Evaluation of bone mineral density in premature ovarian failure

This study was performed to evaluate whether or not early menopause and premature ovarian failure can cause an increased risk of osteoporosis. The bone mineral density (BMD) of the 2nd and 4th lumbar spine as well as femoral neck in 29 cases with secondary amenorrhea were compared with a reference data using a dual-energy X-ray absorptiometry on a bone densitometer: Serum levels of luteinizing hormone, follicular stimulating hormone, calcium and phosphorus were also measured. Both in 20-29 years and in 30-39 years, BMD were significantly lower than their normal range as compared with a reference data from a large study of the same population (P value<0.05). At lumbar vertebrae, 2 cases had osteopenia and 17 had osteoporosis while at the femoral neck, 17 cases had osteopenia and 4 osteoporosis. Only serum levels of phosphorus had positive relationship with femoral neck BMD (P value<0.05). It may be possible to decrease fracture incidence through the early diagnosis of individuals at risk by BMD. In conclusion, our study indicates that females with early onset of menopause and premature ovarian failure had lower value of BMD in both femoral neck and lumbar vertebrae implying the need for more bone health measures.     

Peak BMD assessment in a Chinese infantry recruit group

Peak bone mass is an important factor influencing the occurrence of osteoporosis and osteoporotic fracture in adulthood. We measured the areal bone mineral density (BMD) in a Chinese male infantry recruit group ranging in age from 17 to 23 years and subsequently assessed peak BMD at the lumbar vertebrae and hip. This study included 812 Chinese men of Han ethnicity from 11 provinces and municipalities of China. The BMD, bone mineral content and the bone area of the lumbar vertebrae (L1-4), left femoral neck and total hip were measured using dual-energy X-ray absorptiometry. Height, weight, waist and hip circumference were also measured at the same time. BMD at the lumbar vertebrae, femoral neck and total hip reached a plateau at 22 years of age. The peak value of BMD at these 3 sites was 1.209±0.175, 1.098±0.177 and 1.122±0.151 (g/cm2), respectively. Stepwise regression analysis showed that age and weight most contributed to the variance in BMD (P<0.001). The average age when reaching peak BMD in this study is earlier than the ages reported in previous studies, and the value of peak BMD is higher than that reported previously in Chinese males. This study provides the newest peak BMD data on Chinese men.     

Dual-photon Gd-153 absorptiometry of bone

Dual-photon absorptiometry with gadolinium 153 was used to measure the mineral content of lumbar vertebrae in cadavers, excised vertebrae with marrow, and dry, marrow-free vertebrae. The error introduced by the surrounding soft tissue of cadavers was 3%, and the error in determining mineral mass or density in excised vertebrae was about 5%. The correlation coefficient between the results of Gd-153 and corrected iodine 125 (single-photon) absorptiometry on 24 femoral necks was 0.99, and the predictive error was 3.7%. Dual-photon absorptiometry accurately indicates bone mass and bone density and is only slightly affected by either surrounding tissue or fat changes in bone marrow.     

Comparison of dual energy X-ray absorptiometry of the proximal femur with morphologic data.

Measurements of bone mineral density (BMD) of the proximal femur (including femoral neck, Ward's triangle and trochanteric region) were compared with the Singh index grading in 40 normal subjects (20 male, 20 female) and in 116 patients (18 male, 98 female) referred for assessment of possible osteoporosis. Additionally, the BMD and the Singh index of 12 cadaver specimens (6 male, 6 female) of the proximal femur were compared with each other and with the histomorphology of the femoral necks of the specimens. Although there was a good correlation of Singh index with BMD in the group of male patients with suspected osteoporosis and in the series of bone specimens, there was a poor correlation in the group of female patients as well as in the normal controls and in the patient population as a whole. There was also poor correlation of Singh index values with histomorphologic data, whereas the BMD measurements correlated well with the amount of calcified bone found histologically in the femoral necks of the bone specimens. We conclude that the Singh index cannot be used to predict BMD of the proximal femur accurately.     

Alcohol and Active People

BACKGROUND: Although postmenopausal women are encouraged to exercise to preserve bone mineral density (BMD), few studies have looked at what type of exercise is most effective.

OBJECTIVE: To review current data on the effects of exercise training on BMD in postmenopausal women when measured by dual-energy x-ray absorptiometry (DEXA).

METHODS: Thirteen studies met defined inclusion criteria and were analyzed. Length of exercise intervention was annualized, and only one effect at each region of interest (lumbar vertebrae, femoral neck, or distal forearm) per intervention group was recorded.

RESULTS: Overall, exercise training had a positive effect on BMD of the lumbar vertebrae and femoral neck. Aerobic exercise alone and in combination with strength training positively affected lumbar vertebrae BMD. Aerobic exercise also preserved BMD at the femoral neck.

CONCLUSION: These findings provide support for regular aerobic activity in postmenopausal women to offset age-related declines in BMD.     

济南地区正常成年女性腰椎骨密度检测分析

目的了解济南地区正常成年女性L1~L4各椎体骨密度正常值及变化规律。方法采用双能X线骨密度仪(DEXA)检测399例正常成人女性L1~L4各椎体和平均骨密度值(BMD),按5岁一个年龄组对数据进行整理和统计分析。结果女性各腰椎和平均BMD的峰值出现在35~39岁年龄组,后随年龄增加而逐渐变小,在65~74岁年龄组略有反弹;同年龄组L1~L4各个椎体骨密度值有逐渐加大的趋势,且各椎体均值和变化规律有较大差别。结论获取了济南地区正常成年女性各年龄组腰椎体BMD正常数据及变化特点。     

Bone mineral density in professional female dancers.

OBJECTIVES: To measure the long term effects of dance training and the contribution of the timing and duration of any menstrual disruption on bone mineral density (BMD). DESIGN: Measurement of BMD in 57 premenopausal, previously professionally dance trained women and the relationship to menstrual and training history. MAIN OUTCOME MEASURES: Bone density measurements at lumbar spine and femoral neck by dual energy x-ray absorptiometry. RESULTS: The average Z score for BMD at the lumbar spine in the amenorrhoeic dancers was significantly below that for the normal population. The average Z score for BMD at the femoral neck in the eumenorrhoeic dancers was significantly above that for the normal population. There was a significant difference between the average Z score for BMD at both the lumbar spine and femoral neck between the amenorrhoeic and eumenorrhoeic dancers. Significant negative relationships were found between BMD at the lumbar spine and (1) age at menarche, (2) duration of amenorrhoea, (3) BMD at the femoral neck, and (4) the variable of ideal minus lowest weight, which was independent of amenorrhoea. No significant relationships were found between duration of oral contraceptive pill usage and BMD at either the lumbar spine or the femoral neck in eumenorrhoeic or amenorrhoeic dancers. In order to quantify the effect of a combination of these significant factors, a model of BMD was constructed using multiple regression incorporating the variables duration of amenorrhoea, age at menarche, and ideal minus lowest body weight. In this model R2 was 33.6%, in other words 33.6% of the total variation in the Z score for BMD at the lumbar spine could be accounted for by these factors. CONCLUSION: Professional female dancers with a history of delayed menarche and amenorrhoea have been identified as another group of premenopausal women potentially at risk of developing osteoporosis because of a decrease in BMD at the lumbar spine. The femoral neck in dancers with a history of amenorrhoea was partially protected from loss of BMD by virtue of being the major weight bearing site in previous dance training, and in eumenorrhoeic dancers BMD was significantly increased at this site.     

老年男性腰椎的QCT骨密度测量

目的:探讨老年男性腰椎定量CT(QCT)骨密度(BMD)测量的价值及其应用中的注意事项。方法:对516例老年男性进行腰椎体松质骨的QCT骨密度测量。检查时通过L_(1～5)椎体中心和腰椎体模中心行轴位扫描。然后对各椎体及体模图像进行测量。所得数据由腰椎骨密度分析软件分析处理,得出个体腰椎的平均骨密度值及T-Score值、Z-Score值,再将其结果与正常人群的骨密度峰值进行比较,经分析得出诊断结论。诊断标准参照WHO的标准及国内推荐的标准执行。结果:516例中骨密度正常者24例,占4.7%;骨密度降低者109例,占21.1%;骨质疏松症者318例,占61.6%;严重骨质疏松症者65例,占12.6%。结论:腰椎体松质骨的QCT骨密度测量可较早地反映出老年男性体内骨矿含量的变化,对早期发现和确诊老年男性的骨质疏松症具有十分重要的价值。在QCT检查中,需高度重视测量质量的控制。     

The relationship between bone mineral density and immobilization duration in hemiplegic limbs

OBJECTIVE: Prolonged immobilization in stroke is known to result in hypercalciuria, hypercalcemia, accelerated bone resorption, and osteoporosis. Furthermore, bone mineral loss accelerated with increasing duration of hemiplegia. Although stroke is a common disease that causes sudden immobilization, relatively few investigations of bone metabolism in stroke have been reported. The aim of this study was to investigate the changes in bone mineral density of the forearms and legs related to duration of hemiplegia-induced immobilization after stroke. METHODS: Forty-one hemiplegic patients with stroke were evaluated. The patients' age, gender and duration of hemiplegia-induced immobilization were recorded. The measurements of bone mineral density (BMD) in all patients were evaluated with DEXA using the Norland apparatus. The BMD values (g/cm2) were determined by measurements made in the lumbar vertebrae, both forearm and legs (femoral neck and trochanter). RESULTS: We found that bone mineral density was decreased in the affected extremities relative to the intact contralateral side on measurements by dual energy x-ray absorptiometry in bones such as forearm, femoral neck and trochanter. There was a significant difference between bone mineral density of paretic and nonparetic forearms and legs. Bone mineral density of the upper limbs was lower than that of the lower limbs. There was a negative correlation between duration of hemiplegia and BMD values. CONCLUSIONS: Bone mineral loss may be related to the duration of hemiplegia-induced immobilization. Bone mineral loss is accelerated when the duration of hemiplegia is prolonged.     

健康绝经妇女髋关节和腰背肌力与骨密度的关系

目的:探讨健康绝经妇女肌肉力量与骨密度之间的关系。方法:选取52名健康绝经妇女进行肌肉力量和骨密度测试。运用双能X线(DXA)骨密度仪测量全身、腰椎(L1-4)和股骨骨密度,采用等速肌力测试系统测量髋关节和腰背屈、伸肌群向心收缩和等长收缩肌力。结果:(1)绝经妇女髋关节90o等长伸肌力和等速屈肌群(90o/s)肌力分别为175.73±51.31 Nm、44.31±11.16 Nm,腰背屈、伸肌群30o/s等速肌力分别为65.36±18.96 Nm、127.35±35.99 Nm;(2)全身骨密度、L1-4和股骨颈的骨密度分别为1.07±0.08/g/cm2、1.07±0.15 g/cm2、0.90±0.18 g/cm2;(3)髋关节90o等长伸肌力和等速屈肌群(90o/s)肌力与股骨颈骨密度、Wards三角骨密度、股骨的骨密度之间均无显著相关关系,但分别与全身骨密度有相关关系(r=0.359,P<0.01;r=0.361,P<0.01);髋关节90o等长伸肌力与L1-4骨密度相关(r=0.356,P<0.01);(4)腰背屈、伸肌群30o/s和60o/s等速肌力均与L1-4骨密度显著相关(r=0.396,P<0.01;r=0.390,P<0.01;r=0.341,P<0.05;r=0.295,P<0.05)。结论:绝经妇女髋关节肌力与全身骨密度显著相关,腰背屈、伸肌群肌力值与L1-4显著相关。     

The influence of magnetic resonance imaging findings of degenerative disease on dual-energy X-ray absorptiometry measurements in middle-aged men

Purpose: To examine degenerative features based on magnetic resonance imaging (MRI) measurements at the lumbar spine in relation to dual-energy X-ray absorptiometry (DXA), and to investigate whether bone mineral density (BMD) is reflected in the substitution of bone trabecular structure by fat at the vertebral body level indicated by MRI T1 relaxation time, endplate concavity, and hypertrophic (osteophytes and endplate sclerosis) MRI findings.

Material and Methods: The sample for this cross-sectional study was composed of 102 subjects, 35-70 years old, from a population-based cohort. Data collection included DXA in the anterior-posterior projection at the L1-L4 vertebrae and right femoral neck, and MRI of the lumbar spine in the midsagittal plane.

Results: Age, vertebral signal intensity, osteophytes, and endplate concavity collectively explained 20% of the variance in spine BMD.

Conclusion: The study findings suggest that degenerative findings based on MRI measurements at the lumbar spine have an influence on bone assessment using DXA. Therefore, an overall bone assessment such as DXA might not offer an accurate measure of BMD.     

腰椎侧位骨密度测定的应用价值研究

目的 :观察应用双能X线测定腰椎椎体骨密度时正位和侧位结果的差别 ,探讨腰椎侧位测定骨密度辅助诊断骨质疏松症的价值。方法 :以 16 6名平均年龄为 6 4 .7岁的老年女性骨质疏松症患者为对象 ,测试其腰椎骨密度值 ,观察不同年龄受试者腰椎正、侧位骨密度的差别 ,以及由此测试结果得到的诊断骨质疏松结论的差别。结果 :全部受试者的椎体正位骨密度检测均高于侧位(P <0 0 1) ,但在 113名年龄小于 6 5岁的受试者中 ,以此诊断骨质疏松症的结果并无显著性差异(P >0 0 5 ) ;5 3名年龄大于 6 5岁的受试者中 ,根据正、侧位骨密度的变化得到的骨质疏松症诊断出现较大偏差 (P <0 0 5 )。根据正位骨密度测定诊断骨质疏松症约有三分之一漏诊率。结论 :对绝经期骨质疏松患者可以用传统的正位腰椎骨密度测定的方法来诊断 ,不需另作侧位测定 ,对老年性骨质疏松症患者 ,则应加作腰椎侧位骨密度测定 ,以减少漏诊     

选择性雌激素受体调节剂雷诺昔酚对去势后大鼠骨密度及股骨生物力学的影响

目的：观察选择性雌激素受体调节剂（SERM）雷诺昔酚（raloxifene）对去势后大鼠骨密度及股骨生物力学的影响。方法：将5月龄未经产雌性二级SD大鼠24只，随机分为3组，每组8只：A组为假手术（SHAM）组；B组为去势（VOX）组；C组为去势＋雷诺昔酚（V0x＋RAL）组。C组大鼠术后第7d开始给药。术后16w处死各组大鼠，对各组大鼠骨密度（BMD）、骨生物力学指标进行检测，并进行骨组织形态学观察。结果：（1）去势组与对照组比较，去势组股骨近端、股骨干、腰椎BMD明显降低（P．〈0．01）；雷诺昔酚治疗组各部位BMD高于去势组（P〈0．05），但没有恢复到SHAM组水平（P〈0．05）；（2）与Sham组比较，去势组大鼠骨的股骨最大载荷、桡度、最大应力、弹性模量均明显下降（P〈0．05），雷诺昔酚治疗组上述指标高于去势组（P〈0．05），接近对照组水平。结论：去势后16w大鼠松质骨、皮质骨骨量、骨组织形态计量学及生物力学指标均明显下降。雷诺昔酚治疗后大鼠松质骨，皮质骨密度得到较好维持，雷诺昔酚对骨组织形态计量学及生物力学状况有显著改善作用，可减少和抑制骨质疏松性骨折的发生。     

跑台运动训练和停训对去卵巢大鼠腰椎骨密度和骨髓脂肪细胞数目的影响

目的:观察中等强度跑台运动训练和停训对去卵巢大鼠腰椎骨密度、骨组织形态学和骨髓脂肪细胞数目的影响。方法:将60只成年雌性SD大鼠按体重分层后随机分为假手术组、去卵巢静止组和去卵巢运动组,每组20只。去卵巢运动组每周进行4次时间45 min、速度18 m/min、跑道倾角5°的跑台训练。持续训练14周后,将各组大鼠再次按体重分层后随机分为两个亚组,即假手术16周(Sham-16)组和假手术32周(Sham-32)组、去卵巢16周(OVX-16)组和去卵巢32周(OVX-32)组以及去卵巢运动(EX)组和停训组(DEX)。Sham-16、OVX-16和EX三组大鼠在末次训练结束36-48小时内,Sham-32、OVX-32和DEX三组大鼠在停训16周时,用双能Χ线骨密度仪活体检测大鼠腰椎骨密度,常规HE染色对第2腰椎(L2)进行组织形态学观察。结果:(1)训练结束时,OVX-16组L2脂肪细胞数目显著高于Sham-16组和EX组,腰椎骨密度显著低于Sham-16组和EX组。(2)停训16周时,OVX-32组腰椎骨密度与Sham-32组比较显著下降,L2脂肪细胞数目显著增加,而DEX组与OVX-32组比较无显著性差异。结论:中等强度跑台运动对去卵巢大鼠腰椎骨密度下降的减缓效应和对骨髓脂肪细胞数目增加的抑制效应在停训16周后未能保持。     

Physical activity and bone mineral acquisition in peripubertal girls

The association of the amount and type of physical activity with bone mineral acquisition was studied in 191 peripubertal Caucasian girls aged 9-16 years (66 gymnasts, 65 runners, and 60 nonathletic controls). Weight, height, stage of puberty, the amount of leisure-time physical activity, and years of training were recorded, and dietary calcium and vitamin D were assessed by a semi-quantitative questionnaire. The bone area, the bone mineral density (BMD), and the bone mineral content (BMC) of the femoral neck, lumbar spine and antebrachium were measured by dual-energy x-ray absorptiometry. The unadjusted mean values of BMD at the femoral neck were 15.2% higher in the pubertal gymnasts than in the controls (P<0.001). Compared with the controls, the mean BMC adjusted for bone area of the pubertal gymnasts at the femoral neck and lumbar spine was 16.4% and 10.8% higher, respectively. When comparing the association of the type of physical activity among the pubertal athletics by multiple regression analysis, height, physical activity, gymnastics, and Tanner stage emerged as significant variables and accounted for 54.7% and 63.4% of the total variation in BMD of the femoral neck and lumbar spine, respectively. These results indicate that physical activity is associated with bone mineral acquisition in peripubertal girls and that high-impact weight-bearing exercise seems to be particularly associated with the increase of the BMD at the femoral neck.     

类风湿关节炎患者的骨质疏松及其相关影响因素

目的探讨类风湿关节炎(RA)患者骨质疏松的发生情况及其相关影响因素。方法采用双能X线骨密度仪,测定53例(男8例,女45例)RA患者和63例(男18例,女45例)正常人的前臂、L2~4以及股骨颈、Ward区和大转子的骨密度,并同时测定RA患者各临床及实验室指标。结果除股骨颈外,RA患者各测定部位的骨密度均明显低于对照组(P<0.05~0.005);18例患者(34.0%)有至少一个检测部位骨质疏松,21例患者(39.6%)表现为至少一个检测部位骨量低下,总体骨量丢失较对照组明显(P<0.05)。53例RA患者中发生骨质疏松组较非骨质疏松组年龄更大(P<0.0001),关节功能更差(P<0.001),HAQ积分更高(P<0.01),握力更低(P<0.05)。28例服用糖皮质激素的RA患者中有46.4%(13/28)发生骨质疏松,高于未服用糖皮质激素组的20.0%(5/25)(χ2=4.113,P=0.043),服用激素组仅L3的骨密度低于未服用激素组(t=2.163,P=0.035)。19例绝经的女性RA患者中有57.9%(11/19)发生骨质疏松,明显高于未绝经女性RA组的15.4%(4/26)(χ2=8.927,P=0.003),除前臂外,绝经的女性RA患者各测定部位骨密度均明显低于未绝经女性RA患者(P<0.05~0.005)。结论RA患者骨质疏松发生率较正常人更高,多部位的骨密度均显著降低。其骨质疏松的发生是多因素的,与年龄、关节炎的严重程度、绝经及服用糖皮质激素等有关。     

Diagnosis of osteoporosis by planar bone densitometry: can body size be disregarded?

Bone densitometry using dual energy X-ray absorptiometry (DXA) is frequently used to diagnose osteoporosis and to identify patients at risk of later fractures. The parameters of interest are bone mineral content (BMC) and bone mineral areal density (BMD). Bone densitometry results have a large overlap between normals and patient with fractures. This would suggest that other factors are important for the development of fractures or that bone densitometry is not used optimally. It is generally believed that the conversion of BMC to BMD by division of the former by the projected bone area is a good normalization procedure. Other normalization procedures have been attempted in the past with little success. We hypothesized that this might be due to a blurring effect of time since menopause, and that body size could be demonstrated to have an effect on measured BMC and BMD, if this time effect could be eliminated. The results of this study, comprising 1625 early post-menopausal women studied at virtually the same time since menopause, confirm that this is the case. Body surface area was the parameter among conventional body size variables showing the highest correlation with BMC and BMD. It was clearly shown that low values of BMD were seen more often in the lowest than in the highest body surface area quartile. The difference between quartiles was statistically significant. Simple division of BMC by actual body surface area or division of BMD by the square root of body surface removed the uneven distribution between the body surface area quartiles for lumbar spine and femoral neck measurements, and reduced it at peripheral measuring sites. It is suggested that BMC and BMD of the lumbar spine and the femoral neck should be normalized as described to avoid overdiagnosis of osteoporosis in persons of petite body stature and underdiagnosis in tall ones.     

绝经后女性类风湿关节炎患者骨密度的临床研究

目的探讨绝经后女性类风湿关节炎(RA)患者骨密度(BMD)的变化及其骨质疏松(OP)的发生情况。方法采用双能X线骨密度仪,测量45例女性RA患者(绝经前26例和绝经后19例)和45例正常女性(绝经前24例和绝经后21例)的前臂、腰椎2~4以及股骨颈、Ward区和大转子的BMD,并同时测定RA患者各临床及实验室指标。结果19例绝经后女性RA患者中,11例患者(57.9%)有至少1个检测部位为OP,7例患者(36.8%)表现为至少1个检测部位骨量低下,总体骨量丢失较绝经前RA患者明显(P<0.0001),与正常绝经后女性无差别(P>0.05)。除桡骨远端外,绝经后RA患者各测定部位BMD均低于绝经前患者(P<0.05);绝经后女性RA患者股骨Ward区和2~4BMD低于正常绝经后女性(P<0.05),其余各测定部位的BMD与正常绝经后女性间差别无统计学意义(P>0.05)。Logistic Regression分析显示绝经:OR=14.144[(2.303-86.877),P=0.004]为女性RA患者骨质疏松发生的相关因素。结论绝经后女性RA患者的BMD明显降低,骨量丢失较绝经前RA患者明显。绝经和关节炎的严重程度为女性RA患者OP发生的危险因素。     

Dual-energy X-ray absorptiometry of the vertebrae: determining which vertebrae should be scanned]

This study was aimed at verifying whether bone mineral density (BMD) and its loss with aging are different in the lumbar vertebrae and whether the region of interest--which is usually limited to the L2-L4 segment--may be extended to L1-L4. BMD was measured by means of dual-energy X-ray absorptiometry (Hologic QDR 1000) in 74 women, aged 37 to 78 years, not affected with any disease or subjected to any treatment known to interfere with bone metabolism. The relationship between age and BMD was expressed by the following equations for L1, L2, L3: BMD-L1 = 1181.68-7.85 x age, BDM-L2 = 1251.57-7.70 x age, BMD-L3 = 1231.66-6.57 x age, as shown by linear regression analysis. The behavior of the bone density of L4 with age appeared to be different and could not be described by linear regression curves and was therefore not comparable with that of the other vertebrae. BMD was different in the four lumbar vertebrae as shown by: a) the diversity of the intercept of the regression lines describing age-bone density relationships (F = 7.7, p < 0.001); b) the bone density of L1 being lower than the mean bone density of the L2-L4 region (p < 0.005); c) the bone density of L4 being higher than the mean bone density of the L1-L3 region (p < 0.001). In order to evaluate the effect of senile degenerative changes of the vertebrae on the relevant bone density, two groups of women were considered, according to age--i.e., pre- or iuxtamenopausal and late postmenopausal. It appeared that the BMD of L1 was always more correlated to the bone density of L2 and L3 than the BMD of L4. Our results suggest that L1 is homogeneous to the L2-L3 region, relative to both bone density and its loss with aging. Therefore, L1 should be included in the region of interest during the examination. Even though the bone mineral content of L4 and its loss with aging seem to be different, our results do not allow the exclusion of L4 from the scanned area.     

Effects of menopause on bone mineral density in women with endemic fluorosis

PURPOSE: The effects of menopause on bone mineral density (BMD) in women with endemic fluorosis were investigated. MATERIALS AND METHODS: Eighty healthy Turkish women who lived in and around the city of Isparta were selected randomly and enrolled in this study. They were separated into four groups: group 1, 20 premenopausal women with regular menstrual cycles and endemic fluorosis; group 2, 20 postmenopausal women with endemic fluorosis; group 3, 20 premenopausal normal women constituting one control group; and group 4, 20 postmenopausal normal women constituting the other control group. Bone mineral density was measured in the lumbar spine and proximal femur using dual-energy x-ray absorptiometry. RESULTS: In the premenopausal group, BMD values of vertebrae L2-L4 and Ward's triangle in women with endemic fluorosis were significantly greater than the respective values in women without endemic fluorosis (P = 0.024, P = 0.036). There were no differences between the groups in BMD values of the femoral neck (P = 0.156) and intertrochanteric area (P = 0.076). The BMD values of vertebrae L2-L4, the femoral neck, intertrochanteric area, and Ward's triangle in the postmenopausal women with endemic fluorosis were significantly greater than those of postmenopausal women without endemic fluorosis (P < 0.001, P = 0.015, P = 0.002, and P < 0.001, respectively). The BMD values of vertebrae L2-L4, the femoral neck, intertrochanteric area, and Ward's triangle in the premenopausal women with endemic fluorosis were significantly greater than those of postmenopausal women with endemic fluorosis (P = 0.010, P = 0.002, P = 0.004, and P = 0.010, respectively). The BMD values of the sites noted for the premenopausal controls were significantly greater than those of postmenopausal controls (P < 0.001, P < 0.001, P < 0.001, and P < 0.001, respectively). CONCLUSIONS: Postmenopausal BMD values in both endemic fluorosis and controls were significantly less than premenopausal BMD values. Although the differences were less prominent in women with endemic fluorosis, menopause is still the major determinant of BMD in the spine and femur.