Relationship between bone quantitative ultrasound and fractures: a meta-analysis

The Biomechanics of Musculoskeletal Tissues during Activities of Daily Living: Dynamic Assessment Using Quantitative Transmission-Mode Ultrasound Techniques

The measurement of musculoskeletal tissue properties and loading patterns during physical activity is important for understanding the adaptation mechanisms of tissues such as bone, tendon, and muscle tissues, particularly with injury and repair. Although the properties and loading of these connective tissues have been quantified using direct measurement techniques, these methods are highly invasive and often prevent or interfere with normal activity patterns. Indirect biomechanical methods, such as estimates based on electromyography, ultrasound, and inverse dynamics, are used more widely but are known to yield different parameter values than direct measurements. Through a series of literature searches of electronic databases, including Pubmed, Embase, Web of Science, and IEEE Explore, this paper reviews current methods used for the in vivo measurement of human musculoskeletal tissue and describes the operating principals, application, and emerging research findings gained from the use of quantitative transmission-mode ultrasound measurement techniques to non-invasively characterize human bone, tendon, and muscle properties at rest and during activities of daily living. In contrast to standard ultrasound imaging approaches, these techniques assess the interaction between ultrasound compression waves and connective tissues to provide quantifiable parameters associated with the structure, instantaneous elastic modulus, and density of tissues. By taking advantage of the physical relationship between the axial velocity of ultrasound compression waves and the instantaneous modulus of the propagation material, these techniques can also be used to estimate the in vivo loading environment of relatively superficial soft connective tissues during sports and activities of daily living. This paper highlights key findings from clinical studies in which quantitative transmission-mode ultrasound has been used to measure the properties and loading of bone, tendon, and muscle tissue during common physical activities in healthy and pathological populations.

Comparative analysis of bone outcomes between quantitative ultrasound and dual-energy x-ray absorptiometry from the UK Biobank cohort

This large cohort study investigated reliability and validity of heel ultrasound to estimate bone mineral density in adults. Reliability calculated between left and right heels was relatively poor and so was criterion validity assessed relative to dual-energy X-ray absorptiometry. Heel ultrasound should be used cautiously when estimating bone mineral density.

INTRODUCTION

Calcaneal quantitative ultrasound (QUS) may be used as a safe, low cost, and portable means to estimate bone mineral density (BMD) in large cohorts. The purpose of this study was to quantify the reliability and validity of QUS in comparison to dual-energy X-ray absorptiometry (DXA), which is the reference method for BMD measurement and diagnoses of osteopenia and osteoporosis.

METHODS

Bone outcomes measured on the large UK Biobank cohort were used. The reliability of QUS estimated BMD was quantified by comparing values obtained from the left and right heel measured in the same session. Criterion validity was assessed through agreement between QUS and DXA, quantifying correlations, and sensitivity and specificity of osteopenia and osteoporosis diagnoses.

RESULTS

Reliability calculations were made using data from over 216,000 participants demonstrating similar QUS BMD values between left and right heels in the absolute scale (Sd of difference for men: 0.12 and 0.07 g·cm-2). However, when expressed in relative scales, including concordance of quartiles, reliability was poor. Agreement between QUS and DXA was quantified using data from 5042 participants. Low to modest correlations (r = 0.29 to 0.44) were obtained between multiple QUS variables and DXA BMD, with sensitivity identified as very poor (0.05 to 0.23) for osteoporosis, and poor (0.37 to 0.62) for osteopenia diagnoses.

CONCLUSIONS

The findings of this large comparative analysis identify that whilst calcaneal QUS has the potential to produce reliable absolute BMD measurements and demonstrate modest associations with DXA BMD measures, use of that information to make relative statements about participants in the context of the larger population or to appropriately diagnose osteopenia or osteoporosis may be severely limited.

Application of full waveform inversion algorithm in Laplace-Fourier domain for high-contrast ultrasonic bone quantitative imaging

BACKGROUND AND OBJECTIVES

Full waveform inversion (FWI) has been widely applied for the reconstruction of underground medium parameters in seismic communities and has made a great success. It is also a promising way to image hard tissues such as bones by ultrasonic FWI algorithm. However, the ultrasonic FWI methods for bone parameters imaging reported in literature so far are limited to the time domain and/or Fourier domain, and can only achieve quantitative imaging with acoustic velocity of bone less than 3000 m/s. Because the acoustic velocity of actual cortical bones can be as high as 4200 m/s, it is still a challenge for FWI to achieve higher parameter contrast bone imaging.

METHODS

Here, we proposed an ultrasonic FWI algorithm in Laplace-Fourier domain (LFDFWI) for high-contrast bone quantitative imaging. Compared to Time domain and Fourier domain, the LFDFWI algorithm is more appropriate for dealing with the presence of high contrast between bone tissues, reducing the possibility of inversion falling into a local minimum, and obtaining better inversion results. We adapted the seismic FWI algorithm to make it suitable for high-frequency ultrasonic sources and small-sized bone parameter imaging.

RESULTS

We conducted a series of bone models to evaluate the effectiveness of the proposed algorithm, including four kinds of bone model derived from micro computed tomography (Micro-CT) image of rat. We evaluated the experimental results based on visual analysis, error analysis and structural similarity (SSIM). The numerical simulation results showed that, when acoustic approximation is used, the proposed method can obtain accurate high-contrast images of the velocity and density parameters of bone structure, the mean relative error (MRE) in the region of interest (ROI) were all less than 2%, and the SSIM is up to 98%; when the viscoelastic approximation is used, this method can also obtain the desired high-contrast bone parameter distribution, with MRE less than 4% and SSIM higher than 74%, both of which are better than FDFWI in Fourier domain (FDFWI).

CONCLUSION

The results demonstrated that the proposed FWI algorithm can obtain high resolution bone parameter models close to the Micro-CT image, which proves its clinical application potential.

Novel nomograms for predicting the risk of low distal bone strength: development and validation in a Chinese population-based observational study

BACKGROUND

This study aims to develop nomogram models based on the speed of sound (SOS) measurements results along with demographic information to predict the risk of low bone strength (LBS) of radius appropriate to the Chinese population of a broad age spectrum.

METHODS

A population-based cross-sectional study was conducted in 5 outpatient clinics located in Zhejiang, the southern part of China. A total of 38,699 participants from 2013 to 2017 were included. Baseline measurements included SOS of the distal radius and clinical risk factor evaluation. Logistic regression models were used to evaluate prognosis and identify independent predictive factors, which were then utilized to establish nomograms for predicting the low bone strength of radius. The discrimination and calibration of nomograms were validated using the calibration plots, the decision curve analysis (DCA), and the receiver operating characteristics curve (ROC).

RESULTS

A total of 19,845 of the 38,904 participants ranged in age from 10 to 88 years were selected in this process. LBP nomogram model 1 was constructed based on age, weight, height, BMI, and gender. LBP nomogram model 2 was constructed based on age, height, BMI, and gender. The AUCs for model 1 and model 2 were 0.838 (95% CI: 0.832-0.844) and 0.837 (95% CI: 0.831-0.843), respectively. High-quality calibration plots and DCA in nomogram models were noticed, indicated that the constructed nomogram models were clinically useful.

CONCLUSIONS

Our study demonstrates that the nomograms established in this study could effectively evaluate the high-risk population groups of distal radius fracture in China.

Short-termed changes in quantitative ultrasound estimated bone density among young men in an 18-weeks follow-up during their basic training for the Swiss Armed Forces

Background

Quantitative Ultrasound (QUS) methods have been widely used to assess estimated bone density. This study aimed to assess changes in estimated bone density in association with changes in body composition, physical activity, and anthropometry.

Methods

We examined changes in anthropometry, body composition, and physical activity associated with changes in estimated bone mineral density (measured using quantitative ultrasound with a heel ultrasound device indicating broadband ultrasound attenuation BUA and speed of sound SOS) in a follow-up sample of n = 73 young men at the beginning and again 18 weeks later at the end of basic military training.

Results

At the end of the basic training, the subjects were on average significantly heavier (+1.0%), slightly taller (+0.5%) and had a higher fat mass (+6.6%) and grip strength (+8.6%). A significant decrease in mean physical activity (-49.5%) and mean estimated bone density calculated with BUA (-7.5%) was observed in the paired t-test. The results of the multivariable linear regressions (backward selection) show that changes in skeletal muscle mass (delta = 2nd measurement minus 1st measurement) have negative and body weight (delta) have positive association with the speed of sound SOS (delta), while fat mass (delta) and physical activity (delta) had the strongest negative associations with estimated bone mineral density (delta). In particular, we found a negative association between fat mass (delta) and estimated bone mineral density (delta, estimated with BUA).

Conclusion

Our study suggests that estimated bone density from the calcaneus can change within a few months even in young and mostly healthy individuals, depending upon physical activity levels and other co-factors. Further studies including other troop types as control groups as well as on women should follow in order to investigate this public health relevant topic in more depth. To what extent the estimated bone density measurement with quantitative ultrasound is clinically relevant needs to be investigated in further studies.

Relationships between QUS and HR-pQCT, DXA, and bone turnover markers

INTRODUCTION

Relationship of quantitative ultrasound (QUS) with high-resolution peripheral quantitative computed tomography (HR-pQCT), dual-energy X-ray absorptiometry (DXA), and bone-related biochemical markers was analyzed.

MATERIALS AND METHODS

The subjects were 480 individuals. Speed of sound (SOS) was measured by calcaneal QUS. Volumetric bone mineral density (vBMD) and microarchitecture of trabecular and cortical bone in the distal radius and tibia were assessed by HR-pQCT. Areal bone mineral density (aBMD) in the lumbar spine and proximal femur were measured by DXA. TRACP-5b, P1NP, 25 (OH) vitamin D, and pentosidine were evaluated by biochemical tests. The correlation of each parameter was analyzed for all subjects and by sex and age group.

RESULTS

QUS was moderately correlated with Tb.vBMD and Tb.BV/TV in the radius and tibia. No correlation was seen with Ct.vBMD or cortical porosity (Ct.Po). Although a correlation was seen with cortical thickness (Ct.Th) in the tibia in all subjects, no correlation was seen in women aged ≥ 60 years. QUS showed moderate correlations with aBMD in the proximal femur. Although moderate correlation was seen with aBMD in the lumbar spine in all subjects, no correlation was seen in subjects aged ≥ 60 years. No significant correlations were seen between QUS and biochemical markers.

CONCLUSIONS

Moderate correlations were seen between QUS and Tb.vBMD and microarchitecture in the radius and tibia and aBMD of the proximal femur. On the other hand, practically no correlations were seen with Ct.vBMD or Ct.Po and the bone-related biochemical markers. Only in middle age, moderate correlations were seen with Ct.Th in the tibia and with aBMD of the lumbar spine.

Calcaneal quantitative ultrasound is associated with all-cause and cardiovascular disease mortality independent of hip bone mineral density

Osteoporosis has been linked with increased risk of cardiovascular disease previously. However, few studies have detailed bone and vascular information. In a prospective study of older women, we demonstrated heel quantitative ultrasound measures were associated with increased cardiovascular and all-cause mortality, independent of established cardiovascular risk factors.

INTRODUCTION

Osteoporosis and low bone mineral density (BMD) have been previously linked to cardiovascular disease (CVD) and mortality. Calcaneal quantitative ultrasound (QUS) is used to evaluate bone material properties, especially in older women. However, it is uncertain whether it is related to risk of mortality. This study was aimed to investigate the association between calcaneal QUS measurements and 15-year all-cause and CVD mortality in 1404 older women (mean age 75.2 ± 2.7 years).

METHODS

One thousand four hundred four older women, participants of Calcium Intake Fracture Outcome study (CAIFOS), had calcaneal bone measured at baseline (1998) and followed for 15 years. The primary outcomes, any deaths, and deaths attributable to cardiovascular causes ascertained by using linked data were obtained from Western Australia data linkage system.

RESULTS

Over the 15 years of follow-up (17,955 person years), 584 of the women died, and 223 from CVD. For every standard deviation (SD), reduction in broadband ultrasound attenuation (BUA) in minimally and multivariable-adjusted model including cardiovascular risk factors increased relative hazards for all-cause (multivariable-adjusted HR 1.15; 95%CI: 1.06-1.26, p = 0.001) and CVD mortality (multivariable-adjusted HR 1.20; 95%CI: 1.04-1.38, p = 0.010). Such relationships also persisted when hip BMD was included in the model (all-cause mortality HR 1.19; 95%CI: 1.07-1.33, p = 0.002; CVD mortality HR 1.28; 95%CI: 1.07-1.53, p = 0.008).

CONCLUSION

BUA is associated with all-cause and CVD mortality in older women independent of BMD and established CVD risk factors. Understanding why and how these are related may provide further insights about the bone-vascular nexus as well as therapeutic targets benefiting both systems.

Effectiveness of App-Based Intervention to Improve Health Status of Sedentary Middle-Aged Males and Females

BACKGROUND

Adherence to a nutritional program and physical activity are the fundamental aspects of treatment for weight loss and associated problems. Previous research has shown that self-monitoring using a mobile device improves self-management.

METHODS

A total of 35 subjects (40.6 ± 9.24 years) participated in the study. During the control period (3 months), they received physical exercise guidelines and a personalized nutritional program, with the aim of promoting health status. In the experimental period (3 months), there was also a connection between the physical world (health care processes) and the digital world (app). All participants had their body composition and cardiovascular variables measured. They also underwent calcaneal densitometry to determine bone quality. Descriptive statistics, correlations and analysis of variance were performed (by a researcher who was not involved in the data collection) to study the changes between before and after interventions, as well as to make a comparison between treatments.

RESULTS

The use of an app, in which there exist a prediction of the evolution, messages of results and advice, among others, mediated by the assistance of dietitians/nutritionists and sports scientists, had a positive impact on the improvement of health parameters, showing significant differences in all variables except troponin.

CONCLUSIONS

The combination of healthy habits with the use of the app provided benefits, improving health.

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.

Study of Physical Fitness, Bone Quality, and Mediterranean Diet Adherence in Professional Female Beach Handball Players: Cross-Sectional Study

(1) Background: Beach handball is a relatively new type of sport, derived from team handball. The purpose of the study was to evaluate the physical fitness of elite players of this sport by studying some variables of sports performance, including strength, endurance and power, and dietary habits, and to assess bone ultrasonographic variables. (2) Methods: 33 beach handball players have participated in this research; 18 juniors (age: 16.7 ± 0.50) and 15 seniors (age: 24.8 ± 4.71). The athletes' strength was evaluated using the Handgrip Test on the dominant hand, the height of jump was evaluated by a counter-jump on a contact platform, and velocity, agility, and resistance by the Yo-Yo test. The broadband ultrasound attenuation (BUA) and the sound of speed (SOS) through the calcaneus were also measured. The Mediterranean diet adherence (KIDMED) was the questionnaire used to evaluate eating habits. In the statistical analysis, descriptions and correlations were made between the study variables. (3) Results: Both in the case of the dynamometric hand strength test (p < 0.05) and in the lower extremity power test (p < 0.01), senior players presented significantly higher values compared to junior players (35.1 ± 3.84 vs. 31.8 ± 3.37 and 35.1 ± 6.89 vs. 28.5 ± 5.69 with the dynamometry and Abalakov tests, respectively). However, no differences were observed in the variables by playing position. Significant correlations between different variables have been established, highlighting negative correlations between BMI and weight with the Abalakov Jump Test and positive correlations between Yo-Yo and BUA, and, between BMI and BUA. (4) Conclusions: Older and trained players are in better physical fitness; high weight and BMI have a negative influence on power, agility, speed, and endurance. In general, adherence to the Mediterranean diet is moderate and it seems evident that there is a beneficial influence of beach handball on bone condition, as measured by ultrasound. However future research should be carried on, including dual-energy x-ray absorptiometry assessments and food intake registers for a whole week.

Associations between Bone Material Strength Index, Calcaneal Quantitative Ultrasound, and Bone Mineral Density in Men

OBJECTIVES

Impact micro-indentation (IMI) measures bone material strength index (BMSi) in vivo. This study investigated how IMI is associated with calcaneal quantitative ultrasound and bone densitometry parameters in men.

METHODS

BMSi was measured on the tibial plateau using the OsteoProbe in 377 men (age 33-96 years) from the Geelong Osteoporosis Study. Broadband ultrasound attenuation (BUA), speed of sound (SOS), and stiffness index (SI) were assessed at the calcaneus using an ultrasonometer. Areal BMD was measured at several skeletal sites using dual-energy x-ray absorptiometry. Linear associations between parameters were tested using Pearson's correlation. Multivariable regression techniques were used to determine associations between BMSi and other measures of bone, independent of confounders.

RESULTS

BMSi was negatively correlated with age (r = -0.171, P = .001), weight (r = -0.100, P = .052), and body mass index (r = -0.187, P = .001), and positively with height (r = +0.109, P = .034). There was some evidence to support a positive association between BMSi and BUA (β = 0.052, P = .037), SOS (β = 0.013, P = .144), and SI (β = 0.036, P = .051). After age adjustment, this association was attenuated. No correlations were observed between BMSi and BMD at any skeletal site (r values ranged from -0.006 to +0.079, all P ≥ .13).

CONCLUSION

There was a small positive association between BMSi and quantitative ultrasound (QUS) parameters, which were not independent of age. No associations were detected between BMSi and BMD. This suggests that BMSi and QUS are capturing common age-dependent properties of bone. Further research on the utility of IMI alone and complementary to conventional bone testing methods for predicting fracture risk is warranted.

Discordance between quantitative ultrasound and dual-energy X-ray absorptiometry in bone mineral density: The Vietnam Osteoporosis Study

Objectives

Calcaneal quantitative ultrasound measurement (QUS) has been considered an alternative to dual-energy X-ray absorptiometry (DXA) based bone mineral density (BMD) for assessing bone health. This study sought to examine the utility of QUS as an osteoporosis screening tool by evaluating the correlation between QUS and DXA.

Methods

The study was a part of the Vietnam Osteoporosis Study that involved 1270 women and 773 men aged 18 years and older. BMD at the femoral neck, total hip and lumbar spine was measured using DXA. Osteoporosis was diagnosed based on the femoral neck T-score using World Health Organization criteria. Broadband ultrasound attenuation (BUA) at the calcaneus was measured by QUS. The concordance between BUA and BMD was analyzed by the linear regression model.

Results

In all individuals, BUA modestly correlated with femoral neck BMD (r = 0.35; P < 0.0001) and lumbar spine BMD (r = 0.34; P < 0.0001) in both men and women. In individuals aged 50 years and older, approximately 16% (n = 92/575) of women and 3.2% (n = 10/314) of men were diagnosed to have osteoporosis. Only 0.9% (n = 5/575) women and 1.0% (n = 3/314) men were classified as "Low BUA". The kappa coefficient of concordance between BMD and BUA classification was 0.09 (95% CI, 0.04 to 0.15) for women and 0.12 (95% CI, 0.03 to 0.22) for men.

Conclusions

In this population-based study, QUS BUA modestly correlated with DXA BMD, suggesting that BUA is not a reliable method for screening of osteoporosis.

Application of an Improved Ultrasound Full-Waveform Inversion in Bone Quantitative Measurement

Inspired by the large number of applications for symmetric nonlinear equations, an improved full waveform inversion algorithm is proposed in this paper in order to quantitatively measure the bone density and realize the early diagnosis of osteoporosis. The isotropic elastic wave equation is used to simulate ultrasonic propagation between bone and soft tissue, and the Gauss–Newton algorithm based on symmetric nonlinear equations is applied to solve the optimal solution in the inversion. In addition, the authors use several strategies including the frequency-grid multiscale method, the envelope inversion and the new joint velocity–density inversion to improve the result of conventional full-waveform inversion method. The effects of various inversion settings are also tested to find a balanced way of keeping good accuracy and high computational efficiency. Numerical inversion experiments showed that the improved full waveform inversion (FWI) method proposed in this paper shows superior inversion results as it can detect small velocity–density changes in bones, and the relative error of the numerical model is within 10%. This method can also avoid interference from small amounts of noise and satisfy the high precision requirements for quantitative ultrasound measurements of bone.

Fragility fracture discriminative ability of radius quantitative ultrasound: a systematic review and meta-analysis

The fragility fracture discriminative ability of radius quantitative ultrasound (QUS) was evaluated in a systematic review of 13 studies, including 16,681 individuals and 1296 fractures. The radial speed of sound (SOS) per standard deviation (SD) decrease contributed to an increased risk of total and hip fracture by 32% and 66% in women. Osteoporotic fracture, as a devastating consequence of osteoporosis, brings severe socio-economic burden. The availability of dual-energy X-ray absorptiometry (DXA), as the gold standard of diagnosis, was quite limited in remote areas. Radius QUS measured by SOS shows potential in fracture discriminative ability where DXA equipment is not available. This study aimed to provide a comprehensive evaluation of the association between radius QUS and fracture risk. A detailed article search was carried out on PubMed, EMBASE, Cochrane Libraries, CNKI, Wan-Fang database, VIP, and SinoMed for studies published between January 1980 and February 2020. We determined the estimated relative risk (RR) for fracture per each radial SOS SD decrease. A meta-analysis of studies was performed under the random-effects model. A total of 16,681 individuals were included in this review. Among the participants, 5892 were male and 10,789 were female. A total of 1296 cases of fragility fracture were included. With each SD decrease in radial SOS, the risk of overall fragility fracture and hip fracture was increased by 21% and 55%, respectively. Particularly, the risk was increased by 32% and 66% for women. The association was even stronger for postmenopausal women. Radius QUS showed great potential as an effective tool for fracture risk evaluation, especially for women.

Estimating regional bone mineral density-based T-scores using clinical information; tools validated for postmenopausal women in Sri Lanka

Objectives

This study aims to develop and validate a country specific osteoporosis risk assessing tool for Sri Lankan postmenopausal women.

Methods

Community-dwelling postmenopausal women were enrolled to development (n = 602) and validation (n = 339) samples. Clinical risk factors (CRFs) of osteoporosis were assessed. Bone mineral densities (BMD) of femoral neck, total hip and lumbar spine were assessed by dual energy X-ray absorptiometry (DXA) scan. Radial ultrasound (US) bone scan was done. Linear regression analysis was performed in development sample considering regional BMDs as dependent and CRFs as independent variables. Regression equations were developed to estimate regional BMDs using best predictive CRFs. Sensitivity, specificity, positive and negative predictive values (PPV and NPV) were assessed to validate the new tools.

Results

Age, body weight and US T-scores showed positive correlations with BMDs of all 3 sites. Two osteoporosis risk assessing tools (OPRATs) were developed as OPRAT-1 and OPRAT-2. Prevalence of osteoporosis, in the validation sample was 74.3%. Sensitivity were high in both tools (OPRAT-1 and OPRAT-2; 83.2% and 82.5%) while specificity were moderate (44.8% for both). PPV of OPRAT-1 and OPRAT-2 were 79.5% and 81.2%. Both tools showed moderate NPV (OPRAT-1 and OPRAT-2; 51% and 47%).

Conclusions

Both OPRAT-1 and OPRAT-2 have high performance in screening postmenopausal women in Sri Lanka for risk of osteoporosis. OPRAT-2 is more convenient and can be used in any healthcare setting with limited resources to identify women who will be benefitted by DXA. OPRAT-1 can be used if the radial US facility is available.

Quantitative Musculoskeletal Ultrasound

Ultrasound (US) imaging plays a crucial role in the assessment of musculoskeletal (MSK) disorders. Several quantitative tools are offered by US systems and add information to conventional US imaging. This article reviews the quantitative US imaging tools currently available in MSK radiology, specifically focusing on the evaluation of elasticity with shear-wave elastography, perfusion with contrast-enhanced US and noncontrast superb microvascular imaging, and bone and muscle mass with quantitative US methods. Some of them are well established and already of clinical value, such as elasticity and contrast-enhanced perfusion assessment in muscles and tendons. MSK radiologists should be aware of the potential of quantitative US tools and take advantage of their use in everyday practice, both for clinical and research purposes.

NEUROMUSCULAR FITNESS IN EARLY LIFE AND ITS IMPACT ON BONE HEALTH IN ADULTHOOD: A SYSTEMATIC REVIEW

Objective:

To systematically review the literature to verify the relationship between neuromuscular fitness indicators in childhood/adolescence and bone strength variables in adulthood.

Data sources:

A systematic review was conducted in PUBMED, SCOPUS, SPORTDiscus, Web of Science, PsycINFO, LILACS, and SciELO, covering the entire period until March 2019.

Data synthesis:

The search identified 1149 studies. After duplicity analysis and eligibility criteria, four studies were reported. In one study, baseline was childhood and, in the others, adolescence. In childhood, when adjusting the model for age and body mass index, a statistically significant relation was found for girls: standing long jump with quantitative ultrasound index (β=0.11; p<0.05) and with speed of sound (β=0.14; p<0.01). However, when controlling muscular performance in adulthood, the relationship was no longer significant. In adolescence, coefficients ranged from 0.16 for neuromotor battery and bone mineral density (BMD) in the lumbar region to 0.38 for hanging leg lift test and BMD of arms. The explained variance varied between 2% (bent arm hang for BMD total) and 12% (hanging leg-lift for BMD arms), therefore, a higher performance in neuromuscular fitness in adolescence was associated with better bone strength in adulthood.

Conclusions:

In adults, bone strength variables showed significant correlation from low to moderate magnitude with neuromuscular fitness indicators in adolescence, but not in childhood, after controlling for adult performance in neuromuscular fitness. However, there is limited evidence to support the neuromuscular fitness in early life as a determinant of bone strength in adulthood.

Predictive value of quantitative ultrasound parameters in individuals with chronic kidney disease: A population-based analysis of CARTaGENE

BACKGROUND

The use of calcaneal quantitative ultrasound (QUS) to predict fractures has not been well studied in early CKD populations. We compared the association of QUS with incidental fractures and its predictive properties in non-CKD and CKD individuals.

METHODS

Analysis of a prospective population-based survey of 40- to 69-year-old individuals recruited between 2009 and 2010. QUS parameters (stiffness index [SI], speed of sound [SOS], broadband attenuation [BUA]) were measured at baseline. Renal function was measured using baseline creatinine and was classified into CKD stages (non-CKD, stage 2, stage 3). Fracture incidence at any site or at major osteoporotic fracture sites for up to 7 years of follow-up was identified in administrative databases using a validated algorithm. The association (age-adjusted hazard ratio per standard deviation decrease in Cox models), discrimination (c-statistic) and calibration (standardized incidence ratio [SIR]) of QUS parameters with fracture outcomes was computed in each CKD stratum.

RESULTS

We included 18,306 individuals (9,011 non-CKD; 8,595 CKD stage 2; 700 CKD stage 3). During a median follow-up of 70 months, we identified 782 fractures at any site and 326 major osteoporotic fractures. Although all QUS parameters (SI, SOS and BUA) were associated with any or major fracture incidence in non-CKD and CKD patients, the magnitude of these associations was lower for any fracture and for BUA. QUS parameters moderately discriminated incidental fractures across CKD strata but underestimated fracture incidence in CKD stage 3 even after adjustment for demographics and clinical risk factors. At a given QUS value, CKD stage 3 patients had higher fracture risk than non-CKD and CKD stage 2 patients.

CONCLUSIONS

QUS parameters are associated with fracture incidence in both non-CKD and CKD but underestimate fracture incidence in individuals with early CKD.

Dietary Patterns of Greek Adults and Their Associations with Serum Vitamin D Levels and Heel Quantitative Ultrasound Parameters for Bone Health

The aim of this study is to investigate the dietary patterns which indicate the nutritional habits of Greek adults and their effects on serum 25(OH)D levels and quantitative ultrasound (QUS) parameters for bone health. This study is part of OSTEOS, an observational cross-sectional study. In total, 741 adults from rural and urban areas throughout Greece were recruited. A validated food frequency questionnaire (FFQ) was used for assessment of the population’s dietary habits. Serum 25(OH)D was measured by enzyme immunoassay; QUS parameters were assessed with an Achilles device. Principal component analysis (PCA) was carried out for dietary pattern determination, and univariate analysis of variance was used for the assessment of 25(OH)D, broadband ultrasound attenuation (BUA), speed of sound (SOS), and stiffness index (SI) determinants. Six dietary patterns explain 52.2% of the variability of Greek adults’ nutritional habits. The ‘vegetables–fruit’ dietary pattern explains the biggest rate of variability. Determinants of serum 25(OH)D are body mass index (BMI), elderly status, summer sun exposure, organized physical activity, a ‘healthy’ pattern in winter months, and adherence to a ‘sweet’ pattern. Determinants of QUS parameters are age, BMI, sedentary time, organized physical activity participation, and adherence to a ‘healthy’ pattern.

Radiofrequency echographic multi-spectrometry for the in-vivo assessment of bone strength: state of the art-outcomes of an expert consensus meeting organized by the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO)

PURPOSE

The purpose of this paper was to review the available approaches for bone strength assessment, osteoporosis diagnosis and fracture risk prediction, and to provide insights into radiofrequency echographic multi spectrometry (REMS), a non-ionizing axial skeleton technique.

METHODS

A working group convened by the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis met to review the current image-based methods for bone strength assessment and fracture risk estimation, and to discuss the clinical perspectives of REMS.

RESULTS

Areal bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA) is the consolidated indicator for osteoporosis diagnosis and fracture risk assessment. A more reliable fracture risk estimation would actually require an improved assessment of bone strength, integrating also bone quality information. Several different approaches have been proposed, including additional DXA-based parameters, quantitative computed tomography, and quantitative ultrasound. Although each of them showed a somewhat improved clinical performance, none satisfied all the requirements for a widespread routine employment, which was typically hindered by unclear clinical usefulness, radiation doses, limited accessibility, or inapplicability to spine and hip, therefore leaving several clinical needs still unmet. REMS is a clinically available technology for osteoporosis diagnosis and fracture risk assessment through the estimation of BMD on the axial skeleton reference sites. Its automatic processing of unfiltered ultrasound signals provides accurate BMD values in view of fracture risk assessment.

CONCLUSIONS

New approaches for improved bone strength and fracture risk estimations are needed for a better management of osteoporotic patients. In this context, REMS represents a valuable approach for osteoporosis diagnosis and fracture risk prediction.

Agreement Between Dual-Energy X-Ray Absorptiometry and Quantitative Ultrasound to Evaluate Bone Health in Adolescents: The PRO-BONE Study

PURPOSE

The present study aims to investigate the association between dual-energy X-ray absorptiometry (DXA) and quantitative ultrasound (QUS) parameters and the intermethods agreement in active males.

METHODS

In this cross-sectional study, bone health (by DXA and calcaneal QUS), physical activity (by accelerometers), and anthropometrics measurements were assessed in 117 active adolescents (12-14 y old). Bivariate correlation coefficients were calculated to assess the relationships between DXA standard regions of interest and QUS parameters. Intraclass correlation coefficients and Bland-Altman plots were used to assess the level of agreement between bone mineral content regions derived from DXA and stiffness index. The measurements were z score transformed for comparison.

RESULTS

Most QUS parameters were positive and significantly correlated with DXA outcomes (stiffness index: r = .43-.52; broadband ultrasound attenuation: r = .50-.58; speed of sound: r = .25-.27) with the hip showing the highest correlations. Moreover, the present study found fair to good intraclass correlation coefficients of agreement (.60-.68) between DXA and QUS to assess bone health. The Bland-Altman analysis showed a limited percentage of outliers (3.2%-8.6%).

CONCLUSION

QUS device could represent an acceptable alternative method to assess bone health in active adolescent males.

Serum 25-hydroxyvitamin D status, quantitative ultrasound parameters, and their determinants in Greek population

Vitamin D deficiency and quantitative ultrasound measurements are associated with bone fragility. We assessed these parameters and their correlates. 87.7% of the population has vitamin D inadequacy and this correlated with lifestyle factors. These results contribute to epidemiological data needed for population guidelines for bone health.

PURPOSE

Vitamin D deficiency and quantitative ultrasound (QUS) parameters are among the most important clinical risk factors of bone fragility. Few data are available for Greek population. The aim of the study was to evaluate the serum 25-hydroxyvitamin D [25(OH)D] level and their determinants, as well as QUS parameters in Greek population.

METHODS

OSTEOS is an observational cross-sectional study conducted from June 2010 to July 2012. Nine hundred seventy adults were recruited from rural and urban areas throughout Greece and completed the appropriate questionnaire. Serum 25(OH)D measured by enzyme immunoassay, QUS parameters, broadband ultrasound attenuation (BUA), speed of sound (SOS) and stiffness index (SI), was assessed with an Achilles device. Univariate Analysis of Variance was used for the assessment of serum 25(OH)D determinants.

RESULTS

Mean serum 25(OH)D of the total population was 20,00 ± 8,00 ng/mL. Females had lower levels than males. The negative determinants of serum 25(OH)D in the total population were the female sex and the winter-spring season of sampling while age proved negative association solely in obese subjects. Positive determinants of vitamin D status were summer sun exposure and organized physical activity as expected. Urban had lower SOS and SI than rural residents. Individuals with 25(OH)D ≥ 20 ng/mL had higher SOS than those with 25(OH)D < 20 ng/mL. BUA, SOS, and SI are positively correlated with organized physical activity and negatively with PTH.

CONCLUSIONS

This study reports that vitamin D deficiency is highly prevalent among healthy Greek men and women, demonstrates the multifactorial causation of 25(OH)D levels, and points out that further research is required to determine more factors related to vitamin D status and bone health.

The Prevalence of Osteopenia and Osteoporosis Among Malaysian Type 2 Diabetic Patients Using Quantitative Ultrasound Densitometer

Background:

Type 2 Diabetes Mellitus (T2DM) and osteoporosis are both chronic conditions and the relationship between them is complex.

Objective:

The aims of this study were to assess the prevalence of Low Bone Mineral density (LBMD, i.e., osteopenia and osteoporosis), as well as, the difference and associations between Quantitative Ultrasound Scan (QUS) parameters with socio-demographic data and clinical related data among T2DM in Penang, Malaysia.

Method:

An observational, cross-sectional study with a convenient sample of 450 T2DM patients were recruited from the outpatient diabetes clinic at Hospital Pulau Pinang (HPP) to measure Bone Mineral Density (BMD) at the heel bone using QUS. In addition, a self-reported structured questionnaire about the socio-demographic data and osteoporosis risk factors were collected. Moreover, the study included the retrospective collection of clinical data from patients’ medical records.

Results:

The mean value of T-score for normal BMD, osteopenic and osteoporotic patients’ were (-0.41±0.44), (-1.65±0.39) and (-2.76±0.27), respectively. According to QUS measurements, more than three quarters of T2DM patients (82%) were at high risk of abnormal BMD. The results showed that QUS scores were significantly associated with age, gender, menopausal duration, educational level and diabetic related data. Moreover, the QUS parameters and T-scores demonstrated significant negative correlation with age, menopausal duration, diabetic duration and glycaemic control, as well as, a positive correlation with body mass index and waist to hip ratio. The current study revealed that none of the cardiovascular disease risk factors appear to influence the prevalence of low BMD among T2DM Malaysian patients.

Conclusion:

The study findings revealed that the assessment of T2DM patients’ bone health and related factor are essential and future educational programs are crucial to improve osteoporosis management.

Assessment of Lactose-Free Diet on the Phalangeal Bone Mineral Status in Italian Adolescents Affected by Adult-Type Hypolactasia

Adult-type hypolactasia (ATH) is a clinical syndrome of primary lactase deficiency. A lactose-free diet is advisable to avoid the symptoms linked to the condition, but this potentially creates problems for optimal bone mineralization due to reduced calcium intake. To evaluate the effect of the lactose-free diet on the bone mineral status (BMS), we compared the phalangeal BMS of adolescents with ATH to that of peers on a normal diet. Also, we analyzed the correlations between BMS and dietary behavior, physical exercise, and calcium and vitamin D intake. A total of 102 cases and 102 healthy controls filled out a diet record and underwent phalangeal Quantitative Ultrasound (QUS). No difference in BMS was observed. The time spent on lactose-free diet (4.8 ± 3.1 years) was inversely correlated to the BMS. More than 98% of cases consumed lactose-free milk, but calcium and vitamin D intake were significantly lower. Calcium intake was correlated to physical exercise but not to BMS. Our results suggest that a lactose-free diet does not affect the phalangeal BMS of adolescents with primary lactase deficiency when their diet includes lactose-free cow’s milk. However, there is still a significantly lower calcium intake than in the population reference. The inverse correlation observed between the BMS and the time spent on a lactose-free diet suggests that a long-term follow-up is advisable.

ACR Appropriateness Criteria® Osteoporosis and Bone Mineral Density

Osteoporosis is a considerable public health risk, with 50% of women and 20% of men >50 years of age experiencing fracture, with mortality rates of 20% within the first year. Dual x-ray absorptiometry (DXA) is the primary diagnostic modality by which to screen women >65 years of age and men >70 years of age for osteoporosis. In postmenopausal women <65 years of age with additional risk factors for fracture, DXA is recommended. Some patients with bone mineral density above the threshold for treatment may qualify for treatment on the basis of vertebral body fractures detected through a vertebral fracture assessment scan, a lateral spine equivalent generated from a commercial DXA machine. Quantitative CT is useful in patients with advanced degenerative bony changes in their spines. New technologies such as trabecular bone score represent an emerging role for qualitative assessment of bone in clinical practice. It is critical that both radiologists and referring providers consider osteoporosis in their patients, thereby reducing substantial morbidity, mortality, and cost to the health care system. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Bone volume fraction and structural parameters for estimation of mechanical stiffness and failure load of human cancellous bone samples; in-vitro comparison of ultrasound transit time spectroscopy and X-ray μCT

Conventional mechanical testing is the 'gold standard' for assessing the stiffness (N mm^-1) and strength (MPa) of bone, although it is not applicable in-vivo since it is inherently invasive and destructive. The mechanical integrity of a bone is determined by its quantity and quality; being related primarily to bone density and structure respectively. Several non-destructive, non-invasive, in-vivo techniques have been developed and clinically implemented to estimate bone density, both areal (dual-energy X-ray absorptiometry (DXA)) and volumetric (quantitative computed tomography (QCT)). Quantitative ultrasound (QUS) parameters of velocity and attenuation are dependent upon both bone quantity and bone quality, although it has not been possible to date to transpose one particular QUS parameter into separate estimates of quantity and quality. It has recently been shown that ultrasound transit time spectroscopy (UTTS) may provide an accurate estimate of bone density and hence quantity. We hypothesised that UTTS also has the potential to provide an estimate of bone structure and hence quality. In this in-vitro study, 16 human femoral bone samples were tested utilising three techniques; UTTS, micro computed tomography (μCT), and mechanical testing. UTTS was utilised to estimate bone volume fraction (BV/TV) and two novel structural parameters, inter-quartile range of the derived transit time (UTTS-IQR) and the transit time of maximum proportion of sonic-rays (TTMP). μCT was utilised to derive BV/TV along with several bone structure parameters. A destructive mechanical test was utilised to measure the stiffness and strength (failure load) of the bone samples. BV/TV was calculated from the derived transit time spectrum (TTS); the correlation coefficient (R²) with μCT-BV/TV was 0.885. For predicting mechanical stiffness and strength, BV/TV derived by both μCT and UTTS provided the strongest correlation with mechanical stiffness (R²=0.567 and 0.618 respectively) and mechanical strength (R²=0.747 and 0.736 respectively). When respective structural parameters were incorporated to BV/TV, multiple regression analysis indicated that none of the μCT histomorphometric parameters could improve the prediction of mechanical stiffness and strength, while for UTTS, adding TTMP to BV/TV increased the prediction of mechanical stiffness to R²=0.711 and strength to R²=0.827. It is therefore envisaged that UTTS may have the ability to estimate BV/TV along with providing an improved prediction of osteoporotic fracture risk, within routine clinical practice in the future.

Analysis of SNP-SNP interactions and bone quantitative ultrasound parameter in early adulthood

Background

Osteoporosis individual susceptibility is determined by the interaction of multiple genetic variants and environmental factors. The aim of this study was to conduct SNP-SNP interaction analyses in candidate genes influencing heel quantitative ultrasound (QUS) parameter in early adulthood to identify novel insights into the mechanism of disease.

Methods

The study population included 575 healthy subjects (mean age 20.41; SD 2.36). To assess bone mass QUS was performed to determine Broadband ultrasound attenuation (BUA, dB/MHz). A total of 32 SNPs mapping to loci that have been characterized as genetic markers for QUS and/or BMD parameters were selected as genetic markers in this study. The association of all possible SNP pairs with QUS was assessed by linear regression and a SNP-SNP interaction was defined as a significant departure from additive effects.

Results

The pairwise SNP-SNP analysis showed multiple interactions. The interaction comprising SNPs rs9340799 and rs3736228 that map in the ESR1 and LRP5 genes respectively, revealed the lowest p value after adjusting for confounding factors (p-value = 0.001, β (95% CI) = 14.289 (5.548, 23.029). In addition, our model reported others such as TMEM135-WNT16 (p = 0.007, β(95%CI) = 9.101 (2.498, 15.704), ESR1-DKK1 (p = 0.012, β(95%CI) = 13.641 (2.959, 24.322) or OPG-LRP5 (p = 0.012, β(95%CI) = 8.724 (1.936, 15.512). However, none of the detected interactions remain significant considering the Bonferroni significance threshold for multiple testing (p<0.0001).

Conclusion

Our analysis of SNP-SNP interaction in candidate genes of QUS in Caucasian young adults reveal several interactions, especially between ESR1 and LRP5 genes, that did not reach statistical significance. Although our results do not support a relevant genetic contribution of SNP-SNP epistatic interactions to QUS in young adults, further studies in larger independent populations would be necessary to support these preliminary findings.

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.

Ethnic Variations in Serum 25(OH)D Levels and Bone Ultrasound Attenuation Measurements in Blacks and Whites

Vitamin D deficiency is more common in Blacks, yet Blacks have lower prevalence of bone fragility fractures or osteoporosis than Whites. Broadband ultrasound attenuation (BUA) has been used to explore the association between serum 25(OH)D levels and bone quality in White and non-white populations. We investigated serum 25(OH)D status with corresponding BUA measurements assessed cross sectionally in a cohort of 232 Blacks and 260 Whites, aged 30-95 years who were part of the calibration study of the large Adventist Health Study-2 (AHS-2). At the calibration clinics, calcaneal BUA was measured and blood drawn for serum 25(OH)D assessment. In multivariable analyses, BUA was negatively associated with age (β-coefficient = -0.38; p < 0.0001) and positively associated with body mass index (BMI) (p _(trend) < 0.0001) and positively, but non-significantly, associated with serum 25(OH)D levels. Also, as expected, females had lower BUA (β-coefficient = -5.19; p < 0.05) and Blacks had higher BUA (β-coefficient = 4.26; p < 0.05). Gender and race modified the relationship of serum 25(OH)D on BUA with a positive association in males (p _(trend) ≤ 0.05), but no significant association in females after also controlling for menopausal status and hormone therapy. After also controlling for serum 25(OH)D levels, Black males had higher BUA than White men, but such differences were not found among the females. When stratifying on race, a positive association between serum 25(OH)D levels and BUA (p _(trend) ≤ 0.05) was found in Blacks, but not among Whites. Further studies are needed to understand how racial/ethnic differences in serum 25(OH)D levels influence bone health.

Epidemiological survey of the feasibility of broadband ultrasound attenuation measured using calcaneal quantitative ultrasound to predict the incidence of falls in the middle aged and elderly

OBJECTIVES

We investigated whether calcaneal quantitative ultrasound (QUS-C) is a feasible tool for predicting the incidence of falls.

DESIGN

Prospective epidemiological cohort study.

SETTING

Community-dwelling people sampled in central western Taiwan.

PARTICIPANTS

A cohort of community-dwelling people who were ≥40 years old (men: 524; women: 676) in 2009-2010. Follow-up questionnaires were completed by 186 men and 257 women in 2012.

METHODS

Structured questionnaires and broadband ultrasound attenuation (BUA) data were obtained in 2009-2010 using QUS-C, and follow-up surveys were done in a telephone interview in 2012. Using a binary logistic regression model, the risk factors associated with a new fall during follow-up were analysed with all significant variables from the bivariate comparisons and theoretically important variables.

PRIMARY OUTCOME MEASURES

The incidence of falls was determined when the first new fall occurred during the follow-up period. The mean follow-up time was 2.83 years.

RESULTS

The total incidence of falls was 28.0 per 1000 person-years for the ≥40 year old group (all participants), 23.3 per 1000 person-years for the 40-70 year old group, and 45.6 per 1000 person-years for the ≥70 year old group. Using multiple logistic regression models, the independent factors were current smoking, living alone, psychiatric drug usage and lower BUA (OR 0.93; 95% CI 0.88 to 0.99, p<0.05) in the ≥70 year old group.

CONCLUSIONS

The incidence of falls was highest in the ≥70 year old group. Using QUS-C-derived BUA is feasible for predicting the incidence of falls in community-dwelling elderly people aged ≥70 years.

Discriminative ability of calcaneal quantitative ultrasound compared with dual-energy X-ray absorptiometry in men with hip or distal forearm fractures

Objectives

The aim of this case–control study was to compare the discriminatory ability of bone mineral density (BMD) measurements and calcaneal quantitative ultrasound (QUS) parameters for fractures and to determine fracture thresholds for each variable in men with hip or distal forearm fractures.

Patients and methods

A total of 20 men with hip and 18 men with distal forearm fractures and 38 age-matched controls were included in this study. Dual-energy X-ray absorptiometry (DXA) BMD (spine and hip) and calcaneal QUS measurements were made. Area under the curves (AUCs) were calculated to assess fracture discriminatory power of DXA and QUS variables.

Results

Quantitative Ultrasound Index (QUI) T-score and Speed of Sound (SOS) were found to be the best parameters for the identification of hip and distal forearm fractures, respectively, with AUCs greater than those of DXA BMD and other QUS parameters. While a QUI T-score of ≤−1.18 could identify and rule out hip fracture cases with approximately 80% sensitivity and specificity, a SOS value of ≤1529.75 reached to almost 90% for ruling in and out distal forearm fractures.

Conclusion

The discriminatory performance of calcaneal QUS variables between fractured and non-fractured men was as good as those of the DXA BMD and even better. Since men appear to sustain fractures at closer QUS variable levels than those of the DXA BMD regardless of the fracture type, it may be speculated that calcaneal QUS may be more helpful in predicting the risk of fractures when BMD alone does not demonstrate impaired bones.

Level of Evidence: Level III, Study of Diagnostic Test

The utility of dual-energy X-ray absorptiometry, calcaneal quantitative ultrasound, and fracture risk indices (FRAX® and Osteoporosis Risk Assessment Instrument) for the identification of women with distal forearm or hip fractures: A pilot study

PURPOSE

Dual-energy X-ray absorptiometry (DXA) is considered the "gold standard" in predicting osteoporotic fractures. Calcaneal quantitative ultrasound (QUS) variables are also known to predict fractures. Fracture risk assessment tools may also guide us for the detection of individuals at high risk for fractures. The aim of this case-control study was to evaluate the utility of DXA bone mineral density (BMD), calcaneal QUS parameters, FRAX® (Fracture Risk Assessment Tool), and Osteoporosis Risk Assessment Instrument (ORAI) for the discrimination of women with distal forearm or hip fractures.

MATERIALS AND METHODS

This case-control study included 20 women with a distal forearm fracture and 18 women with a hip fracture as cases and 76 age-matched women served as controls. BMD at the spine, proximal femur, and radius was measured using DXA and acoustic parameters of bone were obtained using a calcaneal QUS device. FRAX® 10-year probability of fracture and ORAI scores were also calculated in all participants. Receiver operating characteristic (ROC) analysis was used to assess fracture discriminatory power of all the tools.

RESULTS

While all DXA BMD, and QUS variables and FRAX® fracture probabilities demonstrated significant areas under the ROC curves for the discrimination of hip-fractured women and those without, only 33% radius BMD, broadband ultrasound attenuation (BUA), and FRAX® major osteoporotic fracture probability calculated without BMD showed significant discriminatory power for distal forearm fractures.

CONCLUSIONS

It can be concluded that QUS variables, particularly BUA, and FRAX® major osteoporotic fracture probability without BMD are good candidates for the identification of both hip and distal forearm fractures.

Thyrotropin serum levels are differentially associated with biochemical markers of bone turnover and stiffness in women and men: results from the SHIP cohorts

In two large German population-based cohorts, we showed positive associations between serum thyrotropin (TSH) concentrations and the Fracture Risk Assessment score (FRAX) in men and positive associations between TSH concentrations and bone turnover markers in women.

INTRODUCTION

The role of thyroid hormones on bone stiffness and turnover is poorly defined. Existing studies are confounded by differences in design and small sample size. We assessed the association between TSH serum concentrations and bone stiffness and turnover in the SHIP cohorts, which are two population-based cohorts from a region in Northern Germany comprising 2654 men and women and 3261 men and women, respectively.

METHODS

We calculated the bone stiffness index using quantitative ultrasound (QUS) at the calcaneus, employed FRAX score for assessment of major osteoporotic fractures, and measured bone turnover markers, N-terminal propeptide of type I procollagen (P1NP), bone-specific alkaline phosphatase (BAP), osteocalcin, and type I collagen cross-linked C-telopeptide (CTX) in all subjects and sclerostin in a representative subgroup.

RESULTS

There was no association between TSH concentrations and the stiffness index in both genders. In men, TSH correlated positively with the FRAX score both over the whole TSH range (p < 0.01) and within the reference TSH range (p < 0.01). There were positive associations between TSH concentrations and P1NP, BAP, osteocalcin, and CTX (p < 0.01) in women but not in men. There was no significant association between TSH and sclerostin levels.

CONCLUSIONS

TSH serum concentrations are associated with gender-specific changes in bone turnover and stiffness.

Three-dimensional parametric mapping in quantitative micro-CT imaging of post-surgery femoral head-neck samples: preliminary results

Osteoporosis and pathological increased occurrence of fractures are an important public health problem. They may affect patients' quality of life and even increase mortality of osteoporotic patients, and consequently represent a heavy economic burden for national healthcare systems. The adoption of simple and inexpensive methods for mass screening of population at risk may be the key for an effective prevention. The current clinical standards of diagnosing osteoporosis and assessing the risk of an osteoporotic bone fracture include dual-energy X-ray absorptiometry (DXA) and quantitative computed tomography (QCT) for the measurement of bone mineral density (BMD). Micro-computed tomography (micro-CT) is a tomographic imaging technique with very high resolution allowing direct quantification of cancellous bone microarchitecture. The Authors performed micro-CT analysis of the femoral heads harvested from 8 patients who have undergone surgery for hip replacement for primary and secondary degenerative disease to identify possible new morphometric parameters based on the analysis of the distribution of intra-subject microarchitectural parameters through the creation of parametric images. Our results show that the micro-architectural metrics commonly used may not be sufficient for the realistic assessment of bone microarchitecture of the femoral head in patients with hip osteoarthritis. The innovative micro-CT approach considers the entire femoral head in its physiological shape with all its components like cartilage, cortical layer and trabecular region. The future use of these methods for a more detailed study of the reaction of trabecular bone for the internal fixation or prostheses would be desirable.

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

Background

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

Design

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

Methods

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

Results

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

Conclusion

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

Cross-sectional and prospective associations between dietary and plasma vitamin C, heel bone ultrasound, and fracture risk in men and women in the European Prospective Investigation into Cancer in Norfolk cohort

BACKGROUND

Vitamin C sufficiency may help prevent osteoporosis and fractures by mediating osteoclastogenesis, osteoblastogenesis, and bone collagen synthesis.

OBJECTIVE

We determined whether dietary intakes and plasma concentrations of vitamin C were associated with a heel ultrasound and hip and spine fracture risks in older men and women.

DESIGN

Participants were recruited from the European Prospective Investigation into Cancer in Norfolk study with 7-d diet diary estimates of vitamin C intake and plasma concentrations. A random subset (4000 of 25,639 subjects) was available for the cross-sectional (ultrasound) study of broadband ultrasound attenuation (BUA) and velocity of sound (VOS), which were determined during the second health examination. The prospective (fracture) study was a case-cohort sample of all participants with a fracture up to March 2009 and the random subset (n = 5319). ANCOVA-determined associations between quintiles of vitamin C intake and plasma status with adjusted BUA and VOS and adjusted Prentice-weighted Cox proportional HRs were calculated for fracture risk.

RESULTS

Women were 58% of the population (39-79 y old), and the median follow-up was 12.6 y (range: 0-16 y). Positive associations across all quintiles of vitamin C intake but not plasma status were significant for VOS in men (β = 2.47 m/s, P = 0.008) and BUA in women (β = 0.82 dB/MHz, P = 0.004). Vitamin C intake was not associated with fracture risk, but there was an inverse association with plasma concentrations in men, with quintile 4 having significantly lower risks of hip fractures (HR: 0.35; 95% CI: 0.16, 0.80) and spine fractures (HR: 0.26; 95% CI: 0.10, 0.69) than quintile 1.

CONCLUSIONS

Higher vitamin C intake was significantly associated with higher heel ultrasound measures in men and women, and higher plasma vitamin C concentrations were significantly associated with reduced fracture risk in men only. Our findings that vitamin C intake and status were inconsistently associated with bone health variables suggest that additional research is warranted.

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.

Low heel ultrasound parameters predict mortality in men: results from the European Male Ageing Study (EMAS)

Background: low bone mineral density measured by dual-energy x-ray absorptiometry is associated with increased mortality. The relationship between other skeletal phenotypes and mortality is unclear. The aim of this study was to determine the relationship between quantitative heel ultrasound parameters and mortality in a cohort of European men.

Methods: men aged 40–79 years were recruited for participation in a prospective study of male ageing: the European Male Ageing Study (EMAS). At baseline, subjects attended for quantitative ultrasound (QUS) of the heel (Hologic—SAHARA) and completed questionnaires on lifestyle factors and co-morbidities. Height and weight were measured. After a median of 4.3 years, subjects were invited to attend a follow-up assessment, and reasons for non-participation, including death, were recorded. The relationship between QUS parameters (broadband ultrasound attenuation [BUA] and speed of sound [SOS]) and mortality was assessed using Cox proportional hazards model.

Results: from a total of 3,244 men (mean age 59.8, standard deviation [SD] 10.8 years), 185 (5.7%) died during the follow-up period. After adjusting for age, centre, body mass index, physical activity, current smoking, number of co-morbidities and general health, each SD decrease in BUA was associated with a 20% higher risk of mortality (hazard ratio [HR] per SD = 1.2; 95% confidence interval [CI] = 1.0–1.4). Compared with those in higher quintiles (2nd–5th), those in the lowest quintile of BUA and SOS had a greater mortality risk (BUA: HR = 1.6; 95% CI = 1.1–2.3 and SOS: HR = 1.6; 95% CI = 1.2–2.2).

Conclusion: lower heel ultrasound parameters are associated with increased mortality in European men.

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.

Heel bone strength is related to lifestyle factors in Okinawan men with type 2 diabetes mellitus

AIMS/INTRODUCTION

Although male diabetic patients have an increased risk of fracture, there is little information about this in the literature. The association between heel bone stiffness and the lifestyle of male patients with diabetes was evaluated.

MATERIALS AND METHODS

The study included 108 participants with type 2 diabetes mellitus patients and 168 age-adjusted, healthy male volunteers. None of the participants had a history of osteoporosis or other severe diseases. Heel bone stiffness was examined by quantitative ultrasound, and each participant completed a health interview survey questionnaire. Bone stiffness was taken as an indicator of bone strength. Stepwise regression analysis was used to investigate associations between bone stiffness and lifestyle-related factors, such as sunlight exposure, intake of milk or small fish, regular exercise, cigarette smoking, consumption of alcohol, and number of remaining teeth.

RESULTS

Bone stiffness showed a significant negative association with cigarette smoking [standardized coefficient (SC) = -0.297, F-value (F) = 10.059] and age (SC = -0.207, F = 7.565) in diabetic patients. Bone stiffness showed a significant negative association with age (SC = -0.371, F = 12.076) and height (SC = -0.193, F = 7.898), as well as a significant positive association with sunlight exposure (SC = 0.182, F = 9.589) and intake of small fish (SC = 0.170, F = 7.393) in controls.

CONCLUSIONS

These findings suggest that cigarette smoking and age are negatively associated with bone stiffness in Okinawan male patients with type 2 diabetes mellitus.

Techniques for diagnosing osteoporosis: a systematic review of cost-effectiveness studies

OBJECTIVES

The study question was whether dual-energy X-ray absorptiometry (DXA) alone is more cost-effective for identifying postmenopausal women with osteoporosis than a two-step procedure with quantitative ultrasound sonography (QUS) plus DXA. To answer this question, a systematic review was performed.

METHODS

Electronic databases (PubMed, INAHTA, Health Evidence Network, NIHR, the Health Technology Assessment program, the NHS Economic Evaluation Database, Research Papers in Economics, Web of Science, Scopus, and EconLit) were searched for cost-effectiveness publications. Two independent reviewers selected eligible publications based on the inclusion/exclusion criteria. Quality assessment of economic evaluations was undertaken using the Drummond checklist.

RESULTS

Seven journal articles and four reports were reviewed. The cost per true positive case diagnosed by DXA was found to be higher than that for diagnosis by QUS+DXA in two articles. In one article it was found to be lower. In three studies, the results were not conclusive. These articles were characterized by the differences in the types of devices, parameters and thresholds on the QUS and DXA tests and the unit costs of the DXA and QUS tests as well as by variability in the sensitivity and specificity of the techniques and the prevalence of osteoporosis.

CONCLUSIONS

The publications reviewed did not provide clear-cut evidence for drawing conclusions about which screening test may be more cost-effective for identifying postmenopausal women with osteoporosis.

Association between low-frequency ultrasound and hip fractures -- comparison with DXA-based BMD

BACKGROUND

New methods for diagnosing osteoporosis and evaluating fracture risk are being developed. We aim to study the association between low-frequency (LF) axial transmission ultrasound and hip fracture risk in a population-based sample of older women.

METHODS

The study population consisted of 490 community-dwelling women (78-82 years). Ultrasound velocity (V(LF)) at mid-tibia was measured in 2006 using a low-frequency scanning axial transmission device. Bone mineral density (BMD) at proximal femur measured using dual-energy x-ray absorptiometry (DXA) was used as the reference method. The fracture history of the participants was collected from December 1997 until the end of 2010. Lifestyle-related risk factors and mobility were assessed at 1997.

RESULTS

During the total follow-up period (1997-2010), 130 women had one or more fractures, and 20 of them had a hip fracture. Low V(LF) (the lowest quartile) was associated with increased hip fracture risk when compared with V(LF) in the normal range (Odds ratio, OR = 3.3, 95% confidence interval (CI) 1.3-8.4). However, V(LF) was not related to fracture risk when all bone sites were considered. Osteoporotic femoral neck BMD was associated with higher risk of a hip fracture (OR = 4.1, 95% CI 1.6-10.5) and higher risk of any fracture (OR = 2.4, 95% CI 1.6-3.8) compared to the non-osteoporotic femoral neck BMD. Decreased VLF remained a significant risk factor for hip fracture when combined with lifestyle-related risk factors (OR = 3.3, 95% CI 1.2-9.0).

CONCLUSION

Low V(LF) was associated with hip fracture risk in older women even when combined with lifestyle-related risk factors. Further development of the method is needed to improve the measurement precision and to confirm the results.

Ultrasound to assess bone quality

Bone quality is determined by a variety of compositional, micro- and ultrastructural properties of the mineralized tissue matrix. In contrast to X-ray-based methods, the interaction of acoustic waves with bone tissue carries information about elastic and structural properties of the tissue. Quantitative ultrasound (QUS) methods represent powerful alternatives to ionizing x-ray based assessment of fracture risk. New in vivo applicable methods permit measurements of fracture-relevant properties, [eg, cortical thickness and stiffness at fragile anatomic regions (eg, the distal radius and the proximal femur)]. Experimentally, resonance ultrasound spectroscopy and acoustic microscopy can be used to assess the mesoscale stiffness tensor and elastic maps of the tissue matrix at microscale resolution, respectively. QUS methods, thus, currently represent the most promising approach for noninvasive assessment of components of fragility beyond bone mass and bone microstructure providing prospects for improved assessment of fracture risk.

The association between plasma homocysteine levels and bone quality and bone mineral density parameters in older persons

INTRODUCTION

High plasma homocysteine levels have been associated with incident osteoporotic fractures, but the mechanisms underlying this association are still unknown. It has been hypothesized that homocysteine might interfere with collagen cross-linking in bone, thereby weakening bone structure. Therefore, we wanted to investigate whether plasma homocysteine levels are associated with bone quality parameters, rather than with bone mineral density.

METHODS

Cross-sectional data of the B-PROOF study (n=1227) and of two cohorts of the Rotterdam Study (RS-I (n=2850) and RS-II (n=2023)) were used. Data on bone mineral density of the femoral neck and lumbar spine were obtained in these participants using dual-energy X-ray assessment (DXA). In addition, participants of B-PROOF and RS-I underwent quantitative ultrasound measurement of the calcaneus, as a marker for bone quality. Multiple linear regression analysis was used to investigate the associations between natural-log transformed plasma levels of homocysteine and bone mineral density or ultrasound parameters.

RESULTS

Natural-log transformed homocysteine levels were inversely associated with femoral neck bone mineral density in the two cohorts of the Rotterdam Study (B=-0.025, p=0.004 and B=-0.024, p=0.024). In B-PROOF, no association was found. Pooled data analysis showed significant associations between homocysteine and bone mineral density at both femoral neck (B=-0.032, p=0.010) and lumbar spine (B=-0.098, p=0.021). Higher natural-log transformed homocysteine levels associated significantly with lower bone ultrasound attenuation in B-PROOF (B=-3.7, p=0.009) and speed of sound in both B-PROOF (B=-8.9, p=0.001) and RS-I (B=-14.5, p=0.003), indicating lower bone quality. Pooled analysis confirmed the association between homocysteine and SOS (B=-13.1, p=0.016). Results from ANCOVA-analysis indicate that differences in SOS and BUA between participants having a plasma homocysteine level above or below median correspond to 0.14 and 0.09 SD, respectively.

DISCUSSION

In this study, plasma levels of homocysteine were significantly inversely associated with both bone ultrasound parameters and with bone mineral density. However, the size of the associations seems to be of limited clinical relevance and may therefore not explain the previously observed association between plasma homocysteine and osteoporotic fracture incidence.

Discontinuation of leisure time impact-loading exercise is related to reduction of a calcaneus quantitative ultrasound parameter in young adult Japanese females: a 3-year follow-up study

A 3-year follow-up study on 334 young Japanese females enrolled in a university at the age of 18 years revealed that discontinuation of leisure time impact-loading exercises performed in junior high and/or high school was associated with increased risk of reduction in calcaneus osteo-sono assessment index (OSI).

INTRODUCTION

Bone strength rapidly increases during puberty and reaches its peak by the end of adolescence. The aim of this study was to determine the lifestyle factors that influence the maintenance of calcaneus OSI in young adult females around the time when peak bone mass is attained.

METHODS

Annual health checkups including OSI measurements, anthropometrics, lifestyle analysis, and blood examination were performed 4 times on 334 Japanese females enrolled in a university at the age of 18 years. According to the slope of OSI change during the 3-year follow-up, the subjects were grouped into two categories: OSI loss (the lowest tertile) and OSI gain/stable (the second and third tertiles).

RESULTS

At the baseline assessment, the OSI loss group had higher OSI and height and an earlier menarche age than the OSI gain/stable group. Performing leisure time impact-loading exercise in junior high and/or high school but discontinuing it at university was associated with increased risk of OSI loss, independent of OSI, height and weight at the age of 18 years, weight change during follow-up, age of menarche, energy-adjusted nutrient intake, and alcohol drinking; the odds ratios were 4.1-4.9 compared with those performing impact-loading exercise at university. In particular, duration, frequency, and subjective intensity of impact-loading exercise during high school were positively associated with OSI loss.

CONCLUSION

Discontinuation of leisure time impact-loading exercises performed during late adolescence is associated with an increased risk of OSI loss in young adult females during the 3-year follow-up period.

Understanding the links among neuromedin U gene, beta2-adrenoceptor gene and bone health: an observational study in European children

Neuromedin U, encoded by the NMU gene, is a hypothalamic neuropeptide that regulates both energy metabolism and bone mass. The beta-2 adrenergic receptor, encoded by the ADRB2 gene, mediates several effects of catecholamine hormones and neurotransmitters in bone. We investigated whether NMU single nucleotide polymorphisms (SNPs) and haplotypes, as well as functional ADRB2 SNPs, are associated with bone stiffness in children from the IDEFICS cohort, also evaluating whether NMU and ADRB2 interact to affect this trait. A sample of 2,274 subjects (52.5% boys, age 6.2±1.8 years) from eight European countries, having data on calcaneus bone stiffness index (SI, mean of both feet) and genotyping (NMU gene: rs6827359, rs12500837, rs9999653; ADRB2 gene: rs1042713, rs1042714), was studied. After false discovery rate adjustment, SI was significantly associated with all NMU SNPs. rs6827359 CC homozygotes showed the strongest association (recessive model, Δ = −1.8, p = 0.006). Among the five retrieved haplotypes with frequencies higher than 1% (range 2.0–43.9%), the CCT haplotype (frequency = 39.7%) was associated with lower SI values (dominant model, Δ = −1.0, p = 0.04) as compared to the most prevalent haplotype. A non-significant decrease in SI was observed in in ADRB2 rs1042713 GG homozygotes, while subjects carrying SI-lowering genotypes at both SNPs (frequency = 8.4%) showed much lower SI than non-carriers (Δ = −3.9, p<0.0001; p for interaction = 0.025). The association was more evident in preschool girls, in whom SI showed a curvilinear trend across ages. In subgroup analyses, rs9999653 CC NMU or both GG ADRB2 genotypes were associated with either lower serum calcium or β-CrossLaps levels (p = 0.01). This study in European children shows, for the first time in humans, a role for NMU gene through interaction with ADRB2 gene in bone strength regulation, more evident in preschool girls.