牛奶与钙剂对老年人骨密度作用的8年临床观察

目的 观察牛奶与钙剂对老年人骨密度作用.方法 采用日本东芝公司制造的Xpress-GX螺旋CT(QCT),对本院老年职工进行第3腰椎骨密度(L3BMD)检测.选择L3BMD降低的82名(男性35,女性47)老年人,根据本人意愿(是否饮用牛奶和服用钙剂)分成观察组(n=43)和对照组(n=39),观察组(男性18,女性25),每人每日饮鲜牛奶250 ml～500 ml并日服含维生素D的钙剂(元素钙600～1200 mg、维生素D3 125～300 IU);对照组(男性17,女性22)未饮牛奶、未服钙剂,两组连续观察96个月为终点.在治疗前后分4个时间段(0、6、30、96个月)应用QCT检测参组老人L3BMD值,同时进行肝、肾功能、血清钙、尿钙及肝、胆、肾B超检查,并同步座谈访问,了解治疗后反应.结果 ①两组老人L3BMD均随增龄逐渐降低,其中,男女性观察组在长期钙奶干预下,自身配对比较L3BMD值,虽然逐次降低,但幅度很小;而男女性对照组的L3BMD逐年降低幅度明显增大,但无统计学意义(P>0.05).②两组间(观察组与对照组)分4个时间段成组比较L3BMD值,前3个时间段,对照组比观察组降低,但无明显差异(P>0.05),观察至第4个时间段(96个月)时,男女性对照组L3BMD比观察组明显降低,差异有显著性(P<0.05).结论 老年人长期饮用牛奶与含维生素D钙剂,能有效地延缓中轴骨BMD降低;长期钙奶干预对骨量增加能起到累积效应;对BMD降低而引起临床症状的老年人起到了重要辅助治疗作用;长时间应用钙剂未发现与之相关疾病发生.     

Linkage Screen for BMD Phenotypes in Male and Female COP and DA Rat Strains

Because particular inbred strains of experimental animals are informative for only a subset of the genes underlying variability in BMD, we undertook a genome screen to identify quantitative trait loci (QTLs) in 828 F₂ progeny (405 males and 423 females) derived from the Copenhagen 2331 (COP) and dark agouti (DA) strains of rats. This screen was performed to complement our study in female Fischer 344 (F344) and Lewis (LEW) rats and to further delineate the factors underlying the complex genetic architecture of BMD in the rat model. Microsatellite genotyping was performed using markers at an average density of 20 cM. BMD was measured by pQCT and DXA. These data were analyzed in the R/qtl software to detect QTLs acting in both sexes as well as those having sex‐specific effects. A QTL was detected in both sexes on chromosome 18 for midfemur volumetric BMD (vBMD; genome‐wide, p < 0.01). On distal chromosome 1, a QTL was found for femur and vertebral aBMD as well as distal femur vBMD, and this QTL appears distinct from the proximal chromosome 1 QTL impacting BMD in our F344/LEW cross. Additional aBMD and vBMD QTLs and several sex‐specific QTLs were also detected. These included a male‐specific QTL (p < 0.01) on chromosome 8 and a female‐specific QTL on chromosomes 7 and 14 (p < 0.01). Few of the QTLs identified showed overlap with the significant QTLs from the F344/LEW cross. These results confirm that the genetic influence on BMD in the rat model is quite complex and would seem to be influenced by a number of different genes, some of which have sex‐specific effects.     

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.     

The Ability of a Single BMD and Fracture History Assessment to Predict Fracture Over 25 Years in Postmenopausal Women: The Study of Osteoporotic Fractures

The ability of bone mineral density (BMD) and other risk factors to predict fracture risk is well‐established for as long as 5 to 10 years. However, their value to predict risk over a longer term has not been directly studied. We investigated whether a single assessment of femoral neck BMD and fracture history can predict fracture risk over 20 to 25 years. We used data from the Study of Osteoporotic Fractures (SOF) that assessed BMD and risk factors in 7959 women age ≥67 (mean = 73.4) in 1988–1990. Follow‐up for fractures continued for 25 years for hip fracture, and for 20 years for any nonvertebral fracture. Using age‐adjusted proportional hazards models, we analyzed the relationships between a single baseline assessment of femoral neck BMD, fracture history and age, and 20–25‐year fracture incidence. The 25‐year cumulative incidence of hip fracture was 17.9%; 20‐year incidence of any nonvertebral fracture was 46.2%. The 25‐year hip fracture incidence was highest in those ≥80 years old (22.6%) compared to 13.9% in women aged <70 years. A single femoral neck BMD measurement strongly predicted long‐term hip fracture risk to 25 years: 29.6% risk in the lowest BMD quartile versus 7.6% with the highest relative hazard (RH) = 4.9 (95% CI, 4.1 to 6.0). Femoral neck BMD predicted hip fracture with little degradation over time from RH/SD = 2.6 (2.2 to 3.0) for 0 to 5 years to RH/SD = 1.8 (1.4 to 2.4) for 20 to 25 years. Lifetime hip fracture risk was similar (～30%) regardless of age from 67 to >80 years. History of hip fracture predicted hip fractures only slightly better than history of nonvertebral fracture (RH = 1.6 [95% CI, 1.1 to 2.2] versus RH = 1.4 [95% CI, 1.2 to 1.5], respectively). Fracture history remained strongly predictive up to 25 years. We conclude that a single BMD and fracture history assessment can predict fracture risk over 20 to 25 years. Long‐term risk of hip fracture remains extremely high in the oldest age groups, supporting risk assessment and consideration of treatment even in the oldest, highest‐risk women.© 2017 American Society for Bone and Mineral Research.     

DXA骨密度仪在国内标一化回顾性研究

目的由于各种骨密度测量仪器的厂家类别和型号的不同,国内各地骨密度测量结果不尽相同。为了得到各仪器之间换算公式,对国内相关文献进行回顾性研究,真实反映中国人标准化骨密度状况。方法检索自1994年至2004年10月期间国内所有中文期刊中发表的全文文献,摘录并对137 929例次中国女性骨密度测量数据,按照测量部位分类,应用SPSS统计软件,得出各类骨密度仪之间的换算公式。结果以国内最多使用的LUNAR-DRX-L型骨密度仪为代表,推算出下面换算公式。腰椎正位: LUNAR-DPX-L=NORLAND-XR×1．102 0．00137,LUNAR-DPX-L=LUNAR-ExPERT×0．991 0．0005,LUNAR-DPX-L=LUNAR-DPX-IQ× 1．025 0．0003,LUNAR-DPX-L=HOLOGIC-QDR4500×1．184 0．0281,LUNAR-DPX-L=HOLOG- IC-QDR2000×1．156 0．00048。股骨颈:LUNAR-DPX-L=NORLAND-XR×1．0377 0．00026,LU- NAR-DPX-L=LUNAR-EXPERT×0．965 0．00083,LUNAR-DPX-L=LUNAR-DPX-IQ×0．986 0．00031,LUNAR-DPX-L=HOLOGIC-QDR4500×1．142 0．00033,LUNAR-DPX-L=HOLOG- IC-QDR2000×1．126 0．00042,股骨的TROCH区:LUNAR-DPX-L=NORLAND-xR×1．137 0．0021,LUNAR-DPX-L=LUNAR-EXPERT×0．985 0．0124,LUNAR-DPX-L LUNAR-DP×4Q× 0．972 0．00024,LUNAR-Z-DPX-L=HOLOGIC-ODR4500×1．031 0．0001,LUNAR-DPX-L=HO- LOGIC-QDR2000×1．205 0．00019。因此,总的各个仪器之间换算公式为:LUNAR-DPX-L=NOR- LAND-XR×1．092 0．0012,LUNAR-DPX-L=LUNAR-EXPERT×0．980 0．00706,LUNAR-DPX-L= LUNAR-DPX-IO×0．994 0．00028,LUNAR-DPX-L=HOLOGIC-QDR4500×1．119 0．0094,LU- NAR-DPX-L=HOLOGIC-QDR2000×1．162 0．00036。结论对中国人进行测量的骨密度结果是可以通过一定的系数互换的。回顾性研究能够基本真实反映各个仪器之间的换算公式,有一定的可信性。可以通过这样的研究方法尝试建立中国人的标准化骨密度(sBMD)。     

Genetic Hypercalciuric Stone‐Forming Rats Have a Primary Decrease in BMD and Strength

Kidney stone patients often have a decrease in BMD. It is unclear if reduced BMD is caused by a primary disorder of bone or dietary factors. To study the independent effects of hypercalciuria on bone, we used genetic hypercalciuric stone‐forming (GHS) rats. GHS and control (Ctl) rats were fed a low Ca (0.02% Ca, LCD) or a high Ca (1.2% Ca, HCD) diet for 6 wk in metabolic cages. All comparisons are to Ctl rats. Urine Ca was greater in the GHS rats on both diets. GHS fed HCD had reduced cortical (humerus) and trabecular (L₁–L₅ vertebrae) BMD, whereas GHS rats fed LCD had a reduction in BMD similar to Ctl. GHS rats fed HCD had a decrease in trabecular volume and thickness, whereas LCD led to a ～20‐fold increase in both osteoid surface and volume. GHS rats fed HCD had no change in vertebral strength (failure stress), ductibility (failure strain), stiffness (modulus), or toughness, whereas in the humerus, there was reduced ductibility and toughness and an increase in modulus, indicating that the defect in mechanical properties is mainly manifested in cortical, rather than trabecular, bone. GHS rat cortical bone is more mineralized than trabecular bone and LCD led to a decrease in the mineralization profile. Thus, the GHS rats, fed an ample Ca diet, have reduced BMD with reduced trabecular volume, mineralized volume, and thickness, and their bones are more brittle and fracture prone, indicating that GHS rats have an intrinsic disorder of bone that is not secondary to diet.     

中药复方护骨胶囊对糖皮质激素诱导骨质疏松 大鼠骨密度和骨形态计量学的研究

目的 探讨中药复方护骨胶囊(主要由制何首乌、淫羊藿、熟地黄等多味中药加工而成的复方制剂)对糖皮质激素诱导骨质疏松大鼠骨丢失的影响.方法 3月龄SPF级雄性SD大鼠30只,随机平均分为3组:正常对照组(Nrm)、激素组(Met)和中药组(CH).Met组:皮下注射甲强龙(Met)5mg/kg/d,每周5次;CH组:在Met组基础上给予中药复方护骨胶囊(150 mg/kg/d)灌胃,实验期12w.大鼠右侧股骨和腰椎行骨密度(BMD)测定,右侧胫骨行骨形态计量学分析.结果 Met组腰椎和股骨BMD显著低于Nrm组;CH组腰椎和股骨BMD显著高于Met组.Met组Tb.N、%Tb.Ar、MS/BS、MAR和BFRs显著低于Nrm组,Tb.Sp、ES/BS显著高于Nrm组;中药组Tb.N、%Tb.Ar、MS/BS、MAR和BFRs显著高于Met组,Tb.Sp,ES/BS显著低于Met组.结论 中药复方护骨胶囊在提高激素诱导骨质疏松大鼠的骨密度,促进骨形成,降低骨吸收,延缓骨丢失方面有积极作用,对继发性骨质疏松的预防和治疗有一定前景.     

中药复方护骨胶囊对糖皮质激素诱导骨质疏松大鼠骨密度和骨形态计量学的研究

目的 探讨中药复方护骨胶囊(主要由制何首乌、淫羊藿、熟地黄等多味中药加工而成的复方制剂)对糖皮质激素诱导骨质疏松大鼠骨丢失的影响。方法 3月龄SPF级雄性SD大鼠30只,随机平均分为3组：正常对照组(Nrm)、激素组(Met)和中药组(CH)。Met组：皮下注射甲强龙(Met)5 mg/kg/d,每周5次;CH组：在Met组基础上给予中药复方护骨胶囊(150mg/kg/d)灌胃,实验期12w。大鼠右侧股骨和L5行骨密度(BMD)测定,右侧胫骨行骨形态计量学分析。结果 Met组L5和股骨BMD显著低于Nrm组;CH组L5和股骨BMD显著高于Met组。Met组Tb.N、%Tb.Ar、MS/BS、MAR和BFRs显著低于Nrm组,Tb.Sp、ES/BS显著高于Nrm组;中药组Tb.N、%Tb.Ar、MS/BS、MAR和BFRs显著高于Met组,Tb.Sp,ES/BS显著低于Met组。结论 中药复方护骨胶囊在提高激素诱导骨质疏松大鼠的骨密度,促进骨形成,降低骨吸收,延缓骨丢失方面有积极作用,对继发性骨质疏松的预防和治疗有一定前景。     

Dietary Calcium and Serum 25‐Hydroxyvitamin D Status in Relation to BMD Among U.S. Adults

A higher calcium intake is still the primary recommendation for the prevention of osteoporosis, whereas vitamin D deficiency is often not addressed. To study the relative importance of dietary calcium intake and serum 25‐hydroxyvitamin D [25(OH)D] status in regard to hip BMD, 4958 community‐dwelling women and 5003 men ≥20 yr of age from the U.S. NHANES III population‐based survey were studied. Calcium supplement users and individuals with a prior radius or hip fracture were excluded. We calculated standardized means for BMD by quartiles of sex‐specific calcium intake for three 25(OH)D categories (<50, 50–74, and 75+ nM) among men and women, separately controlling for other important predictors of BMD. A higher calcium intake was significantly associated with higher BMD (p value for trend: p = 0.005) only for women with 25(OH)D status <50 nM, whereas calcium intake beyond the upper end of the lowest quartile (>566 mg/d) was not significantly associated with BMD at 25(OH)D concentrations >50 nM. Among men, there was no significant association between a higher calcium intake beyond the upper end of the lowest quartile (626 mg/d) and BMD within all 25(OH)D categories. Among both sexes, BMD increased stepwise and significantly with higher 25(OH)D concentrations (<50, 50–74, 75+ nM; p value for trend: women < 0.0001; men = 0.0001). Among men and women, 25(OH)D status seems to be the dominant predictor of BMD relative to calcium intake. Only women with 25(OH)D concentrations <50 nM seem to benefit from a higher calcium intake.     

骨折愈合过程中骨痂骨密度的定量分析

目的：应用双能X线骨密度测定仪（DEXA）观察骨折愈合过程中骨痂听骨密度变化，说明临床测定骨折愈合程度的方法。方法：对171例前臂骨折在正常愈合过程中骨折端区有其相邻两侧非骨折区骨矿物密度（BMD）变化，将结果进行自身对照研究。结果：在整个观察期内，骨折区BMD值呈显著上升趋势（P＜0．01）。结论：DEXA对骨折端听BMD跟踪可测定可客观准确地反映骨折端骨痂生长状况，从而使骨折愈合检测数量化。     

玉溪地区2593例男性骨密度调查分析

目的通过2593例玉溪地区男性骨密度测定,为了解玉溪地区男性骨密度(BMD)正常值及峰值骨量,分析骨质疏松症(Osteoporosis,OP)的发病规律,为OP的预防和治疗提供帮助。方法采用日本Aloka生产的DCS-600EX型骨密度仪,检测非优势侧前臂远端三分之一处BMD。将2593例检测结果以5岁为1个年龄段进行统计学分析BMD均值,计算出各年龄组的OP患病率。结果玉溪地区男性BMD峰值为0.588±0.081(g/cm2),其BMD峰值出现在30～岁年龄段。各年龄段OP的患病率为20～岁7.41%、25～岁11.70%、30～岁9.68%、35～岁7.49%、40～岁13.84%、45～岁10.93%、50～岁17.20%、55～岁23.59%、60～岁30.22%、65～岁44.32%、70～岁42.34%、75～岁48.94%、80～岁38.89%。结论玉溪地区男性BMD30岁前随年龄增加而增加,BMD峰值出现在30～岁,峰值为0.588±0.081(g/cm2),其后BMD测定值随年龄增加开始逐渐下降,OP的患病率随年龄增加而增加,但80～岁年龄组反而有所下降。     

前臂骨折愈合过程中骨痂骨密度的变化

目的：应用双有Ｘ线骨密度测定仪（ＤＥＸＡ）观察前臂骨折愈合过程中骨痂的骨密度变化,为临床提供一种测定骨折愈人事程度的方法。方法：对１７１例前臂骨折在正常愈合过程中骨折端区及其相邻两侧非骨折区骨矿物密度（ＢＭＤ）变化,将结果进行自身对照研究。结果：在观察期内,骨折区ＢＭＤ值呈显著上升趋势。非骨折区的ＢＭＤ则明显降低。结论：ＢＥＸＡ对骨折谪蝗ＢＭＤ跟踪测定可客观准确地反映骨折端骨痂生长状况,从而使骨折     

复方贞术调脂胶囊对糖皮质激素诱导骨质疏松大鼠股骨和腰椎骨密度及生物力学特性的研究

目的观察复方贞术调脂胶囊(FTZ)对糖皮质激素诱导骨质疏松大鼠股骨和腰椎骨密度及生物力学特性的影响。方法SPF级雄性SD大鼠32只,随机等分为4组:Nrm组为正常对照组,Met组为皮下注射甲强龙(Met)5 mg/(kg·d),每周5次,FTZL组和FTZH组在Met组基础上每日分别给予低剂量FTZ(1.5g/kg)和高剂量FTZ(6g/kg)灌胃,实验期为12w。QDR4500A型双能X线骨密度测定仪测定股骨和腰椎骨密度,MTS-858型生物力学实验机测定股骨和腰椎生物力学性能。结果Met组大鼠股骨和腰椎的骨密度、最大载荷、刚度、弹性模量、皮质骨厚度、股骨中段截面面积和椎体横断面面积均显著低于Nrm组相应指标(P0.001,P0.01),股骨骨髓腔面积显著高于Nrm组(P0.01);FTZL组大鼠的股骨骨密度,最大载荷、刚度、弹性模量、皮质骨厚度、股骨中段截面面积和椎体横断面面积较Met组有升高趋势,股骨骨髓腔面积较Met组减少,但两组间各指标均无显著性差异(P0.05);FTZH组大鼠股骨和腰椎的骨密度、最大载荷、刚度、弹性模量、皮质骨厚度和椎体横断面面积显著高于Met组相应指标(P0.01,P0.05),股骨骨髓腔面积显著低于Met组(P0.05),股骨中段截面面积较Met组有增加趋势,但无显著性差异(P0.05),FTZH组腰椎的骨密度和最大荷载显著高于FTZL组(P0.05),余各项指标间无显著性差异(P0.05)。结论高剂量FTZ对改善糖皮质激素诱导骨质疏松大鼠股骨和腰椎的骨密度及生物力学特性效果显著。     

The relationship of sodium intake to calcium and sodium excretion and bone mineral density of the hip in postmenopausal African-American and Caucasian women

During the past several decades in the United States, there has been a shift in dietary habits, with an increased consumption of processed foods that are high in sodium. It is known that calcium and sodium metabolism are linked and that higher sodium intakes may increase calcium excretion. Epidemiological studies in patients with idiopathic hypercalciuria suggest that hypercalciuria is linked to low bone mass. However, the relationship of sodium intake to bone mineral density (BMD) is controversial in Caucasians and has not been explored in African-Americans. To determine the consequences of sodium intake on bone in African-American and Caucasian postmenopausal women, sodium and calcium excretion and BMD of the total hip were measured in 50 Caucasian and 39 African-American postmenopausal women. After adjustment for race and urine volume, sodium excretion was a significant predictor of calcium excretion (P 0.01). This relationship was modulated by calcium intake (P 0.01), but not by race (P = 0.63). There was no significant effect of sodium excretion (P = 0.42) or calcium excretion (P = 0.90) on BMD of the total hip after adjusting for race and urine volume. Sodium excretion is a significant predictor of calcium excretion in both postmenopausal African-American and Caucasian women. The relationship between sodium and calcium excretion is modulated by calcium intake, and the relationship is strongest at low calcium intakes (1000mg/day). However, sodium excretion in the range of 53.75–283.33mmole/g/total volume (mmole/g/TV) is not a significant predictor of total hip BMD in elderly African-American and Caucasian postmenopausal women.     

Identification of a Linkage Disequilibrium Block in Chromosome 1q Associated With BMD in Premenopausal White Women

Osteoporosis is a complex disease with both genetic and environmental risk factors. A major determinant of osteoporotic fractures is peak BMD obtained during young adulthood. We previously reported linkage of chromosome 1q (LOD = 4.3) with variation in spinal areal BMD in healthy premenopausal white women. In this study, we used a two‐stage genotyping approach to identify genes in the linked region that contributed to the variation of femoral neck and lumbar spine areal BMD. In the first stage, 654 SNPs across the linked region were genotyped in a sample of 1309 premenopausal white women. The most significant evidence of association for lumbar spine (p = 1.3 × 10^?6) was found with rs1127091 in the GATAD2B gene. In the second stage, 52 SNPs around this candidate gene were genotyped in an expanded sample of 1692 white women. Significant evidence of association with spinal BMD (p < 10^?5), and to a lesser extent with femoral neck BMD, was observed with eight SNPs within a single 230‐kb linkage disequilibrium (LD) block. The most significant SNP (p = 3.4 × 10^?7) accounted for >2.5% of the variation in spinal BMD in these women. The 230‐kb LD block contains 11 genes, but because of the extensive LD, the specific gene(s) contributing to the variation in BMD could not be determined. In conclusion, the significant association between spinal BMD and SNPs in the 230‐kb LD block in chromosome 1q indicates that genetic factor(s) in this block plays an important role in peak spinal BMD in healthy premenopausal white women.     

Genetic Analyses in a Sample of Individuals With High or Low BMD Shows Association With Multiple Wnt Pathway Genes

Using a moderate‐sized cohort selected with extreme BMD (n = 344; absolute value BMD, 1.5–4.0), significant association of several members of the Wnt signaling pathway with bone densitometry measures was shown. This confirms that extreme truncate selection is a powerful design for quantitative trait association studies of bone phenotypes. Introduction : Although the high heritability of BMD variation has long been established, few genes have been conclusively shown to affect the variation of BMD in the general population. Extreme truncate selection has been proposed as a more powerful alternative to unselected cohort designs in quantitative trait association studies. We sought to test these theoretical predictions in studies of the bone densitometry measures BMD, BMC, and femoral neck area, by investigating their association with members of the Wnt pathway, some of which have previously been shown to be associated with BMD in much larger cohorts, in a moderate‐sized extreme truncate selected cohort (absolute value BMD Z‐scores = 1.5–4.0; n = 344). Materials and Methods : Ninety‐six tag‐single nucleotide polymorphism (SNPs) lying in 13 Wnt signaling pathway genes were selected to tag common genetic variation (minor allele frequency [MAF] > 5% with an r² > 0.8) within 5 kb of all exons of 13 Wnt signaling pathway genes. The genes studied included LRP1, LRP5, LRP6, Wnt3a, Wnt7b, Wnt10b, SFRP1, SFRP2, DKK1, DKK2, FZD7, WISP3, and SOST. Three hundred forty‐four cases with either high or low BMD were genotyped by Illumina Goldengate microarray SNP genotyping methods. Association was tested either by Cochrane‐Armitage test for dichotomous variables or by linear regression for quantitative traits. Results : Strong association was shown with LRP5, polymorphisms of which have previously been shown to influence total hip BMD (minimum p = 0.0006). In addition, polymorphisms of the Wnt antagonist, SFRP1, were significantly associated with BMD and BMC (minimum p = 0.00042). Previously reported associations of LRP1, LRP6, and SOST with BMD were confirmed. Two other Wnt pathway genes, Wnt3a and DKK2, also showed nominal association with BMD. Conclusions : This study shows that polymorphisms of multiple members of the Wnt pathway are associated with BMD variation. Furthermore, this study shows in a practical trial that study designs involving extreme truncate selection and moderate sample sizes can robustly identify genes of relevant effect sizes involved in BMD variation in the general population. This has implications for the design of future genome‐wide studies of quantitative bone phenotypes relevant to osteoporosis.     

Longitudinal Changes in BMD and Bone Geometry in a Population‐Based Study

We prospectively examined vBMD and structural bone parameters assessed by QCT among participants of the InCHIANTI study over a 6‐yr follow‐up. Periosteal apposition occurred both in men and women. Endocortical resorption causes bone loss in older women despite periosteal apposition. Introduction: To address the hypothesis that age‐related changes in BMD and bone geometry may be different in men and women, we prospectively examined volumetric BMD (vBMD) and structural bone parameters assessed by QCT among participants of the InCHIANTI study over a 6‐yr follow‐up. Materials and Methods: Three hundred forty‐five men and 464 women 21–102 yr of age from the InCHIANTI study, a population‐based study in Tuscany, Italy, were included. Tibial QCT bone parameters were measured at enrollment (1998–2000) and at 3‐ (2001–2003) and 6‐yr (2004–2006) follow‐ups. Results: Periosteal apposition occurred both in men and women. The annual rate of bone periosteal apposition was higher in younger than in older men, whereas in women, the rate of apposition was homogenous across age groups. The age‐related medullary expansion, expression of endocortical resorption, was significantly higher in women compared with men. In women, but not in men, accelerated endocortical resorption not sufficiently balanced by periosteal apposition caused accelerated loss in cortical bone mass. The cross‐sectional moment of inertia decreased progressively over the life span in both sexes. Conclusions: Endocortical resorption causes bone loss in older women despite periosteal apposition. Obtaining a balance between endocortical resorption and periosteal apposition should be the target for interventions aimed to decrease bone loss and prevent osteoporosis in older women.     

Correlates of Trabecular and Cortical Volumetric BMD in Men of African Ancestry

QCT provides a measure of volumetric BMD (vBMD) and distinguishes trabecular from cortical bone. Few studies have determined the factors related to vBMD in men, especially among men of African heritage. This study evaluated the relationship of anthropometric, medical, and behavioral factors and vBMD in a population‐based cohort of men of African ancestry (n = 1901) ≥40 yr of age who had undergone screening for prostate cancer for the first time. Trabecular and cortical vBMD were measured at the radius and tibia by pQCT. Multiple linear regression analysis identified age, height, body weight, cigarette smoking, history of diabetes, fracture, and prostate cancer as the independent correlates of vBMD. However, associations with several variables differed between cortical and trabecular vBMD and between the radius and tibia. Longitudinal studies are needed to gain a better understanding of the mechanisms underlying these differential associations that may show new insight into the etiology of trabecular and cortical bone loss in men.     

体育锻炼时长对苏南老年男性骨密度和平衡能力的影响

目的为了探讨每次锻炼时间长短对老年男性骨密度和平衡能力的关系。方法选取苏南地区200名60岁以上老年男性中每周锻炼3~4次的87名为研究对象,采用单光子吸收法(SPA)和平衡仪系统对其骨密度(BMD)和平衡能力(Fall Index)进行检测,结果采用SPSS17.0分析处理。结果 (1)对于老年男性来说,每周3~4次体育锻炼,每次锻炼时间控制在45 min~1.5 h,无论对延缓机体BMD的下降还是提高自身的平衡能力方面,都是最优的;(2)有跌倒史(骨折史)的老年男性平衡能力比无跌倒史的差,同时前者BMD也明显低于后者。结论有跌倒史老年男性更加容易跌倒并且更容易有骨折风险,在体育锻炼中要十分注意。切忌只关注曾经跌倒受伤、骨折部位而忽视其它身体部位的风险,定期检查。