporotic fractures are warranted.     

Bone mineral density of proximal femur and spine in Korean children between 2 and 18 years of age

Ethnic factors affect bone mass acquisition during childhood. The aim of our study was to establish normative data for bone mineral content (BMC) and bone mineral density (BMD) in healthy Korean children and adolescents, using 446 lumbar spine scans (224 males and 222 females) and 364 proximal femur scans (181 males and 183 females) of healthy children between ages 2 and 18 years measured by dual-energy X-ray absorptiometry using Hologic QDR Discovery A 2004. There was an increase in both BMC and BMD during early childhood, acceleration during the adolescence spurt, and a slower increase later. Until 11 years of age, both male and female BMC and BMD were not statistically different. There was a rapid increase in both BMC and BMD in females earlier than in males, and later males caught up with the females and overshot the female values. When compared with Canadian children, BMD and BMC of total proximal femur was found to be more and BMD and BMC of total lumbar spine to be less at some ages. Tanner's stage was significantly associated with BMD and BMC of spine and proximal femur in males and BMC of spine in females in the first three Tanner's stages. Height, body weight, fat content, and body mass index influenced BMC and BMD at different sites by variable amount. Hence, the values presented in this study should be used as reference values in Korean children and adolescents.     

Sex differences in peak adult bone mineral density

Osteoporotic fractures are more common in women than men. Although accelerated bone loss following the menopause is recognized as of major importance, it is generally considered that a lower peak adult bone mass in females also contributes to their increased risk of osteoporosis in later life. To examine potential sex differences in peak adult bone mass we studied 29 pairs of dizygotic twins of differing within-pair sex in whom the female twin was premenopausal (mean age 37 years, range 21-55). Bone mineral density (BMD, g/cm2) was measured at the lumbar spine and femoral neck by dual-photon absorptiometry; 22 pairs also had BMD measured in the distal and 21 pairs in the ultradistal radius by single-photon absorptiometry. There was no significant difference in usual dietary calcium intake or tobacco consumption between the twin pairs. Consistent with accepted dogma, BMD at both radial sites were higher (+27%) in the males than their female cotwins. In contrast, there was no sex difference (male versus female) in BMD (mean +/- SEM) in the femoral neck (0.96 +/- 0.02 versus 0.97 +/- 0.03), and surprisingly, the females had a greater lumbar spine BMD than their male cotwins (1.19 +/- 0.03 versus 1.26 +/- 0.03, p less than 0.05). This difference was observed despite the fact that the males were taller (p = 0.033). If the femoral neck BMD values in the females were corrected for this difference in BMI, their values (0.99 +/- 0.03 g/cm2) were significantly higher than those in their male cotwin (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

骨小梁评分在2型糖尿病患者中评价骨质量的应用

目的探讨骨小梁评分(trabecular bone score,TBS)在评价2型糖尿病患者骨质量中的应用。方法回顾性分析128例2型糖尿病患者和64例非糖尿病患者的腰椎骨密度(bone mineral density,BMD)图像,通过骨小梁评分软件(TBS i Nsight software)计算得出骨小梁评分,分析两组患者的骨密度、骨小梁评分差异,并分析骨小梁评分和骨密度、年龄、体重的关系。结果和非糖尿病组相比,2型糖尿病患者组腰椎BMD升高(0.9103±0.1742 vs 0.8382±0.1422,P=0.005),TBS降低(1.2787±0.122 vs 1.3166±0.1016,P=0.033),在排除年龄、体重、骨密度的干扰后差异依然有统计学意义(P=0.008);相关性分析方面发现TBS和年龄呈负相关(r=-0.395,P0.001),和体质量指数呈负相关(r=-0.270,P0.001); TBS和腰椎BMD呈正相关,非糖尿病患者比糖尿病患者的相关性更强(r=0.563,P0.001 vs r=0.766,P0.001)。结论在2型糖尿病患者中骨小梁评分降低,这和2型糖尿病患者骨折风险增高的事实相符合,骨小梁评分可能成为评估2型糖尿病患者骨质量的指标。     

Correlation between hand and total body bone density in normal Chinese children

Hand bone mineral density (BMD) in adults was found to be significantly correlated with various skeletal sites, including the total body. However, the relationships between hand and total body bone measurements have yet to be explored for children. We conducted a cross-sectional study of 892 normal Chinese children (511 males, 381 females) aged 5-14 years by measuring the BMD and bone mineral content (BMC) at the total hand, upper limb, subtotal body, and total body using dual-energy X-ray absorptiometry (DXA). We found that hand BMD and BMC increased with age for both genders. Female children had significantly higher hand BMD and BMC than males. Age explained more variance in hand BMD for females (R2=0.727) than for males (R2=0.596). For both genders, hand BMD and BMC correlated highly with age, weight, height, total body lean mass, and BMD and BMC at the upper limb, subtotal body, and total body (r=0.730-0.965, p<0.001) and moderately with body mass index and total body fat mass (r=0.525-0.701, p<0.001). Therefore, the hand DXA scan can potentially be a new tool for the clinical assessment of bone health in children.     

Bone mineral density and serum levels of aminoterminal propeptides and cross-linked N-telopeptides of type I collagen in elderly men

Serum levels of aminoterminal extension propeptides (PINP), the carboxyterminal telopeptide (ICTP), and the cross-linked N-telopeptides (NTx) of type I collagen were determined in 78 healthy, elderly men aged 76 +/- 5 years in 1993 and 1996 and compared with bone mineral density (BMD) measurements of their lumbar spine, femoral neck, and total body regions made using dual X-ray absorptiometry. Compared with 11 men who had normal lumbar spine (SBMD) and femoral neck BMD (NBMD), 13 of the subjects with SBMD and NBMD classified as osteopenic by t-score criterion had higher mean serum levels of PINP and alkaline phosphatase activity, but these increases were not statistically significant at the 95% confidence interval. In osteopenic men, a correlation between SBMD and NTx was detected (r = -0.66, p = 0.01). Within the entire population, the serum NTx level correlated with NBMD (r = -0.26, p < 0.05) and PINP (r = +0.63, p < 0.0001), and the change in the circulating concentration of PINP over the 3 year interval correlated with the magnitude of change in total body BMD (r = -0.28, p = 0.02), NBMD (r = -0.24, p = 0.05), and SBMD (r = -0.36, p = 0. 03) as well as with the change in serum NTx levels (r = 0.43, p < 0. 001). The change in the circulating ICTP level was also related to the change in NBMD (r = -0.24, p = 0.01). Together, weight and the serum PINP level accounted for 25% of total body BMD variance in elderly men. These results indicate that larger populations of men and women should be screened over longer time intervals to explore the value of serial measurement of serum collagen metabolites in predicting bone loss in the spine and hip.     

Low lumbar spine bone mineral density in both male and female endurance runners

There have been many reports of low bone mineral density (BMD) in female endurance runners. Although there have been several reports of low BMD in male runners, it is unclear how comparable the problem is to that in females. We compared BMD between male and female endurance runners and with a reference population. One hundred and nine endurance runners (65 females, 44 males) aged 19-50 years participated and had been training regularly for at least 3 years (32-187.2 km week(-1)) in events from 3 km to the marathon. BMD was measured at the lumbar spine (L2-L4) and hip by DXA. A questionnaire assessed training and menstrual status. Lumbar spine T scores were similar in male and female runners (-0.8 (0.8) versus -0.8 (0.7); f = 0.015; P = 0.904) as were total hip T scores (0.6 (7.9) versus 0.5 (9.2); f = 0.192; P = 0.662). The proportion of male runners with low lumbar spine BMD (<-1.0) (n = 16 from 44) compared to that of females (n = 27 from 65) (P = 0.675). Males had lower spine T scores than eumenorrhoeic females (-0.8 (0.7) versus -0.4 (0.7); f = 5.169; P = 0.03). There were moderate negative correlations between weekly running distance and lumbar spine BMD in males and females (r(2) = 0.267; 0.189; P < 0.001), independent of menstrual status in females (r(2) = 0.192; P < 0.001). Lumbar spine but not hip T scores were greater in runners who participated in resistance training at least twice-a-week (male: -0.4 versus -1.1; female: -0.5 versus -1.1; P < 0.01). Using multiple regression, running distance (-) and BMI (+) together best predicted lumbar spine T scores (r(2) = 0.402; P < 0.01) in females. Although weak, BMI (+) best predicted hip T scores (r(2) = 0.167; P < 0.05). In males, running distance and training years (-) together best predicted lumbar spine T scores (r(2) = 0.400; P < 0.01). Training years (-) best predicted hip T scores (r(2) = 0.361; P < 0.01). To conclude, our findings suggest that male runners face the same bone threat at the spine, as female runners. Further research in male athletes is required. Incorporation of regular resistance training into an athlete's training programme may be a useful preventative strategy.     

Measurement of bone in the os calcis: a clinical evaluation

Bone mineral content (BMC) was measured in the os calcis of 232 normal subjects aged 17-82 years. The mean reproducibility (coefficient of variation) of the measurement was 1.8%. Substantial bone loss occurred between the ages of 20 and 50 years, and in females the menopause was associated with additional bone loss. There was no significant difference in the rate of bone loss in females and males, but the mean BMC was greater at all ages in males than in females. We also compared os calcis BMC with spinal bone mineral density (BMD), measured by quantitative computed tomographic (CT) scanning, in 85 subjects: 33 were normal controls, 19 had osteoporosis defined by the presence of one or more pathological fractures, and in the remainder the CT examination was performed at the patient's request. Os calcis BMC correlated with spinal BMD in both females (r = 0.69, p less than 0.001) and males (r = 0.84, p less than 0.001). However, the os calcis BMC did not reliably predict spine values around the CT "fracture threshold" of 90-100 mg/cm3 and did not correlate with osteoporotic fracture as well as did spinal BMD. It is concluded that measurement of the os calcis BMC is of limited clinical usefulness for the early diagnosis of osteoporosis.     

Discordance in DXA male reference ranges.

Previous studies have reported discordance in female lumbar spine and proximal femur dual-energy X-ray absorptiometry (DXA) reference ranges. Although the NHANES III reference range is recommended for the proximal femur in males and females, there are no published data in men on the concordance or otherwise of the different manufacturer-specific lumbar spine bone mineral density (BMD) reference ranges. Potentially, the use of different reference populations by different manufacturers could result in inconsistencies in the diagnosis of osteopenia or osteoporosis. We compared lumbar spine BMD, as well as T-scores and Z-scores, in 45 men scanned using Lunar DPXL and Norland Excel densitometers. The BMD measured by the two instruments was highly correlated (lumbar spine: r = 0.99, p < 0.0001). However, the two instruments assigned significantly different BMD T-scores. These differences relate primarily to the different standard deviations employed in the calculations. There were also significant differences when BMD was expressed with respect to age-matched values (Z-scores). This study shows that in men, as previously demonstrated in women, two commonly used DXA instruments provide comparable lumbar spine standardized BMD, but there are significant differences in derived T-scores because of differences in the manufacturer-specific reference ranges. Standardization of lumbar spine reference ranges in men should be a high priority.     

Interleukin-6 gene polymorphism is related to bone mineral density during and after puberty in healthy white males: a cross-sectional and longitudinal study.

Bone mineral density (BMD) is under strong genetic control and is the major determinant of fracture risk. The cytokine interleukin-6 (IL-6) is an important regulator of bone metabolism and is involved in mediating the effects of androgens and estrogens on bone. Recently, a G/C polymorphism in position -174 of the IL-6 gene promoter was found. We investigated this genetic polymorphism in relation to BMD during late puberty and to peak bone mass, in healthy white males. We identified the IL-6 genotypes (GG, GC, and CC) in 90 boys, age 16.9 +/- 0.3 years (mean +/- SD), using polymerase chain reaction (PCR). BMD (g/cm2) at the femoral neck, lumbar spine, and total body was measured using dual energy X-ray absorptiometry. The volumetric BMD (vBMD; mg/cm3) of the lumbar spine was estimated. Differences in BMD in relation to the genotypes were calculated using analysis of variance (ANOVA). Subjects with the CC genotype had 7.9% higher BMD of the femoral neck (p = 0.03), 7.0% higher BMD of the lumbar spine (p < 0.05), and 7.6% higher vBMD of the lumbar spine (p = 0.04), compared with their GG counterparts. Using multiple regression, the IL-6 genotypes were independently related to total body BMD (CC > GG; p = 0.03), humerus BMD (CC > GG; p < 0.05), neck BMD (CC > GG; p = 0.01), spine BMD (CC > GG; p = 0.01), and spine vBMD (CC > GG; p = 0.008). At age 19.3 +/- 0.7 years (mean +/- SD; 88 men) the IL-6 genotypes were still independent predictors for total body BMD (CC > GG; p = 0.03), humerus BMD (CC > GG; p = 0.03), spine BMD (CC > GG; p = 0.02), and spine vBMD (CC > GG; p = 0.003), while the IL-6 genotypes were not related to the increase in bone density seen after 2 years. We have shown that polymorphism of the IL-6 gene is an independent predictor of BMD during late puberty and of peak bone mass in healthy white men.