绝经后妇女骨质疏松性椎体骨折与腰椎骨密度的关系

目的探讨绝经后妇女骨质疏松性椎体骨折与腰椎骨密度的关系。方法选择骨质疏松性椎体骨折的绝经后妇女23例为骨折组,无椎体骨折的25例绝经后骨质疏松妇女为对照组。两组的年龄、绝经年限、身高、体重、体重指数差异无显著性,均行胸腰椎正侧位X线摄片。用双能X线吸收仪（DXA）测量的腰椎（L2-4）前后位骨密度（BMD）、骨矿含量（BMC）和T值。结果骨折组BMD、BMC和T值均低于对照组（P〈0.01）。结论腰椎BMD降低与绝经后妇女的骨质疏松性椎体骨折相关。绝经后骨质疏松妇女应重视BMD变化,预防椎体骨折的发生。     

Lower vitamin E serum levels are associated with osteoporosis in early postmenopausal women: a cross-sectional study

The aim of this study was to evaluate the relationship between vitamin E status and osteoporosis in early postmenopausal women. Anthropometric data, osteoporosis risk factors, vitamin E serum levels, bone mineral density (BMD) and other serum parameters which may influence bone mineral density in postmenopausal women were analyzed in a cross-sectional study. The association between osteoporosis and age, age of menopause, body mass index, osteocalcin, calcium, vitamin D, vitamin E (measured as 25 hydroxyvitamin D and as α-tocopherol:lipids ratio, respectively), bone alkaline phosphatase, smoking status, leisure physical activity and alcohol intake were modeled by a multivariate logistic regression and multi-linear regression analysis in 232 early postmenopausal women. A lower vitamin E:lipid ratio was associated with osteoporosis in multivariate logistic regression. In a multivariate linear model with BMD of the lumbar spine as a dependent variable, the vitamin E:lipid ratio was clearly related with BMD of the lumbar spine (F ratio = 6.30, p = 0.002). BMD of the lumbar spine was significantly higher in the highest tertile of the vitamin E:lipid ratio than in the lowest tertile. The mean vitamin E:lipid ratio was significantly lower in osteoporotic postmenopausal women (T score ≤?2.5) (3.0 ± 0.6 μmol/mmol) than normal (neither osteoporotic nor osteopenic) postmenopausal women (T score >?1) (3.5 ± 0.7 μmol/mmol) using multivariable-adjusted BMD. These findings highlight that vitamin E may increase BMD in healthy postmenopausal women.     

Determinants of Bone Mineral Density and Spinal Fracture Risk in Postmenopausal Japanese Women

The present study analyzed the factors that determine bone mineral density (BMD) and predict spinal fracture risk in postmenopausal Japanese women. Two hundred and five postmenopausal Japanese women aged 48–84 years (mean age 64 years) were enrolled in the cross-sectional study. BMD of the lumbar spine, femoral neck and total body as well as body composition were measured by dual-energy X-ray absorptiometry (DXA). Mid-radial BMD was measured by single-photon absorptiometry. We also determined serum levels of insulin-like growth factor (IGF)-I, IGF binding protein-2, -3 and osteocalcin as well as urinary levels of pyridinoline (Pyr), deoxy-Pyr (D-Pyr) and growth hormone. Multiple regression analysis revealed that lean body mass (LBM) was positively correlated with BMD at all sites. In contrast, femoral neck BMD was highly related to fat mass as well as LBM, although fat mass was not an independent correlate of total body and mid-radial BMD. LBM and urinary D-Pyr were crucial determinants at all sites except the mid-radius in stepwise regression analysis. Fat mass and serum IGF-I were determinants of femoral neck and mid-radial BMD, respectively. In terms of reproductive history, parity affected lumbar BMD. Factors affecting BMD differed according to the site. On the other hand, lumbar BMD as well as serum levels of IGF-I and albumin were selected as predictors of spinal fracture risk in multiple logistic regression analysis. Lumbar BMD, serum IGF-I and LBM were selected in women with lumbar BMD above 0.727 g/cm². In conclusion, the present study indicates that LBM is a more important determinant of BMD than fat mass at any site except the femoral neck. Age, serum IGF-I and urinary D-Pyr were also determinants of BMD, dependent on the regions measured. Lumbar BMD and LBM as well as serum levels of IGF-I and albumin were useful markers which predicted the risk of osteoporotic spinal fractures in postmenopausal Japanese women. Received: 6 June 2000 / Accepted: 11 January 2001     

绝经后女性的体成分与年龄和绝经的关系及其对不同部位骨密度的影响

目的 调查绝经后女性的体成分与年龄、绝经年龄、绝经年限和腰椎、髋部BMD之间的关系.方法 用双能X线骨密度仪测量919例绝经后女性的体成分、正位腰椎和髋部BMD.结果 下身脂肪量、全身脂肪量和全身瘦组织量与年龄、绝经年龄和绝经年限都相关(P＜0.05～0.01),但只有绝经年限进入体成分的多元逐步回归方程,采用复合或三次回归模型拟合优度最佳.体成分随绝经年限的延长有下降趋势.绝经10年以上女性的下身脂肪量和全身瘦组织量显著减少,分别较绝经年限5年以内女性下降8.6%和3.1%.所有部位的体成分与所测区域的BMD 均呈正相关(P＜0.05～0.01),控制体重变量后,仅有全身脂肪量与腰椎BMD 呈正相关(P＜0.05),而全身瘦组织量与髋部BMD 呈正相关(P＜0.05).多元逐步回归分析发现体成分是影响腰椎和髋部BMD的一个重要因素,但对腰椎BMD影响最大的是全身脂肪量,而对髋部BMD影响最大的是全身瘦组织量.BMD 越低者,全身脂肪量和全身瘦组织量也越低,组间比较有显著性差异.结论 绝经后女性的体成分与年龄、绝经年龄、绝经年限和腰椎、髋部BMD相关,其中,绝经年限对体成分的影响最大,体成分组分对BMD的影响存在部位差异.     

探讨体重指数对绝经后老年妇女不同部位骨密度的影响

目的分析不同体重指数患者的腰椎和股骨近端、股骨颈、Ward’s三角区的骨密度及T值评分,探讨体重指数对绝经老年妇女不同部位骨密度的影响。方法以我院225例年龄均为60以上的绝经老年妇女为研究对象,计算体重指数将患者分为体瘦组、正常组和肥胖组,检测患者腰椎和股骨近端、股骨颈、Ward’s三角区的骨密度,分析各部位骨密度变化与体重指数的关系。结果体瘦组的患者各部位骨密度明显低于正常和肥胖组的患者,体瘦组与正常组或肥胖组比较,腰椎(L1～L4)、股骨颈、股骨近端、Ward’s三角区的骨密度均有显著的差异(P<0.01);正常组与肥胖组比较,仅L3和L4的骨密度有显著的差异(P<0.05),其余部位的骨密度无显著的差异(P>0.05)。结论体重和体重指数是影响骨密度的一个重要因素,体重和体重指数与绝经老年妇女不同部位的骨密度存在一定的相关性,低体重指数的绝经老年妇女,骨丢失而引起的骨量减少明显,易发生骨质疏松。     

Long-Term Vegetarian Diet and Bone Mineral Density in Postmenopausal Taiwanese Women

This study examined bone density among postmenopausal Buddhist nuns and female religious followers of Buddhism in southern Taiwan and related the measurements to subject characteristics including age, body mass, physical activity, nutrient intake, and vegetarian practice. A total of 258 postmenopausal Taiwanese vegetarian women participated in the study. Lumbar spine and femoral neck bone mineral density (BMD) were measured using dual-photon absorptimetry. BMD measurements were analyzed first as quantitative outcomes in multiple regression analyses and next as indicators of osteopenia status in logistic regression analyses. Among the independent variables examined, age inversely and body mass index positively correlated with both the spine and femoral neck BMD measurements. They were also significant predictors of the osteopenia status. Energy intake from protein was a significant correlate of lumbar spine BMD only. Other nutrients, including calcium and energy intake from nonprotein sources, did not correlate significantly with the two bone density parameters. Long-term practitioners of vegan vegetarian were found to be at a higher risk of exceeding lumbar spine fracture threshold (adjusted odds ratio = 2.48, 95% confidence interval = 1.03–5.96) and of being classified as having osteopenia of the femoral neck (3.94, 1.21–12.82). Identification of effective nutrition supplements may be necessary to improve BMD levels and to reduce the risk of osteoporosis among long-term female vegetarians. Received: 10 May 1996 / Accepted: 9 August 1996     

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.     

Once-weekly teriparatide reduces serum sclerostin levels in postmenopausal women with osteoprosis

Once-weekly teriparatide treatment is widely used in the treatment of osteoporosis in Japan but the mechanisms causing the increase in bone mineral density (BMD) of the lumbar spine remain unknown. Methods: This prospective study examined the effects of once-weekly teriparatide treatment on the serum levels of sclerostin, osteocalcin, and bone formation markers as well as BMD of the lumbar spine and femoral neck in 32 postmenopausal women with osteoporosis. Results: The mean age of subjects was 76.3 ± 7.0 years old. Teriparatide significantly reduced serum sclerostin levels at 12 and 18 months in postmenopausal women with osteoporosis, and significantly increased serum osteocalcin levels at 3,12 and 18 months and PINP levels at 1 and 3 months, respectively. Teriparatide treatment significantly increased BMD of the lumbar spine at 6, 12, and 18 months, but did not affect BMD of the femoral neck. Examination of the relationships between percent changes in bone metabolic indices and BMD of the lumbar spine during the teriparatide treatment showed serum sclerostin changes at 3 months were negatively correlated with BMD changes of the lumbar spine at 6, 12, and 18 months. Serum osteocalcin changes were not correlated with BMD changes in the lumbar spine at 12 months. Conclusions: The present study showed that once-weekly teriparatide treatment reduced serum sclerostin levels in postmenopausal women with osteoporosis. The effects of teriparatide on sclerostin may be associated with the response of the BMD of the lumbar spine.     

Relative contribution of body composition to bone mineral density at different sites in men and women of South Korea

We examined the relative contribution of body composition to bone mineral density (BMD) at various sites in 1406 Korean rural men and women, aged 19–80 years, from July to August 2004. The BMD was measured at peripheral (distal forearm and calcaneus) and central (lumbar spine at L1–L4, femoral neck, trochanter, and Ward's triangle) using dual-energy X-ray absorptiometry. In multivariate analyses, the linear regression models were adjusted for relevant covariates. In premenopausal women, only lean mass had a significant positive correlation with BMD at all sites. In postmenopausal women, fat mass was significantly positively correlated with BMD at all sites, except the Ward's triangle; fat mass was the only determinant of BMD at the lumbar, distal forearm, and calcaneus sites, whereas both lean and fat mass contributed to BMD at the hip, with the effect of lean mass being slightly greater than that of fat mass. In younger men, lean mass had a significant positive contribution to BMD at all sites, whereas fat mass appeared to contribute negatively to BMD at all sites, except the calcaneus. In older men, lean mass made a significant positive contribution to the BMD at all sites; fat mass also made a significant positive contribution to the BMD at the forearm and calcaneus. These data indicate that in the Korean rural population, lean mass may be an important determinant of the BMD, whereas fat mass may contribute positively to BMD only in postmenopausal women and older men.     

Relation of axial bone mass to habitual calcium intake and to cortical bone loss in healthy early postmenopausal women

A group of 60 healthy early postmenopausal women participating in an ongoing study on the effect of habitual calcium intake on the rate of cortical bone loss at the radius, were subjected to additional skeletal measurements at the lumbar spine and femoral neck. The women were between 58 and 64 years of age, and 3 to 10 years postmenopausal. No correlations were found between habitual calcium intake (range 560 to 2580 mg/day) and either bone mineral content of the radius, the lumbar spine and the femoral neck, or spine deformity index. Body mass index was found to be positively correlated with bone mass indices of the radius (decrease of BMD and BMD) and femoral neck (BMC), but not with of the lumbar spine (BMC, BMD and SDI), even after adjustments had been made for confounding factors. Although the rate of cortical bone loss at the radius correlated significantly with bone mineral content of lumbar spine and femoral neck, the error in predicting bone mass of the lumbar spine or the femoral neck from longitudinal measurements of cortical bone at the radius was high. The rate of cortical bone loss did not correlate with the spine deformity index. We conclude that in healthy women in early menopause, the bone mineral content of both the appendicular and the axial skeleton are not influenced by habitual calcium intake. A higher body mass index has a protective effect on the appendicular skeleton but appears to be less protective to the axial skeleton. Longitudinal measurements of cortical bone mass are of limited value to predict bone density of the appendicular and axial skeleton.     

Effect of alendronate on bone mineral density and bone turnover markers in post-gastrectomy osteoporotic patients

Alendronate decreases the urinary levels of cross-linked N-terminal telopeptides of type I collagen (NTX; about 45% at 3 months) and serum levels of alkaline phosphatase (ALP; about 27% at 24 months), leading to an increase in lumbar spine bone mineral density (BMD; about 9% at 24 months) in postmenopausal Japanese women with osteoporosis. However, the effectiveness of oral bisphosphonates on osteoporosis remains to be established in patients who have undergone a gastrectomy. The objective of the present case series study was to examine the effect of alendronate on BMD and bone turnover markers in post-gastrectomy osteoporotic patients. Sixteen patients (3 men and 13 postmenopausal women) with osteoporosis, who had undergone a gastrectomy (mean age: 69.1 years), were recruited in our outpatient clinic. All the patients were treated with alendronate (5 mg daily or 35 mg weekly) for 24 months. The effects of alendronate on lumbar spine (women) or total hip (men) BMD and urinary NTX and serum ALP levels were examined. A total or partial gastrectomy had been performed for eight patients each. The mean duration after surgery was 16.0 years. With alendronate therapy, urinary NTX levels significantly decreased at 3 months (−27.0%). Serum ALP levels decreased (−12.1%) and lumbar spine BMD increased (+5.2%), but total hip BMD did not significantly change (+0.6%) at 24 months. No severe adverse events were observed, and alendronate therapy was well tolerated. These results suggest that alendronate mildly increases lumbar spine BMD by mildly reducing bone turnover in osteoporotic patients after a gastrectomy.     

Relationship of Body Fat and Its Distribution With Bone Mineral Density in Indian Population

Obesity has been associated with increased bone mineral density (BMD). There is evidence of differential effect of regional fat on BMD. Hence, we undertook this study to evaluate the correlation between total body fat and its distribution with BMD in nonobese (mean body mass index: 25.0 ± 4.7 kg/m²) Indian adult volunteers. A total of 2347 participants (men: 39.4% and women: 60.6%) included in this cross-sectional study were divided according to sex and age. Fasting blood samples were drawn for biochemical parameters. Percent total body, truncal, and leg fat and BMD at lumbar spine, femur, and forearm were measured by dual-energy X-ray absorptiometry. The BMD at all sites (radius, femur, and spine) increased from lowest to highest quartiles of percent body fat. Percent truncal fat was positively correlated with BMD at all sites in both sexes, except for femoral neck in men, where it had negative correlation. Percent leg fat was positively related with BMD at all sites in premenopausal women, and spine and radius BMD in postmenopausal women. However, in men, it had negative correlation with femoral neck BMD. On multiple regression analysis, regional fat had positive association with BMD at all sites after adjusting for age, sex, lean mass index, 25-hydroxyvitamin D, and intact parathyroid hormone levels. Leg-to-total body fat ratio was negatively associated with BMD at all sites in men and pre- and postmenopausal women. Percent total body and regional fat have positive association with BMD at all sites in men and women.     

Influence of Weight Gain on Spine Mineral Density in Postmenopausal Women

We studied the relationships between weight variables and spine bone mineral density (BMD) in 183 postmenopausal women aged 34–76 years. There was a significant positive correlation of current body mass index (cBMI) and % of ideal body weight (IBW) with BMD. Moreover, the increase in BMI and % IBW was also positively and significantly associated with a higher age-adjusted lumbar BMD. Weight gain, estimated as the difference between current body weight and past ``ideal' body weight, was associated with significant age-adjusted BMD with a threshold of 17%, and postmenopausal women with a gain of over 17% had significantly higher spine BMD. Received: 21 October 1997 / Accepted: 6 October 1998     

Association Between Lean Mass and Handgrip Strength With Bone Mineral Density in Physically Active Postmenopausal Women

The present study evaluated 117 physically active postmenopausal women (67.8 ± 7.0 yr) who performed neuromotor physical tests (strength, balance, and mobility). Body composition (lean mass [g], fat mass [g], and % fat) and bone mineral density (BMD) of lumbar spine (L1–L4), femoral neck, and total body were measured by dual-energy X-ray absorptiometry. Following the World Health Organization criteria, osteoporosis was found in at least 1 analyzed site in 33 volunteers (28.2%): 30 (25.6%) in lumbar spine and 9 (7.7%) in femoral neck. Body weight was strongly and positively related to BMD in all sites, but the most important component of body composition was lean mass, also significantly related to all BMD sites, whereas fat mass was weakly related to the femoral neck BMD. Percent fat did not correlate with any BMD site. Of all the physical tests, the handgrip strength was most importantly related to lumbar spine, femoral neck, and total body (r = 0.49, p < 0.001; r = 0.56, p < 0.001; and r = 0.52, p < 0.001, respectively). The static body balance presented a weak but significant positive correlation only with lumbar spine. Our results suggest that strategies aiming to improve muscle strength and lean mass must contribute to the bone health of physically active postmenopausal women.     

Efficacy of risedronate administration in osteoporotic postmenopausal women affected by inflammatory bowel disease

Patients with inflammatory bowel disease (IBD) have frequently a bone mineral density (BMD) significantly lower than age-matched healthy subjects. The low BMD observed in IBD patients is related also to a higher incidence of bone fractures. In this prospective randomized study we evaluated the effect of 1-year risedronate administration on bone mass and turnover, and on vertebral fractures in osteoporotic postmenopausal women with IBD in remission. Ninety osteoporotic postmenopausal women were randomized to receive oral risedronate 35 mg/week (risedronate group) or placebo tablets (placebo group; one tab/week). The duration of treatment was 12 months. At entry and after treatment, lumbar spine and hip BMD, and serum osteocalcin (OC) and urinary deoxypyridinoline/creatinine ratio (DPD-Cr) levels were evaluated. Vertebral fractures were assessed from thoracic and lumbar lateral and anterior-posterior spinal radiographs taken at baseline, and from lateral spinal radiographs taken at the end of the study. At study entry, no difference between groups was also detected in BMD and in bone turnover markers. At the end of the study, lumbar spine, trochanter and femoral neck BMD was significantly ( p <0.05) higher in comparison with baseline in the risedronate group, whereas a significant ( p <0.05) decrease was observed in the placebo group. For the same visit, a significant ( p <0.05) difference in lumbar spine, trochanter and femoral neck BMD was detected between groups. After 12-month follow-up, serum OC and urinary DPD-Cr levels were significantly ( p <0.05) lower and higher in comparison with basal values in risedronate and placebo group, respectively. At the same time, a significant ( p <0.05) difference in serum OC and urinary DPD-Cr levels was observed between groups. Throughout the study, the incidence of vertebral fractures was significantly ( p <0.05) lower in the risedronate group than in the placebo group (12.5% vs 34.1%). The relative risk (RR) to develop a new vertebral fracture after 1 year of risedronate administration was of 0.36 (95% confidence interval, 0.14–0.85). In conclusion, risedronate administration is an effective anti-osteoporotic treatment in osteoporotic postmenopausal women with IBD in remission.     

Determinants of bone density in 30- to 65-year-old women: a co-twin study.

Reported effects of body composition and lifestyle on bone mineral density in pre-elderly adult women have been inconsistent. In a co-twin study, we measured bone mineral density, lean and fat mass, and lifestyle factors. Analyzing within pair differences, we found negative associations between bone mineral density and tobacco use (2.3-3.3% per 10 pack-years) and positive associations with sporting activity and lean and fat mass. INTRODUCTION: Reported effects of body composition and lifestyle of bone mineral density in pre-elderly adult women have been inconsistent. METHODS: In a co-twin study of 146 female twin pairs aged 30 to 65 years, DXA was used to measure bone mineral density at the lumbar spine, total hip, and forearm, total body bone mineral content, and lean and fat mass. Height and weight were measured. Menopausal status, dietary calcium intake, physical activity, current tobacco use, and alcohol consumption were determined by questionnaire. Within-pair differences in bone measures were regressed through the origin against within-pair differences in putative determinants. RESULTS: Lean mass and fat mass were associated with greater bone mass at all sites. A discordance of 10 pack-years smoking was related to a 2.3-3.3% (SE, 0.8-1.0) decrease in bone density at all sites except the forearm, with the effects more evident in postmenopausal women. In all women, a 0.8% (SE, 0.3) difference in hip bone mineral density was associated with each hour per week difference in sporting activity, with effects more evident in premenopausal women. Daily dietary calcium intake was related to total body bone mineral content and forearm bone mineral density (1.4 +/- 0.7% increase for every 1000 mg). Lifetime alcohol consumption and walking were not consistently related to bone mass. CONCLUSION: Several lifestyle and dietary factors, in particular tobacco use, were related to bone mineral density. Effect sizes varied by site. Characterization of determinants of bone mineral density in midlife and thereafter may lead to interventions that could minimize postmenopausal bone loss and reduce osteoporotic fracture risk.     

Measurements of bone mineral density by DXA total body absorptiometry in different skeletal sites in postmenopausal osteoporosis.

In order to evaluate the bone mineral density (BMD) of the entire skeleton and its major anatomical areas, total body DXA absorptiometry was performed in 330 postmenopausal women whose ages ranged from 42-85 years. Sixty-three of them were normal women and constituted the control group (Group 1). Two hundred sixty-seven were patients affected with postmenopausal osteoporosis: 107 osteoporotic patients had vertebral biconcavity deformities of grade 1 (Group 2), and the other 160 had vertebral wedge, biconcavity, and compression deformities of grade 2 (Group 3). Total body absorptiometry was assessed by a DXA system (Lunar DPX). Significant reduction in total body BMD values was observed in patients in Groups 2 and 3 (p less than 0.01): the bone loss was more intense in osteoporotic women of Group 3. The low values of the BMD in osteoporotic patients are, moreover, localized in the areas of spine, arms, and legs; the osteopenia was particularly enhanced in patients with grade 2 vertebral deformities. Multiple linear regression indicated that values of total BMD were significantly related to age and BMI. Receiver operating characteristic (ROC) analysis showed that total BMD provided high sensitivity: At 90% of specificity it was 78% for Group 2 and 89% for Group 3. DXA total body absorptiometry has demonstrated that, in postmenopausal osteoporotic women, the reduction in bone mass is not localized only in the spine, but also involves the appendicular skeleton.     

Bone mass and density in preadolescent boys with and without Down syndrome

Summary

Preadolescent boys with Down syndrome at 7–10 years of age have lower bone mass and density in the pelvis than age-matched children without Down syndrome. However, bone mass and density of total body less head and lumbar spine are not different between these two groups.

Introduction

This study aimed to assess bone mineral content (BMC) and density (BMD) in preadolescent boys with and without Down syndrome (DS) at 7–10 years of age.

Methods

Eleven preadolescent boys with DS and eleven age-matched children without DS participated in this study. Dual-energy X-ray absorptiometry was used to measure BMC and BMD in whole body and lumbar spine. Both BMC and BMD of total body less head (TBLH) and lumbar spine (vertebrae L2–L4) were compared between the two groups, with and without adjusting for physical characteristics such as bone area, body height, and total lean mass. Two bone mineral apparent density (BMAD) variables were calculated to estimate volumetric BMD in the lumbar spine.

Results

Both BMC and BMD in the pelvis were lower in the DS group, after adjusting for physical characteristics. However, with and without adjusting for physical characteristics, the two groups were not different in BMC and BMD of the arms, legs, and TBLH from the whole body scan and in BMC, BMD, and BMAD of the lumbar spine from the lumbar spine scan.

Conclusions

These findings indicate that the pelvis may be the first site to show the significant difference in BMC and BMD between preadolescent boys with and without DS. It also suggests that significantly lower BMC and BMD in whole body and lumbar spine, which is usually observed in young adults with DS, may not occur before adolescence.     

Screening for osteopenia and osteoporosis: Selection by body composition

There is a great need for simple means of identifying persons at low risk of developing osteoporosis, in order to exclude them from screening with bone mineral measurements, since this procedure is too expensive and time-consuming for general use in the unselected population. We have determined the relationships between body measure (weight, height, body mass index, lean tissue mass, fat mass, waist-to-hip ratio) and bone mineral density (BMD) in 175 women of ages 28–74 years in a cross-sectional study in a county in central Sweden. Dual-energy X-ray absorptiometry was performed at three sites: total body, L2-4 region of lumbar spine, and neck region of the proximal femur. Using multiple linear regression models, the relationship between the dependent variable, BMD, and each of the body measures was determined, with adjustment for confounding factors. Weight alone, in a multivariate model, explained 28%, 21% and 15% of the variance in BMD of total body, at the lumbar spine and at the femoral neck according to these models. The WHO definition of osteopenia was used to dichotomize BMD, which made it possible, in multivariate logistic regression models, to estimate the risk of osteopenia with different body measures categorized into tertiles. Weight of over 71 kg was associated with a very low risk of being osteopenic compared with women weighing less than 64 kg, with odds ratios (OR) of 0.01 (95% confidence interval (CI) 0.00–0.09), 0.06 (CI 0.02–0.22) and 0.13 (CI 0.04–0.42) for osteopenia of total body, lumbar spine and femoral neck, respectively. Furthermore a sensitivity/specificity analysis revealed that, in this population, a woman weighing over 70 kg is not likely to have osteoporosis. Test specifics of a weight under 70 kg for osteoporosis (BMD less than 2.5 SD compared with normal young women) of femoral neck among the postmenopausal women showed a sensitivity of 0.94, a specificity of 0.36, positive predictive value (PPV) of 0.21, and negative predictive value (NPV) of 0.97. Thus, exclusion of the 33% of women with the highest weight meant only that 3% of osteoporotic cases were missed. The corresponding figures for lumbar spine were sensitivity 0.89, specificity 0.38, PPV 0.33, and NPV 0.91. All women who were defined as being osteoporotic of total body weighed under 62 kg. When the intention was to identify those with osteopenia of total body among the postmenopausal women we attained a sensitivity of 0.92 and a NPV of 0.91 for a weight under 70 kg, whereas we found that weight could not be used as an exclusion criterion for osteopenia of femoral neck and lumbar spine. Our data thus indicate that weight could be used to exclude women from a screening program for postmenopausal osteoporosis.     

Bone mass and body composition in normal women.

The interrelationships between measurements of bone mass and total-body bone mineral were examined in a cross-sectional study of normal healthy women aged 17-82 years. In addition we evaluated the relationship between measures of body composition, estimated by four independent techniques, and bone mass in the same population. Considering the group as a whole, bone mass at all sites correlated with each other and with total-body bone mineral (TBBM). Cancellous and cortical sites could predict TBBM equally well. As expected, all measurements of bone mass were significantly lower in postmenopausal women in comparison to premenopausal women. Declines in bone mass were only seen in premenopausal women in the femoral neck and Ward's triangle, not in lumbar spine, radius, or skeleton as a whole. In postmenopausal women bone mass correlated negatively with age and years from menopause equally at all sites. TBBM was significantly related to height and weight in both premenopausal and postmenopausal women. In premenopausal and postmenopausal women TBBM also correlated with fat mass, but TBBM was much better correlated with percentage body fat in premenopausal than postmenopausal women. TBBM was a constant proportion of lean body mass in premenopausal women, but the fraction of lean mass occupied by the skeleton declined with age in postmenopausal women. Correction of TBBM for lean mass did not change the relationship between TBBM and percentage fat in premenopausal women but eliminated the relationship in postmenopausal women. Regional measurements, which are at least partially corrected for body size by dividing mass by area, correlated less well with height and weight and with any index of obesity, especially in postmenopausal women.