Relationship between bone mineral density of the proximal femur and lumbar spine and quadriceps and hamstrings torque in healthy Japanese subjects

The purpose of this study was to examine the corelations between the muscle torque of the leg extensors (quadriceps femoris) and leg flexors (Hamstrings) and the bone mineral density (BMD) of the proximal femur and lumbar spine. To investigate the decline in BMD of proximal femur and lumbar spine, we examined the relative importance of muscle torque, age, and body weight in the prediction of BMD in 340 healthy volunteers (109 males, and 231 females). Age and body weight were independent predictors of femoral BMD in men. Body weight and quadriceps torque were independent predictors of femoral BMD in premenopausal women. Body weight and years after menopause were independent predictors of BMD in postmenopausal women. The BMD was greatly affected by menopause, whereas the muscle torque was independent of the menopause, and showed the negative relationship to age. These results suggest that muscle-building exercise may have the potentiality to elevate the BMD in the proximal femur in premenopausal women.     

Epidemiological study on the bone mineral density of inhabitants in Miyama Village, Wakayama prefecture (Part II) bone mineral density of the spine and proximal femur

Reference values of bone mineral density (BMD) have mainly been based on hospital volunteers in Japan. Consequently, these values may be inappropriate for the use as a standard in the osteoporotic study. In order to establish reference values, BMD was measured of 400 age-stratified inhabitants of Miyama Village, utilizing dual energy x-ray absorptiometry (DEXA). The mean BMD of L2–L4 in males in each age group was 1.19±0.16 g/cm² (mean±standard deviation) in 40's, 1.15±0.19 g/cm² in 50's, 1.03±0.18 g/cm² in 60's and 1.06±0.25 g/cm² in 70's. The difference of BMD was statistically significant between the 50 and 60 age groups. On the other hand, in females the mean BMD of L2–L4 was 1.18±0.16 g/cm² in 40's; 0.99±0.18 g/cm² in 50's, 0.84±0.19 g/cm² in 60's and 0.78±0.17 g/cm² in 70's. The BMD was significantly lower in the 50 age group than in the 40 age group and was similarly lower in the 60 age group than in the 50 age group.     

Influence of body weight on rates of change in bone density of the spine,hip, and radius in postmenopausal women

Summary Interrelationships between percent of ideal body weight (%IBW), serum estrogen levels, and change in bone mineral density (BMD) and bone mineral content (BMC) were studied in 288 postmenopausal women aged 41–71 years who participated in a 2-year calcium supplement trial. The spine (L2–L4) and femoral neck were measured by dualphoton absorptiometry, and the radius was measured by single-photon absorptiometry. Years since menopause, calcium intake, and initial BMD or BMC were included as independent variables in two-phase regressions of BMD and BMC on %IBW. Increased %IBW protected against loss of spine BMD [regression slope estimate=0.05, 95% C.I.: (0.03, 0.26)] and BMC in women up through about 106 %IBW but not in heavier women. Increased %IBW was not significantly related to BMD or BMC at the femoral neck or radius. Women above 106%IBW had significant gains in spine and femoral neck area (P< 0.05). Serum estrone and estradiol were positively correlated with BMD and BMC at the femoral neck only.     

Bone mineral density of the proximal femur and lumbar spine in glucocorticoid-treated asthmatic patients

The importance of the proximal femur as a site of osteoporotic fractures, the development of techniques for bone mineral density (BMD) measurement at this site and the apparent selectivity of the osteopenic effects of glucorticoids have focused attention on the assessment of proximal femoral BMD in steroid-treated subjects. We have, therefore, measured BMD (Lunar DPX) in the lumbar spine and proximal femur of 31 asthmatic patients receiving long-term glucocorticoid therapy (mean ± SEM dose 16 ± 1 mg prednisone/day, mean duration 10 ± 2 years). BMD values expressed as the percentage of normal age- and sex-appropriate mean values, after weight adjustment, were as follows: lumbar spine 80 ± 2%, femoral neck 83 ± 2%, Ward's triangle 78 ± 3% and trochanter 86 ± 2%. All these values were significantly less than control (p<0.0001) and the decrement in BMD was more marked in Ward's triangle than at the other two femoral sites (p<0.05). In all regions BMD was unrelated to dose or duration of steroid treatment. It is concluded that there are reductions in the BMD of the lumbar spine and proximal femur in glucocorticoid-treated asthmatics, probably reflecting the mixed cortical/trabecular makeup of both regions.     

Comparison between menopause-related changes in bone mineral density of the lumbar spine and the proximal femur in Japanese female athletes: A long-term longitudinal study using dual-energy X-ray absorptiometry

This longitudinal study examined whether bone mineral density (BMD) of the lumbar spine and the proximal femur is maintained in pre-, peri-, and postmenopausal women by regular exerise. BMD was measured using dualenergy X-ray absorptiometry (DXA). Twenty-six Japanese women (mean age 47.8 years) were followed 4–5 years. Twenty-two subjects from volleyball or jogging clubs had participated in the same exercise for more than 5 years at the initial BMD measurement. Longitudinally, for these 22 athletes, the rate of change per year in BMD of the lumbar spine was -0.17% in the premenopause group and -2.60% in the perimenopause group. In the proximal femur of the athletes, BMD increased (rate of increase per year 1.80%) in the premenopause group, but decreased (rate of decrease per year 1.07%) in the perimenopause group. In the premenopause group, BMD of the proximal femur increased in all athletes. However, in the proximal femur, the nonexercise group showed a 0.31% decrease, a significant difference (P <0.05) compared with the athletes. These findings suggest that women can achieve continuous gains in bone mass in the proximal femur before menopause by regular intense exercise. However, continued high-level physical activity in the perimenopausal women was not able to prevent bone loss.     

Lumbar vertebral bone mineral density in Japanese infants and children: Measurement with dual x-ray absorptiometry

Dual x-ray absorptiometry (DXA) (Hologic QDR-1000/W; Hologic, Inc.) was used to measure lumbar vertebral bone mineral density (BMD) in 83 healthy Japanese infants and children (55 boys and 28 girls) aged 0–17 years, and the values obtained were correlated with age, body weight and body height. The lumbar BMD (average of L1–L4 values) increased with age, with a nearly twofold increase found from preschool age to adolescence. It also increased with body weight and body height. Our results on normal Japanese infants and children appear almost similar to those reported in French and American studies. Because of its great precision and accuracy, low radiation exposure and rapid scanning, DXA may be the most suitable for use in infants and children. With normal Japanese data now available with this technique, pediatricians can better detect metabolic bone diseases in infants and children and follow the bone response to medical intervention in patients with these conditions.     

Bone mineral density of the spine in normal Japanese subjects using dual-energy X-ray absorptiometry: Effect of obesity and menopausal status

Summary Bone mineral density (BMD) of the lumbar spine was measured to determine normal Japanese values and to examine the effect of obesity and menopausal status on BMD. Normal Japanese subjects (N=1,296, 1,048 women and 248 men) were examined using dual-energy X-ray absorptiometry. BMD for men peaked between age 20 and 29. For women, there was abrupt bone loss after age 50. Obese women within the same age bracket had a higher BMD than thin women after age 40–49. We determined that BMD began to decline during the irregular menstruation period before the onset of menopause. We conclude that there is a positive correlation between obesity and BMD, particularly in postmenopausal women. In addition, we found that bone loss related to menopause begins during the irregular menstruation period before menopause.     

The effects of high potassium consumption on bone mineral density in a prospective cohort study of elderly postmenopausal women

Summary  Few studies have investigated the long-term effects of potassium intake on BMD. In a cohort of 266 elderly women, we found that baseline potassium intake as reflected by 24-hour urine potassium excretion had positive association with BMD measured at 1 and/or 5 years later, suggesting a role of dietary potassium on osteoporosis prevention. Introduction  High dietary potassium intake has been suggested to be beneficial for bone structure, but few studies have investigated the long-term effects of potassium intake on BMD in elderly women. We examined the relationship between potassium intake as reflected by 24-hour urine potassium excretion and bone density in a cohort of elderly women. Methods  The study subjects were 266 elderly postmenopausal women aged 70–80 years. Twenty-four-hour urinary potassium excretion was determined at baseline. At one year hip DXA BMD was measured, at 5 years hip and total body DXA BMD and distal radius and tibia pQCT vBMD were measured. The effects of potassium were evaluated by ANCOVA according to the quartile of baseline urinary potassium excretion. Results  After adjustment for confounding factors, subjects in the highest quartile of urinary potassium excretion had significantly higher total hip BMD at 1 (5%) and 5 years (6%), and significantly higher total body BMD (4%) and 4% distal tibia total (7%) and trabecular vBMD (11%) at 5 years than those in the lowest quartile. Conclusions  Potassium intake shows positive association with bone density in elderly women, suggesting that increasing consumption of food rich in potassium may play a role in osteoporosis prevention.     

A comparison of quantitative dual-energy radiographic absorptiometry and dual photon absorptiometry of the lumbar spine in postmenopausal women

Summary Noninvasive bone densitometry is an important aspect in the detection and management of osteoporosis and other forms of metabolic disease of calcified tissue. A system using quantitative dual-energy digital projection radiography (QDR) of the lumbar spine was systematically tested against dual-photon absorptiometry (DPA) of the lumbar spine in 131 women over 55 years of age and free from major risk factors for osteoporosis. All subjects were scanned by both QDR and DPA under the same conditions. Measurements for a given subject were made within 15 minutes of each other. Bone mineral densities (BMD) were determined for four individual levels in the lumbar spine (L1-L4). Regression equations for BMD vs. age, height, and weight were calculated. The results of this investigation indicate that DPA- and QDR-derived BMD values are comparable. BMD values derived by QDR were consistently lower than those obtained by DPA (DPA=1.115 QDR+0.137, r=0.942). The L2 lumbar region was the most strongly correlated determination.     

Bone density in white Brazilian women: Rapid loss at the time around the menopause

Dual energy x-ray absorptiometry (DXA) was used to measure bone mineral density (BMD) of the lumbar spine and proximal femur (neck, Ward's triangle, and trochanter) in 417 normal women (aged 20–79) living in São Paulo, Brazil. Bone density decreased with age at all sites. At the spine, the greatest decrease occurred during the sixth decade, with an average 11.4% bone loss compared with the previous decade. Stratifying the subjects according to menopausal status revealed that the fastest bone occurred at the time around the menopause (ages 45–60) when the rate of bone loss (-0.66%/year) was almost twice as rapid as in postmenopausal women (-0.39%/year). Although significant linear rates of bone loss were detected in all proximal femur sites before the menopause, a menopause-dependent pattern was less evident that at the spine. Lifetime rates of bone loss at the appendicular skeleton were-0.43,-0.62, and-0.35%/year at the femoral neck, Ward's triangle, and trochanteric area, respectively. After the menopause, BMD declined with menopausal age at all sites, although the rate of bone loss was faster at the femoral neck (-0.62%/year) and Ward's triangle (-0.84%/year) than at the spine-0.49%/year). The results are consistent with the notion that in women, the fastest bone loss occurs at the time round the menopause, most likely consequent to ovarian failure; and that faster rates of bone loss are detected at the proximal femur than at the lumbar spine in late postmenopausal women.     

Determination of bone mineral density by dual x-ray absorptiometry in patients with uncemented total hip arthroplasty.

Bone remodeling is an expected sequela with total hip arthroplasty (THA). Although there are several methods of estimating bone response in THA patients from radiographs, there are no accurate and generally accepted methods for quantitative determinations in vivo. In this study, we describe an application of dual x-ray absorptiometry (DXA) for measuring bone mineral content and bone mineral density in the proximal femur following THA. DXA is a noninvasive technique with minimal radiation exposure (< 5 mrem). Various aspects of measurement error (accuracy and reliability) of this application of DXA were determined in a series of studies reported here. Accuracy error (how similar are the measured and actual values) was < 1% determined in bone phantoms of four densities. Precision error (how reproducible are the measurements) was also < 1% at all four densities in the phantoms and was only slightly elevated (0.9-1.5%) in repeated measurements of implanted cadaver femora. Precision error in vivo, determined both from multiple replicates on five patients and from duplicate scans on 30 patients, was further elevated but remained < 5%. Contributions to precision error, rotation of the leg, and interoperator variability were assessed; none was found to elevate precision error appreciably. We suggest that DXA is a feasible method for quantifying bone response following THA, and will allow discrimination of small changes (> 5%) not previously measurable.     

去卵巢对大鼠骨密度的影响

目的：探讨去卵巢对大鼠骨密度（BMD）的影响。方法；20只3．5月龄SD雌性大鼠分别除双侧卵巢（OVX）或假性去卵巢（Sham)，术后14周处死，应用QDR－4500A型扇形束双能X射线吸收法（DXA）测量大鼠全身、离体股骨、胫骨、腰维及兴趣区的BMD。结果：①术后6周OVX组全身BMD显低Sham组（P＝0．048），术后14周两组无显性差异；②术后14周OVX组离体股骨BMD显低于Sham组（P＜0．01），股骨远侧干骺端平均降低11．6％（P＜0．001）；③术后14周右侧离体胫骨BMD两组间差异无显性，但OVX组胫骨的端干骺端BMD显低于Sham组（P＜0．001）；④术后14周OVX组腰椎（L4－L6）的BMD显低于Sham组（P＝0．014），第六腰椎降低明显，平均降低8．1％（P＝0．005）。结论：去卵巢所致骨丢失以松质骨含量丰富的兴趣区明显。     

Age changes in the bone mineral of the lumbar spine in normal women

Summary The bone mineral content (BMC) and the bone mineral areal content (BMAC) were determined with dual-photon absorptiometry in the third lumbar vertebra in a random sample of 214 women between 35 and 80 years of age in the city of G?teborg, Sweden. A continuous aging decrease (1%/year) of both the BMC and the BMAC was noted after age 35. The rate at which bone loss occurred was similar for all age groups when analyzed by 5 year intervals. No clear acceleration of bone loss was noted around the usual time of the menopause.     

High bone mineral density is associated with high body mass index

Summary  High BMD is an infrequent finding. In this retrospective cohort study of women 50 years and older, we documented a strong association between high BMD and high BMI. Introduction  High bone mineral density (BMD) has been associated with genetic disorders and a variety of dietary, endocrine, metabolic, infectious and neoplastic diseases that in many cases warrant medical attention. Since body mass index (BMI) is closely correlated with BMD, we sought to explore the relationship between these two parameters in older women. Methods  We conducted a retrospective clinical cohort study of 16,500 women 50 years and older who underwent baseline BMD testing between May 1998 and October 2002. Mean T-scores and Z-scores, and the proportions of women with high BMD (T-score +2.5 or greater, Z-score +2.0 or greater), were assessed according to BMI category. Results  Higher BMI category was associated with higher mean T-scores and Z-scores at all sites (P < 0.001). The proportion of women with high BMD increased with each BMI category (P for trend <0.05). In women with a lumbar spine T-score of +2.5 or more, 43.5% were obese with BMI > 30 kg/m² (55.6% for the femoral neck and 73.1% for the total hip). For women with a lumbar spine Z-score of +2.0 or more, 37.2% were obese (42.0% for the femoral neck and 50.9% for the total hip). There was no evidence of a paradoxical increase in fracture rates in women with high BMD. Conclusions  High BMD is closely associated with elevated BMI in women. This should be taken into consideration prior to initiating extensive investigations for rare pathologies. This study was supported in part by an unrestricted educational grant from the CHAR/GE Healthcare Development Awards Programme.     

Long-term unilateral loading and bone mineral density and content in female squash players

We examined 19 female Finnish national level squash players and 19 healthy female controls with a dual energy x-ray absorptiometric (DXA) scanner for the determination of the association between long-term unilateral activity and bone mineral density (BMD) and content (BMC) of the upper extremities. In players, the BMDs and the BMCs were significantly higher in each bone site of the playing extremity. The side-to-side difference was largest in the proximal humerus (BMD 15.6%, BMC 17.8%) and smallest in the ulnar shaft (BMD 5.6%, BMC 7.3%). In sex-, age-, weight-, and height-matched controls, the side-to-side differences were significantly smaller, ranging from 1.6% to 4.1%. The number of training years and elbow flexion strength correlated positively with the relative BMD and BMC in the humerus of the playing arm (r=0.632–0.685). The starting age training in turn correlated negatively (r=-0.483 to-0.577) with these bone parameters. Significantly larger side-to-side differences (average 22%) were found in players who had started their career before or during menarche than in those who had begun the training 1 year or more after the menarche (9%). These findings suggest that the bones of the playing extremity clearly benefit from active squash playing. The benefit is largest in humerus and smaller in the bone of the forearm. The benefit of playing is stronger if the athlete has started the training at or before menarche than after it. Thus, physical activity seems to best enhance bone mineralization at childhood and puberty, the time when the natural rapid increase in bone mass also occurs.     

Lumbar spine bone density in argentine children

It has been demonstrated that bone mineral density (BMD) in children and adolescents is influenced by individual height. The aim of the present work was to introduce a formula to include height in the BMD analysis. Postero-anterior (PA) (L2–L4) and lateral (L2–L3) lumbar BMD was assessed by dual X-ray absorptiometry (DXA) in 433 and 393, respectively, healthy Caucasian females from 2 to 20 years of age. A complete medical examination including weight, height, and Tanner puberal stage was performed in all the subjects. Bone age was assessed by left wrist radiographs and analyzed by the TW2 method to insure that it was within 1 year of chronological age. Bone mineral density adjusted for height (BMD_corr=BMC/projected area × height), was calculated for each individual. As analyzed by Tanner stage, both PA and lateral BMD increased up to stage 3, and there were no significant differences among stages 3–5. Results of BMD_corr variations related to Tanner stage suggested that the increase in lateral BMD before puberty might be related to height. PA BMD_corr increased up to Tanner stage 3, and there were no differences among stages 3–5. The BMD_CORR approach can be used to get a more reliable analysis of BMD studies in children and adolescents. This study was presented in part at the 16th Annual Meeting of the American Society for Bone and Mineral Research, Kansas City, Missouri, September, 1994 This study has been supported by a grant from the Metabolic Research Foundation, Buenos Aires, Argentina     

Dual X-ray absorptiometry for the evaluation of bone density from the proximal femur after total hip arthroplasty: Analysis protocols and reproducibility

Summary Dual X-ray absorptiometry (DXA) instruments are now able to evaluate bone mineral density (BMD) of bone surrounding metal implants. The assessment of BMD around prosthetic components could provide additional information for the follow-up of total hip arthroplasty (THA). In this study, we evaluated the potential application of DXA in the field of THA. BMD was measured in the proximal femur of both THA and THA-free sides in 14 postmenopausal women 6–18 months after THA. The explored segment was divided into seven zones as proposed by Gruen et al. [18]. The precision error of BMD measurements ranged from 1.8 to 6.8% on the THA side and from 1.1 to 2% to the THA-free side. The reduction of BMD of the THA versus the THA-free side was significant in all seven zones (P < 0.01, t-test for paired data). These results showed significant differences in BMD around femoral components of THA with respect to contralateral healthy side, and demonstrate the sensitivity of DXA for detecting these changes.     

Bone density of the radius,spine, and hip in relation to percent of ideal body weight in postmenopausal women

Summary Bone mineral content (BMC) and bone mineral density (BMD) of the spine (L2–L4) and hip (at femoral neck, Ward's triangle, and greater trochanter sites) were determined by dual-photon absorptiometry (DPA), and of the radius by single-photon absorptiometry (SPA) in healthy postmenopausal women aged 40–70 years. The relationships of BMC and BMD to years since menopause were examined separately in 97 women who were above 115% of ideal body weight (IBW) and in 128 women below. The heavier women had significantly greater mean BMC and BMD at each site than did the normal-weight women. In the normal-weight women, there was a significant negative correlation between BMD and years since menopause at each measurement site except the greater trochanter. In the obese women, BMD decreased with increasing years since menopause at the radius site only and BMC declined with increasing years after menopause at the hip (femoral neck and Ward's triangle region) as well as the radius. Thus, body size is a significant determinant of BMD in this population. The pattern of loss of BMD from Ward's triangle and femoral neck regions of hip are similar to that of the spine. The BMC and BMD findings in the hip suggest that remodeling occurs at this weight-bearing site which has a favorable effect on bone strength.     

The accuracy of volumetric bone density measurements in dual X-ray absorptiometry

New developments in dual x-ray absorptiometry (DXA) allow the performance of high precision anteroposterior (AP) and lateral scans of spinal bone mineral density (BMD, units: g/cm²) without the patient moving from the supine position. Data from both projections may be combined to give an estimate of the true volumetric bone mineral density (VBMD, units: g/cm³) of the lumbar vertebral bodies. This report presents a cadaver study designed to validate DXA measurements of volumetric bone density. Sections of whole lumbar spine were scanned in AP and lateral projections in a water tank to simulate soft tissue. Individual vertebrae were then divided to separate the vertebral body from the neural arch, and vertebral body volume was measured using the displacement of sand. The bone mineral content (BMC) of vertebral bodies and neural arches was measured by ashing at 250°C for 60 hours followed by 500°C for a further 24 hours. The results showed that DXA scanning systematically underestimated ashing data by 14% for AP BMC, 33% for vertebral body BMC, 23% for vertebral body volume, and 12% for VBMD. Despite these significant systematic errors, the DXA measurements and ashing values were highly correlated (r=0.979-0.992). The results suggested that after allowing for the systematic errors, lateral DXA parameters related closely to true BMC, volume, and VBMD.     

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.