Quantitative ultrasound: an indicator of osteoporosis in perimenopausal women

Sex Differences in Age-Related Physical Changes among Community-Dwelling Adults

The prevalence of physical functioning limitations is positively correlated with age in both men and women. However, whether the appearance of deterioration differs depending on physical function and sex remains unclear. This study aimed to clarify the modes of age-related changes in physical function and sex differences in middle-aged and older adults. This study comprised 124 (46 men and 78 women) healthy adults aged 30 years or older and examined gender differences in physical function. The results of this study showed that one-leg standing time had the highest rate of age-related decline in both men and women, followed by knee extension strength, skeletal muscle mass, the 5 m walking test, and the timed up and go test. The sex-specific points showed a high rate of decline in trunk forward bending in men and a high rate of decline in forced expiratory volume (1 s) and gradual rate of decline in the bone area ratio in women. After middle age, it is desirable to start monitoring and training balance, muscle function, and walking. Men require early intervention for flexibility, and women require early intervention for respiratory function and continued intervention for bone mineral density.

Diagnostic devices for osteoporosis in the general population: A systematic review

INTRODUCTION

A diagnostic gap exists in the current dual photon X-ray absorptiometry (DXA) based diagnostic approach to osteoporosis. Other diagnostic devices have been developed, but no comprehensive review concerning the applicability of these diagnostic devices for population-based screening have been performed.

MATERIAL AND METHODS

A systematic review of Embase, Medline and the Cochrane Central Register for Controlled Trials was performed for population-based studies that focused on technical methods that could either indicate bone mineral density (BMD) by DXA, substitute for DXA in prediction of fracture risk, or that could have an incremental value in fracture prediction in addition to DXA. Quality of included studies was rated by QUADAS 2.

RESULTS

Many other technical devices have been tested in a population-based setting. Five studies aiming to indicate BMD and 17 studies aiming to predict fractures were found. Overall, the latter studies had higher methodological quality. The highest number of studies was found for quantitative ultrasound (QUS). The ability to indicate BMD or predict fractures was moderate to minor for all examined devices, using reported area under the curve (AUC) of Receiver Operating Characteristic curves values as standard.

CONCLUSIONS

Of the methods assessed, only QUS appears capable of perhaps replacing DXA as standalone examination in the future whilst radiographic absorptiometry could provide important information in areas with scarcity of DXA. QUS may be of added value even after DXA has been performed. Evaluation of proposed cutoff-values from population-based studies in separate population-based cohorts is still lacking for most examination devices.

Is calcaneal quantitative ultrasound useful as a prescreen stratification tool for osteoporosis?

Calcaneal quantitative ultrasound (QUS) is attractive as a prescreening tool for osteoporosis, alternative to dual-energy X-ray absorptiometry. We investigated the literature of the usability of calcaneal QUS. We found large heterogeneity between studies and uncertainty about cutoff, device, and measured variable. Despite osteoporosis-related fractures being a major health issue, osteoporosis remains underdiagnosed. Dual-energy X-ray absorptiometry (DXA) of the hip or spine is currently the preferred method for diagnosis of osteoporosis, but the method is limited by low accessibility. QUS is a method for assessing bone alternative to DXA. The aim of this systematic review was to explore the usability of QUS as a prescreen stratification tool for assessment of osteoporosis. Studies that evaluated calcaneal QUS with DXA of the hip or spine as the gold standard was included. We extracted data from included studies to calculate number of DXAs saved and misclassification rates at cutoffs equal to high sensitivity and/or specificity. The number of DXAs saved and percentage of persons misclassified were measures of usability. We included 31 studies. Studies were heterogeneous regarding study characteristics. Analyses showed a wide spectrum of percentage of DXAs saved (2.7-68.8%) and misclassification rates (0-12.4%) depending on prescreen strategy and study characteristics, device, measured variable, and cutoff. Calcaneal QUS is potentially useful as a prescreen tool for assessment of osteoporosis. However, there is no consensus of device, variable, and cutoff. Overall, there is no sufficient evidence to recommend a specific cutoff for calcaneal QUS that provides a certainty level high enough to rule in or out osteoporosis. Calcaneal QUS in a prescreen or stratification algorithm must be based on device-specific cutoffs that are validated in the populations for which they are intended to be used.

Wave dispersion and attenuation on human femur tissue

Cortical bone is a highly heterogeneous material at the microscale and has one of the most complex structures among materials. Application of elastic wave techniques to this material is thus very challenging. In such media the initial excitation energy goes into the formation of elastic waves of different modes. Due to “dispersion”, these modes tend to separate according to the velocities of the frequency components. This work demonstrates elastic wave measurements on human femur specimens. The aim of the study is to measure parameters like wave velocity, dispersion and attenuation by using broadband acoustic emission sensors. First, four sensors were placed at small intervals on the surface of the bone to record the response after pencil lead break excitations. Next, the results were compared to measurements on a bulk steel block which does not exhibit heterogeneity at the same wave lengths. It can be concluded that the microstructure of the tissue imposes a dispersive behavior for frequencies below 1 MHz and care should be taken for interpretation of the signals. Of particular interest are waveform parameters like the duration, rise time and average frequency, since in the next stage of research the bone specimens will be fractured with concurrent monitoring of acoustic emission.

Quantitative Ultrasonography of Calcaneal Bone Mass and Its Relationship to Calcium Consumption Among Impoverished Hispanic Women

Perimenopausal Hispanic women need to be able to build and sustain peak bone mass, but this may be affected by their low socioeconomic status. This feasibility research study provided descriptive information on the relationship between calcium consumption and bone mass measured with sonography at the calcaneus. Little research exists to examine bone health with this specific age or ethnic group of women. This research found a strong positive correlation between the amount of self-reported calcium food consumed and the bone stiffness index recorded using quantitative sonography. The translational impact of this project will inform the development of culturally relevant patient education for Hispanic women of low socioeconomic status to encourage the development of peak bone mass.

A systematic review of persistence and compliance with bisphosphonates for osteoporosis

Fourteen reports utilizing data from de-identified administrative databases were reviewed. Studies contained at least one measure of patient persistence or compliance with bisphosphonates or bisphosphonates and other anti-osteoporosis medications. These studies confirm that women with osteoporosis have suboptimal persistence and compliance rates with bisphosphonate therapy.

INTRODUCTION

This review summarizes patient persistence and compliance with bisphosphonates for the treatment of osteoporosis.

METHODS

We conducted a MEDLINE search for the period from January 1998 to May 2006, using a detailed list of terms related to persistence and compliance with anti-osteoporosis medications. Studies were included if they contained at least one measure of persistence or compliance derived from de-identified administrative databases containing patient demographics and prescription information.

RESULTS

We reviewed 14 reports, which described 14 databases. The percentage of patients persisting with therapy for 1 year ranged from 17.9% to 78.0%. Compliance, assessed as mean medication possession ratio (MPR), ranged from 0.59 to 0.81. When comparing compliance with weekly and daily bisphosphonates, the mean MPR was consistently higher for weekly versus daily therapy (0.58 to 0.76 versus 0.46 to 0.64 for patients receiving weekly and daily bisphosphonate therapy respectively). Persistence was also improved in patients receiving weekly bisphosphonates, assessed by both length of persistence (194 to 269 days [weekly] and 134 to 208 days [daily]) and percentage of persistent patients at the end of the follow-up period (35.7% to 69.7% [weekly] and 26.1% to 55.7% [daily]).

CONCLUSION

Although patients using weekly bisphosphonate medication follow their prescribed dosing regimens better than those using daily therapy, overall compliance and persistence rates were suboptimal.

Determining the prevalence of osteoporosis and related factors using quantitative ultrasound in Vietnamese adult women

In 2003, the authors conducted a population-based, cross-sectional survey to determine the prevalence of osteoporosis and related factors in Vietnamese adult women by using quantitative ultrasound at the heel bone (calcaneus). A total of 2,232 adult women aged > or =20 years, living in Hanoi City, and free of illnesses affecting bone metabolism were randomly selected to participate in the study. Subjects' bone mass was assessed by speed of sound at the calcaneus, referred to as quantitative ultrasound measurement. The T-score threshold, defined as < or =-1.8, was used to identify subjects with osteoporosis. The crude prevalence of osteoporosis in Hanoi City was 15.4%; after adjustment for age, it was 9.0%. Among premenopausal women, the crude prevalence of osteoporosis was higher in the urban areas compared with the rural areas. By contrast, postmenopausal women in the rural areas had a higher prevalence of osteoporosis. Multiple logistic regression analysis revealed that factors associated with low speed of sound were age, menopause, educational level, lifelong occupation, recreational weight-bearing exercise, number of births, and height. Results suggest that osteoporosis is a noteworthy problem in Vietnam, and intervention strategies should be considered to control it, especially in high-risk populations.

An in vitro study of the ultrasonic axial transmission technique at the radius: 1-MHz velocity measurements are sensitive to both mineralization and intracortical porosity

The ultrasonic axial transmission technique allows for investigating skeletal sites such as the cortical layer of long bones (radius, tibia, phalanges). Using synchrotron radiation microCT, we investigated, in vitro, the relationships between 1-MHz axial transmission SOS measurements at the radius and site-matched measurements of C.Th, POR, MIN, and vBMD.

INTRODUCTION

The ultrasonic axial transmission technique allows for investigating skeletal sites such as the cortical layer of long bones (radius, tibia, phalanges).

MATERIALS AND METHODS

Using synchrotron radiation microCT, we investigated, in vitro, the relationships between 1-MHz axial transmission speed of sound (SOS) measurements at the radius and site-matched measurements of cortical thickness (C.Th), intracortical porosity (POR), tissue mineralization (MIN), and volumetric BMD (vBMD). SOS measurements were based on bidirectional axial transmission and were performed with a 1-MHz proprietary probe on 39 excised human radii.

RESULTS

The highest correlations between SOS values and bone parameters (R(2)(SOS/POR) = 0.28, p < 10(-3); R(2)(SOS/MIN) = 0.38, p < 10(-4); R(2)(SOS/vBMD) = 0.57, p < 10(-3)) were found for bone parameters assessed in a 1-mm-thick periosteal region of the cortex rather than throughout the whole cortex. The observed moderate correlation between SOS and C.Th values (R(2)(SOS/C.Th) = 0.20, p < 10(-2)) disappeared when controlled for other variables. The two best multilinear predictive models, including either BMD alone or the pair of dependent variables MIN and POR (all assessed in the periosteal cortex), were equally accurate in predicting SOS values (R(2)(SOS/(POR,MIN)) = 0.59, p < 10(-5); R(2)(SOS/vBMD) = 0.57, p < 10(-5)).

CONCLUSION

For the first time, the respective adjusted contributions of POR (-24 m/s%(-1)) and tissue mineralization (+3.5 m/s/mg/cm(-3)) to SOS values were assessed. These results suggest potential sensitivity of axial transmission SOS values to changes in cortical bone status under different pathological conditions or treatments affecting POR and/or tissue mineralization.

Biomarkers of bone turnover can be assayed from human saliva

The purpose of this study was to determine if biomarkers of bone turnover [deoxypyridinium (D-PYR) or osteocalcin (OC)] could be detected in human saliva. These biomarkers have been measured in ovariectomized sheep saliva, but not in human saliva. Saliva was collected from 37 women. The bone mineral density of the calcaneus was assessed by quantitative ultrasound and expressed as a T score. Salivary D-PYR and OC concentrations were determined by enzyme-linked immunosorbent assay. Data were analyzed by a Spearman's rho correlation test and factorial analysis of variance was followed by a post hoc Tukey's test. There were significant correlations between age, body mass index, D-PYR, or OC concentration and calcaneus T scores (p<.05), suggesting that saliva could be used as a fluid for assay of human biomarkers of bone turnover. Our data suggest a beneficial use of saliva in situations where a large number of patients are to be screened for metabolic bone diseases.

Age-related variation in quantitative ultrasound at the tibia and prevalence of osteoporosis in native Chinese women

This study investigated the variations in age-related speed of sound (SOS) at the tibia and prevalence of osteoporosis in native Chinese women, and establishment of a reference database by quantitative ultrasound. SOS at the right midtibia was measured using a quantitative ultrasound device (SoundScan 2000, Myriad Ultrasound Systems, Israel) in 1596 healthy Chinese women ranging from 12 years to 96 years of age. Healthy women were selected on the basis of (1). a detailed questionnaire about their medical history, (2). face to face questioning about their medical history, and (3). a physical examination. Women with a medical condition that required medication that affected bone metabolism or those who had had a pathologic or moderate traumatic fracture were excluded. We followed the diagnostic criteria provided by the instrument's manufacturer and equivalent to the WHO criteria (using the T-score cut-off that diagnoses 30% of the post-menopausal women aged >or =50 years with osteoporosis) as the diagnostic criteria for osteoporosis in this group of women. Data were analyzed in age groups divided by intervals of 5 years. The peak SOS at the tibia of 3991+/-68 m s(-1) (mean+/-SD) occurred in the 35-39 year age group and the T-score precision was 0.99 T-score units. The SOS value increased with age up to 34 years of age and then declined with age after 40 years of age with the rate of decrease at 9.68 m s(-1) per year. The curve representing the SOS change according to age is best fitted by the regression analysis of cubic model, and the cubic equation for SOS=3383+39.9 (age)-0.78 (age)(2)+0.0039 (age)(3) (R(2)=0.505, p=0.000). The T-score cut-off that diagnoses 30% of the post-menopausal women (n=559, mean age 63.2+/-8.97 years) aged >or=50 years with osteoporosis was SOS<or=3733 m s(-1), T-score<or=-3.8. In the 40-49, 50-59, 60-69 and 70-79 years age groups and the group aged >or=80 years, the prevalences of osteoporosis detected using equivalent to the WHO criteria were 0.39%, 9.27%, 30.3%, 58.4% and 69.0%, respectively. The prevalences detected following the manufacturer's diagnostic criteria (cut-off value: SOS<or=3800 m s(-1), T-score<or=-2.0) were 3.14%, 20.5%, 53.2%, 78.8% and 89.7%, respectively. There were significant differences in the prevalence between the diagnostic criteria in the various age groups (p=0.000-0.002). In 769 women from 40 years to 59 years of age, the mean SOS was significantly higher in pre-menopausal women (n=500) than in post-menopausal women (n=269) (3977+/-89 vs 3881+/-118 m s(-1), p=0.000). The prevalence of osteoporosis in these women was 0.40% in pre-menopausal women, 8.92% in post-menopausal women, respectively. There were significant differences in prevalence of osteoporosis between the two groups of pre- and post-menopausal women (p=0.000). In conclusion, SOS at tibia can provided useful information about bone status in the normative population of native Chinese women for determination of osteoporosis. The reference database based on these data will be appropriate for the diagnosis of osteoporosis by tibial quantitative ultrasound in native Chinese women.

The use of ultrasound in the assessment of bone status

The assessment of skeletal status has wide clinical applications, especially in the management of osteoporosis. Osteoporosis, once thought of as an unpreventable and untreatable aging process, has revealed many of its secrets over the last decade, and the advent of successful drug therapy has changed our perception of the disease. Non-invasive techniques play a fundamental role in the diagnosis of osteoporosis and in the assessment of the efficacy of drug treatments. The primary technique used in osteoporosis is dual X-ray absorptiometry (DXA), that has been established as a reliable means of measuring bone density. Quantitative ultrasound (QUS), because of the relative portability of the equipment, ease of use, lack of ionizing radiation and low cost, has great potential for widespread use. Five devices for QUS assessment have recently been approved by the Food and Drug Administration and many more applications are in progress. QUS is a relatively new technology, at least in its application to bone fragility. Nevertheless, QUS has demonstrated that it is able to detect bone fragility as well as DXA. However, diagnosis of osteoporosis by QUS remains contentious, but the problems are due more to the limitations of the present T-scores rather than to the technique. A better option for QUS would be to report results in terms of remaining lifetime fracture risk, keeping in mind that a risk estimate needs not only the QUS or DXA measurement, but also the specific data, such as age, weight, gender, hormonal status and fracture history of the patient.