女性不同骨骼部位骨密度峰值和参考图的建立方法

目的建立女性不同骨骼部位骨密度(BMD)参考图和确定峰值BMD(PBMD). 方法 用DXA QDR 4500A型扇形束骨密度仪测量3378例5～96岁女性腰椎前后位(AP)和仰卧侧位、髋部和前臂的BMD,用8种回归模型拟合BMD随年龄的变化,找出最佳拟合模型方程建立参考图和确定PBMD.结果三次回归模型拟合程度最佳,即方程的决定系数(R2)最大.我们应用拟合曲线建立了BMD参考图,拟合曲线方程计算各骨骼部位最高的BMD(A方法)和BMD最高的5岁年龄组(B方法)及年龄横断面(C方法)计算PBMD,发现在大多数骨骼部位,三种方法计算的PBMD的差异有显著性.结论此研究建立了女性不同骨骼部位BMD参考图.应用拟合曲线方程计算PBMD(A方法)可获得符合骨骼部位特异性的真正的PBMD,不同方法计算PBMD将对PBMD和诊断骨质疏松产生严重影响.     

不同国家和地区各种族人群骨密度参考值及其相互比较

目的了解各种族之间骨密度(BMD)参考值的差异。方法收集科学引文索引(SCI)收录杂志发表的20多个国家和地区不同种族人群的BMD参考值,并进行分类整理和比较分析。结果BMD拟合参考曲线显示,各种族女性和男性人群不同骨骼部位的峰值BMD(PBMD),绝大多数发生在20~30岁,日本女性股骨颈达到PBMD的年龄最早(15岁),中国香港男性腰椎达到PBMD的年龄最晚(40岁)。中国人群的PBMD和BMD参考曲线显著低于其他种族,黑人BMD显著高于所有种族。在腰椎、股骨颈和总体髋部,中国女性的PBMD比美国白人女性分别低6.7%、4.9%和6.1%;美国黑人女性股骨颈和总体髋部的PBMD比中国长沙女性分别高13.9%和13.7%,比美国白人女性分别高10.4%和8.8%;墨西哥女性股骨颈的PBMD与北欧女性人群一致。美国黑人男性股骨颈的PBMD与中国香港男性人群的差异最大,为20.9%。结论不同国家和地区各种族人群之间的BMD参考值绝大多数存在种族或地域差异。     

A Comparison Study of the Reference Curves of Bone Mineral Density at Different Skeletal Sites in Native Chinese,Japanese, and American Caucasian Women

To understand the differences among reference curves for bone mineral density (BMD) for Chinese, Japanese, and American Caucasian women, we measured the BMD at the anteroposterior (AP) lumbar spine (L1–L4), lateral lumbar spine (L2–L4), hip (including the femoral neck, trochanter, intertrochanter, Wards triangle, and total hip), and ultradistal forearm by the dual-energy X-ray absorptiometry (DXA) in a total of 2728 healthy Chinese women, aged 5–96 years. Documented BMD data for Japanese women and device manufacturers BMD new reference databases (including the NHANES III dataset) for American Caucasian women were also used in this study. The cubic regression model was found to fit best in analyzing the age-associated variations of BMD at various sites in Chinese women, i.e., the equations had the largest coefficient of determination (R ²). At the AP/Lat spine, trochanter, intertrochanter, and Wards triangle, BMD reference curves for Chinese women were lower than those for Japanese or Caucasian women, while at the femoral neck, total hip, and ultradistal forearm, the reference curves for Chinese women were higher than those for Japanese women, with overlaps and crossing of the curves for some age spans in comparing the Chinese and Caucasian women. There were significant differences in the peak BMD (PBMD) at various sites among the Chinese, Japanese, and Caucasian women (P = 0.000). The PBMDs for Chinese women at the lumbar spine and various sites of the hip were 5.7% ± 2.1% (mean ± SD, range, 2.7–7.9%) lower than those for Japanese women and 5.1% ± 2.7% (range, 0.5–7.2%) lower than those for Caucasian women; however, the PBMDs for Chinese women were 26.2% higher than those for Japanese women and 10% higher than those for Caucasian women at the ultradistal forearm. After the PBMD, average T-scores of Chinese women for losses at the AP lumbar spine with increasing age were nearly identical to those for Japanese women, but both were greater than those for Caucasian women. The average T-scores for BMD loss at various sites in Chinese women were higher than those for both Japanese and Caucasian women except at the femoral neck, where the T-scores of Chinese women were exceeded by those of both Japanese and Caucasian women. Estimated from the T-score curve of BMD loss, the age of osteoporosis occurrence at the femoral neck in Chinese women was about 10 years later than that in Japanese or Caucasian women; at the AP spine, Chinese women were similar to Japanese women; at the other sites, the age for occurrence of osteoporosis in Chinese women was about 5–15 years earlier than that in either Japanese or Caucasian women. There are differences in prevalence or odds ratio (OR) of osteoporosis at the same skeletal region for Chinese, Japanese, and Caucasian women aged 50 years or at different skeletal regions in women of the same race. The prevalences of osteoporosis at various regions of the hip in Chinese women are 10.1–19.8% and ORs are 22.0–32.3, of which prevalence at the femoral neck is the lowest (10.1%); the prevalences of osteoporosis in Japanese women are 11.6–16.8% and ORs are 21.1–26.3, of which prevalence at the femoral neck is the lowest (11.6%); and the prevalences of osteoporosis in Caucasian women are 13.0–20.0% and ORs are 19.4–48.9, of which prevalence at the femoral neck is the highest (20%). In conclusion, racial differences in BMD reference curves, prevalences, and risks of osteoporosis at various skeletal sites exist among native Chinese, Japanese, and American Caucasian women.     

Determination of age-specific bone mineral density and comparison of diagnosis and prevalence of primary osteoporosis in Chinese women based on both Chinese and World Health Organization criteria

The aim of this study was to determine age-specific bone mineral density (BMD) at various skeletal regions in a native Chinese reference population, and to explore the differences in the diagnosis of primary osteoporosis and estimated prevalence of osteoporosis based on both Chinese criteria (BMD of subjects, 25% lower than the peak BMD) and WHO criteria (BMD of subjects, 2.5 SD [T-score –2.5] lower than the young adult mean [YAM]). There were 3406 subjects in our female reference population, ranging in age from 10 to 90 years. A dual-energy X-ray absorptiometry (DXA) fan-beam bone densitometer (Hologic QDR 4500A) was used to measure the BMD in subjects at the posteroanterior (PA) spine (L1–L4), supine lateral spine (L2–L4 including areal BMD [aBMD] and volumetric BMD [vBMD]), hip (including femoral neck and total hip), and radius + ulna ultradistal (R + UUD) of the forearm. Cross-sectional data analysis in stratified 5-year age intervals revealed that the peak BMD (PBMD) at various skeletal regions occurred within the age range of 30–44 years, with PBMD at the lateral spine and femoral neck occurring at 30–34 years, posteroanterior spine and total hip at 35–39 years, and ultradistal forearm at 35–44 years. The reference values of BMD (PBMD) calculated using Chinese criteria for the diagnosis of primary osteoporosis were significantly higher than the young adult mean (YAM) using WHO criteria for all skeletal regions except for the total hip, at a range of 0.9%–3.8% higher. The BMD cutoff values using Chinese criteria for the diagnosis of osteoporosis were 3.7%–10.9% higher than those using WHO criteria for various skeletal regions. The prevalence rate of primary osteoporosis according to Chinese criteria in subjects ranging from 50 to 90 years was 41.5% at the PA spine, 53.9% at the lateral spine, 34.2% at the femoral neck, 30.7% for total hip, and 51.4% at R + UUD; while according to WHO criteria, this rate was 32.1% at the PA spine, 34.9% at the lateral spine, 16.3% at the femoral neck, 18.9% for total hip, and 45.2% at R + UUD. The prevalence of primary osteoporosis according to both criteria varied with the age and skeletal region of the subjects. The prevalence of primary osteoporosis using Chinese criteria, compared with WHO criteria was 31% higher at the lumbar spine, 109% higher at the femoral neck, and 14% higher at the ultradistal forearm. In conclusion, PBMD occurs in the age range of 30–44 years in native Chinese females. The BMD reference values, BMD cutoff values, and prevalence of primary osteoporosis determined by Chinese criteria are all higher than those determined by the WHO criteria; thus, the application of Chinese criteria may overestimate the number of patients with primary osteoporosis.     

Establishment of peak bone mineral density in Southern Chinese males and its comparisons with other males from different regions of China

Peak bone mineral density (PBMD) is an important determinant of osteoporotic fracture and a precondition for correct diagnosis of osteoporosis. The objective of this study was to establish the reference data of PBMD at the lumber spine and hip in Southern Chinese males. Bone mineral density (BMD) was measured at the lumbar spine and hip (femoral neck, trochanter, intertrochanter, and total) in 1155 Chinese men aged 15–39 years, using dual-energy X-ray absorptiometry (DXA). We utilized a fit curve method to determine the best age range over which to calculate PBMD. Our results indicated that the PBMD was observed at the age range of 18–25 years at the various sites. The mean value and standard deviation of PBMD was 0.753 ± 0.117, 1.156 ± 0.148, 0.896 ± 0.120, 0.989 ± 0.122, and 0.980 ± 0.116 g/cm² at the trochanter, intertrochanter, femoral neck, total hip, and spine, respectively. When the present PBMD reference was compared with the documented PBMD reference of males from other regions of China, we found great difference in standardized PBMD between Changsha males and those from other regions of China. The PBMD for Chinese males in Changsha at the various sites were 3.19%–11.33% lower than that for American Caucasian males. In conclusion, the PBMD at the spine and hip may be used as normal reference data for Southern Chinese males in Changsha instead of documented PBMD from other regions of China and the manufacturer's reference data.     

Effects of the sample size of reference population on determining BMD reference curve and peak BMD and diagnosing osteoporosis

Summary Establishing reference databases generally requires a large sample size to achieve reliable results. Our study revealed that the varying sample size from hundreds to thousands of individuals has no decisive effect on the bone mineral density (BMD) reference curve, peak BMD, and diagnosing osteoporosis. It provides a reference point for determining the sample size while establishing local BMD reference databases. Introduction This study attempts to determine a suitable sample size for establishing bone mineral density (BMD) reference databases in a local laboratory. Methods The total reference population consisted of 3,662 Chinese females aged 6–85 years. BMDs were measured with a dual-energy X-ray absorptiometry densitometer. The subjects were randomly divided into four different sample groups, that is, total number (Tn) = 3,662, 1/2n = 1,831, 1/4n = 916, and 1/8n = 458. We used the best regression model to determine BMD reference curve and peak BMD. Results There was no significant difference in the full curves between the four sample groups at each skeletal site, although some discrepancy at the end of the curves was observed at the spine. Peak BMDs were very similar in the four sample groups. According to the Chinese diagnostic criteria (BMD >25% below the peak BMD as osteoporosis), no difference was observed in the osteoporosis detection rate using the reference values determined by the four different sample groups. Conclusions Varying the sample size from hundreds to thousands has no decisive effect on establishing BMD reference curve and determining peak BMD. It should be practical for determining the reference population while establishing local BMD databases.     

Establishment of BMD reference curves at different skeletal sites in women, using a Cartesian coordinate numeration system

The BMD reference curve is the reference value used for diagnosing osteoporosis and assessing bone mass changes. Its accuracy would affect the correctness of T -score and Z -score values and thus the reliability of diagnostic results. In this paper, we report the use of a new method, a Cartesian coordinate numeration system, to establish BMD reference curves at different skeletal sites in women. In a reference population of 3,919 women ranging in age from 5–85 years, we used the dual X-ray absorptiometry (DXA) bone densitometer to measure BMD at the posteroanterior spine (PA; vertebrae L1–L4), followed by a paired PA/lateral spine scan of the vertebral bodies of L2–L4, expressed in g/cm² and g/cm³, and of the hip and forearm. We chose the cubic regression model to best fit BMD curves that varied with age at different skeletal sites. We then referred the BMD of the fitting curves established by the method of the coordinate numeration system as reference curves, compared them to BMD reference curves derived from the fitting curve equation or age cross-section, and calculated the deflection degrees of the BMD reference curves acquired from the fitting curve equation. At the PA spine, lateral spine (expressed in g/cm³), femoral neck, Wards triangle and radius + ulna ultradistal, the reference curves calculated from the equation were significantly lower than those confirmed by the method of the coordinate numeration system; whereas, at the lateral spine (expressed in g/cm²), total hip, and radius + ulna 1/3 sites, the reference curves derived from the equation were markedly higher than those acquired from the coordinate numeration system. The differences in the two kinds of reference curves calculated by these two different methods gradually increased along with the increment in ages of the women. At the peak value of the reference curves, the BMD calculated from the equation deflected from 2.02% to –10.0% from the BMD acquired from the coordinate numeration system at different skeletal sites, and from 21.5% to –121.8% until the age of 85 years. The highest positive deflection of 65.2% existed at the lateral spine (expressed in g/cm²) and the lowest positive deflection of 21.5% at the total hip. The maximum negative deflection of –121.8% was at the radius + ulna ultradistal, and the minimum negative deflection of –32.6% at the PA spine. The BMD curve acquired from age cross-section was highly positive compared with the one derived from the coordinate numeration system ( r =0.955–0.985 p =0.000) with no significant difference between them. Various analysts used such a method to obtain the coefficient of variance (CV) in BMD precision on each curve that was from 0.05–0.19%. Our study shows that the Cartesian coordinate numeration system is an accurate, precise and reliable method and can serve to reveal the serious drawbacks of using the fitting curve equation to calculate BMD. The BMD reference curves established by this coordinate numeration system maintained the authenticity of the fitting curve, whereas, using the fitting curve equation to obtain BMD reference curves at different skeletal sites led to distortion, and resulted in false increases or decreases in T -score and Z -score values.     

绝经后2型糖尿病患者不同部位骨密度的 变化情况及影响因素

目的探讨绝经后2型糖尿病女性不同部位骨密度的变化、影响因素及骨质疏松诊断率,为早期诊断、早期防治糖尿病并发骨质疏松提供理论依据。方法回顾性分析在我院内分泌科住院的绝经后2型糖尿病患者169例,采用双能X线骨密度测量仪检测腰椎1-4椎体、左侧股骨颈、Ward’s三角及全髋的骨密度,统计各年龄组不同部位的骨密度值及T≤-2.5SD所占百分比,采用多元逐步回归分析各部位骨密度影响因素。结果各部位骨密度随着年龄的增长而下降,股骨颈及Ward’s三角、全髋部位的骨密度下降幅度较大,腰椎部位骨密度下降相对平缓。随着年龄增长,腰椎和髋部骨质疏松检出率增加。其中在50～59岁年龄组中,骨质疏松检出率最高的部位是L1-L4正位,在60岁以上的年龄组中检出率最高的部位是Ward’s三角。多元回归分析结果显示L1、L2、L3、L4、股骨颈、Ward’s三角及全髋部位骨密度均与BMI呈正相关,除L3、L4外,所有部位骨密度与年龄呈负相关,L3、L4部位骨密度与绝经年限及空腹C肽有关。各部位骨密度与空腹血糖、HbA1C未见相关性。结论随年龄的增长,绝经后糖尿病患者骨质疏松症检出率随测量部位不同而不同。腰椎正位(L1-L4正位)和Ward’s三角分别是50～59岁及60岁以上女性诊断骨质疏松最敏感的部位。影响绝经后2型糖尿病患者骨密度的主要因素为年龄、BMI。低体重、高龄的糖尿病女性因定期检查骨密度预防骨质疏松骨折的发生。     

Relationship of body surface area with bone density and its risk of osteoporosis at various skeletal regions in women of mainland China

The aim of this study was to investigate the relationship between body surface area (BS) and bone mineral density (BMD) and the associated osteoporosis risk at various skeletal regions in women from mainland China. BMD was measured at the posteroanterior (PA) spine (L1–L4), supine lateral spine (L2–L4) including volumetric BMD (vBMD), hip including femoral neck, trochanter and total hip, and forearm, including radius+ulna ultradistal (R+UUD), 1/3 site (R+U1/3) and total region (R+UT) using a dual-energy X-ray absorptiometry (DXA) fan-beam bone densitometer (Hologic QDR 4500A) in 3418 females aged from 18 to 75 years. Data analysis revealed a positive correlation between BS and BMD at the various skeletal regions (r=0.114–0.373, all P=0.000), but no correlation with vBMD (r=0.000, P=0.934). Using the stepwise regression model, BMDs at various skeletal regions were dependent variables while height, weight, body mass index (BMI), BS and projective bone area (BA) were independent variables; BS was determined to be the most important variable that affected the PA spine, hip and forearm BMDs. Subjects were divided into three groups according to size: large BS group (LBSG), intermediate BS group (IBSG) and small BS group (SBSG). The BMD at different skeletal regions of subjects between groups exhibited a significant gradient difference, with LBSG>IBSG>SBSG, but this was not seen for vBMD. On the fitting curves where BMD varied with age at the PA spine, femoral neck, total hip and R+UUD, BMDs of LBSG were 6.93–9.29% higher than those of IBSG and 12.1–16.9 % higher than those of SBSG, whereas those of SBSG were 6.12–9.59% lower than those of IBSG at various skeletal regions, respectively. The prevalence rates and risks of osteoporosis of LBSG were significantly lower than those of SBSG and IBSG, whereas those of IBSG were obviously lower than those of SBSG at various skeletal regions, respectively, presenting a gradient difference among the three study groups, LBSG<IBSG<SBSG. Our study shows that the relationship between BS and BMD exceeds that between BMD and height or weight in women in mainland China. When areal BMD is employed, those with a larger BS have higher areal BMD and lower risks of osteoporosis while, conversely, those with a smaller BS have lower areal BMD, and therefore higher risk for osteoporosis. However, when vBMD is used, these differences diminish or even disappear.     

Large-scale genome-wide linkage analysis for loci linked to BMD at different skeletal sites in extreme selected sibships.

Few genome-wide linkage studies of osteoporosis have been conducted in the Asian population. We performed a genome-wide scan involving 3093 adult siblings with at least one sib-pair extremely concordant or discordant for hip BMD. Our results indicated four genome-wide significant QTLs for BMD. In comparison with 12 previous reported linkage studies, we reveal novel linkage regions that have reaching global significance. INTRODUCTION: The genetic basis for osteoporosis has been firmly established, but efforts to identify genes associated with this complex trait have been incomplete, especially in Asian populations. The purpose of this study was to identify quantitative trait loci (QTLs) for BMD in a Chinese population. MATERIALS AND METHODS: We performed a genome-wide scan involving 3093 siblings 25-64 years of age from 941 families, with at least one sib-pair extreme concordant or discordant for total hip BMD from a large community-based cohort (n = 23,327) in Anhui, China. Linkage analysis was performed on BMD residuals adjusted for age, height, weight, occupation, cigarette smoking, physical activity, and alcohol consumption using the revised Haseman-Elston regression-based linkage model. RESULTS: Our results revealed significant QTLs on chromosome 7p21.2 for femoral neck BMD (LOD = 3.68) and on chromosome 2q24.3 for total hip BMD (LOD = 3.65). Suggestive linkage regions were found to overlap among different skeletal sites on chromosomes 2q, 7p, and 16q. Sex-specific linkage analysis further revealed a significant QTL for lumbar spine BMD on chromosome 13q21.1 (LOD = 3.62) in women only. When performing multivariate linkage analysis by combining BMDs at four skeletal sites (i.e., whole body, total hip, femoral neck, and lumbar spine BMD), an additional significant QTL was found at chromosome 5q21.2 (LOD = 4.56). None of these significant QTLs found in our study overlapped with major QTLs reported by other studies. CONCLUSIONS: This study reveals four novel QTLs in a Chinese population and suggests that BMD at different skeletal sites may also share common genetic determinants.