Correlation of bone mineral density and femoral neck hardness in bovine and human samples

Bone mineral density (BMD) was measured in 353 healthy white women using dual-energy X-ray absorptiometry (DXA). Measurements were made of both the posterior-anterior (PA) and lateral spine, as well as the proximal femur (neck and Ward's triangle). From age 50 to 80 years, the BMD of the PA spine and femur neck BMD had an 18% diminution (0.6%/year), and BMD of the lateral spine showed about a 35–40% decline (1.4%/year). The Ward's triangle region of the femur was not quite as decreased (30% or 1.1%/year). The BMD decrease associated with aging did not differ as much among sites when expressed relative to the intrapopulation variation rather than as a percentage. The Z-score for PA spine and femur neck BMD (-1.1) was significantly different than that for lateral spine BMD (-1.6); Ward's triangle was intermediate (-1.3), i.e., the lateral spine still showed the highest sensitivity to aging. However, the ability to detect age changes in an individual subject can be increased only if the precision error for lateral spine BMD is not increased to a greater extent than the sensitivity.Deceased     

Bone Mineral Density of Opposing Hips Using Dual Energy X-Ray Absorptiometry in Single-Beam and Fan-Beam Design

Bone densitometry focuses on bone mineral area density (BMD in g/cm²) of the proximal femur and spine in anterior-posterior (AP) projections. Artifacts, such as osteoarthritis and osteophytic calcifications (OC) influence spine BMD, especially in AP scans. If only two sites are measured, as is usual in clinical practice, there may be advantages to measuring both femora rather than one femur and the spine. This would not be useful, however, if there was strong symmetry between the two sides. Furthermore, fan beam (FB) techniques have become available for measuring BMD with less data acquisition time. We compared densitometry of opposing femora in 421 patients (369 women, mean age 59.0 ± 4.8; 52 men, mean age 56.9 ± 7.4) using dual-energy X-ray absorptiometry (DXA): both single-beam (SB) and FB modes were evaluated. The precision errors in vivo (short- and midterm) of total BMD were 0.7% for both SB and FB. The total BMD and BMC of the left hip (0.817 ± 0.124 g/cm², 31.3 ± 6.4 g) were significantly (P < 0.001) higher (2–3%) than the corresponding values of the right hip (0.801 ± 0.125 g/cm², 30.3 ± 6.3 g) in both SB and FB (left BMD 0.802 ± 0.117 g/cm², BMC 30.0 ± 6.2 g versus right BMD 0.795 ± 0.117 g/cm², BMC 29.3 ± 6.3 g) modes. However, BMD of the femoral neck and Ward's triangle were not significantly (P > 0.05) different between the two sides. The FB results were generally 2% lower than SB results. There were highly significant (P < 0.001) correlations (r > 0.9) between both hips using both SB and FB. For diagnostic procedures and longitudinal studies, one should consider that there are bilateral differences of femur BMD, as well as differences between FB and SB scan modes.     

A longitudinal study of supine lateral DXA of the lumbar spine: A comparison with posteroanterior spine,hip and total-body DXA

We report a study to assess whether supine lateral dual-energy X-ray absorptiometry (DXA) scans of the lumbar spine provide better data for monitoring response to treatment than alternative measurement sites such as the posteroanterior (PA) spine, hip and total body. The study population was 152 women enrolled in a placebo-controlled clinical trial of cyclical etidronate therapy. All subjects were 1–10 years after the menopause with bone mineral density (BMD) between 0 and –2 SD of age-matched normal women. Paired PA and lateral spine, left hip and total-body DXA scans were performed at baseline, 1 year and 2 years on a Hologic QDR-2000. One hundred and thirty-one subjects completed the study. Mean percentage change from baseline at 2 years in the treated (n=61) and control (n=70) groups was calculated for vertebral body, width-adjusted (WA) vertebral body, mid-vertebral body and WA mid-vertebral body BMD measurements on the lateral scans and compared with the percentage changes in PA spine, femoral neck, trochanter, Ward's triangle and total-body BMD. The long-term precision for each BMD measurement site was obtained by linear regression analysis in subjects taking placebo. Overall treatment effect, defined as the difference in the percentage change in BMD in the two treatment groups at 2 years, was divided by long-term precision to give an index of the ability of each site to monitor response to treatment. Results (and standard errors) normalized to the ratio of treatment effect/precision for PA spine BMD were as follows: PA spine, 1.00; vertebral body, 0.89 (0.14); WA vertebral body, 0.78 (0.14); mid-vertebral body, 0.65 (0.14); WA mid-vertebral body, 0.60 (0.13); femoral neck, 0.35 (0.15); trochanter, 0.45 (0.15); Ward's triangle, 0.59 (0.22); total body, 0.52 (0.19). Although treatment effect was larger for lateral than for PA spine BMD, this advantage was offset by the greater precision errors. PA spine BMD remains the optimum measurement for longitudinal studies in recently postmenopausal women.     

Age-related bone mineral density, bone loss rate, prevalence of osteoporosis, and reference database of women at multiple centers in China.

Our study surveyed age-related bone mineral density (BMD), bone loss rate, and prevalence of osteoporosis in women at multiple research centers in China. Survey results were used to establish a BMD reference database for the diagnosis of osteoporosis in Chinese women nationwide. We used dual-energy X-ray absorptiometry bone densitometers to measure BMD at posteroanterior (PA) lumbar spine (L1-L4; n=8142) and proximal femur (n=7290) in female subjects of age 20-89 yr from Beijing, Shanghai, Guangzhou, Chengdu, Nanjing, and Jiaxing. A cubic regression-fitting model was used to describe the change of BMD with age at various skeletal sites. Peak BMD occurred between 30 and 34 yr of age for femur neck and total femur, and between 40 and 44 yr for spine and trochanter measurement sites. Young adult (YA) BMD values (mean and standard deviation [SD], calculated as the average BMD in the age range of 20-39, were 1.116+/-0.12, 0.927+/-0.12, 0.756+/-0.11, and 0.963+/-0.13 g/cm2 at PA spine, femoral neck, trochanter, and total femur, respectively. The BMD of 85-yr-old women reflected a loss of 32% at the spine and 30-35% at femur measurement sites. The prevalence of osteoporosis, defined as a BMD of 相似文献   

Dual photon absorptiometry of the proximal tibia

Summary Bone mineral content (BMC) and bone mineral density (BMD) of the proximal tibia were determined by dual photon absorptiometry on 44 women, aged 23–87 years. The area of the tibia measured was a 2.01 cm region immediately distal to the medial and lateral tuberosities. Values of BMC ranged between 5.09 and 14.57 g and BMD between 0.380 and 1.180 g/cm². Both tibial BMC and BMD declined with age and tibial BMD was significantly correlated with lumbar spine (r=0.70), femoral neck (r=0.73), and femoral trochanter (r=0.74). However, the large standard errors of estimate (SEE) (0.08–0.14 g/cm²) do not allow for reliable prediction in an individual of other skeletal sites by the tibia. Repeated measurements demonstrated that dual photon absorptiometry of the proximal tibia is a reliable measurement and may be a useful tool in the monitoring of therapeutic or intervention modalities in those individuals with skeletal diseases in whom measurement of the lumbar spine or proximal femur may not be possible.     

Bone Mineral Density in Flatwater Sprint Kayakers

To elucidate the possible skeletal benefits of the muscular contractions and the nonweight-bearing loading pattern associated with kayaking, we investigated the bone mineral density (BMD, g/cm²) of 10 elite kayakers, six males and four females, with a median age of 19 years. Each subject was compared with the mean value of two matched controls. BMD of the total body, head, ribs, humerus, legs, proximal femur (neck, wards, trochanter), spine, lumbar spine, and bone mineral content (BMC, g), of the arms was obtained using a dual energy X-ray absorptiometer (DXA). Body composition was also assessed. The kayakers had a significantly (P < 0.05–0.01) greater BMD in most upper body sites: left and right humerus (10.4% and 11.7%), respectively, ribs (6.4%), spine (10.9%), and a greater BMC of the left and right arm (15.7% and 10.6%, respectively). No significant differences in the BMD of the total body, head, or any of the lower body sites were found, except for the pelvis, which was significantly greater in kayakers (5.1%). The controls had a significantly lesser lean body mass (10.4%) and greater percentage of body fat (19.5%) than the kayakers. Bivariate correlation analysis in the controls demonstrated significant and strong relationships between BMD in upper body sites and lean body mass, weight, and fat; the effects of training seem to outweigh most such relationships in kayakers. In conclusion, it seems that the loading pattern and muscular contractions associated with kayaking may result in site-specific adaptations of the skeleton. Received: 21 April 1998 / Accepted: 1 October 1998     

Bone Density of the Spine and Femur in Adult White Females

We measured bone mineral density (BMD in g/cm²) of the spine (L2-L4) and femur (four regions) in 1472 and 1487 cases, respectively, of ambulatory white women ages 20–79 years in the USA. A DPX densitometer was used in a mobile setting. The BMD values for women up to 69 years corresponded closely with published values for the USA, the UK, and northern Europe; our values were somewhat lower than those from other studies only in women over 70 years. The USA data were combined with data from Europe to give reference curves on about 12,000 subjects. Decreases of BMD with age in women below 50 years were much smaller than in older women (0.2% versus 0.6–1.0% per year). Femoral bone decreased from the neck region, but not the trochanter with age; the decrease of total femur BMD with age was due to loss from the former region. Loss of bone mineral content (BMC in g) from the femur neck and total femur region did not accelerate until after age 50 years, much like the spine. The apparent decrease of BMD in these regions that begins about age 40 actually is due to an increase of bone area. About 20% of USA women aged 50–79 years had BMD levels for the lumbar spine, or for the femur neck, more than −2.5 SD below the average values in young adult women 20–39 years old. Body weight had several times more impact on BMD than height, and in fact, a change of 1 kg in postmenopausal women was commensurate with the effect of a 1-year change in age. Subjects in the lowest quartile of body weight had T-scores that were 1 SD below those in the highest quartile. Received: 10 September 1998 / Accepted: 15 December 1998     

In vivo and in vitro precision for bone density measured by dual-energy X-ray absorption

An investigation was made into some of the major sources of error influencing the bone mineral density (BMD) measurements of the lumbar vertebrae, the femoral neck and the greater trochanter. The effect on accuracy and reproducibility of the following parameters was investigated: influence of patient positioning, patient size, scan speed, the technique of scan analysis and the temporal variation in instrument performance.The in vitro precision, both long-term and short-term, was assessed using aluminium phantoms supplied by the manufacturer. For the spine phantom, the precision expressed as a percentage coefficient of variation (%CV) was found to be 0.4% (10 scans) in the short term and 0.55% (15 scans) in the long term. Measured precision (short-term) for the three regions of the femur phantom analysed by the software was 1.3% for the neck of femur, 1.7% for Ward's triangle and 0.6% for the trochanter. Long-term precision was 1.0%, 1.9% and 1.1% respectively. No statistically significant difference was found between long- and short-term results.Short-term in vitro precision on a low density anthropological phantom was 4.1%, 4.2%, 2.4% and 0.61% for neck of femur, Ward's triangle, trochanter and spine respectively.In vivo short-term precision for the lumbar spine (L2–L4), measured by scanning four normal volunteers five times in one session, was found to be 0.8±0.25%. In vivo precision for the femur, measured on seven volunteers was 1.6±0.8% for the neck of femur, 3.2±1.7% for Ward's triangle and 2.2±1.1% for the trochanter.The variation in density results caused solely by analysis was investigated by analysing ten randomly selected normal femoral scans five times on five different days. Again results are expressed as a coefficient of variation and were 1.3±0.8% for the neck of femur, 2.4±1% for Ward's triangle and 0.8±0.7% for the trochanter, suggesting that most of the variation in the femur density results can be attributed to the analysis procedure.     

Bone Mineral Density During Reduction, Maintenance and Regain of Body Weight in Premenopausal, Obese Women

Weight loss may lead to bone loss but little is known about changes in bone mass during regain of reduced weight. We studied changes in bone mineral density (BMD) and bone mineral content (BMC) during voluntary weight reduction and partial regain. The study consisted of three phases: a 3 month weight reduction with very-low-energy diet (VLED), a 9 month randomized, controlled walking intervention period with two training groups (target energy expenditure 4.2 or 8.4 MJ/week) and a 24-month follow-up. The participants were premenopausal women with a mean body mass index of 34.0 (SD 3.6) kg/m². Seventy-four of 85 subjects completed the whole study. Total body, lumbar spine, proximal femur and dominant radius BMD and BMC were measured with dual-energy X-ray absorptiometry (DXA). The mean weight loss during VLED was 13.2 (3.4) kg, accompanied by unchanged total body BMC and decreased lumbar, trochanteric and radial BMD (p<0.05). During months 3–36, an average of 62% of the weight loss was regained, total body BMC decreased and trochanteric BMD increased (p<0.05). At the end of the study, total body BMC and lumbar and femoral neck BMD were lower than initially (p<0.05). Weight change throughout the study correlated significantly with the change in radial (r= 0.54), total body (r= 0.39) and trochanteric (r= 0.37) BMD. Exercise-group assignment had no effect on BMD at weight-bearing sites. In conclusion, the observed changes in BMD and BMC during weight reduction and its partial regain were clinically small and partly reversible. More studies are needed to clarify whether the observed weight changes in BMD and BMC are real or are artifacts arising from assumptions, inaccuracies and technical limitations of DXA. Received: 20 April 2000 / Accepted: 20 September 2000     

Precision of single vs bilateral hip bone mineral density scans.

This study was performed to determine and compare the precision of single and bilateral hip bone mineral density (BMD) measurements and to determine the precision of spinal and total body measurements by dual-energy X-ray absorptiometry (DXA). Precision (group root-mean-square average coefficient of variation) was determined in 6 subjects scanned six times each at the spine, both hips, and total body, with repositioning after each scan. Mean percentage coefficients of variance (%CVs) in BMD for single and bilateral hip scans were, respectively: 0.65% and 0.67% for the total hip, 1.16% and 1.03% for the trochanter, and 1.66% and 1.31% for the femoral neck, respectively. Mean %CV was 1.04% for spine BMD (L2-L4), 0.67% for total body BMD, 1.12% for total body bone mineral content (BMC), 0.94% for total body fat tissue, and 0.77% for total body nonfat soft tissue. We conclude that precision overall is excellent and that femoral neck precision can be improved with bilateral compared with the traditional single hip scans.     

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.     

体重、身高对成都地区青壮年腰椎、髋部骨量的影响

目的　研究体重、身高对青壮年腰椎、髋部骨量的影响。方法　随机抽取成都地区年龄在 2 0～ 39岁 ,排除心肝肺肾、内分泌等慢性病、骨代谢疾病及脊椎畸形者 2 37名 (其中男性 10 8名 ,女性 12 9名 ) ,采用美国Lunar公司生产DPX L型双能X线骨密度仪测定受试者腰椎和髋部的骨矿含量 (BMC)、面积 (AREA)、骨密度 (BMD)。全部资料输入微机 ,用SPSS软件进行统计学处理。结果　体重、身高、体重指数 (BMI)与腰椎、髋部的BMC、Area、BMD呈正相关 ,其中体重与腰椎、髋部的BMC、Area中等程度相关 (r=0 39～ 0 5 5 ,P <0 0 1) ,身高与腰椎 (L2 - 4)AREA相关性最好 (r=0 75 8,P <0 0 1) ,体重、身高与BMD相关性差 (r=0 15 2～ 0 2 2 5 ,P <0 0 5 )。男性腰椎及髋部的BMC、AREA均明显高于同年龄组女性 (P <0 0 1) ,男、女L2 - 4BMD无显著性差异 (P >0 0 5 ) ,男性略低于女性。L2 - 4BMC与体重比值及L2 - 4AREA与体重比值 ,男、女无显著性差异 (P >0 0 5 )。L2 - 4Area与身高比值男性明显高于女性 (P <0 0 1)。结论　体重对青壮年BMC的影响大于身高 ,身高对L2 - 4AREA影响最大 ,男、女体重、身高的差异决定了峰值骨量的差异。BMC、Area、BMD 3项指标中 ,BMC更能反映体重、身高的差异 ,用BMC诊断骨质疏松     

Physical Activity Benefits the Skeleton of Children Genetically Predisposed to Lower Bone Density in Adulthood

Both genetics and physical activity (PA) contribute to bone mineral density (BMD), but it is unknown if the benefits of physical activity on childhood bone accretion depend on genetic risk. We, therefore, aimed to determine if PA influenced the effect of bone fragility genetic variants on BMD in childhood. Our sample comprised US children of European ancestry enrolled in the Bone Mineral Density in Childhood Study (N = 918, aged 5 to 19 years, and 52.4% female). We used a questionnaire to estimate hours per day spent in total, high‐, and low‐impact PA. We calculated a BMD genetic score (% BMD lowering alleles) using adult genome‐wide association study (GWAS)‐implicated BMD variants. We used dual‐energy X‐ray absorptiometry to estimate femoral neck, total hip, and spine areal‐BMD and total body less head (TBLH) bone mineral content (BMC) Z‐scores. The BMD genetic score was negatively associated with each bone Z‐score (eg, TBLH‐BMC: estimate = –0.03, p = 1.3 × 10^?6). Total PA was positively associated with bone Z‐scores; these associations were driven by time spent in high‐impact PA (eg, TBLH‐BMC: estimate = 0.05, p = 4.0 × 10^?10) and were observed even for children with lower than average bone Z‐scores. We found no evidence of PA‐adult genetic score interactions (p interaction > 0.05) at any skeletal site, and there was no evidence of PA‐genetic score–Tanner stage interactions at any skeletal site (p interaction > 0.05). However, exploratory analyses at the individual variant level revealed that PA statistically interacted with rs2887571 (ERC1/WNT5B) to influence TBLH‐BMC in males (p interaction = 7.1 × 10^?5), where PA was associated with higher TBLH‐BMC Z‐score among the BMD‐lowering allele carriers (rs2887571 AA homozygotes: estimate = 0.08 [95% CI 0.06, 0.11], p = 2.7 × 10^?9). In conclusion, the beneficial effect of PA on bone, especially high‐impact PA, applies to the average child and those genetically predisposed to lower adult BMD (based on GWAS‐implicated BMD variants). Independent replication of our exploratory individual variant findings is warranted. © 2016 American Society for Bone and Mineral Research.     

Is a Fixed Value for the Least Significant Change Appropriate?

The least significant change (LSC) represents the smallest difference between successive measurements of bone mineral density (BMD) that can be considered to be a real change and not attributable to chance. The LSC is derived from same-day in vivo BMD precision measurements. Our first objective was to determine if the LSC differs between technologists. Our second objective was to determine if patient body size influenced the LSC. Each of 8 technologists measured same-day precision in groups of 30 patients for the lumbar spine and the total trochanter and neck regions of the proximal femur. At the spine, precision ranged from 0.008 to 0.011 g/cm² and did not differ between technologists. Precision for the total region of the left proximal femur ranged from 0.006 to 0.016 g/cm² and did differ between technologists. For the trochanter and neck regions, precision ranged from 0.008 to 0.013 g/cm² for the former and from 0.010 to 0.020 g/cm² for the latter, again, with inter-technologist differences. The LSC for the lumbar spine increased linearly from 0.022 to 0.031 g/cm² when body mass index (BMI) increased from 19.5 to 31.3 kg/m². In contrast, there was no discernable impact of BMI on the LSC for any of the proximal femur regions. The LSC at the spine is determined by the patient, whereas the LSC at the femur is determined by the technologist. Use of a single value for the LSC will lead to misinterpretations of the significance of BMD changes at both the spine and the proximal femur.     

Proximal femur bone mineral levels of US adults

This paper describes bone mineral levels in the proximal femur of US adults based on a nationally representative sample of 7116 men and women aged 20 years and older. The data were collected in phase 1 of the third National Health and Nutrition Examination Survey (NHANES III, 1988–1991) using dual-energy X-ray absorptiometry, and included bone mineral density (BMD), bone mineral content (BMC) and area of bone scanned in five selected regions of interest (ROI) in the proximal femur: femur neck, trochanter, intertrochanter, Ward's triangle and total. These variables are provided separately by age and sex for non-Hispanic whites (NHW), non-Hispanic blacks (NHB) and Mexican Americans (MA). BMD and BMC in the five ROI tended to decline with age, whereas area did not. BMD and BMC were highest in NHB, intermediate in MA and lowest in NHW, but areas were highest in NHW, intermediate in NHB and lowest in MA. Men had greater BMD, BMC and area than women in all three race/ethnic groups. Differences by age, sex or race/ethnicity tended to be the largest in Ward's triangle, followed by the femur neck; patterns in the trochanter, intertrochanter and total ROI were reasonably similar to each other. This report provides extensive data on femur bone mineral levels of adults from one of the largest samples available to date and should be valuable as reference data for other studies which examine this skeletal site in adults.     

Differential action of pamidronate on trabecular and cortical bone in women with involutional osteoporosis

Since osteoporotic fractures are mainly related to the diminution of the bone mineral density (BMD), the effect of pamidronate (3-amino-1-hydroxy-propylidene) 1,1-bisphosphonate on the BMD of the spine, proximal femur and radius shaft was evaluated in an initial cohort of 35 postmenopausal women with at least one vertebral fracture due to involutional osteoporosis.Pamidronate was given continuously during 18 months in a daily oral dose of 4.8 to 6.0 mg/kg supplemented with calcium (1 g/day).BMD — measured by dual photon absorptiometry — increased after one year 5.3±1.0% (P<0.001) in lumbar spine and 5.3±1.5% (P<0.001) over trochanter. However no significant changes were observed in the BMD of the femoral neck, Ward's triangle or in the cortical bone of the radius shaft measured by single photon absorptiometry.Pamidronate also decreased significantly urinary hydroxyproline-creatinine excretion after 6 months and thereafter maintained a plateau. After 18 months of treatment the diminution was 42.6±4.9% (P<0.001).The differing effects of pamidronate on the BMD of lumbar spine and proximal femur might be ascribed to dissimilarities between the proportions of trabecular and cortical bone in these. These results suggest that pamidronate may be prescribed to prevent fractures in cases of involutional osteoporosis with a significant decrease of BMD in lumbar spine and/or trochanter.     

Bone mineral density measured by dual-energy X-ray absorptiometry in healthy finnish women

Summary A cross-sectional study of 351 healthy Finnish women aged 20–76 years was done to establish reference values of bone mineral density (BMD) using dual-energy X-ray absorptiometry (DEXA). The effects of age and of several physical and lifestyle factors on BMD of the lumbar spine and proximal femur (femoral neck, trochanter, and Ward's triangle area) were investigated. Altogether 58 women were excluded from the final analysis due to significant spinal osteoarthritis or other diseases or drugs known to influence calcium or bone metabolism. The precision of the method was 0.9, 1.2, 2.7, and 2.4% in the lumbar, femoral neck, Ward's triangle and trochanter area, respectively. Lumbar BMD was increased by 30% (P<0.001) in 15 patients with osteoarthritis (21% of women 50 years or older), but it was apparently unaffected in 5 cases with aortic calcification. Except for the trochanter area, BMD diminished along with age, and this was significant after the menopause. The peak of mean BMD was observed at the age of 31–35 years in the spine and at the age of 20–25 years in the femoral neck and Ward's triangle. BMD was in a positive relationship to weight both in premenopausal and postmenopausal women and to the use of oral contraceptives in premenopausal women and to that of estrogen replacement therapy in postmenopausal women. Labors and pregnancies had a weak positive effect on BMD in premenopausal women. As compared with nonusers premenopausal women who had used alcohol showed a slightly decreased BMD of Ward's triangle. In postmenopausal women there was a positive correlation between alcohol intake and BMD.     

Habitual and Low-Impact Activities are Associated with Better Bone Outcomes and Lower Body Fat in Older Women

The influence of habitual and low-impact physical activity (PA) on bone health and soft tissue including bone-free lean (BFL) and fat mass is less elucidated than the influence of high-impact activities. This study examines the interactive effects of PA and soft tissue on bone mineral density (BMD) and content (BMC) in healthy Caucasian women, aged 68.6 ± 7.1 years, with body mass index (BMI) of 26.0 ± 3.8 kg/m² evaluated at baseline and every 6 months for 3 years. Measurements/assessments included BMD/BMC and soft tissue (by dual-energy X-ray absorptiometry), anthropometrics, dietary intake, and PA. Activities assessed were past activity, present heavy housework, gardening, do-it-yourself activities, stair-climbing, walking, walking pace, sports/recreation, and total activity. Baseline analyses revealed significant positive associations between past activity, heavy housework, faster-paced walking, BFL, and BMD/BMC of various skeletal sites. Prospective analyses showed subjects with more walking hours/week had significantly higher BMD/BMC of several skeletal sites (P < 0.05). Stratification by cumulative (over 3 years) median for heavy housework, walking, sports/recreational, and total activities revealed higher BMD and BMC in the femur and spine (P = 0.01) in subjects with those activities above median. Multivariate analysis of covariance results revealed that weight had the strongest influence on BMD and BMC, followed by BFL. Various modes of PA were negatively associated with BMI and fat but not with BFL. In conclusion, heavy housework, walking (faster pace), sports/recreational activities, and overall total participation in low-impact PA were beneficial for bone and for achieving more favorable body weight and fat but were not associated with BFL. The results indicate that even habitual activities engaged in by older women could benefit their bone and diminish body fat.     

Bone diminution of osteoporotic females at different skeletal sites

Summary The bone mineral density (BMD) of the radius and spine was determined by photo absorptiometry in a large number of controls (radius: n=111; spine: n=85; age range: 50–79 years) and osteoporotic women (radius: n=98; spine n=140; age range: 50–79 years) with at least one “atraumatic” vertebral compression fracture. Compared to age-matched controls, the BMD of the osteoporotic women showed the following diminutions: sixth decade: radius:−9.1%; spine:−25%; femur: −33%; seventh decade: radius:−16%; spine: −19%; femur:−23%; eighth decade: radius: −21%; spine:−20%; femur:−24%. The BMD was significantly diminished at all sites in all decades but in contrast to the radius, the difference from controls was bigger in the spine and femur in the sixth decade than in the seventh and eighth decade. In the osteoporotic women there was a significant correlation between radius BMD and age (4=−0.56;P<0.01) but not between spine or femoral BMD and age. The femoral neck BMD was also determined in a subset group of female controls (n=68), patients with crush fractures of the spine without a fracture of the hip (n=46), and in patients with fractures of the proximal femur (n=21). There was no difference among these groups in mean age (64±7, range: 50–79 years). Patients with hip fracture and spine fracture showed bone diminution in all three regions that was significantly below controls (P<0.001). The Ward's triangle region was specially diminished (−35%) and as a consequence the neck BMD was low (−26%). Trochanteric density was lower (−25%) in spine fracture cases than in hip fracture (−16%). The difference between the two groups of osteoporotic women was significant (P<0.05). In the hip fractures cases, spine BMD was reduced only moderately compared to controls (−14%,P<0.01) and slightly elevated compared to spinal osteoporosis where the diminution was greater (−24%,P<0.001). Again, the difference between the two osteoporotic groups was significant (P<0.05). It appeared that spinal osteoporosis involved loss of bone from both the spine and hip, whereas femoral osteoporosis showed a preferential loss of bone from the femur neck region, and a lesser loss from the trochanter or the spine.     

Comparative evaluation of the DPX and DPX-IQ lunar densitometer systems following software upgrade.

Bone densitometry research departments perform system and software upgrades infrequently in order to maintain high precision. This study compares the results obtained on a Lunar densitometer with DPX, and DPX-IQ installed to achieve year 2000 compliance. The DPX-IQ provides an improved femur edge detection algorithm with an expanded reference database. Two hundred data files for each measurement site acquired on DPX were reanalyzed on DPX-IQ. There was no change to the bone mineral density (BMD), bone mineral content (BMC), T-scores or Z-scores for the L2-L4 spine, radius (ultradistal and 33%), and total body. There was a significant high correlation for the femoral neck BMD (r = 0.98; p < 0.05). The mean differences in BMD, BMC, T-scores, and Z-scores at the femoral neck and Ward's and trochanteric regions were not significant (p > 0.05). The limits of agreement within the 95% confidence interval for the femoral neck BMD using the Bland and Altman method was between -0.057 and 0.063 g/cm(2). This order of magnitude magnifies the long-term precision error and alters the usual confidence limits for interpretation of true change in densitometry practice. Therefore, it is important for reanalysis of DPX data files with the DPX-IQ to be performed so that longitudinal changes in BMD can be accurately assessed.