How does quantitative ultrasound compare to dual X-ray absorptiometry at various skeletal sites in relation to the WHO diagnosis categories?

Effect of the "Building Osteo Neatly Exercise" program on quantitative ultrasound parameters and plantar pressure distribution for college-aged females

[Purpose] We investigated the effects of a specifically designed exercise program that focused on the arches of the foot and the forefoot (the "Building Osteo Neatly Exercise" program) in college-aged females. [Participants and Methods] Forty college-aged females were divided randomly into experimental and control groups. The experimental group underwent the Building Osteo Neatly Exercise program for 60 min once a week for 4 months. In both groups, the plantar pressure distribution and quantitative ultrasound parameters of the calcaneus (speed of sound and bone area ratio) were evaluated at the beginning and end of the study. The plantar pressure distribution during walking was measured using a pressure plate to evaluate the deviation from the ideal values for the following: contact time, contact duration, peak pressure time, and foot pressure, all measured in the rear foot (the external and internal sides), medial forefoot including (the hallux and second and third toes), and lateral forefoot (the fourth and fifth toes). [Results] After completing the program, the speed of sound and bone area ratio had increased significantly in the experimental group and were significantly higher than those in the control group. The experimental group showed significant improvements in the deviations from the ideal values in contact time and contact duration in the medial forefoot, all four parameters in the lateral forefoot, and pressure in the rear foot. [Conclusion] College-aged females who participated in the Building Osteo Neatly Exercise program once weekly for 4 months exhibited significant improvements in bone strength in the calcaneus and in foot function, as shown by the plantar pressure distribution. Further studies are needed to examine the outcomes of the Building Osteo Neatly Exercise program in an elderly population.

Correlation between Parameters of Calcaneal Quantitative Ultrasound and Hip Structural Analysis in Osteoporotic Fracture Patients

Background

Calcaneal quantitative ultrasound (QUS), which is used in the evaluation of osteoporosis, is believed to be intimately associated with the characteristics of the proximal femur. However, the specific associations of calcaneal QUS with characteristics of the hip sub-regions remain unclear.

Design

A cross-sectional assessment of 53 osteoporotic patients was performed for the skeletal status of the heel and hip.

Methods

We prospectively enrolled 53 female osteoporotic patients with femoral fractures. Calcaneal QUS, dual energy X-ray absorptiometry (DXA), and hip structural analysis (HSA) were performed for each patient. Femoral heads were obtained during the surgery, and principal compressive trabeculae (PCT) were extracted by a three-dimensional printing technique-assisted method. Pearson’s correlation between QUS measurement with DXA, HSA-derived parameters and Young’s modulus were calculated in order to evaluate the specific association of QUS with the parameters for the hip sub-regions, including the femoral neck, trochanteric and Ward’s areas, and the femoral shaft, respectively.

Results

Significant correlations were found between estimated BMD (Est.BMD) and BMD of different sub-regions of proximal femur. However, the correlation coefficient of trochanteric area (r = 0.356, p = 0.009) was higher than that of the neck area (r = 0.297, p = 0.031) and total proximal femur (r = 0.291, p = 0.034). Furthermore, the quantitative ultrasound index (QUI) was significantly correlated with the HSA-derived parameters of the trochanteric area (r value: 0.315–0.356, all p<0.05) as well as with the Young’s modulus of PCT from the femoral head (r = 0.589, p<0.001).

Conclusion

The calcaneal bone had an intimate association with the trochanteric cancellous bone. To a certain extent, the parameters of the calcaneal QUS can reflect the characteristics of the trochanteric area of the proximal hip, although not specifically reflective of those of the femoral neck or shaft.

Impact of Walking and Running on the Heel bone: the Adventist Health Study-2

Aims

Physical activity is well recognized for its bone health benefit. We examined the benefit of walk/run/jog on bone health using broadband ultrasound attenuation (BUA) of the calcaneus.

Methodology

Caucasian and African American males (n=593) and females (n=1,106) had their calcaneal BUA measured two years later after enrollment into the AHS-2. The association between calcaneal BUA (dB/Mhz) and the distance of walk/run/ jog level per week (miles) was assessed using multiple linear regression.

Results

In a multivariable model adjusted for important covariates, BUA was positively associated with BMI (P < .001), total calcium intake (P =0.31), total protein intake (P =0.38) and inversely associated with age (P < .001) and smoking (P < .05). Compared to women who did not walk/ run/ jog, women walking 10 or more miles per week had an increase in BUA by 4.08 (dB/Mhz) (P _trend=0.03). Similarly, compared to men who did not walk/ run/ jog, men walking 10 or more miles per week had an increase in BUA by 5.97 (dB/Mhz) (P _trend=0.01).

Conclusions

We concluded that BUA is positively associated with walk/ run/jog after accounting for age, BMI, smoking status, calcium intake, protein intake and estrogen usage.

Evaluation of the osteoporotic proximal humeral fracture and strategies for structural augmentation during surgical treatment

Fractures of the proximal humerus are relatively common injuries in the elderly population. Given the association between proximal humeral fractures and osteoporosis, elderly patients who sustain these injuries should always undergo a fragility fracture workup. Furthermore, a preoperative assessment of local bone quality can be critical in facilitating decision making regarding surgical and nonsurgical treatment. Modalities for quantifying osteoporosis in the proximal humerus include plain radiography and spiral computed tomography imaging. Optimal management of osteoporotic proximal humeral fractures has evolved and may now includes use of locking plates and augmentation with intramedullary fibular grafts, calcium phosphate or sulfate cement, and iliac crest bone graft. This article reviews the demographics of patients who sustain proximal humerus fractures, the appropriate postinjury fragility fracture workup, modalities for quantifying osteoporosis in the proximal humerus, techniques for augmenting fixation of proximal humerus fractures, and the authors' preferred approach to the treatment of these injuries.

Soy milk and dairy consumption is independently associated with ultrasound attenuation of the heel bone among postmenopausal women: the Adventist Health Study-2

Soy milk has become a popular substitute for dairy milk with important health claims. We hypothesized that soy milk, based on its nutrient composition, is comparable to dairy products and, therefore, beneficial for bone health. To test this hypothesis, we examined the benefit of soy milk and dairy products intake on bone health using broadband ultrasound attenuation of the calcaneus. Postmenopausal white women (n = 337) who had completed a lifestyle and dietary questionnaire at enrollment into the Adventist Health Study-2 had their calcaneal broadband ultrasound attenuation measured 2 years later. The association between osteoporosis (defined as a T-score <-1.8) and some dietary factors (soy milk, dairy) and selected lifestyle factors was assessed using logistic regression. In a multivariable model adjusted for demographics, hormone use, and other dietary factors, osteoporosis was positively associated with age (odds ratio [OR] = 1.08; 95% confidence interval [CI], 1.06-1.12) and inversely associated with body mass index (OR = 0.91; 95% CI, 0.86-0.97) and current estrogen use (OR = 0.27; 95% CI, 0.13-0.56). Compared with women who did not drink soy milk, women drinking soy milk once a day or more had 56% lower odds of osteoporosis (OR = 0.44; 95% CI, 0.20-0.98; P(trend) = .04). Women whose dairy intake was once a day or more had a 62% reduction in the likelihood of having osteoporosis (OR = 0.38; 95% CI, 0.17-0.86; P(trend) = .02) compared with women whose dairy intake was less than twice a week. Among individual dairy products, only cheese showed an independent and significant protection (OR = 0.28; 95% CI, 0.12-0.66; P(trend) = .004) for women eating cheese more than once per week vs those who ate cheese less than once a week. We concluded that osteoporosis is inversely associated with soy milk intake to a similar degree as dairy intake after accounting for age, body mass index, and estrogen use.

Variation in bone mineral density by anatomical site in patients with proximal humeral fractures

Low-energy fractures of the proximal humerus indicate osteoporosis and it is important to direct treatment to this group of patients who are at high risk of further fracture. Data were prospectively collected from 79 patients (11 men, 68 women) with a mean age of 69 years (55 to 86) with fractures of the proximal humerus in order to determine if current guidelines on the measurement of the bone mineral density at the hip and lumbar spine were adequate to stratify the risk and to guide the treatment of osteoporosis. Bone mineral density measurements were made by dual-energy x-ray absorptiometry at the proximal femur, lumbar spine (L2-4) and contralateral distal radius, and the T-scores were generated for comparison. Data were also collected on the use of steroids, smoking, the use of alcohol, hand dominance and comorbidity.

The mean T-score for the distal radius was −2.97 (sd 1.56) compared with −1.61 (sd 1.62) for the lumbar spine and −1.78 (sd 1.33) for the femur. There was a significant difference between the mean lumbar and radial T scores (1.36 (1.03 to 1.68); p < 0.001) and between the mean femoral and radial T-scores (1.18 (0.92 to 1.44); p < 0.001). The inclusion of all three sites in the determination of the T-score increased the sensitivity to 66% compared with that of 46% when only the proximal femur and lumbar spine were used. This difference between measurements in the upper limb compared with the axial skeleton and lower limb suggests that basing risk assessment and treatment on only the bone mineral density taken at the hip or lumbar spine may misrepresent the extent of osteoporosis in the upper limb and the subsequent risk of fracture at this site.

The assessment of osteoporosis must include measurement of the bone mineral density at the distal radius to avoid underestimation of osteoporosis in the upper limb.

Broadband ultrasound attenuation in the calcaneal region: a comparative study of single-position versus scanning systems

This work describes a system developed to measure the broadband ultrasound attenuation (BUA) in the calcaneal region. The patient's calcanei were inspected using a microcomputer-controlled X-Y axis displacement unit with two 500-kHz, central-frequency, ultrasound transducers. The transducers facing each other are submerged in a small water tank with a support for the patient's foot between them. The system allows data to be collected from a single position or by scanning the calcaneal region to obtain a BUA map. Tests were carried out on 201 patients (110 using the single-position method, and 91 using the scanning method). The results were compared with those of densitometry tests performed using the dual energy X-ray absorptiometry (DEXA) technique (single position: r=0.50; P<0.0001; scanner: r=0.75; P<0.0001). It was concluded that the single position method is more susceptible to errors due to the difficulty in positioning the transducers relative to the calcaneus. The scanning method provides better results and can be used to screen patients before referring them for DEXA.

Quantitative ultrasound is better correlated with bone mineral density and biochemical bone markers in elderly women

The association between quantitative ultrasound (QUS) and bone turnover in postmenopausal women of different ages is an area of continuous investigation. The aim of this study was to investigate the relationship of ultrasound parameters [broadband ultrasound attenuation (BUA) and speed of sound (SOS)] to bone mineral density (BMD) and biochemical markers of bone turnover in three age groups of postmenopausal women. One hundred and twenty-three postmenopausal Caucasian women were divided into three groups according to their age: group A, range 44-54 years, mean age (+/-SD) 48.3 +/- 2.3; group B, range 55-65 years, mean age 59.4 +/- 2.1; and group C, range 66-77 years, mean age 68.2 +/- 3.1. Ultrasound parameters were measured by the DTU-one imaging ultrasonometer in the calcaneus. BMD was assessed by dual-energy X-ray absorptiometry (DEXA) at the lumbar spine, femoral neck, and trochanter. Bone turnover was assessed by serum bone-specific alkaline phosphatase (BAP), urinary excretion of free deoxypyridinoline, N-telopeptides (NTX), and C-telopeptide breakdown products of type I collagen (CTX). QUS and BMD were significantly correlated in all sites, except hip BMD in group A. The most significant correlation was observed between BUA and femoral neck BMD in group C (r = 0.626, p < 0.01). BUA correlated significantly with BAP, NTX, and CTX (r = -0.434, -0.511, -0.478, respectively; p < 0.01), and SOS with BAP and NTX (r = -0.351 and -0.356, respectively; p < 0.05) only in group C. In groups A and B, ultrasound parameters did not correlate significantly to biochemical markers. Ultrasound parameters were better correlated to hip BMD and to biochemical markers of bone turnover in elderly postmenopausal women. These ultrasound measurements could be used as a screening test for bone status, either in nonambulatory third aged women or in those living in rural areas where attending medical centers with DEXA equipment and biochemical laboratories is difficult.

Screening for low bone mass with quantitative ultrasonography in a community without dual-energy X-ray absorptiometry: population-based survey

BACKGROUND

Dual-energy x-ray absorptiometry (DXA) is the criterion standard to identify low bone mineral density (BMD), but access to axial DXA may be limited or cost prohibitive. We screened for low bone mass with quantitative ultrasonography (QUS) in a community without DXA, analyzed its reliability and obtained reference values and estimated the prevalence of low QUS values.

METHODS

We enrolled 6493 residents of Kinmen, Taiwan, and a reference group (96 men and 70 women aged 20-29 years) for this cross-sectional, community-based study. All participants completed a questionnaire and underwent ultrasonographic measurements. Reliability and validity of QUS measurements were evaluated. Broadband ultrasound attenuation (BUA) values were obtained and statistically analyzed by age, sex and weight. Annual loss of BUA was determined. Trends in the prevalence of QUS scores were evaluated.

RESULTS

Two QUS were used and had a correlation coefficient of 0.90 (p < 0.001). Calcaneal BUA was significantly correlated with BMD in the femoral neck (r = 0.67, p < 0.001) and BMD of the total lumbar spine (r = 0.59, p < 0.001). BUAs in the reference group were 92.72 +/- 13.36 and 87.90 +/- 10.68 dB/MHz for men and women, respectively. Estimated annual losses of calcaneal BUA were 0.83% per year for women, 0.27% per year for men, and 0.51% per year for the total population. The prevalence of severely low QUS values (T-score = -2.5) tended to increase with aging in both sexes (p < 0.001). Across age strata, moderately low QUS values (-2.5 < T-score < -1.0) were 31.6-41.0% in men and 23.7-38.1% in women; a significant trend with age was observed in men (p < 0.001).

CONCLUSION

Age-related decreases in calcaneal ultrasonometry, which reflected the prevalence of low bone mass, were more obvious in women than in men.

Correlation of quantitative heel ultrasonography with central dual-energy X-ray absorptiometric bone mineral density in postmenopausal women

OBJECTIVES

In this study, we sought the proper cutoff level for quantitative ultrasonography (QUS) of the heel in identifying bone mineral density (BMD) categories as determined by dual-energy x-ray absorptiometry (DXA) in postmenopausal women.

METHODS

With the use of DXA, BMD categories of the lumbar spine and different areas of the left femur of 420 healthy women according to World Health Organization definitions were determined. Quantitative ultrasonography of the heel was also performed in each subject. Receiver operating characteristic curves were plotted, and sensitivity and specificity of QUS to diagnose osteoporosis were examined at different points to identify the best cutoff level. The diagnostic agreement between the two techniques in identifying osteoporosis was assessed with kappa scores.

RESULTS

The kappa scores were 0.31 for the lumbar region and 0.5 for the femoral neck region. On the receiver operating characteristic study, a score of -1 was found to be the appropriate cutoff point for QUS studies, in which the sensitivity of QUS to diagnose BMD osteoporosis varied between 78% and 87.5% depending on the site of the DXA study. With the proposed cutoff point (-1), sensitivity and specificity of QUS in detecting osteoporosis at the lumbar spine were 83.9% and 51%, respectively, and at the femoral neck were 84% and 50%, respectively.

CONCLUSIONS

Insufficient agreement between QUS and DXA led to uncertainty on expected BMD in people tested by QUS. The proposed cutoff value could achieve higher sensitivity but only by accepting higher rates of false-positive results.

Low BMD is a risk factor for low-energy Colles' fractures in women before and after menopause

Until now, it was unclear if low volumetric bone mineral density at the distal radius was also a risk factor for Colles' fracture, especially in patients with low-energy trauma. In our study, we used peripheral quantitative computed tomography to measure volumetric bone mineral density of a nonfractured distal radius and dual-energy x ray absorptiometry to measure areal bone mineral density at the spine and hip in patients with Colles' fractures, including 45 women who were premenopausal (age range, 40-50 years) and 39 women who were postmenopausal (age range, 51-65 years). In each group, the patients were subdivided into low-energy and high-energy fracture groups. Ninety-five age-matched healthy women who were premenopausal and 90 age-matched healthy women who were postmenopausal without fracture history served as controls. The results showed that patients with low-energy fractures had a lower bone mineral density at all measurement sites, compared with either patients with high-energy fractures or control subjects. More patients were found with a bone mineral density less than -2.5 standard deviations (Z-score) in the premenopausal group (12.5% measured by dual-energy x ray absorptiometry and 41.2% measured by peripheral quantitative computed tomography) than in the postmenopausal group (6.0% measured by dual-energy x ray absorptiometry and 4.8% measured by peripheral quantitative computed tomography). These results suggest that low bone mineral density, particularly measured using peripheral quantitative computed tomography at the distal radius of women who were premenopausal, was an important risk factor for low-energy Colles' fractures.

LEVEL OF EVIDENCE

Prognostic study, Level I-1 (prospective study). See the Guidelines for Authors for a complete description of levels of evidence.

The influence of corticosteroids on quantitative ultrasound parameters of the calcaneus in the 1st year after renal transplantation

Steroid-related bone loss is a recognized complication after renal transplantation. Quantitative ultrasound (QUS) of bone measures bone structure besides bone mass. We investigated the influence of corticosteroid therapy on QUS parameters in the 1st year after renal transplantation. A total of 119 renal transplant recipients were randomized to receive either a steroid-free regimen or a regimen with prednisone during 4 months. In 96 patients (steroid-free n=49, steroids n=47), dual-energy X-ray absorptiometry (DXA) parameters of the lumbar spine and the right hip, and QUS parameters of the right calcaneus were measured at baseline, 3, and 12 months after transplantation. Despite a significant difference in steroid use between the two groups, there was no statistically significant difference between the two groups in DXA and QUS parameters at any time point. BMD of the lumbar spine decreased at 3 months and recovered hereafter to the baseline value. BMD of the femoral trochanter decreased at 3 months and remained stable hereafter. The QUS parameter broadband ultrasound attenuation (BUA) was significantly lower at 12 months after transplantation compared with baseline (steroid-free -4.1+/-1.5%, steroids -2.6+/-1.5%). In contrast to the DXA parameters, BUA continued to decrease (P<0.05) between 3 and 12 months after transplantation in both groups. It is concluded, that the usage of a moderate dose of steroids during 4 months after renal transplantation had no important influence on QUS parameters of the calcaneus. While BMD remained stable or improved between 3 and 12 months after transplantation, the decrease in BUA seems to reflect a continuing change in bone structure in this population with preexistent renal osteodystrophy.

Age-related decline in bone mass measured by dual-energy X-ray absorptiometry and quantitative ultrasound in a population-based sample of both sexes: identification of useful ultrasound thresholds for osteoporosis screening

Quantitative ultrasound (QUS) can be used as a screening tool for low bone mineral density (BMD), but clinical guidelines have not been set. The aim of this population-based, cross-sectional study was to compare age-related changes in bone mass measured by QUS (Lunar, Achilles Plus) and dual-energy X-ray absorptiometry (DXA) in a random sample of 1630 individuals (1041 females, 589 males) 30-85 yr of age. Individuals with DXA T-scores < or =-2.5 at the femoral neck or total hip were identified and receiver operating curves (ROCs) were used to calculate cutoff points for QUS. Sensitivity, specificity, and kappa statistics were calculated. Age-related bone loss was significantly larger with QUS than DXA at all sites in women. For men, the curves were similar for QUS and DXA in the hip. Similar correlations were found between QUS and DXA in different age groups of both sexes (0.36-0.60). For women aged 50-65 yr, a QUS T-score >-1.0 was found to be the most applicable for identifying normal BMD. In the 70-85 yr age group, a T-score <-2.5 for women and a T-score <-0.5 for men seemed reasonable cutoffs for identifying normal BMD (sensitivity: 86-93%; specificity: 28-44%; discordance: 33-73%). Calcaneal QUS cannot be used for the diagnosis of osteoporosis according to WHO criteria, but it can be of use to exclude osteoporosis in 30-40% of our cases.

Distal tibia areal bone mineral density: use in detecting low aBMD of the hip in young women

Dual-energy X-ray absorptiometry (DXA) is a primary clinical tool for identification of adults with low areal bone mineral density (aBMD) and who are at increased risk for future osteoporosis and fragility fractures. Procedures for several aBMD scans of clinical interest might be limited by artifact, inaccessible anatomical regions, and positioning errors. Sites for scanning that overcome these limitations need further investigation for application to large-scale screening and relevance to clinical decisions regarding diagnosis and treatment. In this study, 146 women (mean +/- SE age = 20.1 +/- 0.1 yr, height = 163.3 +/- 0.2 cm, weight = 60.0 +/- 0.2 kg) underwent DXA of the total body (TB) and right and left total proximal femurs (TPF), total forearms (TF), and distal tibiae (DT). Osteopenia was identified in 24 women. Areal BMD was positively related among all measurement sites (r = 0.55-0.81, all p < 0.001). Total body, TF, and DT aBMD each displayed low sensitivity (0.29-0.33) and high specificity (0.95-0.98) to detect osteopenia of the TPF. Addition of TB fat-free mass slightly enhanced the predictive value of DT aBMD. Overall, DT aBMD can discriminate between osteopenic and normal subjects with comparable accuracy to TB or TF aBMD.

Updating a 3-D vertebral body finite element model using 2-D images

In osteoporotic patients, vertebral strength is often evaluated in the clinical setting using bone densitometry methods, such as dual energy X-ray absorptiometry. Finite element models based on computed tomography (CT) have been shown to outperform such methods in predicting fracture strength, but repetitive use of CT scans may be impractical due to cost, availability, and radiation exposure. We propose a method of generating a vertebral model at an initial time point which can subsequently be updated using several digital radiographs by using an algebraic reconstruction technique (ART) to find the three-dimensional density distribution. The effectiveness of the algorithm was measured by comparison of the error of the reconstructed model to the error incurred by using the outdated model. Application of the ART was able to reduce density errors from 30% to under 7% and to reduce errors in calculated vertebral stiffness from 125% to under 10%. This preliminary study demonstrates that the method is valid and could potentially improve fracture risk diagnostics drastically.

Osteoporosis: Point-of-Care Testing

OBJECTIVE

To review the literature concerning the utility of point-of-care (POC) testing devices for the diagnosis and management of osteoporosis.

DATA SOURCES

Articles were identified from a MEDLINE search (1993–June 2003). Additional references were obtained from cross-referencing the bibliographies of selected articles.

STUDY SELECTION AND DATA EXTRACTION

After evaluation of clinical trials and select review articles, articles comparing peripheral dual-energy absorptiometry (pDXA) or quantitative ultrasound (QUS) with central DXA (cDXA) measurements were emphasized in this analysis.

DATA SYNTHESIS

Sensitivity for detecting osteoporosis by QUS or pDXA varies widely (range 35–75%). Using adjusted T-score cutoffs increases sensitivity to 85–95%, at the price of reducing device specificity to 23–49%. Many states require a radiology technician to perform pDXA tests.

CONCLUSIONS

POC testing with peripheral devices should only be considered in areas with limited access to cDXA or for women who initially refuse cDXA testing. T scores of −1.0 or less with POC testing typically require further evaluation via cDXA. Many states require pDXAs to be performed by certified radiology technologists, making QUS use more feasible for pharmacists. POC testing should not be used for assessing response to osteoporosis therapy.

Correlation of quantitative ultrasound parameters of the calcaneus with bone density of the spine and hip in women with prevalent hypovitaminosis D

Quantitative ultrasound (QUS) of the calcaneus correlates modestly with axial dual-energy X-ray absorptiometry (DXA). Because bone mineral density (BMD) might be influenced by vitamin D status, we assessed the correlation between both techniques in 56 Arabian women, a population with high prevalence of hypovitaminosis D. The speed of sound (SOS), broadband ultrasound attenuation (BUA), and estimated BMD of the right calcaneus were determined by QUS. Spine and right hip BMD were measured by DXA scan. The serum 25-hydroxyvitamin D (25OHD) level was measured by radioimmunoassay. The correlations of QUS parameters (estimated calcaneal BMD, BUA, and SOS) with spine and hip BMD were modest (r = 0.50, r = 0.53, r = 0.41 for the spine and r = 0.54, r = 0.56, and r = 0.46 for the hip, respectively; p < 0.01 for all comparisons), but stronger in postmenopausal women. All postmenopausal women with low estimated calcaneal BMD (T-score pound -1) had a T-score pound -1 by DXA of the spine or hip. Of the 21 premenopausal women with spine or hip T-score pound -1 who had 25OHD measurements, 20 (95.2%) had levels below 50 nmol/L and 12 (57%) had levels below 30 nmol/L. The subgroup with 25OHD < 30 nmol/L had significantly lower spine (p < 0.01) and hip BMD (p < 0.05) than the subgroup with 25OHD >/= 30 nmol/L. QUS parameters were not significantly different between the two subgroups. The QUS and DXA correlated modestly well in women with prevalent hypovitaminosis D. QUS could be used in postmenopausal women with hypovitaminosis D to identify those at risk for osteoporotic fracture.

Does Lower-Body BMD Develop at the Expense of Upper-Body BMD in Female Runners?

PURPOSE

Evidence suggests that exercise plays an important role in stimulating site-specific bone mineral density (BMD). However, what is less well understood is how these benefits dissipate throughout the body. Hence, the purpose of the present study was to compare the levels of, and the correlation between, BMD recorded at 10 sites in female endurance runners, and to investigate possible determinants responsible for any inter-site differences observed.

METHODS

Repeated measures ANOVA was used to compare the BMD between sites and factor analysis was used to describe the pattern of intersite correlations. Allometric ANCOVA was used to identify the primary determinants of bone mass and how these varied between sites.

RESULTS

The ANOVA and factor analysis identified systematic differences in BMD between sites, with the greatest BMD being observed in the lower-body sites, in particular the legs. An investigation into the possible mechanisms responsible for these differences revealed "distances run" (km.wk-1) as a positive, and "years of training" as a negative determinant of bone mass (P < 0.001). However, the effect of a number of determinants varied between sites (P < 0.05). Specifically, the ANCOVA identified that running further distances resulted in higher bone mass in the arms and legs. In contrast, training for additional years appeared to result in lower bone mass in the arms and lumbar spine. Calcium intake was also found to be positively associated with bone mass in the legs but negatively associated at all other sites.

CONCLUSIONS

A combination of running exercise and calcium intake would appear to stimulate the bone mass of women endurance runners at lower-body sites but at the expense of bone mass at upper-body sites.

Leisure physical activity is associated with quantitative ultrasound measurements independently of bone mineral density in postmenopausal women

The purpose of this study was to assess the magnitude of the relationship between leisure physical activity and bone status as measured either by an Achilles ultrasound bone densitometer (QUS) or dual-energy X-ray absorptiometry (DXA) in postmenopausal women. We studied 1162 French Canadian postmenopausal women, aged 33-84 years (mean age 58 years), for QUS parameters [broadband ultrasound attenuation (BUA), speed of sound (SOS), and stiffness index (SI)] measured at the right calcaneus, and bone mineral density (BMD) measured at the lumbar spine and femoral neck. Multivariate regression analyses revealed that leisure physical activity level was an independent predictor of the heel QUS parameters and of femoral neck BMD. No such association was observed for BMD of the lumbar spine. Heel QUS parameters (BUA, SOS, SI) and femoral neck BMD adjusted for interfering covariables showed a statistically significant difference between sedentary (less than three sessions/month) and active women (three or more sessions/week) (P < or = 0.001). Furthermore, after adjusting each heel QUS parameters for the mean lumbar spine BMD value, the association observed between leisure physical activity and QUS remained significant. These results suggest that regular leisure physical activity could influence QUS parameters, independently of BMD, and that quantitative ultrasound could be a suitable outcome measure in exercise studies in postmenopausal women.

Can radial bone mineral density and quantitative ultrasound measurements reduce the number of women who need axial density skeletal assessment?

The purpose of this study was to investigate the clinical usefulness of forearm bone mineral density (BMD) and speed of sound (SOS) at the phalanx and radius as pre-selection tests to identify women with low BMD at the axial skeleton. BMD was measured by dual-energy X-ray absorptiometry (DXA) in the forearm, lumbar spine and femoral neck. SOS at the radius and phalanx was measured using a multisite quantitative ultrasound (QUS) device. Measurements were performed on 524 consecutive women referred for the assessment of BMD. Women with a T-score <-1 and T-score < or =-2.5 at either spine or femoral neck were identified, and T-score cut-off values for the forearm DXA and QUS variables were determined. Cut-off values for the forearm BMD estimated to detect normal women and those with T-score <-1 at the axial skeleton identified a total of 82% of subjects with 91% certainty. Cut-off values for the forearm BMD determined to detect women with T-score >-2.5 and those with osteoporosis allowed the identification of 62% of the study population with 90% certainty. Cut-off values for the phalangeal and radial SOS estimated to detect normal women and those with T-score <-1 at the axial skeleton identified a total of 49% and 1% of subjects, respectively. Cut-off values estimated for QUS variables to detect women with T-score >-2.5 and those with osteoporosis at the axial skeleton either failed to detect subjects with sufficient certainty (phalangeal SOS) or detected a negligible percentage of patients (radial SOS). In conclusion, forearm BMD may be used as a pre-selection test to identify women with low BMD at the axial skeleton, thus enabling reduction of the number of women who need axial BMD assessment. SOS of the phalanges and radius appears to have less value in the detection of the women with low axial BMD.

A comparison of calcaneal dual-energy X-ray absorptiometry and calcaneal ultrasound for predicting the diagnosis of osteoporosis from hip and spine bone densitometry

Peripheral densitometry is increasingly being used in the management of osteoporosis, but the optimal diagnostic thresholds have not been defined. The aim of this study was to determine the optimal T-score for peripheral dual-energy X-ray absorptiometry (pDXA) of the heel using a GE Lunar PIXI and quantitative ultrasound (QUS) of the heel using a GE Lunar Achilles Plus when compared with dual-energy X-ray absorptiometry (DXA) of central sites (spine, femoral neck, or total hip). Ninety-nine women (mean age 69 +/- 8, range 33-86 yr) referred from the metabolic bone clinic were studied. The optimal T-score for pDXA from ROC analysis was -1.7 and for QUS was -2.5. The pDXA T-score that defined the same prevalence of osteoporosis at any central site was also -1.7 and for QUS was -2.4. These results are similar to the manufacturer's recommendations. There is no significant difference in performance between the PIXI and QUS.

Odds ratios for hip- and lower forearm fracture using peripheral bone densitometry; a case-control study of postmenopausal women

BACKGROUND

Dual-energy X-ray absorptiometry (DXA) measured at the lumbar spine and particularly at the hip remain the gold-standard for diagnosing osteoporosis. However, devices for assessing the peripheral skeleton present several advantages in terms of lower price and portability. A major concern when using peripheral densitometry is the poor correlation with the central measurements. The main aim of this study is, therefore, to assess the possibility of expressing ultrasound measurements at the heel and bone mineral density (BMD) measured at the distal forearm as fracture odds ratios rather than an absolute measure of bone mass.

METHODS

A total of 76 women with lower forearm fracture, 47 women with hip fracture and 231 age-matched women (controls) were included. All had broadband ultrasound attenuation (BUA) and speed of sound (SOS) measured at the heel using the DTU-one ultrasound scanner as well as BMD measured by dual X-ray absorptiometry on the DTX-200 at the distal forearm.

RESULTS

BUA, SOS and BMD at the distal forearm were all significantly lower in fracture patients compared with their respective control groups. The odds ratio for lower forearm fracture was 3.1 (95% CI: 1.8; 5.2) for heel-BUA (T-score cutoff: -2.3), 4.1 (2.3; 7.4) for heel-SOS (-2.1) and 2.2 (1.3; 3.7) for lower forearm BMD (-2.7). The odds ratio for hip fracture was 3.4 (1.5-7.7) for heel-BUA (-2.7), 3.6 (1.6; 8.1) for heel-SOS (-2.6) and 3.2 (1.4; 7.4) for lower forearm BMD (-2.9).

CONCLUSION

Peripheral densitometry can discriminate between hip- and lower forearm fracture patients and age-matched controls. Significantly elevated odds ratios for incurring these fractures can be calculated using device- and site specific t-score cutoff values. The results from this case-control study need to be confirmed by prospective cohort studies.

Comparison of heel ultrasound and finger DXA to central DXA in the detection of osteoporosis. Implications for patient management

The goal of the study was to investigate the potential discordance in patient management when a clinician assumes that a peripheral device is a diagnostic surrogate for central DXA in the detection and treatment of osteoporosis. Over a period of 2 mo, asymptomatic women seeking conventional central DXA evaluation for osteoporosis at a diagnostic imaging center were also evaluated with heel ultrasound and finger DXA peripheral imaging devices. T-Scores of -2.5 or less in screening examinations were used to evaluate the discordance between the two peripheral devices and central DXA in the identification of patients with osteoporosis. Higher T-score cutoffs (>-2.5) were also evaluated. Using central DXA as the standard for comparison, the sensitivity of heel ultrasound for screening cases was 0.34 and specificity was 0.92. For finger DXA, sensitivity was 0.23 and specificity was 0.92. Overall discordance between the peripheral devices and central DXA was 21% (heel) and 23% (finger). Heel ultrasound identified 7 out of every 22 osteoporotic patients diagnosed with central DXA. Finger DXA identified 5 out of every 22 osteoporotic patients. Using lower T-scores for the peripheral devices increased sensitivity but markedly increased discordance with DXA. The peripheral devices we studied cannot be considered equivalent surrogates for central DXA in the screening of asymptomatic women for osteoporosis.