Quantitative ultrasound in the assessment of skeletal status in children and adolescents

The association between overweight and obesity on bone mineral density in 12 to 15 years old adolescents in China

Overweight/obesity can influence bone mineral accretion, but the conclusions are not consistent. We aimed to examine the association between bone mineral density (BMD) levels and body mass index (BMI) in 12 to 15 years old adolescents.We performed a cross-sectional study including 8365 adolescents. BMD was evaluated using a quantitative ultrasound device. Z scores for BMI were evaluated using World Health Organization references. Logistic regression models were performed to evaluate the association between BMD levels and BMI.Totally 1866 (22.3%) adolescents had low /reduced BMD, and boys had a higher rate than girls (72.6% vs 27.4%, P < .001). The rates of thinness, normal weight, overweight, and obesity were 2.8%, 57.1%, 22.3%, and 17.8%, respectively. The multivariable-adjusted (age, sex, systolic blood pressure, and height Z score) ORs (95% CIs) of low/reduced BMD associated with BMI groups (thinness, normal [reference], overweight, and obesity) were 0.59 (0.39-0.89), 1.00, 1.61 (1.41-1.84), and 1.98 (1.69-2.30), respectively (Ptrend < .001). This positive association existed in boys and girls though the differences were not significant between normal weight and thin girls. The multivariable-adjusted ORs for each 1-unit increase in BMI Z score were 1.36 (1.24-1.49) for girls, and 1.23 (1.16-1.30) for boys, and 1.26 (1.20-1.32) for all participants.We observed a positive association between BMI and low/reduced BMD in 12 to 15 years old adolescents. More attention should be paid on overweight and obese adolescents to reduce the risk of low BMD. Further studies are needed to explore the mechanisms of this association.

Skeletal status assessed by quantitative ultrasound and dual-energy X-ray absorptiometry in children with inflammatory bowel disease: A 2-year prospective study

PURPOSE

To assess the bone status in children with inflammatory bowel diseases (IBD) using quantitative ultrasound (QUS) measurement and dual-energy X-ray absorptiometry (DXA) at baseline and after two years of adequate treatment of the IBD and bone protection medication.

METHODS

Sixteen children (six boys) with IBD, aged 13.4±2.4 years, were examined at baseline and two years later. DXA was used to asses bone mineral density (BMD) and reference data were provided by the device's manufacturer (Hologic Explorer). QUS measurements were performed in patients and controls - 48 healthy children.

RESULTS

Mean Z-scores for TB- and s-BMD were significantly below zero for both, baseline and follow-up (-2.61±0.99 and -2.48±0.88 for TB, and -1.83±1.33 and -1.61±1.19 for s-BMD, respectively), and did not differ significantly, as well as mean Ad-SoS Z-score. The changes in time of TB Z-score and body weight Z-score correlated positively (r=0.63; P<0.01). The QUS results did not differ between patients and controls. There was a negative correlation between the baseline nutritional status and the activity of the disease, as well as of the number of flares before the enrolment and Ad-SoS Z-score.

CONCLUSIONS

BMD was found to be lowered both at baseline and follow-up. No further deterioration was observed during 2-year follow-up. Proper treatment, defined as treatment following ECCO Guidelines, may allow to keep a similar trend in the development of bone tissue as in healthy children. The bone properties assessed by QUS method did not differ between patients and controls. QUS at hand phalanges appears not to be proper diagnostic tool in IBD children.

Skeletal status assessment by quantitative ultrasound and bone densitometry in children with different renal conditions

Two methods of skeletal status assessment-quantitative ultrasound (QUS) and densitometry (DXA)-were applied and compared in a group of children with different renal disorders. Skeletal assessments in children with different renal conditions should rather not be based on a single diagnostic tool. Lumbar spine DXA is very effective to reveal disturbances secondary to glucocorticoids, whereas total body DXA and QUS are both better in identification of disturbances related to decreased GFR.

INTRODUCTION

The aim of the study was to evaluate the skeletal status in children in different stages of chronic kidney disease (CKD) or treated with glucocorticoids, using either densitometry (DXA) or quantitative ultrasound (QUS) methods.

METHODS

Seventy-six subjects (27 girls/49 boys) at the mean age of 11.8 ± 4.0 years were enrolled to the reported study. They were divided into three subgroups: with normal glomerular filtration rate (GFR) but treated with glucocorticoids (GCs, n = 38), with decreased GFR (CKD 2-5, n = 26) and with normal GFR and without any bone-toxic treatment (CKD 1, n = 12). DXA scans were carried out at lumbar spine (LS) and at total body (TB), and quantitative ultrasound (QUS) imaging was done at hand phalanges. QUS results were compared to those obtained from 310 healthy matched controls.

RESULTS

The average Z-score for LS-BMD and TB-BMD was below zero in all the study subgroups. Neither were there any significant differences in the mean Z-score for LS among the subgroups. The mean Z-score for TB was significantly the lowest in the CKD 2-5 subgroup. The percentage of subjects with TB Z-score ≤ - 2.0 was the highest in the CKD 2-5 subgroup (69.2%), whereas the percentage of subjects with LS Z-score ≤ - 2.0 was the highest in the GC subgroup (23.7%). QUS results in CKD 2-5 were significantly lower than those in the controls, whereas the results, obtained in GC and CKD 1 subgroups, were similar to those in healthy subjects.

CONCLUSIONS

Skeletal status assessment in children and adolescents with different renal conditions should not be based on single diagnostic approach. DXA scanning, performed at lumbar spine, is potentially more appropriate to reveal disturbances secondary to long-term GC therapy, whereas TB-DXA is highly effective in the identification of skeletal disturbances related to decreased kidney function. QUS at hand phalanges seems to be a useful diagnostic means in CKD with diminished GFR but insufficient to detect GC-related disturbances.

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.

Quantitative Ultrasonography Measurements of the Phalanges in Adolescents: A Mixed Longitudinal Study

This study examined the effect of pubertal development on Amplitude Dependent Speed of Sound (AD-SoS), accounting for the growth in stature among adolescents. A mixed-longitudinal design with 3 assessments across a 15-mo period in 439 adolescents (girls: 215; boys: 224) aged 9-16 y was used. Bayesian multilevel models were used to describe gender-specific AD-SoS variations among participants during pubertal years. Substantial increments in AD-SoS during pubertal years were observed in both genders. AD-SoS changes were positively related to stature, and the rate of stature growth per year. Quantitative ultrasonography was sensible to describe age-related changes of bone mass during pubertal development. It seemed clinically reliable to use AD-SoS in the study of bone growth and development.

Quantitative Ultrasound Measurement at the Hand Phalanges Does Not Reveal Skeletal Disturbances in Children With Bronchial Asthma: A Longitudinal Observation

OBJECTIVES

To assess the skeletal status in asthmatic children treated with inhaled corticosteroids in a longitudinal observation by quantitative ultrasound (US) measurement at the hand phalanges.

METHODS

Thirty-four children were studied prospectively. Quantitative US measurements were performed at baseline and after a mean ± SD of 2.35 ± 0.20 years. The obtained results were compared to age-, sex-, and body size-matched control participants selected from a database of previously examined healthy children. Individual changes in the amplitude-dependent speed of sound (Ad-SoS) during the follow-up period were also analyzed.

RESULTS

The mean age of the asthmatic children was 10.6 ± 2.5 years. The mean Ad-SoS in the asthmatic children at baseline was 1940.5 ± 49.6 m/s, and the mean Z score was -0.26 ± 0.80. Corresponding values at the follow-up examination were 1976.2 ± 63.6 m/s and -0.18 ± 1.16. The results did not differ significantly in comparison to the healthy controls. The analysis of individual changes in Ad-SoS revealed that 18 participants had a significant increase in this parameter (ie, exceeding the least significant change threshold), and 16 did not have a significant change in their values. No one had a significant decrease in Ad-SoS.

CONCLUSIONS

Quantitative US at the hand phalanges applied as a diagnostic tool revealed no essential differences in the pattern of skeletal development between asthmatic children treated with inhaled glucocorticosteroids and healthy controls.

Bone status assessed by quantitative ultrasound in children with inflammatory bowel disease: a comparison with DXA

BACKGROUND

To determine the bone status in children with inflammatory bowel diseases (IBD) using quantitative ultrasound (QUS) measurement at hand phalanges and compare the obtained results with dual-energy X-ray absorptiometry (DXA).

METHODS

Fifty-one children with IBD underwent DXA and QUS measurements at hand phalanges in the year 2013. The control group for the QUS consisted of 460 children. Reference data for DXA comes from Hologic Explorer.

RESULTS

QUS measurements did not differ significantly between IBD patients and healthy controls. There was no difference between UC and CD subjects. DXA measurements in patients with IBD were lower than in the healthy population. Tanner stage and nutritional status correlated with bone status contrary to steroids therapy.

CONCLUSION

Low bone mineral density often complicates IBD in children. QUS is not an appropriate method for the assessment of bone status in children. Nutritional status seems to have a greater impact on bone status than corticosteroids therapy.

Sex- and Maturity-Related Differences in Cortical Bone at the Distal Radius and Midshaft Tibia Evaluated by Quantitative Ultrasonography

Boys usually have higher values of bone mineral density measured by dual-energy X-ray absorptiometry than girls, but contradictorily also have a greater incidence of fractures during growth. The purpose of this study was to investigate sex- and maturity-related differences in bone speed of sound (SoS) at the radius and tibia in a sample of 625 healthy children aged 10-14 y and to analyze the contributions of physical activity (PA) to possible dissimilarities. Radial and tibial SoS was evaluated by quantitative ultrasound, maturity was estimated as the years of distance from the peak height velocity age, and PA was assessed by accelerometry. Comparisons between sexes and maturity groups (low: below average [<-2.5 y], high: average or above [≥-2.5 y]) were made by two-sample t-tests with unequal variances. Girls in the high-maturity group had higher SoS at the radius and tibia compared with girls in the low-maturity group (p < 0.001). There were no SoS differences at the radius or tibia between the high- and low-maturity groups in boys. Within high-maturity children, girls had higher SoS than boys at the radius and tibia (p < 0.001). There were no differences at the radius and tibia between girls and boys with low maturity. The results were not modified after controlling for PA. Regardless of PA, the results provide insight into sex- and maturity-related differences in bone SoS at the distal radius and midshaft tibia from maturity less than 2.5 y from the peak height velocity age, with boys having lower SoS.

Brazilian pediatric reference data for quantitative ultrasound of phalanges according to gender, age, height and weight

Aims

To establish normative data for phalangeal quantitative ultrasound (QUS) measures in Brazilian students.

Methods

The sample was composed of 6870 students (3688 females and 3182 males), aged 6 to 17 years. The bone status parameter, Amplitude Dependent Speed of Sound (AD-SoS) was assessed by QUS of the phalanges using DBM Sonic BP (IGEA, Carpi, Italy) equipment. Skin color was obtained by self-evaluation. The LMS method was used to derive smoothed percentiles reference charts for AD-SoS according to sex, age, height and weight and to generate the L, M, and S parameters.

Results

Girls showed higher AD-SoS values than boys in the age groups 7–16 (p<0.001). There were no differences on AD-SoS Z-scores according to skin color. In both sexes, the obese group showed lower values of AD-SoS Z-scores compared with subjects classified as thin or normal weight. Age (r² = 0.48) and height (r² = 0.35) were independent predictors of AD-SoS in females and males, respectively.

Conclusion

AD-SoS values in Brazilian children and adolescents were influenced by sex, age and weight status, but not by skin color. Our normative data could be used for monitoring AD-SoS in children or adolescents aged 6–17 years.

Reference equations for ultrasound bone densitometry of the radius in Central European children and adolescents

Bone density measurements are important for evaluation and follow-up of children with alterations in their mineral status (increased risk for fractures and osteoporosis subsequently). Interpretation of these measurements relies on the availability of appropriate reference equations. We developed gender-specific, age-dependent reference values of bone density for Central European children.

INTRODUCTION

In recent years, there has been an increasing demand for the measurement of bone density in children exposed to an increased risk of early alterations in their bone status. These values must be compared to an adequate reference population. The aim of the present study was to create reference equations of radial speed of sound (SOS) for Central European children and adolescents.

METHODS

In this cross-sectional study, SOS values were measured at the distal third of the radius in 581 Swiss children and adolescents (321 girls and 260 boys) aged 6 to 16 years using the Sunlight Omnisense® 7000P quantitative ultrasound system.

RESULTS

Gender-specific reference equations for SOS values were derived by polynomial regression and combined a cubic dependence of age and a linear dependence of height. The fitted SOS curves in our study population show a plateau period in both genders for younger ages followed by an increase phase beginning at the age of 12 in girls and 14 in boys. Neither the reported level of physical activity nor additional sport nor self-reported calcium intake influenced the reference equations.

CONCLUSIONS

Our results show a good agreement with similar studies using the same measurement technique on other body parts, suggesting a wide applicability of the obtained reference curves over different European populations.

[Factors that influence bone mass of healthy children and adolescents measured by quantitative ultrasound at the hand phalanges: a systematic review]

Objective:

To analyze the main factors that influence bone mass in children and teenagers assessed by quantitative ultrasound (QUS) of the phalanges.

Data source:

A systematic literature review was performed according to the PRISMA method with searches in databases Pubmed/Medline, SciELO and Bireme for the period 2001-2012, in English and Portuguese languages, using the keywords: children, teenagers, adolescent, ultrasound finger phalanges, quantitative ultrasound of phalanges, phalangeal quantitative ultrasound.

Data synthesis:

21 articles were included. Girls had, in QUS, Amplitude Dependent Speed of Sound (AD-SoS) values higher than boys during pubertal development. The values of the parameters of QUS of the phalanges and dual-energy X-ray Absorptiometry (DXA) increased with the increase of the maturational stage. Anthropometric variables such as age, weight, height, body mass index (BMI), lean mass showed positive correlations with the values of QUS of the phalanges. Physical activity has also been shown to be positively associated with increased bone mass. Factors such as ethnicity, genetics, caloric intake and socioeconomic profile have not yet shown a conclusive relationship and need a larger number of studies.

Conclusions:

QUS of the phalanges is a method used to evaluate the progressive acquisition of bone mass during growth and maturation of individuals in school phase, by monitoring changes that occur with increasing age and pubertal stage. There were mainly positive influences variables of sex, maturity, height, weight and BMI, with similar data when compared to the gold standard method, the DXA.

Cross-sectional study of the association of body composition and physical fitness with bone status in children and adolescents from 11 to 16 years old

Background

The aim of the study was to verify the association between body composition and physical fitness with bone status in children and adolescents.

Methods

A cross-sectional study was conducted with 300 healthy students (148 boys, 152 girls). Weight, height, fat and fat-free mass, and percentage of body fat (%BF) were evaluated, as were physical fitness (abdominal exercise, flexibility, and horizontal jump tests) and maximum oxygen consumption. Bone parameters (amplitude-dependent speed of sound; AD-SoS) and the Ultrasound Bone Profile Index (UBPI) were evaluated using DBM Sonic BP ultrasonography.

Results

In the study group, girls had higher bone parameter values than boys. A univariate analysis assessed in a stepwise multiple regression model was conducted. It showed that for boys, the %BF and height were significant independent variables for AD-SoS and UBPI, but the horizontal jump test only for AD-SoS (adjusted r² = 0.274; p < 0.001), and pubertal maturation only for UBPI (adjusted r² = 0.295; p < 0.001). For girls, age and %BF were identified as significant independent variables for AD-SoS and UBPI (adjusted r² = 0.093; p < 0.001) but height only for AD-SoS (adjusted r² = 0.408; p < 0.001).

Conclusions

Variables related to growth (age, height, and pubertal maturation) are independent positive predictors for the bone parameters in both boys and girls. %BF is an independent negative predictor. For boys, the horizontal jump test was an independent positive predictor for AD-SoS, indicating that physical fitness related to the neuromotor system can influence the amount of bone present.

Quantitative ultrasound bone measurements in pre-pubertal children with type 1 diabetes

This case-control study aimed to assess bone status in children with type 1 diabetes mellitus (T1DM). Fifty-seven pre-pubertal patients (37 boys, aged 7.9 ± 2.5 years, T1DM duration 3.1 ± 1.6 years) and 171 age-matched healthy controls (111 boys) were studied. Quantitative ultrasound (QUS) was used to measure amplitude dependent speed of sound (Ad-SoS) at hand phalanges (expressed as standard deviation score [SDS]). Anthropometric and disease-related data (including mean HbA(1c) from whole T1DM duration [T], last year [Y], examination day [D]) were collected. Mean Ad-SoS SDS in patients -0.13 ± 1.32 (95% confidence interval [CI] -0.48, 0.22) was similar to that of controls. Subgroups discriminated according to HbA(1c) D, Y and T (cut-off 7.0%) did not differ regarding analyzed parameters. In patients, Ad-SoS SDS was comparable for both genders. Multivariable stepwise regression analysis showed significant negative influence of diabetes duration on Ad-SoS SDS. QUS findings in pre-pubertal children with T1DM do not differ from those in healthy children. Disease duration seems to affect negatively Ad-SoS SDS. However, independent prospective studies are needed to elucidate the true associations.

Longitudinal changes in calcaneal quantitative ultrasound measures during childhood

This longitudinal study examined how calcaneal quantitative ultrasound (QUS) measures change during childhood while taking into account skeletal maturation, body mass index (BMI), and physical activity. The study reported sex differences in QUS growth curves and an inverse relationship between BMI and speed of sound (SOS) measures.

INTRODUCTION

The aim of this study was to examine how calcaneal QUS parameters change over time during childhood and to determine what factors influence these changes.

METHODS

The study sample consisted of a total of 192 Caucasian children participating in the Fels Longitudinal Study. A total of 548 calcaneal broadband ultrasound attenuation (BUA) and SOS observations were obtained between the ages of 7.6 and 18 years. The best fitting growth curves were determined using statistical methods for linear mixed effect models.

RESULTS

There are significant sex differences in the pattern of change in QUS parameters (p < 0.05). The relationship between QUS measures and skeletal age is best described by a cubic growth curve in boys and a linear pattern among girls. Boys experience their most rapid growth in BUA and SOS in early and late adolescence, while girls experience constant growth throughout childhood. Adiposity levels were significantly associated with the changes in SOS among boys (p < 0.001) and girls (p < 0.01), indicating that children with higher BMI are likely to have lower SOS over time compared to children with lower BMI. For girls, physical activity levels showed positive associations with changes in QUS measures (p < 0.05).

CONCLUSION

This study documents significant sex differences in the pattern of change in QUS measures over childhood and adolescence. Our study also shows significant influences of adiposity and physical activity on the pattern of change in QUS measures during childhood.

[Calcium intake and bone mineral density in a group of Spanish school-children]

INTRODUCTION

There are limited data available on bone mass status in Spanish children and or whether the differences are associated with diet/hygiene habits or geographical variability.

SUBJECTS AND METHODS

To determine this association a cross-sectional study was carried out in three different areas (northern, central and southern Spain) and included 1176 schoolchildren between 5 and 12 years old, randomly selected from schools in those areas. Bone density of the distal phalanges was measured by bone ultrasound. We examine the correlations between these data and calcium and vitamin D intake, physical activity and bone mass index.

RESULTS

Of the 1176 children initially included, 1035 nutritional questionnaires were completed and bone ultrasound data were obtained on 991 of them. Eighteen percent of girls and 13% of boys had a calcium intake below 800 mg per day. More than 70% of children have a daily vitamin D intake under 2.5 mcg. Age and exercise showed a direct linear relationship with bone mineral density, and an inverse one for overweight.

CONCLUSIONS

Both high physical activity and high calcium intake were associated with a higher bone mineral density, while overweight showed the opposite effect. Diet habits and exercise must be considered the main strategies to prevent adult osteoporosis during childhood.

Normative calcaneal quantitative ultrasound data as an estimation of skeletal development in Swedish children and adolescents

We present age- and gender-specific normative bone status data evaluated by quantitative ultrasound (QUS) in the calcaneus with the Lunar Achilles device and compare these estimates with bone mineral content (BMC) and bone mineral density (BMD) estimated by dual X-ray absorptiometry (DXA). Included were a sample of 518 population-based collected Swedish girls and 558 boys aged 6-19 years. QUS measurements included speed of sound (SOS), broadband ultrasound attenuation (BUA), and stiffness index (SI) in the calcaneus. DXA measurements included BMC and BMD in the femoral neck (FN), lumbar spine (L2-L4), and total body (TB). Height and weight were measured with standard equipment. Age, height, and weight were significantly associated with SOS, BUA, and SI. Compared to SOS, in both girls and boys there was a higher correlation between BUA and FN BMC (r = 0.71 and r = 0.73, respectively), FN BMD (r = 0.68 and r = 0.67, respectively), L2-L4 BMC (r = 0.70 and r = 0.64, respectively), L2-L4 BMD (r = 0.69 and r = 0.64, respectively), TB BMC (r = 0.76 and r = 0.75, respectively), and TB BMD (r = 0.74 and r = 0.74, respectively). The correlations between SOS and FN BMC (r = 0.38 and r = 0.52, respectively), FN BMD (r = 0.41 and r = 0.52, respectively), L2-L4 BMC (r = 0.31 and r = 0.40, respectively), L2-L4 BMD (r = 0.32 and r = 0.41, respectively), TB BMC (r = 0.42 and r = 0.49, respectively), and TB BMD (r = 0.48 and r = 0.54, respectively) were lower, although still significant (all P < 0.001). BUA seems to be the QUS parameter that best resembles the changes in BMC during growth.

Bone status in adolescents with type 1 diabetes

AIMS

The aim of the study was to investigate the potential negative impact of type 1 diabetes on bone status of adolescents. Bone status in adolescents with type 1 diabetes was assessed by means of quantitative ultrasound (QUS) and the influence of metabolic control and other disease-related and growth variables was analysed.

METHODS

Group I consisted of 99 pubertal (Tanner > or = 2) adolescents (49 female), aged 14.3 +/- 2.5 years, diabetes duration 4.6 +/- 2.3 years. Controls (group II) were 297 children, matched by sex and age, from a healthy population. The influence of glycated haemoglobin (current: HbA(1c)D; last year's mean: HbA(1c)Y; whole duration mean: HbA(1c)T), diabetes duration, percentage of life with disease and daily insulin requirement (DIR) on amplitude dependent speed of sound (Ad-SoS) at distal phalanges was studied.

RESULTS

In comparison to the control group, adolescents with type 1 diabetes presented significantly higher BMI SDS (0.82 [95% CI 0.54, 1.10] vs -0.06 [95% CI -0.16, 0.04] p < 0.001) and lower Ad-SoS SDS (-0.34 [95% CI -0.57, -0.11] vs -0.03 [95% CI -0.15, 0.08], p < 0.05). No correlation between Ad-SoS SDS and sex, DIR or diabetes duration was observed. The lower Ad-SoS SDS reflects reduced bone status, and the reduction was significantly more marked in those patients whose HbA(1c)T was higher than 7.0% when compared with those whose HbA(1c)T was lower.

CONCLUSIONS

Bone status of adolescents with type 1 diabetes mellitus assessed with QUS differs from that of healthy peers and is dependent on long-term metabolic control.

Reference values for quantitative ultrasonography (QUS) of radius and tibia in healthy greek pediatric population: clinical correlations

The aim of this study was to provide reference standards for measurements of quantitative ultrasonography (QUS) of radius and tibia in normative Greek pediatric population. Analysis was performed in 1549 healthy subjects (814 girls and 735 boys) with a mean decimal age of 11.41+/-3.52 yr (range: 3.78-18.33 yr). Results showed a gradual increase of absolute values of radial and tibial speed of sound (SOS), with aging and with pubertal progressing, in both girls and boys. Gender comparison showed significantly increased SOS values measured both at radius and at tibia in girls more than 13 yr of age compared with aged-matched boys. Significant but mild correlation was noted between standard deviation scores (SDS) of SOS at radius and at tibia (r = 0.259, p < 0.001). Additionally, tibial SOS SDS were significantly negatively correlated with body mass index (BMI) SDS (r = -0.230, p < 0.001). Finally, subjects that spend more than 3h of daily "screen time" (television and personal computer) showed significantly decreased SOS values measured both at radius and at tibia. On the contrary, no correlation was observed between SOS values and the amount of physical activity reported.

Quantitative ultrasound in the assessment of skeletal status

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

Quantitative ultrasound measurements at hand phalanges in children and adolescents: a longitudinal study

The purpose of this longitudinal study was to characterize changes in quantitative ultrasound (QUS) values over a 1-y period in healthy boys and girls aged 7 to 12 y at baseline and assess the relation between the increase in anthropometric parameters and amplitude dependent speed of sound (Ad-SoS). A total of 269 children completed the study (139 girls and 130 boys). Ultrasound measurements were performed with a DBM Sonic 1200 device (IGEA, Carpi, Italy), which measures the Ad-SoS, m/s. Girls had significantly higher QUS values than boys at first and second measurements (p < 0.01 and p < 0.00001, respectively). Both girls and boys experienced statistically significant increases in Ad-SoS and all anthropometric parameters over a 1-y period. When the studied group was divided into age groups by year, the differences in QUS values between genders were significant only for 11 and 12 y groups at baseline (p < 0.02 and p < 0.01, respectively) and second visit (p < 0.00001 and p < 0.001, respectively). Stepwise regression analyses models with Ad-SoS at baseline and after 1 y as dependent variables showed a strong correlation between Ad-SoS and Tanner stage in girls but not in boys. In the entire survey group, only 21.5% of the boys and 41% of the girls experienced increases in Ad-SoS more than least significant change. This article suggests that QUS measurements allow the investigation of longitudinal changes and give reliable information about skeletal status in a manner similar to other methods.

Quantitative ultrasound methods to assess bone mineral status in children: technical characteristics, performance, and clinical application

Measurement of bone mineral status may be a useful tool in identifying the children who could be exposed to an increased risk of osteoporosis in adulthood. Dual energy x-ray absorptiometry and peripheral quantitative computed tomography may be used to this purpose, but the exposure to ionizing radiation is a limiting factor for preventive studies in large populations of children. In the last years, quantitative ultrasound (QUS) methods have been developed to assess bone mineral status in some peripheral skeletal sites such as calcaneus, phalanges of the hand, and tibia. QUS techniques are safe, easy to use, radiation-free, and devices are portable, so that they are particularly indicated to assess bone mineral status in children. This review will concentrate on the main methodological principles of ultrasounds and the QUS variables derived from their application to bone tissue, technical differences and performance of QUS methods, factors influencing QUS measurements, normative data and results obtained in children with disturbances of growth or affected by disorders of bone and mineral metabolism, including the assessment of fracture risk, and comparison among QUS, dual energy x-ray absorptiometry, and peripheral quantitative computed tomography methods.

Skeletal status and laboratory investigations in adolescent girls with anorexia nervosa

To our knowledge anorexia nervosa (AN) adversely influences bone density, but whether qualitative characteristics of bone are also affected is not known. For this reason we investigated prospectively the changes in skeletal status in a population of 18 adolescent girls with AN aged 11.5-18.1 years (mean 15.9+/-1.9 years) using both dual-photon X-ray absorptiometry (DXA) and quantitative ultrasound (QUS) measurements, bone turnover markers (osteocalcin, bone alkaline phosphatase - bALP, carboxy-terminal cross-linked telopeptide of type I collagen - ICTP), and laboratory investigations (serum total and ionised calcium, serum phosphate, urine calcium/creatinine ratio, luteinizing hormone - LH, follicle-stimulating hormone - FSH, estradiol). Measurements of bone mineral density at the spine (s-BMD) and total body (TB-BMD) and amplitude-dependent speed of sound (Ad-SOS) of the hand phalanges were performed at baseline, 7.8+/-2.4 and 19.4+/-5.6 months of follow-up. The mean values of TB-BMD, s-BMD and Ad-SOS measurements did not change during the period of observation. The mean Z-scores for TB-BMD and Ad-SOS were significantly lower after 19.4 months of observation vs. baseline (-1.06+/-1.00 vs. -0.67+/-0.98 vs. and -0.50+/-0.88 vs. 0.26+/-1.75, respectively). Z-scores for s-BMD decreased non-significantly (p=0.08). Among bone turnover markers, we observed a significant increase in bALP and a non-significant increase in osteocalcin serum concentrations which were below normal ranges for age, sex and Tanner stage at baseline. High baseline serum ICTP concentration decreased non-significantly, reaching normal ranges during the observation. We conclude that anorexia nervosa seriously affects skeletal status in adolescent girls. Bone turnover markers analysed together with densitometric parameters suggest that AN influences both bone formation and resorption processes. QUS measurements at hand phalanges may be an appropriate method in the evaluation of skeletal status in patients with AN.

Ultrasound bone densitometry of the calcaneus in healthy Chinese children and adolescents

INTRODUCTION

We evaluate reference data to examine whether there are sex-, age-, height-, weight- and BMI-related differences of quantitative ultrasound parameters (QUS) for healthy Chinese children and adolescents.

METHODS

A total of 726 healthy children and adolescents (360 male and 366 female) aged from 10-21 years were examined with a Lunar Achilles Express densitometer. The measurements on the right heel included speed of sound (SOS), broadband ultrasound attenuation (BUA), and a calculated stiffness index (SI).

RESULTS

Our results found that there were no significant differences for BUA, SOS and SI between males and females, except in the age range of 12 to 13 years. The values of all parameters were significantly higher in the 12-year-old females compared to males, and BUA values were significantly higher in 13-year-old females compared to males. A spurt in QUS parameters were observed at 12 years in females and at 14 years in males. A steady increase of BUA, SOS, and SI was seen with increasing body height and weight in both sexes.

CONCLUSION

In conclusion, the present results can be used as reference data for children and adolescents in China.

Phalangeal quantitative ultrasound measurements in former pre-term children aged 9-11 years

The objective of this study was to compare phalangeal ultrasound values in 38 former pre-term children, aged 9-11 years, with 50 age-matched term controls. Skeletal status was evaluated using phalangeal quantitative ultrasound measurements (QUS) by DBM Sonic 1200 (IGEA, Carpi, Italy) which measures the amplitude dependent speed of sound (Ad-SoS, m s(-1)). There were no significant differences in values of Ad-SoS, weight and height between patients and controls irrespective of birth weight or prematurity. In conclusion, phalangeal ultrasound measurements performed in prematurely born infants show that at the age of 9-11 years their bone status does not differ from children born at term.

Physical activity for bone health in inactive teenage girls: is a supervised, teacher-led program or self-led program best?

PURPOSE

To investigate the effect of a six-month teacher-led osteogenic physical activity program, vs. a self-led activity program, on ultrasound measurements of bone in inactive teenage girls.

METHODS

Ninety sedentary girls [mean (SD) age 16.3 (.6) years] were identified from 300 assessed for physical activity across five schools in southeast Ireland. Schools were matched and randomly assigned to a teacher-led physical activity (TLPA) program, a self-led physical activity (SLPA) program, or a control group. Broadband ultrasound attenuation (BUA), speed of sound (SOS), and os calcis stiffness index (OCSI) were measured using a portable ultrasound machine. Anthropometry, aerobic fitness, calcium intake, and physical activity were assessed, and focus groups held one month after program completion. Descriptive statistics, paired t-tests, and analysis of variance were used to analyze the data.

RESULTS

Both intervention groups demonstrated significant improvements (p < .05) in BUA, SOS, OCSI and aerobic fitness, i.e., TLPA: +14.9%, +21.9%, + 15.9%, and +8.5%, respectively, and SLPA: +10.6%, +30.3%, + 15.6%, and +5.1%, respectively, with no change in controls. Differences between intervention groups and controls were significant for BUA and OCSI (p < .05). TLPA and SLPA groups engaged in an average of 4.5 and 3.4 hours/week of physical activity, respectively, over the intervention period. The SLPA group continued to exercise after the intervention had ceased, whereas the TLPA group did not.

CONCLUSIONS

Previously inactive teenage girls can adhere to an osteogenic activity program whether supervised or directing their own activity. Longer-term, sustainable initiatives with this age group are needed and might focus on developing personal skills for physical activity.

Assessing the cortical thickness of long bone shafts in children, using two-dimensional ultrasonic diffraction tomography

Echography is one of the first-line techniques used in clinical practice to diagnose osteoarticular diseases in children. However, this technique involves the use of standard equipment, which is not adapted to the morphology or the acoustical properties of children's bones. In this study, we developed an ultrasonic tomography method for measuring the cortical thickness of children's long bones. Ultrasonic tomography gives cross-sectional images showing the spatial distribution of some of the physical components of an object, based on scattered ultrasound measurements. These measurements are carried out using variably dense sets of transmitter and receiver positions and various the wave frequencies. We solved this inverse scattering problem using a Born approximation, which yields an attractively simple linear relation between the object function and the scattered field, particularly in the far field. Experiments with a 2D-ring antenna show the applicability of the method and its various improvements to bone thickness imaging.

Longitudinal assessment of bone quality by quantitative ultrasonography in children and adolescents

Among the techniques available to assess bone quality, quantitative ultrasonography of the proximal phalanges of the hand (QUS) has emerged as particularly attractive. In this study, amplitude-dependent speed of sound (AD-SoS) and bone transmission time (BTT) were obtained by the sonographic device DBM Sonic BP IGEA in two sessions at two years' interval, in a school-age population (589 subjects, 290 mol/L and 299F, aged 3 to 16 y) with the aim to determine accuracy of QUS measurements, evaluate QUS variable changes during growth, relate these values with age and growth variables. Mean AD-SoS and BTT at age classes from 5 to 12 y as determined at the first and second measurement sessions were not significantly different. A significant increment (p < 0.0001) between the first and the second measurement was observed for both QUS variables. AD-SoS and BTT showed significantly different variations in the various age groups (ANOVA). Correlations were found of AD-SoS and BTT increments with age, height, weight, pubertal stage and with height growth velocity (p < 0.05). AD-SoS and BTT increment curves presented a very similar trend decreasing from 4 to 7 y of age. Thereafter a plateau was reached up to the age of 10 to 11 y in girls and 11 to 12 y in boys, when an increase was observed corresponding to pubertal growth rate acceleration. In conclusion, the present study would confirm that QUS measurements are accurate. Ad-SoS and BTT increment models are similar to most growth velocity curves and follow a strongly age- and growth-dependent pattern.

Quantitative ultrasound and peripheral bone densitometry in patients with genetic disorders

The aim of the study was comparison of quantitative ultrasound and densitometric peripheral measurements in subjects with genetic disorders. The study included 52 subjects (35 boys and 17 girls) in mean age 13.1 +/- 4.8 y. Patients with following disorders were evaluated: Down syndrome (n = 21), Martin-Bell syndrome (n = 14) and other (n = 17). There were no additional factors potentially influencing bone metabolism. Bone status was assessed by quantitative ultrasound at the hand phalanges using DBM Sonic 1200 (IGEA, Italy), which measures amplitude-dependent speed of sound (Ad-SoS [m/s]) and bone densitometry at the calcaneus and forearm by the use of PIXI (GE, USA), which measures bone mineral density (BMD, g/cm2). Ad-SoS correlated significantly with forearm and calcaneus BMD in the whole group (r = 0.66, p < 0.000001 and r = 0.51, p < 0.0001, respectively), in females (r = 0.58, p < 0.05 and r = 0.5, p < 0.05) and in males (r = 0.70, p < 0.000001 and r = 0.54, p < 0.001). Calcaneus BMD correlated with wrist BMD in the whole group, in females and males: r = 0.66, p < 0.000001, r = 0.67, p < 0.01 and r = 0.75, p < 0.0001, respectively. These coefficients of correlation were compared and did not reveal significant differences in the whole group and in the gender subgroups. ROC analysis of Ad-SoS values versus calcaneus and forearm BMD showed area under curve 0.89 for forearm BMD and 0.79 for calcaneus BMD (subjects with Ad-SoS T-score below -3.2 were considered as abnormal). Age correlated significantly with Ad-SoS, forearm and calcaneus BMD (r ranged from 0.53 to 0.9, p from 0.05 to 0.000001). In all patients and males, age more strongly influenced Ad-SoS than calcaneus BMD (p < 0.05). Also, body weight and height correlated significantly with Ad-SoS, forearm and calcaneus BMD, except for correlation between forearm BMD and height in female patients (r from 0.58 to 0.84, p < 0.05). Generally, in multiple stepwise regression analysis of age and body size on skeletal parameters, age had positive influence, and body size was a positive or a negative factor. In conclusion, both quantitative ultrasound and peripheral densitometry may be recommended for the assessment of skeletal status in subjects with genetic disorders, although measurements of phalanges seem to be more sensitive for detecting age-related bone changes.

Comparison of phalangeal ultrasound and dual energy X-ray absorptiometry in healthy male and female adolescents

The aims of this study were to determine if there is a correlation between dual energy X-ray absorptiometry (DXA) and phalangeal quantitative ultrasound (QUS) in identifying children and adolescents with low bone density, and to assess if body size influences the results of the two techniques to the same degree. Measurements were performed in 67 girls and 83 boys aged 14 to 19 y using DBM Sonic 1200 (IGEA, Carpi, Italy) and the DXA equipment (LUNAR Radiation Corp., Madison, WI, USA). Twelve adolescents (eight males and four females) reported a past history of nonosteoporotic fractures. Lumbar spine bone mineral density (LS BMD), total body bone mineral density (TB BMD) and total body bone mineral content (TB BMC) correlated positively with age, height, BMI and weight, in both genders. Amplitude-dependent speed of sound (Ad-SOS) was positively correlated with age, height and Tanner stages in both genders and negatively correlated with BMI in females. TB BMD, TB BMC and LS BMD positively correlated with Ad-SOS only in males. In females, there were no significant correlations between Ad-SOS, TB BMD, TB BMC and LS BMD measurements. Twelve teenagers with previous fractures (high impact fractures) were found to have lower DXA and QUS values than age-matched teenagers without fractures but the statistical significance was found only in relation to TB BMD values (p = 0.02). In conclusion, we obtained results similar to those that have been reported by other authors using different QUS techniques. Furthermore, the Ad-SOS measurements taken at the distal metaphysis of the proximal phalanges correlate poorly with LS BMD and TB BMD measured by DXA in growing subjects.