Relationship between risk factors and QUS in a European Population: The OPUS study

Evaluation of the validity of treatment decisions based on surrogate country models before introduction of the Polish FRAX and recommendations in comparison to current practice

INTRODUCTION

Patients diagnosed before the Polish FRAX was introduced may require re-evaluation and treatment changes if the diagnosis was established according to a surrogate country FRAX score. The aim of the study was to evaluate the validity of treatment decisions based on the surrogate country model before introduction of the Polish FRAX and to provide recommendations based on the current practice.

MATERIAL AND METHODS

We evaluated a group of 142 postmenopausal women (70.7 ±8.9 years) who underwent bone mineral density measurements. We used 22 country-specific FRAX models and compared these to the Polish model.

RESULTS

The mean risk values for hip and major osteoporotic fractures within 10 years were 4.575 (from 0.82 to 8.46) and 12.47% (from 2.18 to 21.65), respectively. In the case of a major fracture, 94.4% of women would receive lifestyle advice, and 5.6% would receive treatment according to the Polish FRAX using the guidelines of the National Osteoporosis Foundation (NOF). Polish treatment thresholds would implement pharmacotherapy in 32.4% of the study group. In the case of hip fractures, 45% of women according to the NOF would require pharmacotherapy but only 9.8% of women would qualify according to Polish guidelines. Nearly all surrogate FRAX calculator scores proved significantly different form Polish (p > 0.05).

CONCLUSIONS

More patients might have received antiresorptive medication before the Polish FRAX. This study recommends re-evaluation of patients who received medical therapy before the Polish FRAX was introduced and a review of the recommendations, considering the side effects of antiresorptive medication.

An Advanced Quantitative Echosound Methodology for Femoral Neck Densitometry

The aim of this paper was to investigate the clinical feasibility and the accuracy in femoral neck densitometry of the Osteoporosis Score (O.S.), an ultrasound (US) parameter for osteoporosis diagnosis that has been recently introduced for lumbar spine applications. A total of 377 female patients (aged 61-70 y) underwent both a femoral dual X-ray absorptiometry (DXA) and an echographic scan of the proximal femur. Recruited patients were sub-divided into a reference database used for ultrasound spectral model construction and a study population for repeatability assessments and accuracy evaluations. Echographic images and radiofrequency signals were analyzed through a fully automatic algorithm that performed a series of combined spectral and statistical analyses, providing as a final output the O.S. value of the femoral neck. Assuming DXA as a gold standard reference, the accuracy of O.S.-based diagnoses resulted 94.7%, with k = 0.898 (p < 0.0001). Significant correlations were also found between O.S.-estimated bone mineral density and corresponding DXA values, with r(2) up to 0.79 and root mean square error = 5.9-7.4%. The reported accuracy levels, combined with the proven ease of use and very good measurement repeatability, provide the adopted method with a potential for clinical routine application in osteoporosis diagnosis.

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.

Predictive ability of heel quantitative ultrasound for incident fractures: an individual-level meta-analysis

The relationship between bone quantitative ultrasound (QUS) and fracture risk was estimated in an individual level data meta-analysis of 9 prospective studies of 46,124 individuals and 3018 incident fractures. Low QUS is associated with an increase in fracture risk, including hip fracture. The association with osteoporotic fracture decreases with time.

INTRODUCTION

The aim of this meta-analysis was to investigate the association between parameters of QUS and risk of fracture.

METHODS

In an individual-level analysis, we studied participants in nine prospective cohorts from Asia, Europe and North America. Heel broadband ultrasonic attenuation (BUA dB/MHz) and speed of sound (SOS m/s) were measured at baseline. Fractures during follow-up were collected by self-report and in some cohorts confirmed by radiography. An extension of Poisson regression was used to examine the gradient of risk (GR, hazard ratio per 1 SD decrease) between QUS and fracture risk adjusted for age and time since baseline in each cohort. Interactions between QUS and age and time since baseline were explored.

RESULTS

Baseline measurements were available in 46,124 men and women, mean age 70 years (range 20-100). Three thousand and eighteen osteoporotic fractures (787 hip fractures) occurred during follow-up of 214,000 person-years. The summary GR for osteoporotic fracture was similar for both BUA (1.45, 95 % confidence intervals (CI) 1.40-1.51) and SOS (1.42, 95 % CI 1.36-1.47). For hip fracture, the respective GRs were 1.69 (95 % CI, 1.56-1.82) and 1.60 (95 % CI, 1.48-1.72). However, the GR was significantly higher for both fracture outcomes at lower baseline BUA and SOS (p < 0.001). The predictive value of QUS was the same for men and women and for all ages (p > 0.20), but the predictive value of both BUA and SOS for osteoporotic fracture decreased with time (p = 0.018 and p = 0.010, respectively). For example, the GR of BUA for osteoporotic fracture, adjusted for age, was 1.51 (95 % CI 1.42-1.61) at 1 year after baseline, but at 5 years, it was 1.36 (95 % CI 1.27-1.46).

CONCLUSIONS

Our results confirm that quantitative ultrasound is an independent predictor of fracture for men and women particularly at low QUS values.

A novel ultrasound methodology for estimating spine mineral density

We investigated the possible clinical feasibility and accuracy of an innovative ultrasound (US) method for diagnosis of osteoporosis of the spine. A total of 342 female patients (aged 51-60 y) underwent spinal dual X-ray absorptiometry and abdominal echographic scanning of the lumbar spine. Recruited patients were subdivided into a reference database used for US spectral model construction and a study population for repeatability and accuracy evaluation. US images and radiofrequency signals were analyzed via a new fully automatic algorithm that performed a series of spectral and statistical analyses, providing a novel diagnostic parameter called the osteoporosis score (O.S.). If dual X-ray absorptiometry is assumed to be the gold standard reference, the accuracy of O.S.-based diagnoses was 91.1%, with k = 0.859 (p < 0.0001). Significant correlations were also found between O.S.-estimated bone mineral densities and corresponding dual X-ray absorptiometry values, with r(2) values up to 0.73 and a root mean square error of 6.3%-9.3%. The results obtained suggest that the proposed method has the potential for future routine application in US-based diagnosis of osteoporosis.

Impact of femoral neck and lumbar spine BMD discordances on FRAX probabilities in women: a meta-analysis of international cohorts

There are occasional marked discordances in BMD T-scores at the lumbar spine (LS) and femoral neck (FN). We investigated whether such discordances could contribute independently to fracture prediction using FRAX. We studied 21,158 women, average age 63 years, from 10 prospective cohorts with baseline FRAX variables as well as FN and LS BMD. Incident fractures were collected by self-report and/or radiographic reports. Extended Poisson regression examined the relationship between differences in LS and FN T-scores (ΔLS-FN) and fracture risk, adjusted for age, time since baseline and other factors including FRAX 10-year probability for major osteoporotic fracture calculated using FN BMD. To examine the effect of an adjustment for ΔLS-FN on reclassification, women were separated into risk categories by their FRAX major fracture probability. High risk was classified using two approaches: being above the National Osteoporosis Guideline Group intervention threshold or, separately, being in the highest third of each cohort. The absolute ΔLS-FN was greater than 2 SD for 2.5% of women and between 1 and 2 SD for 21%. ΔLS-FN was associated with a significant risk of fracture adjusted for baseline FRAX (HR per SD change = 1.09; 95% CI = 1.04-1.15). In reclassification analyses, only 2.3-3.2% of the women moved to a higher or lower risk category when using FRAX with ΔLS-FN compared with FN-derived FRAX alone. Adjustment of estimated fracture risk for a large LS/FN discrepancy (>2SD) impacts to a large extent on only a relatively small number of individuals. More moderate (1-2SD) discordances in FN and LS T-scores have a small impact on FRAX probabilities. This might still improve clinical decision-making, particularly in women with probabilities close to an intervention threshold.

A European multicenter comparison of quantitative ultrasound measurement variables: the OPUS study

Quantitative ultrasound (QUS) measurement variables vary between European countries in a different way to hip bone mineral density. Standardization of data can be achieved through statistical approaches to reduce any between-center differences in QUS measurement variables. However, further validation of this method is required before it can be widely applied.

INTRODUCTION

European between-center differences in hip bone mineral density (BMD) have been shown to exist; however, little is known about the geographical heterogeneity of QUS measurement variables. We aimed to examine the differences in QUS variables between three different European countries.

METHODS

Five calcaneal and phalangeal QUS devices in Sheffield, Aberdeen (UK), Kiel and Berlin (Germany), and three devices in Paris (France) were used to measure QUS variables in younger (n = 463, 20-39 years old) and older (n = 2,399, 55-79 years old) women participating in the European multicenter Osteoporosis and Ultrasound (OPUS) study. Broadband ultrasound attenuation, speed of sound, stiffness index, amplitude-dependent speed of sound, bone transmission time, and ultrasonic bone profiler index data were collected. Between-center differences were examined using ANOVA followed by post hoc Fisher's least significant difference tests, and ANCOVA with linear contrasts. p < 0.05 indicated statistical significance.

RESULTS

Between-center differences in nonstandardized QUS measurement variables existed for younger (p = 0.0023 to p < 0.0001) and older women (p < 0.001). Anthropometric characteristics exerted a significant influence on nonstandardized data (p = 0.045 to p < 0.001). However, following statistical standardization, based on height and weight or based on measurements made in young people, geographical heterogeneity in QUS measurement variables was no longer apparent.

CONCLUSIONS

QUS measurement variables vary between European countries in a different way to those for hip BMD. Standardization of data can be achieved through statistical approaches to reduce any between-center differences in QUS measurement variables. However, further validation of this method is required before it can be widely applied.

Impact of age, anthropometric data and body composition on calcaneal bone characteristics, as measured by quantitative ultrasound (QUS) in an older German population

The impact of fat-free mass (FFM), fat mass (FM), body mass index (BMI), body mass and body height on calcaneal bone characteristics as measured with quantitative ultrasound (QUS) was investigated in 137 women and 85 men aged 62-92 years, considering age, smoking, waist-to-hip ratio (WHR) and physical activity level (PAL). In regression analyses using various models, in women, age was a negative predictor of speed of sound (SOS), broadband ultrasound attenuation (BUA) and stiffness index (SI) and smoking was a negative predictor of SOS; positive predictors of SOS, BUA, and SI were BMI, body mass and FFM. In men, smoking was a negative predictor and BMI, body mass and FFM were positive predictors of BUA and SI. In both sexes, PAL, body height, WHR and FM had no effect on QUS parameters. The influence of BMI on calcaneal bone characteristics in elderly people depends on FFM rather than on FM.

Thyroid function within the upper normal range is associated with reduced bone mineral density and an increased risk of nonvertebral fractures in healthy euthyroid postmenopausal women

CONTEXT

The relationship between thyroid function and bone mineral density (BMD) is controversial. Existing studies are conflicting and confounded by differences in study design, small patient numbers, and sparse prospective data.

OBJECTIVE

We hypothesized that variation across the normal range of thyroid status in healthy postmenopausal women is associated with differences in BMD and fracture susceptibility.

DESIGN

The Osteoporosis and Ultrasound Study (OPUS) is a 6-yr prospective study of fracture-related factors.

SETTING

We studied a population-based cohort from five European cities.

PARTICIPANTS

A total of 2374 postmenopausal women participated. Subjects with thyroid disease and nonthyroidal illness and those receiving drugs affecting thyroid status or bone metabolism were excluded, leaving a study population of 1278 healthy euthyroid postmenopausal women.

INTERVENTIONS

There were no interventions.

MAIN OUTCOME MEASURES

We measured free T(4) (fT4) (picomoles/liter), free T(3) (fT3) (picomoles/liter), TSH (milliunits/liter), bone turnover markers, BMD, and vertebral, hip, and nonvertebral fractures.

RESULTS

Higher fT4 (beta = -0.091; P = 0.004) and fT3 (beta = -0.087; P = 0.005) were associated with lower BMD at the hip, and higher fT4 was associated with increasing bone loss at the hip (beta = -0.09; P = 0.015). After adjustment for age, body mass index, and BMD, the risk of nonvertebral fracture was increased by 20% (P = 0.002) and 33% (P = 0.006) in women with higher fT4 or fT3, respectively, whereas higher TSH was protective and the risk was reduced by 35% (P = 0.028). There were independent associations between fT3 and pulse rate (beta = 0.080; P = 0.006), increased grip strength (beta = 0.171; P<0.001), and better balance (beta = 0.099; P < 0.001), indicating that the relationship between thyroid status and fracture risk is complex.

CONCLUSIONS

Physiological variation in normal thyroid status is related to BMD and nonvertebral fracture.

Imaging of metabolic bone diseases

Bone scintigraphy and X-ray are complementary in the assessment of Paget's disease. Whereas bone scintigraphy allows visualization of the whole skeleton and 'hot spots', X-ray enables visualization of more detailed images of the pagetic bone lesion. X-ray may be invaluable in the diagnosis of osteomalacia, especially in children. As osteomalacia is characterized by impaired bone mineralization, the use of bone density measures may lead to misinterpretation of the condition as osteoporosis. Dual-energy X-ray absorptiometry at the femoral neck is the 'gold standard' for the assessment of osteoporosis. However, all devices are useful to predict the risk of fracture. In the future, high-resolution computer tomography and magnetic resonance imaging may become valuable clinical tools, capturing the architectural aspect of bone strength and improving fracture prediction models.

Quantitative ultrasound in relation to risk factors for low bone mineral density in South African pre-menopausal women

SUMMARY: The study describes the association between risk factors and quantitative ultrasound bone measures in black and mixed-race pre-menopausal South African women. Despite some differences between the two study groups, the findings generally lend support to the use of ultrasound for epidemiological studies of bone mass in resource-limited settings. INTRODUCTION: Quantitative ultrasound at the calcaneus is a convenient and inexpensive method of estimating bone strength well suited to community-based research in countries with limited resources. This study determines, in a large sample of pre-menopausal South African women, whether characteristics associated with quantitative ultrasound measures are similar to those shown to be associated with bone mineral density as measured by dual X-ray absorptiometry. METHODS: This cross-sectional study included 3,493 women (1,598 black and 1,895 mixed race), aged 18-44 living in Cape Town. Study nurses administered structured interviews on reproductive history, lifestyle factors, and measured height and weight. Calcaneus quantitative ultrasound measurements were obtained using the Sahara device. Adjusted means of ultrasound measures according to categories of risk factors were obtained using multivariable regression analysis. RESULTS: Associations between quantitative ultrasound measures and age, body mass index, age at menarche, parity, and primary school physical activity were similar to those known for bone mineral density as measured by dual X-ray absorptiometry. There were no clear associations between quantitative ultrasound measures and educational level, alcohol use, cigarette smoking, and current calcium intake. CONCLUSION: The data give qualified support to the use of quantitative ultrasound as an epidemiological tool in large studies of bone strength in pre-menopausal women.

Bone mass and architecture determination: state of the art

Bone fracture occurs when the bone strength (i.e. the ability of the bone to resist a force) is less than the force applied to the bone. In the elderly, falls represent the more severe forces applied to bone. Bone density is a good marker of bone strength, and has been used widely in this respect. Nevertheless, many aspects of bone strength cannot be explained by bone density alone. For this reason there has been increasing interest in studying architectural parameters of bone, beyond bone density, which may affect bone strength. Macro-architectural parameters include e.g. bone size and geometry assessed with techniques such as radiography, dual-energy x-ray absorptiometry (DXA), peripheral quantitative computed tomography (QCT), computed tomography (CT) and magnetic resonance imaging (MRI). Micro-architectural parameters include fine cortical and trabecular structural detail which can be evaluated using high-resolution imaging techniques such as multidetector CT, MRI, and high-resolution peripheral QCT. These techniques are providing a great deal of new information on the physiological architectural responses of bone to aging, weightlessness, and treatment. This will ultimately lead to the prediction of fracture risk being improved through a combined assessment of bone density and architectural parameters.

Osteoporosis in orthopaedic trauma patients: a diagnosis and treatment protocol

OBJECTIVES

The purpose of this study was to determine the prevalence of patients at risk for osteoporosis and fracture in a cohort of orthopaedic trauma patients and to subsequently determine the efficacy of a protocol for evaluation, education, and treatment in these patients.

DESIGN

Prospective study of "osteoporosis protocol" for evaluation, education, initiation of treatment, and 1-year follow-up in orthopaedic trauma patients.

SETTING

Level 2 regional trauma center.

PATIENTS

Two hundred sixty consecutive adult patients treated by an orthopaedic trauma surgeon for an acute orthopaedic injury were prospectively enrolled in an osteoporosis protocol between January and August 2005.

INTERVENTION

Patients were evaluated using quantitative ultrasound (QUS) of the heel administered at the bedside and with comprehensive medical, osteoporotic, ovarian, nutritional, family, and current injury histories. For patients identified as high risk for osteoporosis (QUS of the calcaneus-derived T-score <or= -1.6), treatment was initiated. Intervention included (1) direct patient education, (2) twice-daily calcium and vitamin D therapy during the hospitalization and a prescription to continue after discharge, and (3) referral to the patient's primary care physician (PCP) with a copy of the QUS results for discussion of further treatments. A telephone interview was conducted at 12 months to determine the status of the patients' osteoporosis treatment.

MAIN OUTCOME MEASUREMENTS

Patient and injury data including QUS results (osteoporosis risk), treatment efficacy at hospitalization, and 12 months postinjury

RESULTS

Complete data were available for 238 (92%), in whom the average age was 51 years (18-93). Seventy-three patients (30%) had a high risk for osteoporosis, and an additional 51 patients (21%) were at moderate risk. Intervention with education and initiation of medical therapy was successfully achieved in 69 of the 72 (96%) patients in the high-risk group. Odds ratios for variables and high-moderate osteoporosis risk were determined. At the 12-month follow-up, 57% of patients in the high-risk osteoporosis group reported that they had consulted their PCP regarding the osteoporosis, and 47% had continued medical treatment. Bisphosphonates therapy was initiated in 29% of the high-risk patients.

CONCLUSIONS

Following a protocol for osteoporosis identification and initiation of treatment, almost one-third of patients were identified as being at high risk for osteoporosis in this orthopaedic trauma population. Specific components of the protocol included patient education and referral to the PCP, and nearly half of high-risk patients continued osteoporosis treatment at 12 months follow-up. Orthopaedic trauma surgeons can play a significant role in the diagnosis and treatment of osteoporosis in hospitalized patients and may be able to reduce the incidence of secondary fragility fractures.

[Screening for osteoporosis]

Osteoporosis affects approximately 7 million patients in Germany and severely impairs quality of life. The clinical picture, subjective complaints as well as the presence or absence of risk factors are essential to determine the individual risk profile and to decide on possible serum blood tests, osteodensitometry, and X-ray examinations. Back pain or other clinical evidence of impaired bone stability should be evaluated with X-ray studies of the spine. If osteoporosis and an increased risk of fracture are present, treatment is indicated which includes an evidence-based pharmaceutical regimen in order to increase bone stability and to lower the risk of fractures. Drug treatment with adequate calcium and vitamin D supplementation and antiresorptive or osteoanabolic substances, usually for 3-5 years, should be accompanied by pain medication and neuromuscular rehabilitation to help prevent falls and maintain independence of the elderly.

Plasma organochlorine concentrations and bone ultrasound measurements: a cross-sectional study in peri-and postmenopausal Inuit women from Greenland

BACKGROUND

Inuit women are highly exposed through their traditional seafood based diet to organochlorine compounds, some of them displaying endocrine disrupting properties. We hypothesized that this exposure might be related to bone characteristics that are altered in osteoporosis, because hormone deficiency is a known risk factor for the disease.

METHODS

We measured quantitative ultrasound parameters (QUS) at the right calcaneum of 153 peri- and postmenopausal Inuit women (49-64 year old) from Nuuk, Greenland, and investigated the relation between these parameters and plasma organochlorine concentrations. We used high-resolution gas chromatography with electron capture detection to analyze plasma samples for 14 polychlorinated biphenyls (PCB) congeners and 11 chlorinated pesticides and metabolites. We analysed morning urine samples for cadmium, a potential confounder, by atomic absorption spectrometry. We used a validated questionnaire to document dietary and lifestyle habits as well as reproductive and medical histories.

RESULTS

Concentrations of PCB 153, a surrogate of exposure to most organochlorines present in plasma samples, were inversely correlated to QUS parameters in univariate analyses (p < 0.001). However, PCB 153 concentrations were not associated with QUS values in multivariate analyses that comprised potential confounding factors such as age, body weight, former oral contraceptive use and current hormone replacement therapy (HRT) use, which were all significant predictors of bone stiffness (total R2 = 0.39; p < 0.001).

CONCLUSION

Overall we found little evidence that organochlorines exposure is related to osteoporosis in Greenlandic Inuit women, but the hypothesis that exposure to dioxin-like compounds might be linked to decreased bone quality and osteoporosis deserves further attention.