Discriminatory ability of quantitative ultrasound parameters and bone mineral density in a population-based sample of postmenopausal women with vertebral fractures: results of the Basel Osteoporosis Study

Quantitative Ultrasound (QUS) in the Management of Osteoporosis and Assessment of Fracture Risk: An Update

Quantitative ultrasound (QUS) presents a low cost and readily available alternative to DXA measurements of bone mineral density (BMD) for osteoporotic fracture risk assessment. It is performed in a variety of skeletal sites, among which the most widely investigated and clinically used are first the calcaneus and then the radius. Nevertheless, there is still uncertainty in the incorporation of QUS in the clinical management of osteoporosis as the level of clinical validation differs substantially upon the QUS models available. In fact, results from a given QUS device can unlikely be extrapolated to another one, given the technological differences between QUS devices. The use of QUS in clinical routine to identify individuals at low or high risk of fracture could be considered primarily when central DXA is not easily available. In this later case, it is recommended that QUS bone parameters are used in combination with established clinical risk factors for fracture. Currently, stand-alone QUS is not recommended for treatment initiation decision making or follow-up. As WHO classification of osteoporosis thresholds cannot apply to QUS, thresholds specific for given QUS devices and parameters need to be determined and cross-validated widely to have a well-defined and certain use of QUS in osteoporosis clinical workflow. Despite the acknowledged current clinical limitations for QUS to be used more widely in daily routine, substantial progresses have been made and new results are promising.

Long-term exposure to air pollution might increase prevalence of osteoporosis in Chinese rural population

OBJECTIVES

The associations of long-term exposure to air pollution with osteoporosis are rarely reported, especially in rural China. This study aimed to explore the association among rural Chinese population.

METHODS

A total of 8033 participants (18-79 years) derived from the Henan Rural Cohort Study (n = 39,259) were included in this cross-sectional study. Exposure to air pollutants was estimated using machine learning algorithms with satellite remote sensing, land use information, and meteorological data [including particulate matter with aerodynamic diameters ≤1.0 μm (PM₁), ≤2.5 μm (PM_2.5), and ≤10 μm (PM₁₀), and nitrogen dioxide (NO₂)]. The bone mineral density of each individual was measured by using ultrasonic bone density apparatus and osteoporosis was defined based on the T-score ≤ -2.5. Multiple logistic regression models were used to examine the association of air pollution and osteoporosis prevalence.

RESULTS

We observed that per 1 μg/m³ increase in PM₁, PM_2.5, PM₁₀ and NO₂ were associated with a 14.9%, 14.6%, 7.3%, and 16.5% elevated risk of osteoporosis. Compared with individuals in the first quartile, individuals in the fourth quartile had higher odds ratio (OR) of osteoporosis (P-trend < 0.001), the ORs (95% confidence interval) were 2.08 (1.72, 2.50) for PM₁, 2.28 (1.90, 2.74) for PM_2.5, 1.93 (1.60, 2.32) for PM₁₀, and 2.02 (1.68, 2.41) for NO₂. It was estimated that 20.29%-24.36% of osteoporosis cases could be attributable to air pollution in the rural population from China.

CONCLUSIONS

Long-term exposure to air pollutants were positively associated with high-risk of osteoporosis, indicated that improving air quality may be beneficial to improve rural residents health.

Imaging of metabolic bone disease

Osteoporosis is the most important metabolic bone disease, with a wide distribution among the elderly. It is characterized by low bone mass and micro architectural deterioration of bone tissue, leading to enhanced bone fragility and a consequent increase in fracture risk. Identify bone weakening with an appropriate and accurate use of diagnostic imaging is of critical importance in the diagnosis and follow-up of osteoporotic patients. The aim of this review is to evaluate the detection rates of the different imaging modalities in the evaluation of bone strength, in the assessment of fracture risk and in the management of fragility fractures. (www.actabiomedica.it)

A cross-sectional study to evaluate the association of hyperbilirubinaemia on markers of cardiovascular disease, neurocognitive function, bone mineral density and renal markers in HIV-1 infected subjects on protease inhibitors

BACKGROUND

Ongoing inflammation in controlled HIV infection contributes to non-AIDS comorbidities. High bilirubin appears to exhibit an anti-inflammatory effect in vivo. We therefore examined whether increased bilirubin in persons with HIV was associated with differences in markers of inflammation and cardiovascular, bone, renal disease, and neurocognitive (NC) impairment.

METHODS

This cross-sectional study examined inflammatory markers in individuals with stable HIV infection treated with two nucleoside reverse transcriptase inhibitors and a boosted protease inhibitor. Individuals recruited were those with a normal bilirubin (NBR; 0-17 μmol/L) or high bilirubin (>2.5 × upper limit of normal). Demographic and anthropological data were recorded. Blood and urine samples were taken for analyses. Pulse wave velocity (PWV) measurement, carotid intimal thickness (CIT), and calcaneal stiffness (CSI) were measured. Males were asked to answer a questionnaire about sexual function; NC testing was performed using CogState.

RESULTS

101 patients were screened, 78 enrolled (43 NBR and 35 HBR). Atazanavir use was significantly higher in HBR. Whilst a trend for lower CIT was seen in those with HBR, no significant differences were seen in PWV, bone markers, calculated cardiovascular risk (Framingham), or erectile dysfunction score. VCAM-1 levels were significantly lower in the HBR group. HBR was associated with lower LDL and triglyceride levels. NBR was associated with a calculated FRAX significantly lower than HBR although no associations were found after adjusting for tenofovir use. No difference in renal markers was observed. Component tests of NC testing revealed differences favouring HBR but overall composite scores were similar.

DISCUSSION

High bilirubin in the context of boosted PI therapy was found not to be associated with differences in with the markers examined in this study. Some trends were noted and, on the basis of these, a larger, clinical end point study is warranted.

Quantitative Ultrasound (QUS) in the Management of Osteoporosis and Assessment of Fracture Risk

The use of quantitative ultrasound (QUS) for a variety of skeletal sites, associated with the absence of technology-specific guidelines, has created uncertainty with respect to the application of QUS results to the management of individual patients in clinical practice. However, when prospectively validated (this is not the case for all QUS devices and skeletal sites), QUS is a proven, low-cost, and readily accessible alternative to dual-energy X-ray absorptiometry (DXA) measurements of bone mineral density (BMD) for the assessment of fracture risk. Indeed, the clinical use of QUS to identify subjects at low or high risk of osteoporotic fracture should be considered when central DXA is unavailable. Furthermore, the use of QUS in conjunction with clinical risk factors (CRF),allows for the identification of subjects who have a low and high probability of osteoporotic fracture. Device- and parameter-specific thresholds should be developed and cross-validated to confirm the concurrent use of QUS and CRF for the institution of pharmacological therapy and monitoring therapy.

The effect of inhaled corticosteroids on bone mineral density measured by quantitative ultrasonography in an older population

INTRODUCTION

Prolonged use of systemic corticosteroids leads to reduced bone mineral density and osteoporosis, in turn increasing the risk of minimal trauma fractures with their associated morbidity and mortality in elderly populations. However, the effect of inhaled corticosteroids on bone mineral density has been debated in the medical literature.

OBJECTIVES

We aimed to determine the effect of inhaled corticosteroids on bone mineral density measured using calcaneal quantitative ultrasonography in a cohort of older Australians.

METHODS

Data was collected from the Hunter Community Study, a longitudinal cohort of Australians aged 55-85. Simple and multiple linear regression methods were used to test the cross-sectional association between inhaled corticosteroids and calcaneal bone mineral density measured with quantitative ultrasound at baseline. A causal diagram was used to determine the minimally sufficient number of co-variates necessary to determine the unconfounded effect of inhaled corticosteroids on bone mineral density; these included gender, body mass index, smoking, asthma, alcohol use, age, physical activity, and diet.

RESULTS

There were 152 (6.8%) patients on inhaled corticosteroids and 2098 (93%) controls. Simple and multiple linear regression methods showed a non-significant effect of inhaled steroids on BMD with slight decrease of BMD -0.010 g/cm² (95% CI -0.042 to 0.022, P = .55) and -0.013 g/cm² (95% CI -0.062 to 0.036, P = .61) respectively. Age, gender, body mass index, and smoking were stronger predictors of BMD.

CONCLUSIONS

No statistically significant relationship was detected between the use of inhaled corticosteroids and reduced bone mineral density in this observational study of a cohort of older Australians.

Diabetes and Obesity as Independent Risk Factors for Osteoporosis: Updated Results from the ROIS/EMEROS Registry in a Population of Five Thousand Post-Menopausal Women Living in a Region Characterized by Heavy Environmental Pressure

Objectives: We aimed to analyze bone mineralization and the effect of different risk factors for osteoporosis in postmenopausal women. Methods: We found 4909 postmenopausal subjects within ≥10,000 records from the ROIS/EMEROS (Ionian and Salento Osteoporosis Registry/Euro Mediterranean Registry of Osteoporosis) registry, a population study carried out in an area characterized by heavy environmental pressure between Brindisi and Taranto from 2009 to 2016. All subjects were assessed via phalangeal quantitative ultrasound (QUS) to evaluate their bone mineralization (assessed via amplitude dependent speed of sound (AD-SoS)) and the association between demineralization and the presence of other conditions or risk factors. Results: Mean age was 64 ± 9.5 years and mean body mass index (BMI) was 28.7 ± 3.5 kg/m². Pearson correlation analyses revealed a negative association between bone mineralization (AD-SoS) and BMI (p < 0.001). By using multivariate logistic regression analysis, we observed significant values of odds ratios (ORs) of osteoporosis (adjusted for age, physical activity, and the use of drugs known to increase the risk of fractures) in subjects with diabetes and obesity: 1.39 (confidence interval (CI): 1.05-1.83) and 1.46 (CI: 1.20-1.78), respectively. A statistically significant linear trend of higher ORs of osteoporosis was found for increasing values of BMI. Conclusions: Our study confirmed the high impact of obesity and type 1 and type 2 diabetes on osteoporosis.

New perspectives in echographic diagnosis of osteoporosis on hip and spine

Currently, the accepted "gold standard" method for bone mineral density (BMD) measurement and osteoporosis diagnosis is dual-energy X-ray absorptiometry (DXA). However, actual DXA effectiveness is limited by several factors, including intrinsic accuracy uncertainties and possible errors in patient positioning and/or post-acquisition data analysis. DXA employment is also restricted by the typical issues related to ionizing radiation employment (high costs, need of dedicated structures and certified operators, unsuitability for population screenings). The only commercially-available alternative to DXA is represented by "quantitative ultrasound" (QUS) approaches, which are radiation-free, cheaper and portable, but they cannot be applied on the reference anatomical sites (lumbar spine and proximal femur). Therefore, their documented clinical usefulness is restricted to calcaneal applications on elderly patients (aged over 65 y), in combination with clinical risk factors and only for the identification of healthy subjects at low fracture risk. Literature-reported studies performed some QUS measurements on proximal femur, but their clinical translation is mostly hindered by intrinsic factors (e.g., device bulkiness). An innovative ultrasound methodology has been recently introduced, which performs a combined analysis of B-mode images and corresponding "raw" radiofrequency signals acquired during an echographic scan of the target reference anatomical site, providing two novel parameters: Osteoporosis Score and Fragility Score, indicative of BMD level and bone strength, respectively. This article will provide a brief review of the available systems for osteoporosis diagnosis in clinical routine contexts, followed by a synthesis of the most promising research results on the latest ultrasound developments for early osteoporosis diagnosis and fracture prevention.

Diabetes and Obesity as Independent Risk Factors for Osteoporosis in Postmenopausal Women: A Population Study

We aimed to analyze bone mineralization and the effect of different risk factors for osteoporosis in postmenopausal women. We studied 2,756 postmenopausal subjects out of ≥10,000 records from the ROIS registry in the frame of the PROF Project, a population study carried out in Salento (Taranto, Brindisi, Lecce) from 2009 to 2012. All subjects were assessed by phalangeal Quantitative Ultrasound (QUS) to evaluate their bone mineralization (assessed by Amplitude Dependent Speed of Sound, AD-SoS) and the association between demineralization and the presence of other conditions or risk factors. Mean age was 64±9.5 years and mean BMI was 28.7±3.5 Kg/m2. Pearson correlation analyses revealed a negative association between bone mineralization (AD-SoS) and BMI (P<0.001). By using multivariate logistic regression analysis, we observed significant values of Odds Ratios of osteoporosis (adjusted for age, physical activity and the use of drugs known to increase the risk of fractures) in subjects with diabetes and obesity: 1.39 (CI: 1,05–1,83) and 1.46 (CI: 1.20–1.78), respectively. A statistically significant linear trend of higher Odds Ratios of osteoporosis was found for increasing values of BMI. The percent change in the odds of vertebral fractures per single SD decrease of AD-SoS was 47% (P<0.001). Diabetes and obesity in postmenopausal women are likely to represent independent risk factors for osteoporosis. Phalangeal QUS showed a good power of predictivity in identifying subjects with vertebral fractures.

Quantitative ultrasound at the phalanges in a cohort of monozygotic twins of different ages

PURPOSE

The aim of our study was to evaluate bone quality by quantitative ultrasound (QUS) at the phalanges in 129 monozygotic twin couples, outlining the differences between growing subjects and adults.

MATERIALS AND METHODS

A total of 129 healthy monozygotic twin couples (42 of children under 18 years of age and 87 of adults) were studied by phalangeal QUS, measuring amplitude-dependent speed of sound (AD-SoS) and bone transmission time (BTT). Anthropometric data were also recorded.

RESULTS

In children AD-SoS and BTT were positively correlated with age (r = 0.91, r = 0.91), height (r = 0.88, r = 0.90) and weight (r = 0.81, r = 0.87); in adults AD-SoS was negatively related to age (r = -0.36), AD-SoS and BTT were positively related to height (r = 0.37, r = 0.58). Absolute value differences between twins for AD-SoS and BTT were significantly higher in adult twins (25.9 ± 21.9 for AD-SoS and 0.08 ± 0.08 for BTT) than in children (14.5 ± 12.4 for AD-SoS and 0.05 ± 0.04 for BTT).

CONCLUSION

Differentiation in bone tissue quality in twins increases with age, probably reflecting lifestyle, personal habits, likely acting through epigenetic mechanisms.

How accurately can we predict the fracture load of the proximal femur using finite element models?

BACKGROUND

Current clinical methods for fracture prediction rely on two-dimensional imaging methods such as dual-energy X-ray absorptiometry and have limited predictive value. Several researchers have tried to integrate three-dimensional imaging techniques with the finite element (FE) method to improve the accuracy of fracture predictions. Before FE models could be used in clinical settings, a thorough validation of their accuracy is required. In this paper, we try to evaluate the current state of accuracy of subject-specific FE models that are used for prediction of the fracture load of proximal femora.

METHODS

All the studies that have used FE for prediction of fracture load and have compared the predicted fracture load with experimentally measured fracture loads in vitro are identified through a systematic search of the literature. A quantitative analysis of the results of those studies has been carried out to determine the absolute prediction error, percentage error, and linear correlations between predicted and measured fracture loads.

FINDINGS

The reported coefficients of determination (R(2)) vary between 0.773 and 0.96 while the percentage error in prediction of fracture load varies between 5 and 46% with most studies reporting percentage errors between 10 and 20%.

INTERPRETATION

We conclude that FE models, which are currently used only experimentally, are in general more accurate than clinically used fracture risk assessment techniques. However, the accuracy of FE models depends on the details of their modeling methodologies. Therefore, modeling procedures need to be optimized and standardized before FE could be used in clinical settings.

The ability of lumbar spine DXA and phalanx QUS to detect previous fractures in young thalassemic patients with hypogonadism, hypothyroidism, diabetes, and hepatitis-B: A 2-year subgroup analysis from the Taranto Area of Apulia Region

BACKGROUND

Osteoporosis is a leading cause of morbidity in patients affected by β-thalassemia major or intermediate; we aimed to assess the association between demineralization observed in young thalassemic patients.

METHODS

A total of 88 patients with β-thalassemia were recruited at Microcitemia Center of Taranto Hospital under the Prevention Osteoporosis and Fractures research project from 2008 to 2010. All the patients were screened with both dual energy x-ray absorptiometry (DXA) and quantitative ultrasound (QUS). T score and Z score values were obtained for each subject.

RESULTS

The overall prevalence of demineralization was 84% with DXA and 70% with QUS, whereas normality was found in 16% of patients screened with DXA and in 30% of cases with QUS. Hypogonadism, hypothyroidism, diabetes mellitus, hepatitis-B, and the presence of previous fragility fractures were significantly associated with the demineralization status (lower T scores values) both with DXA and QUS.

CONCLUSION

Our data confirm that DXA and QUS examinations are both useful for detecting bone demineralization in thalassemic patients.

Three-year prospective study on fracture risk in postmenopausal women by quantitative ultrasound at the phalanges

The purpose of this study was the calculation of fracture risk in a prospective study on postmenopausal women by quantitative ultrasound (QUS) at the phalanges. A total of 2341 postmenopausal women were recruited in 5 centers in Italy during 2006 and 2007 for QUS measurement during a screening program for osteoporosis. Two ultrasound parameters were collected: amplitude-dependent speed of sound (AD-SoS) and ultrasound bone profile index (UBPI). Women were then recontacted in 2010 and were asked about fracture occurrence during the period since previous QUS measurement. Data about new fracture occurred in this period, site and cause of fracture were requested. Two thousand two hundred eleven women were successfully recontacted. Mean age of the recruited women was 60.9 ± 10.0 yr, mean age at menopause was 49.3 ± 4.4 yr, mean body mass index (BMI) was 26.5 ± 4.6 kg/m². A total number of 108 new major osteoporotic fractures occurred during the 3-yr period, of which 23 are hip fractures, 51 are vertebral fractures. Relative risk (RR) per standard deviation (SD) decrease for major fractures was 1.77 (confidence interval [CI]: 1.59-1.97) for AD-SoS and 2.06 (CI: 1.78-2.37) for UBPI. When corrected for age, BMI, age at menopause, the RRs are still significant and equal to 1.44 (CI: 1.26-1.65) for AD-SoS and 1.67 (CI: 1.39-2.00) for UBPI. RR for vertebral fractures was 1.63 (CI: 1.41-1.88) for AD-SoS and 1.73 (CI: 1.44-2.08) for UBPI. RR for hip fractures was 1.92 (CI: 1.55-2.37) for AD-SoS and 2.68 (CI: 1.86-3.86) for UBPI. Ultrasound parameters AD-SoS and UBPI are able to significantly predict future major fractures in a prospective cohort of more than 2000 postmenopausal women.

Assessment of the fundamental flexural guided wave in cortical bone by an ultrasonic axial-transmission array transducer

The fundamental flexural guided wave (FFGW), as modeled, for example, by the A0 Lamb mode, is a clinically useful indicator of cortical bone thickness. In the work described in this article, we tested so-called multiridge-based analysis, based on the crazy climber algorithm and short-time Fourier transform, for assessment of the FFGW component recorded by a clinical array transducer featuring a limited number of elements. Methods included numerical finite-element simulations and experiments in bone phantoms and human radius specimens (n = 41). The proposed approach enabled extraction of the FFGW component and determination of its group velocity. This group velocity was in good agreement with theoretical predictions and possessed reasonable sensitivity to cortical width (r(2) = 0.51, p < 0.001) in the in vitro experiments. It is expected that the proposed approach enables related clinical application. Further work is still needed to analyze in more detail the challenges related to the impact of the overlying soft tissue.

Bone health comparison in seven Asian countries using calcaneal ultrasound

BACKGROUND

Bone density measurements by DXA are not feasible for large population studies, whereas portable ultrasound heel scanners can provide a practical way of assessing bone health status. The purpose of this study was to assess bone health in seven Asian countries using heel ultrasound.

METHODS

Stiffness index (SI) was measured and T-scores generated against an Asian database were recorded for 598,757 women and 173,326 men aged over 21 years old using Lunar Achilles (GE Healthcare) heel scanners. The scanners were made available in public centres in Singapore, Vietnam, Malaysia, Taiwan, Thailand, Indonesia and the Philippines.

RESULTS

The mean SI was higher for men than women. In women SI as well as T-scores declined slowly until approximately 45 years of age, then declined rapidly to reach a mean T-score of < -2.5 at about 71-75 years of age. For men, SI as well as the T-score showed a slow steady decline to reach a mean of -2.0 to -2.5 at about 81-85 years. The results for females indicate that there are differences in the rate of decline between countries (significant differences between the slopes at P < 0.05). Vietnam had the fastest decrease for both T-Score and SI, resulting in this population having the poorest bone health of all countries at older ages. The results for males aged 46-85 years indicate that there are no significant differences in the rate of decline between countries for SI and T-Score. In both men and women aged 46-85 years, Vietnam and Indonesia have the lowest SI as well as T-Score for all age groups. For Vietnam and Indonesia, more than 50% of the women could be at risk of having osteoporosis and related fractures after the age of 70, while in Thailand and the Philippines this was >80 years.

CONCLUSIONS

The heel scan data shows a high degree of poor bone health in both men and women in Asian countries, raising concern about the possible increase in fractures with ageing and the expected burden on the public health system.

Association between the SPRY1 gene polymorphism and obesity-related traits and osteoporosis in Korean women

BACKGROUND

Emerging evidence has revealed a close relationship between obesity and osteoporosis. It was reported recently that conditional knockout of the Spry1 gene in mice adipocytes causes an increase in body fat and a decrease in bone mass, and that these phenotypes are rescued by Spry1 overexpression in adipose tissue. In this study, we investigated whether genetic variation in the human SPRY1 gene is associated with obesity-related phenotypes and/or osteoporosis in humans.

METHODS

We performed a candidate gene association analysis between the four single nucleotide polymorphisms (SNPs) and 14 imputed SNPs in the SPRY1 gene and obesity-related traits and osteoporosis in a Korean women cohort (3013 subjects).

RESULTS

All four SPRY1 gene SNPs were significantly associated with either obesity-related traits or osteoporosis. The TGCC haplotype in the SRPY1 gene showed simultaneous association with an increased risk for obesity-related traits, percentage body fat (p=0.0087) and percentage abdominal fat (p=0.047), and osteoporosis (odds ratio=1.50; p=0.025) in the recessive genetic model.

CONCLUSIONS

Our results support a previous finding in conditional Spry1 gene knockout mice and suggest that the SPRY1 gene is an important genetic factor for determining the risk of both obesity and osteoporosis in humans.

Heel bone mass of a young South Indian population with a Nigerian population residing in a South Indian suburban neighborhood: a comparative study

This cross-sectional cohort emphasized the impact of heel bone mass in the South Indian population and its comparison with Nigerian ethnicity, residing in South India. Peak bone mass, however, evidenced a significant decrease of around 30% compared to that of Nigerian ethnicity.

INTRODUCTION

In the South Indian population, the local folks do not seem to be well informed about the relative association of bone mass with osteoporosis. Hence, there is an acute necessity to assess the same with respect to the ethnic population, presumed to have possessed high bone mass, i.e., the Nigerian population.

METHODS

The calcaneus of the right foot was measured with a quantitative ultrasound device (Sahara, Hologic Inc., USA) for a total population of 734, out of which 314 were Indian males, 348 Indian females, 41 Nigerian males, and 30 Nigerian females, whose ages ranged from 18 to 35 years.

RESULTS

The peak bone mass in Indian males and females is 0.507 ± 0.1 and 0.479 ± 0.1 g cm(-2), respectively, and it is 0.714 ± 0.2 and 0.682 ± 0.2 g cm(-2) with regard to Nigerian male and female populations, respectively. Indian males and females who were within the age group of 26-30 and ≤ 20 years, respectively, represented high bone mass, and the same was the situation with respect to Nigerian counterparts who were within the age group of 21-25 years. Indian and Nigerian non-vegetarian population of both the genders demonstrated a high significance value of p < 0.000001, deciphered by means of unpaired t test.

CONCLUSION

Peak bone strength was dominant in the Nigerian population compared to that of Indians. The Indian population is approximately lagging by 28-30% with respect to peak bone mass behind their Nigerian equivalents. Indian non-vegetarian male and female populations lagged by 6.15% and 6.16% behind the Indian vegetarian male and female populations, respectively.

A Bayesian path analysis to estimate causal effects of bazedoxifene acetate on incidence of vertebral fractures, either directly or through non-linear changes in bone mass density

BACKGROUND/AIMS

Bone mass density values have been related with risk of vertebral fractures in post-menopausal women. However, bone mass density is not perfectly accurate in predicting risk of fracture, which decreases its usefulness as a surrogate in clinical trials. We propose a modeling framework with three interconnected parts to improve the evaluation of bone mass density accuracy in forecasting fractures after treatment.

METHODS

The modeling framework includes: (1) a piecewise regression to describe non-linear temporal BMD changes more accurately than crude percent changes, (2) a structural equation model to analyze interdependencies among vertebral fractures and their potential risk factors in preference to regression techniques that consider only directional associations, and (3) a counterfactual causal interpretation of the direct and indirect relationships between treatment and occurrence of vertebral fractures. We apply the methods to BMD repeated measurements from a study of the effect of bazedoxifene acetate on incident vertebral fractures in three different geographical regions.

RESULTS

We made four observations: (1) bone mass density changes varied largely across participants, (2) baseline age and body mass index influenced baseline bone mass density that, in turn, had an effect on prevalent fractures, (3) direct and/or indirect effects of bazedoxifene acetate on incident fractures were different across regions, and (4) estimates of indirect effects were sensible to the presence of post-treatment unmeasured confounders. In one region, around 40% of the bazedoxifene acetate effect on the occurrence of fracture is explained by its effect on bone mass density. Under the counterfactual approach, these 40% represent the average difference in the occurrence of fracture observed for untreated individuals when their bone mass density values are set at the value under bazedoxifene acetate versus under placebo.

CONCLUSIONS

Computational methods are available to evaluate and interpret the surrogacytic capability of a biomarker of a primary outcome.

Discriminative ability of heel quantitative ultrasound in postmenopausal women with prevalent vertebral fractures: application of optimal threshold cutoff values using classification and regression tree models

Quantitative ultrasound (QUS) of the heel has been proposed as a screening tool to evaluate the bone status and risk of osteoporotic fragility fractures. The aim of this study was to define threshold values that would maximize the predictive ability of QUS to discriminate subjects with vertebral fractures using the classification and regression trees (CART) models. A cross-sectional analysis was made of a cohort of 1,132 postmenopausal women with a mean age of 58 years. A total of 205 women (18.1 %) presented with a history of vertebral fracture. For all patients, a questionnaire of osteoporosis risk factors was given and measurements of the heel QUS and bone mineral density at the lumbar spine and the proximal femur, obtained by dual-energy X-ray absorptiometry (DXA), were made. Spinal radiographs were assessed for vertebral fractures. Sensitivity, specificity, predictive values, likelihood ratios, and receiver operator characteristics (ROC) curve QUS values were calculated using the optimal threshold identified in the CART models. Cutoff values calculated from best CART model (i.e., a QUS index >90.5 %) yielded a sensitivity of 80.3 % (95 % CI 69.2-88.1), a negative predictive value of 94 % (95 % CI 90.1-96.5), and a specificity of 68.8 % (95 % CI 63.3-73.8). This cutoff value would obviate the need to perform DXA in 32.8 % of the women of our population at risk for vertebral fractures. The area under the ROC curve of the best model was 0.8071. QUS was shown to discriminate between women with and without a history of vertebral fracture and constitutes a useful tool for assessing vertebral fracture risk. The application of decision trees (CART analyses) was helpful to define the optimal threshold QUS values.

Phalangeal quantitative ultrasound in 1,719 children and adolescents with bone disorders

SUMMARY

We measured bone properties by phalangeal quantitative ultrasound in 1,719 pediatric patients with bone disorders, classifying them according to fracture status. Quantitative ultrasound discriminated fractured and nonfractured pediatric patients and enabled us to stratify fractured patients into classes according to the severity of the causative trauma (spontaneous, minimal trauma, appropriate trauma fractures).

INTRODUCTION

The correlation between quantitative bone measurements and fractures is poorly established in pediatric patients with bone disorders. We correlated phalangeal quantitative ultrasound (QUS) and fracture history in children and adolescents with bone disorders and evaluated the ability of QUS to recognize fractured patients.

METHODS

Amplitude-dependent speed of sound (AD-SoS) and bone transmission time (BTT) were measured in 1,719 pediatric patients with bone disorders and related to fracture history. The patients were classified as (1) spontaneously (77), (2) minimal trauma (101), or (3) appropriate trauma fractured (206), and (4) nonfractured (1,335). The likelihood of fracture according to QUS was calculated as odds ratio per SD decrease (OR/SD), and the effectiveness in discriminating fractured patients was evaluated by receiver operating characteristic (ROC) analysis. The influence of age, sex, puberty, height, and BMI was explored by respective adjustments and multiple logistic regression.

RESULTS

Fractured patients showed significantly reduced AD-SoS and BTT standard deviation score (-0.32 ± 1.54 and -0.78 ± 1.49) compared to nonfractured subjects (0.43 ± 1.63 and -0.11 ± 1.34). QUS measurements paralleled the causative trauma severity, ranging from the lowest values in spontaneously fractured patients to normal values in appropriate trauma fractured subjects. The OR/SD were increasingly higher in appropriate trauma fractured, minimal trauma fractured, and spontaneously fractured patients. At ROC analysis, both parameters proved to have significant discrimination power in recognizing spontaneously and minimal trauma-fractured patients.

CONCLUSIONS

QUS identifies fractured pediatric patients with bone disorders, reflecting the severity of the causative trauma with a high discrimination power for fragility fractures.

A population-based study examining calcaneus quantitative ultrasound and its optimal cut-points to discriminate osteoporotic fractures among 9352 Chinese women and men

CONTEXT

No generally accepted thresholds for quantitative ultrasound (QUS) parameters to screen individuals at high risk of osteoporotic fractures have been defined.

OBJECTIVE

We sought to define appropriate cutoff points for osteoporotic fractures of calcaneus ultrasound according to participants' prevalent osteoporotic fractures.

DESIGN AND SETTING

This was a cross-sectional, population-based study conducted in Shanghai, China.

PARTICIPANTS

A total of 9352 Chinese women and men aged 40 and older were studied.

MAIN OUTCOME MEASURES

We measured calcaneus QUS (Achilles Express, GE Lunar) values and their relationships with osteoporotic fractures.

RESULTS

A prevalence of 14.9 and 12.2% of osteoporotic fractures was found in the women and men (P<0.001), respectively. Subjects with osteoporotic fractures had significantly lower QUS values than those without (P<0.001). One sd decline in the stiffness index (SI)-derived T-score was associated with a high risk of nonvertebral fracture [odds ratio (OR)=1.50; 95% confidence interval (CI), 1.39-1.62; P<0.001], clinical vertebral fracture (OR=1.49; 95% CI, 1.18-1.90; P<0.01), and multi-fractures (OR=1.98; 95% CI, 1.63-2.40; P<0.001). The receiver operating characteristic analysis showed that QUS could differentiate osteoporotic fractures in postmenopausal women and men, but not in premenopausal women. The optimal cutoff points for the SI-derived T-score to detect a high risk of nonvertebral fractures, clinical vertebral fractures, and multi-fractures were -1.25, -1.55, and -1.80 in postmenopausal women, respectively, and -1.30, -1.90, and -2.00 in males, respectively.

CONCLUSIONS

As a screening tool, the SI-derived T-score obtained from the Achilles QUS device for a postmenopausal woman or man that is less than -1.25 and -1.30, respectively, may indicate an increased risk of osteoporotic fractures and should be further evaluated by central DXA.

Quantitative ultrasound and vertebral fractures in patients with type 2 diabetes

Patients with type 2 diabetes (T2DM) are known to have increased risks of femoral neck and vertebral fractures, although their bone mineral density (BMD) is normal or even slightly increased compared to non-DM controls. This observation suggests that bone fragility not reflected by BMD, possibly deterioration of bone quality, may participate in their fracture risks. Quantitative ultrasound (QUS), unlike BMD, could possibly evaluate bone quality, especially the microarchitecture, and therefore may be useful for assessing fracture risk in T2DM. To test this hypothesis, we measured calcaneal QUS as well as BMD at the lumbar spine, femoral neck, and 1/3 radius in 96 women (mean age 66.6 years old) and 99 men (64.7 years old) with T2DM, and examined their associations with prevalent vertebral fractures (VFs). Calcaneal QUS was performed by CM-200 (Elk Corp., Osaka, Japan), and speed of sound (SOS) values were obtained. BMD was measured by QDR4500 (Hologic, Waltham, MA). In T2DM patients, VFs were found in 33 and 45 subjects in women and men, respectively. When compared between subjects with and without VFs, there were no significant differences in values of SOS or BMD at any site between the groups in either gender. The distribution of SOS as a function of age showed that those with VFs were scattered widely, and there were no SOS thresholds for VFs in either gender. Logistic regression analysis adjusted for age and BMI showed that either SOS or BMD was not significantly associated with the presence of VFs in either gender. These results show that QUS as well as BMD are unable to discriminate T2DM patients with prevalent VFs from those without VFs. It seems necessary to seek other imaging modalities or biochemical markers evaluating bone fragility and fracture risk in T2DM.

Quantitative ultrasound and radiographic absorptiometry are associated with vertebral deformity in Japanese Women: the Hizen-Oshima study

We evaluated the ability of heel quantitative ultrasound (QUS) and metacarpal radiographic absorptiometry (RA) to identify subjects with vertebral deformities in Japanese women aged ≥40. Both QUS and RA were associated with vertebral deformities, and the estimated prevalence at each T-score widely varied with age.

INTRODUCTION

Heel QUS and metacarpal RA have been used for screening patients to evaluate risk of osteoporotic fractures. The aim of this study was to evaluate the ability of QUS and RA to identify women with vertebral deformities in 570 Japanese women aged ≥40, and to estimate the prevalence of vertebral deformity at each T-score.

METHODS

Calcaneal QUS and metacarpal RA were performed. Radiographic vertebral deformities were assessed by quantitative morphometry, defined as vertebral heights more than 3 SD below the normal mean.

RESULTS

The receiver operating characteristic analysis showed that both calcaneal stiffness index (SI) and metacarpal bone mineral density (BMD) were associated with vertebral deformities. Using the T-score of -2.5 as a cutoff value, the specificity and sensitivity for identifying individuals with vertebral deformities was 65% and 83% for calcaneal SI, and 40% and 88% for metacarpal BMD, respectively. The prevalence of vertebral deformity was estimated using age-adjusted logistic regression models. Women with calcaneal SI T-score of -2.5 had a 2% estimated probability of vertebral deformity at age 40, and 22% at age 80. For metacarpal BMD T-score of -2.5, estimated probability was less than 1% at age 40, and 27% at age 80.

CONCLUSION

Both calcaneal SI and metacarpal BMD were associated with prevalence of vertebral deformity. Furthermore, the prevalence widely varied with age at any given bone value.

Low-frequency axial ultrasound velocity correlates with bone mineral density and cortical thickness in the radius and tibia in pre- and postmenopausal women

Axial transmission velocity of a low-frequency first arriving signal (V (LF)) was assessed in the radius and tibia of 254 females, and compared to site-matched pQCT measurements. V (LF) best correlated with cortical BMD, but significantly also with subcortical BMD and cortical thickness. Correlations were strongest for the radius in postmenopausal females.

INTRODUCTION

Ultrasonic low-frequency (LF; 0.2-0.4 MHz) axial transmission, based on the first arriving signal (FAS), provides enhanced sensitivity to thickness and endosteal properties of cortical wall of the radius and tibia compared to using higher frequencies (e.g., 1 MHz). This improved sensitivity of the LF approach has not yet been clearly confirmed by an in vivo study on adult subjects. The aims of the present study were to evaluate the extent to which LF measurements reflect cortical thickness and bone mineral density, and to assess whether an individual LF measurement can provide a useful estimate for these bone properties.

METHODS

Velocity of the LF FAS (V (LF)) was assessed in the radius and tibia shaft by a new ultrasonometer (CV(RMS) = 0.5%) in a cross-sectional study involving 159 premenopausal (20-58 years) and 95 postmenopausal females (45-88 years). Site-matched volumetric total bone mineral density (BMD), cortical bone mineral density (CBMD), subcortical bone mineral density (ScBMD) and cortical thickness (CTh) were assessed using pQCT.

RESULTS

For the postmenopausal females, V (LF) correlated best with CBMD in the radius (R = 0.850, p < 0.001), but significantly also with ScBMD and CTh (R = 0.759 and R = 0.761, respectively; p < 0.001). Similar trends but weaker correlations were observed for the tibia and for the premenopausal women.

CONCLUSIONS

The LF assessment, with an optimal excitation frequency, thus provided good prediction of both cortical thickness and subcortical bone material properties. These results suggest that the LF approach does indeed have enhanced sensitivity for detecting osteoporotic changes that occur deep in the endosteal bone.

Bone status of children with hemophilia A assessed with quantitative ultrasound sonography (QUS) and dual energy X-ray absorptiometry (DXA)

Recent studies report reduced bone mineral density (BMD) even among young adults and children with hemophilia. Our aim was to assess bone status in children and adolescents with hemophilia with 2 methods: Quantitative UltraSonography (QUS) and Dual energy x-ray Absorptiometry (DXA), and consequently to investigate the degree of correlation between them. Twenty-seven patients (17 with severe hemophilia; residual factor activity <1% and 10 with moderate hemophilia) participated in the study. Mean age was 12.28±4.48 y (range: 4.94 to 18.00 y). All patients were evaluated with QUS at radius and at tibia and had DXA scan at lumbar spine. Anthropometric parameters were measured using standard techniques and joint evaluation was carried out using the Hemophilia Joint Health Score (HJHS). Only 2 out of 27 patients (7.5%) had BMD Z-scores <-2, whereas another 4 patients (15%) had BMD Z-scores between -1 and -2. QUS values in both radius and tibia were generally within the normal limits as only 1 patient had radius and another 1 had tibia QUS Z-score <-2. HJH scores were significantly although negatively correlated to Z-scores of tibia QUS (r=-0.455, P=0.034). No correlations were observed between lumbar BMD and radius or tibia QUS and no agreement was recorded between QUS and DXA in identifying patients at risk for osteoporosis (k=0.262). In conclusion, our study showed that only a small number of children and young adults with hemophilia have impaired bone properties as assessed both by DXA and QUS; no correlation was observed between these 2 methods.

Quantitative ultrasound in osteoporosis and bone metabolism pathologies

Quantitative ultrasound (QUS) has been introduced in the medical field for the study of bone tissue to identify changes in the tissue that could suggest the presence of osteoporosis and bone fragility. The ultrasound technique is simple, versatile, and its low cost and lack of ionizing radiation have led to the diffusion of this method worldwide. The present article is an overview of the most relevant developments in the field of quantitative ultrasound, in clinical and experimental settings. The advantages and limitations of the present technique and suggestions for its use in the clinical practice are reported.

Combining bone resorption markers and heel quantitative ultrasound to discriminate between fracture cases and controls

SUMMARY

This nested case-control analysis of a Swiss ambulatory cohort of elderly women assessed the discriminatory power of urinary markers of bone resorption and heel quantitative ultrasound for non-vertebral fractures. The tests all discriminated between cases and controls, but combining the two strategies yielded no additional relevant information.

INTRODUCTION

Data are limited regarding the combination of bone resorption markers and heel quantitative bone ultrasound (QUS) in the detection of women at risk for fracture.

METHODS

In a nested case-control analysis, we studied 368 women (mean age 76.2 +/- 3.2 years), 195 with low-trauma non-vertebral fractures and 173 without, matched for age, BMI, medical center, and follow-up duration, from a prospective study designed to predict fractures. Urinary total pyridinolines (PYD) and deoxypyridinolines (DPD) were measured by high performance liquid chromatography. All women underwent bone evaluations using Achilles+ and Sahara heel QUS.

RESULTS

Areas under the receiver operating-characteristic curve (AUC) for discriminative models of the fracture group, with 95% confidence intervals, were 0.62 (0.56-0.68) and 0.59 (0.53-0.65) for PYD and DPD, and 0.64 (0.58-0.69) and 0.65 (0.59-0.71) for Achilles+ and Sahara QUS, respectively. The combination of resorption markers and QUS added no significant discriminatory information to either measurement alone with an AUC of 0.66 (0.60-0.71) for Achilles+ with PYD and 0.68 (0.62-0.73) for Sahara with PYD.

CONCLUSIONS

Urinary bone resorption markers and QUS are equally discriminatory between non-vertebral fracture patients and controls. However, the combination of bone resorption markers and QUS is not better than either test used alone.

Performance of five phalangeal QUS parameters in the evaluation of gonadal-status, age and vertebral fracture risk compared with DXA

The aim of this cross-sectional study was to study the value of five different quantified ultrasound (QUS) parameters-amplitude-dependent speed of sound (AD-SoS), Ultrasound Bone Profile Index (UBPI), fast-wave amplitude (FWA), bone transmission time (BTT) and signal dynamic (SDY)-measured at the phalanges of the hand in discriminating women with vertebral fracture and their relationship with some determinants of bone mass, in particular age and gonadal status compared with lumbar spine and hip dual-energy x-ray absorptiometry (DXA). We included 791 women aged 35-84 y, divided into pre-menopause, early menopause and late postmenopause groups on the basis of gonadal status and years since menopause (YSM). The presence of vertebral fracture was evaluated radiographically. All QUS parameters were very sensitive to changes in early postmenopause, with a doubled decrease in early postmenopausal with respect to late postmenopause. In particular AD-SoS and BTT decreases were markedly high in the early postmenopause group. In the late menopause group, similar decreases were observed for AD-SoS, UBPI and hip bone mineral density (BMD). In the multiple logistic model, DXA and QUS significantly discriminate women with and without fractures (p < 0.0001); odds ratio (OR) was higher at lumbar spine BMD (OR 4.01), FWA (OR 3.88), AD-SoS (OR 3.81) and total hip BMD (OR 3.77). Even adjusting the logistic model for age, height, weight, lumbar spine and total hip BMD, all QUS parameters remained significantly predictive of vertebral fracture. AD-SoS showed the best performances both in terms of OR and ROC analysis. QUS parameters show a different behavior in evaluating the effect on bone mass of the time since menopause; AD-SoS and BTT showed a high sensitivity to first changes in bone tissue after menopause. After correction for potential confounders, AD-SoS showed the same ability of lumbar spine BMD in discriminating women with or without vertebral fractures and in the prediction of fracture risk.

Quantitative ultrasound in the assessment of skeletal status

Quantitative ultrasound (QUS) is a non-invasive technique for the investigation of bone tissue in several pathologies and clinical conditions, especially in the field of osteoporosis. The versatility of the technique, its low cost and lack of ionising radiation have led to the diffusion of this method worldwide. Several studies have been conducted in the last years to investigate the potential of QUS in multiple areas with promising results; the technique has been applied in the prediction of osteoporotic fractures, in monitoring therapies, in the investigation of secondary osteoporosis, in paediatrics, neonatology and genetics. Our review article gives an overview of the most relevant developments in the field of quantitative ultrasound, both in clinical and in experimental settings.

Associations of daily walking steps with calcaneal ultrasound parameters and a bone resorption marker in elderly Japanese women

Quantitative ultrasound (QUS) parameters of the calcaneus and bone resorption markers predict osteoporotic fractures. High levels of physical activity have positive effects on bone health. The purpose of this cross-sectional study was to investigate the effects of daily walking activity (number of steps taken), as an outcome of physical activity, on QUS parameters of the calcaneus and urinary deoxypyridinoline (DPD) in elderly Japanese women. The subjects were 113 postmenopausal women aged 60-85 years. The speed of sound (SOS), broadband ultrasound attenuation (BUA), and the stiffness index (Stiffness) of the calcaneus were measured with A-1000 (GE-Lunar, USA). Spot urine samples were collected between 09:00 and 10:00, and the levels of urinary DPD were measured. The subjects were instructed to wear a pedometer during waking hours for 7 consecutive days. In univariate analyses, steps/day significantly decreased with aging (r=-0.306, p<0.001). Steps/day showed significant positive correlations with SOS (r=0.252, p<0.01) and Stiffness (r=0.258, p<0.01). There was a significant decrease in DPD with steps/day (r=-0.262, p<0.01). These effects of walking on QUS parameters and DPD remained significant after adjustment for confounding factors by multiple regression analyses. We conclude that high levels of walking activity may be effective in both maintaining the levels of QUS parameters and reducing bone resorption, and hence preserve bone health in elderly women.

Imaging of metabolic bone diseases

Osteoporosis is a serious public health problem. The incidence of osteoporotic fractures increases with age. As life expectancy increases, social costs associated with osteoporotic fractures will multiply exponentially. The early diagnosis of osteoporosis, thanks to evermore precise devices, becomes, therefore, fundamental to prevent complications of disease and unnecessary suffering.

Vertebral Fracture Assessment: the 2007 ISCD Official Positions

Vertebral fracture assessment (VFA) is an established, low radiation method for detection of prevalent vertebral fractures. Vertebral fractures are usually not recognized clinically at the time of their occurrence, but their presence indicates a substantial risk for subsequent fractures independent of bone mineral density. Significant evidence supporting VFA use for many post-menopausal women and older men has accumulated since the last ISCD Official Position Statement on VFA was published. The International Society for Clinical Densitometry considered the following issues at the 2007 Position Development Conference: (1) What are appropriate indications for Vertebral Fracture Assessment; (2) What is the most appropriate method of vertebral fracture detection with VFA; (3) What is the sensitivity and specificity for detection of vertebral fractures with this method; (4) When should additional spine imaging be performed following a VFA; and (5) What are the reporting obligations for those interpreting VFA images?

Quantitative ultrasound in the management of osteoporosis: the 2007 ISCD Official Positions

Dual-energy X-ray absorptiometry (DXA) is commonly used in the care of patients for diagnostic classification of osteoporosis, low bone mass (osteopenia), or normal bone density; assessment of fracture risk; and monitoring changes in bone density over time. The development of other technologies for the evaluation of skeletal health has been associated with uncertainties regarding their applications in clinical practice. Quantitative ultrasound (QUS), a technology for measuring properties of bone at peripheral skeletal sites, is more portable and less expensive than DXA, without the use of ionizing radiation. The proliferation of QUS devices that are technologically diverse, measuring and reporting variable bone parameters in different ways, examining different skeletal sites, and having differing levels of validating data for association with DXA-measured bone density and fracture risk, has created many challenges in applying QUS for use in clinical practice. The International Society for Clinical Densitometry (ISCD) 2007 Position Development Conference (PDC) addressed clinical applications of QUS for fracture risk assessment, diagnosis of osteoporosis, treatment initiation, monitoring of treatment, and quality assurance/quality control. The ISCD Official Positions on QUS resulting from this PDC, the rationale for their establishment, and recommendations for further study are presented here.

Musculoskeletal affections among kidney recipients: prevalence and risk predictors

The population of kidney recipients (KR) is steadily increasing in Mansoura and more than 1,800 operations were completed. The extent of musculoskeletal affections (MSA) in this population is not fully known. The purpose of this study is to determine MSA in this KR population and find possible risk predictors. Randomly selected KR (n = 117) were subjected to joint examination, joint pain and morbidity measurements and bone mineral density (BMD) estimation. Laboratory measurements included biochemical, haematological and serological variables. The majority of KR (81.2%) were complaining/suffering from MSA. These included bone loss (n = 78), joint pain (n = 63), skeletal muscle affection (n = 21), soft tissue affection (n = 25), and leg bone pain syndrome (n = 7). Serum creatinine and hepatitis PCR serology demonstrated a significant difference (P < 0.05) between KR with MSA and KR without MSA. Negative hepatitis PCR serology was the only significant (P < 0.05) risk predictor for MSA in this population of KR. This study identified MSA in this steadily increasing KR population. That hepatitis infection was a negative risk predictor for MSA in this KR population warrants further studies.

An assessment of the use of quantitative ultrasound and the Osteoporosis Self-Assessment Tool for Asians in determining the risk of nonvertebral fracture in postmenopausal Chinese women

This cross-sectional study aims to assess the effectiveness of a simple, noninvasive scoring system, the Osteoporosis Self-Assessment Tool for Asians (OSTA), and quantitative bone ultrasound (QUS) in assessing nonvertebral fracture risk in Chinese postmenopausal women. A group of 513 community-dwelling women including 271 postmenopausal individuals participated in this study. Speed of sound (SOS m/s) at the radius, phalanx, and tibia were assessed by using the Omnisense prototype (Sunlight Ltd., Israel). Body height and weight were measured, and body mass index (BMI) and OSTA indices were calculated. Self-reported fractures were identified using a structured questionnaire. Phalanx SOS was significantly lower among postmenopausal women with a history of nonvertebral fracture occurred after menopause than those without (3755 m/s vs. 3841 m/s, P = 0.017, adjusted for age and weight), with an AUC of 0.66. The AUC of the OSTA for predicting nonvertebral fracture occurred after menopause was 0.64. SOS at the radius, phalanx, and tibia showed a positive correlation with OSTA index (r = 0.376-0.401, P < 0.001). The prevalence of nonvertebral fractures also increased significantly with the decreasing order of OSTA index (chi2 = 5.432, P = 0.02). The OSTA values of <or=-1 and phalanx QUS T-score of <or=-1.95 can differentiate postmenopausal nonvertebral fracture with sensitivity of 75% and 81%, respectively, and specificity of 48% and 40%, respectively. Combining OSTA and phalanx QUS yielded a sensitivity of 83% and a specificity of 84% to detect postmenopausal nonvertebral fracture, with an AUC of 0.64. We conclude that OSTA and phalanx QUS are simple and effective clinical tools for identifying postmenopausal women at increased risk of nonvertebral fractures and can thereby facilitate the appropriate and more cost-effective use of bone densitometry to prevent osteoporotic fractures in developing countries.

Quantitative bone ultrasound at phalanges and calcaneus in osteoporotic postmenopausal women: influence of age and measurement site

Phalangeal and calcaneal quantitative ultrasound (QUS) measurements were tested in a postmenopausal osteoporotic population of a wide age range to assess their ability to identify subjects with vertebral fractures in a population of postmenopausal women with osteoporosis. A group of 127 osteoporotic women aged from 50 to 85 y, who had been postmenopausal for at least 5 y, were enrolled. All subjects underwent phalangeal and calcaneal QUS measurements, femoral neck and lumbar spine dual energy X-ray absorptiometry (DXA) measurements and lateral thoracic and lumbar spine radiography. Osteoporosis was defined on the basis of femoral neck or lumbar spine bone mineral density (BMD) T-score lower than -2.5 SD or of the presence of one or more vertebral atraumatic fractures, independently of BMD values. Fifty-two women had one or more vertebral fractures, while the remaining 75 had no evidence of previous fracture. Both QUS techniques were able to discriminate between fractured and nonfractured subjects in the whole group (p < 0.05). When patients aged <70 y (n = 43) and patients aged > or = 70 y (n = 84) were considered separately, phalangeal QUS and lumbar spine BMD were able to discriminate vertebral fractures in the younger group (p < 0.05), whereas calcaneal QUS was able to discriminate vertebral fractures in the older one (p < 0.05). The results of this study raise an issue of the optimal use of different QUS techniques and different skeletal sites in the management of osteoporosis in early or late postmenopausal life.

Prediction of absolute risk of non-spinal fractures using clinical risk factors and heel quantitative ultrasound

The relationship between osteoporosis risk factors, bone quantitative ultrasound (QUS) and non-spinal fracture risk was estimated in a cohort of 5,201 postmenopausal women from Spain who were prospectively evaluated during three years. Several clinical risk factors and low heel QUS values were independently associated with non-spinal fracture risk.

INTRODUCTION

Low-trauma, non-spinal fractures are a growing source of morbidity and mortality in the elderly. The aim of the present study was to examine the association of heel quantitative ultrasound (QUS) and a series of osteoporosis and fracture risk factors, with incident low energy non-spinal fractures in a population of elderly women, and to incorporate them into fracture prediction models.

METHODS

5,201 women aged 65 or older were enrolled in a three-year cohort study. Participants completed an osteoporosis and fracture risk factors questionnaire. QUS was measured at the heel with a gel-coupled device. Cox-proportional hazard analyses were performed to evaluate the association with the first incident low-trauma non-spinal fracture.

RESULTS

Three hundred and eleven women (6.0%) sustained a total of 363 low-trauma fractures, including 133 forearm/wrist, 54 hip, 50 humerus, 37 leg and 17 pelvic fractures. For every standard deviation decrease in the quantitative ultrasound index, the adjusted hazard ratios (95% CI) for any non-vertebral, hip, forearm/wrist, and humerus fractures were 1.31 (1.15-1.49), 1.40 (1.01-1.95), 1.50 (1.19-1.89) and 1.35 (0.97-1.87), respectively. Similar results were observed with other QUS variables. The best predictive models indicated that age, a history of falls, a previous low-trauma fracture, a family history of fracture, a calcium intake from dairy products of less than 250 mg/day, and lower values of QUS parameters were independently associated with the risk of non-spinal fractures.

CONCLUSIONS

Both clinical risk factors and QUS are independent predictors of risk of fragility non-spinal fractures. A prediction algorithm using these variables was developed to estimate the absolute risk of non-spinal fractures in elderly women in Spain.

[Quantitative ultrasound]

Methods of quantitative ultrasound (QUS) can be used to obtain knowledge about bone fragility. Comprehensive study results exist showing the power of QUS for the estimation of osteoporotic fracture risk. Nevertheless, the variety of technologies, devices, and variables as well as different degrees of validation of the single devices have to be taken into account. Using methods to simulate ultrasound propagation, the complex interaction between ultrasound and bone could be understood and the propagation could be visualized. Preceding widespread clinical use, it has to be clarified if patients with low QUS values will profit from therapy, as it has been shown for DXA. Moreover, the introduction of quality assurance measures is essential. The user should know the limitations of the methods and be able to interpret the results correctly. Applied in an adequate manner QUS methods could then, due to lower costs and absence of ionizing radiation, become important players in osteoporosis management.

Prevalência de osteoporose e fraturas vertebrais em mulheres na pós-menopausa atendidas em serviços de referência

Este estudo tem por objetivo verificar a prevalência de osteoporose e a presença de fraturas vertebrais em mulheres na pós-menopausa. Foram estudadas, em serviços de referências, 627 mulheres com idade acima de 50 anos, com média de idade de 63,9 ± 8,3 anos, tempo de menopausa de 16,2 ± 8,6 anos, e índice de massa corpórea de 26,6 ± 4.3 Kg/m2. A prevalência de osteoporose foi de 28,8% na coluna lombar e de 18,8% no colo do fêmur. Esta foi maior nas pacientes que apresentaram história de fraturas quando jovens. Na faixa entre 60 a 69 anos, 33,2% tinham osteoporose na coluna lombar e entre 70 e 79 anos, 38,2%. Das pacientes com mais de 80 anos 54,5% apresentam osteoporose na coluna lombar e 72,7% no colo do fêmur. Trinta e sete por cento tinham fraturas, sendo que 9% apresentam fraturas grau I, e 10,9% fraturas severas. Considerando-se os diversos grupos etários, a prevalência de fraturas vertebrais foi de 20% entre 50 e 59 anos, 25,6% entre 60 e 69 anos, 58,3% entre 70 e 79 anos, e 81,8% entre 80 e 89 anos. Em mulheres na pós-menopausa, a maioria sem sintomas clínicos, verificamos uma alta taxa de prevalência de osteoporose, e fraturas vertebrais.

Skeletal measurements by quantitative ultrasound in adolescents and young women with anorexia nervosa

OBJECTIVE

To compare quantitative ultrasound (QUS) measurements in adolescents with anorexia nervosa (AN) with that in healthy control subjects and to determine the utility of QUS as a tool to evaluate skeletal status in these patients.

STUDY DESIGN

Female adolescents with AN (n = 41) and healthy control subjects (n = 105) were recruited. Speed of sound (SOS) was measured at the radius and tibia. Participants with AN also had hip and spinal areal bone mineral density measurements by dual-energy x-ray absorptiometry (DXA); bone mineral apparent density (BMAD) was calculated.

RESULTS

Subjects with AN had higher mean radial SOS (4044 +/- 99 m/s) than did control subjects (3947 +/- 116 m/s; P < .0001). These results were replicated at the tibia (AN, 3918 +/- 85 m/s vs control subjects, 3827 +/- 106 m/s; P < .0001). Neither DXA measures of areal bone mineral density nor BMAD were correlated with SOS. Weight and body mass index were negative predictors of tibial but not radial SOS. AN status remained a significant predictor of SOS after controlling for body mass index, age, and race.

CONCLUSIONS

Subjects with AN had higher mean tibial and radial SOS than did control subjects. QUS variables did not correlate with DXA measures, calculated BMAD, or anthropometric variables. QUS measurements of SOS do not appear to be appropriate for bone density screening in patients with AN.