Evidence-based outcomes on diagnostic accuracy of quantitative ultrasound for assessment of pediatric osteoporosis - a systematic review

Vitamin D Levels in Pregnant Women Do Not Affect Neonatal Bone Strength

Vitamin D plays a key role in regulating calcium and phosphate metabolism. However, whether maternal vitamin D levels affect fetal bone strength is unclear. This study assessed correlations between maternal 25(OH)D status and neonatal bone strength 25(OH)D levels, these were measured in the maternal and infant cord blood of 81 mother−infant dyads. Bone strength was measured using a quantitative ultrasound (QUS) of tibial bone speed of sound (SOS). Maternal vitamin D intake, medical history and lifestyle were evaluated from questionnaires. Maternal 25(OH)D levels were deficient (<25 nmol/L) in 24.7%, insufficient (25−50 nmol/L) in 37% and sufficient (>50 nmol/L) in 38.3%. The maternal and cord blood 25(OH)D levels correlated (r = 0.85, p < 0.001). Cord blood levels (57.9 ± 33.5 nmol/L) were higher than the maternal blood levels (46.3 ± 23.2: p < 0.001). The mean SOS was 3042 ± 130 m/s. The neonatal SOS and 25(OH)D levels were not correlated. The mean bone SOS levels were comparable in the three maternal and cord blood 25(OH)D groups. No correlation was found between the maternal 25(OH)D levels and the neonatal anthropometrics. Although the 25(OH)D levels were higher in Jewish mothers than they were in Muslim mothers (51.1 ± 22.6 nmol/L vs. 24 ± 14.7 nmol/L, respectively: p = 0.002) and in those who took supplemental vitamin D, the bone SOS levels were comparable. In conclusion, maternal vitamin D levels correlate with cord levels but do not affect bone strength or growth parameters.

Characteristics of healthy German children and adolescents across tertiles of calcaneal stiffness index

Aim

Identifying risk factors for low bone stiffness index (SI) might be one crucial strategy for osteoporosis prevention. Purpose was to characterize healthy schoolchildren across tertiles of SI.

Subject and methods

In 248 girls (13.4 ± 1.9 years, BMI: 20.2 ± 4.8 kg/m2) and 231 boys (13.6 ± 1.7 years, BMI: 19.3 ± 3.3 kg/m2), the following parameters were assessed: calcaneal SI (quantitative ultrasound), body composition (bioelectrical impedance analysis), Bone Healthy Eating Index (BoneHEI; food frequency questionnaire), and physical activity level (PAL; activity questionnaire). Participants were classified according to age- and sex-specific SI tertiles (low, medium, and high). Between-group comparisons were achieved by Kruskal–Wallis-H-tests (α = 0.05).

Results

Girls with low SI had significantly lower body mass (49.2 ± 16.7 vs 54.8 ± 12.2 kg; p < 0.01), BMI (19.6 ± 5.4 vs 21.3 ± 3.9 kg/m2; p < 0.0001), fat-free mass (36.3 ± 8.3 vs 39.5 ± 6.0 kg; p < 0.01), and fat mass (23.7 ± 9.1 vs 26.8 ± 7.2%; p < 0.05) compared to those with high SI. In boys, significant differences between low and high SI were obtained for PAL (1.49 ± 0.12 vs 1.56 ± 0.14; p < 0.01). BoneHEI was not significantly different between tertiles in both sexes.

Conclusion

Girls with low body mass and boys with low PAL have a higher risk for low SI. Schoolchildren should strive for normal body mass and perform regular physical activity.

A systematic review and meta-analysis of pediatric normative peripheral quantitative computed tomography data

BACKGROUND

Peripheral-quantitative computed tomography (pQCT) provides an intriguing diagnostic alternative to dual-energy X-ray absorptiometry (DXA) since it can measure 3D bone geometry and differentiate between the cortical and trabecular bone compartments.

OBJECTIVE

To investigate and summarize the methods of pQCT image acquisition of in children, adolescents and/or young adults (up to age 20) and to aggregate the published normative pQCT data.

EVIDENCE ACQUISITION

A literature search was conducted in MEDLINE and EMBASE from 1947 to December 2020. Quality of the included articles was assessed using Standards for Reporting of Diagnostic Accuracy (STARD) scoring system and United States Preventative Services Task Force (USPSTF) Study Design Categorization. Seven articles, encompassing a total of 2134 participants, were aggregated in the meta-analysis. Due to dissimilar age groups and scan sites, only seven pQCT parameters of the 4% radius, 4% tibia and 38% tibia were analyzed in this meta-analysis.

EVIDENCE SYNTHESIS

The overall fixed-effect estimates of trabecular vBMD of the 4% radius were: 207.16 (201.46, 212.86), mg/cm3 in 8 to 9 year-old girls, 210.42 (201.91, 218.93)in 10 to 12 year-old girls, 226.99 (222.45, 231.54) in 12 to 13 year-old girls, 259.97 (254.85, 265.10) in 12 to 13 year-old boys and 171.55 (163.41,179.69) in 16 to 18 year-old girls. 21 of 54 (38.9%) primary papers received a 'good' STARD quality of reporting score (<90 and 70 ≥ %) (mean STARD score of all articles = 69.4%). The primary articles of this review had a 'good' level USPSTF study design categorization. However, most of the normative data in these articles were non-comparable and non-aggregable due to a lack of standardization of reference lines, acquisition parameters and/or age at acquisition.

CONCLUSION

There is not sufficient evidence to suggest that pQCT is appropriately suited for use in the pediatric clinical setting. Normative pediatric data must be systematically derived for pQCT should it ever be a modality that is used outside of research.

CLINICAL IMPACT

We demonstrate the need for normative pQCT reference data and for clinical guidelines that standardize pediatric acquisition parameters and delineate its use in pediatric settings.

Analysis of the Association between Fat Mass Distribution and Bone Mass in Chinese Male Adolescents at Different Stages of Puberty

Background: Bone mineral acquisition during adolescence is crucial for maximizing peak bone mass. Fat mass (FM) and bone mass are closely related. This study investigated the association of FM distribution with bone mass in Chinese male adolescents. Method: A total of 693 male adolescents aged 10–18 years were recruited from a secondary school in Jiangmen, China. Their bone mass and body composition were measured by quantitative ultrasound and bioelectrical impedance analysis, respectively. The associations of the measures of fat distribution with bone parameters, i.e., broadband ultrasound attenuation, speed of sound (SOS), and stiffness index (SI), were analyzed using multiple linear regression. Age, height, body mass index, stage of puberty, physical activity, sedentary behavior, dietary energy intake, and dietary calcium and vitamin D intake were adjusted in the model. Further subgroup analyses of prepubertal and pubertal participants were conducted. Results: The measures of fat distribution showed negative associations with SOS and SI in total subjects (p < 0.010). In prepubertal boys, the measures of fat distribution were only associated with SOS (β = −0.377 to −0.393, p < 0.050). In pubertal boys, the measures of fat distribution had associations with all bone parameters (β = −0.205 to −0.584, p < 0.050). The strongest association was between trunk FM and SOS (β = −0.584, p < 0.001). Conclusion: This study supported that the measures of fat distribution were negatively associated with bone parameters in Chinese male adolescents. Trunk FM had the strongest association with bone parameter. These associations appear to be stronger in pubertal boys than in prepubertal boys.

Obstructive sleep apnoea syndrome (OSAS) as a risk factor for secondary osteoporosis in children

Repetitive hypoxia seen in obstructive sleep apnoea syndrome (OSAS) may affect bone metabolism increasing the risk for secondary osteoporosis. This study investigates the association between OSAS in children and secondary osteoporosis. This cross-sectional study included 150 children aged 10–17 years: 86 with OSAS and 64 with no OSAS. OSAS was confirmed by polysomnography. Quantitative ultrasound (QUS) of calcaneum measuring speed of sound (SoS) and broadband ultrasound attenuation (BUA) were collected. Other parameters collected including bone profile, vitamin D levels, physical activity scoring and dietary calcium intake. Majority were male and Malay ethnicity. OSAS children were mostly obese (84%) and 57% had moderate to severe OSAS. Most had lower physical activities scores. Mean (SD) phosphate and Alkaline phosphatase were lower in OSA children compared to controls: PO₄, p = 0.039 and ALP, p < 0.001. Using both single and multivariate analysis, children with OSAS had a lower mean SoS value, p < 0.001 and p = 0.004 respectively after adjusting for age, BMI and bone profile. Children with OSAS had lower SoS suggesting risk for secondary osteoporosis. QUS calcaneus is a non-invasive, feasible tool and can be used to screen risk of osteoporosis in children. Further bone mineral density assessment is needed in these groups of children to confirm diagnosis of osteoporosis.

Association between Body Composition, Physical Activity, Food Intake and Bone Status in German Children and Adolescents

Achieving a high bone mass during childhood and adolescence is important for the prevention of osteoporosis in later life. Herein, the purpose was to assess the relationship of various lifestyle factors and bone outcomes in school children. In 248 girls (13.4 ± 1.9 years, BMI: 20.2 ± 4.8 kg m⁻²) and 231 boys (13.6 ± 1.7 years, BMI: 19.3 ± 3.3 kg m⁻²), bone mass (stiffness index, SI; calcaneal quantitative ultrasonometry), body composition (bioelectrical impedance analysis), food intake (food frequency questionnaire), and physical activity level (PAL; standardized questionnaire) were assessed. The individual food intake of eight food groups was related to the German recommendations (Bone Healthy Eating Index, BoneHEI; 0–100 points). Relationships between SI and lifestyle factors (Spearman´s rank correlation) and the influence of the factors on the variance of SI (multiple linear regression) were tested (α = 0.05). SI correlated with age, BMI, absolute fat-free mass, relative fat mass, PAL, and puberty category score in both girls and boys (r = 0.18–0.56, p < 0.01), but not with BoneHEI (p > 0.05). Age, absolute fat-free mass, sex, and PAL explained 35% of the variance of SI (p < 0.0001): SI = −0.60 + 2.97∙age (years) + 0.65∙fat-free mass (kg) + 6.21∙sex (0 = male, 1 = female) + 17.55∙PAL. Besides age and sex, PAL and fat-free mass are important factors relating to bone health. School children should perform regular physical activity to improve their bone status.

Validity of quantitative ultrasound and bioelectrical impedance analysis for measuring bone density and body composition in children

BACKGROUND/OBJECTIVES

Using dual X-ray absorptiometry (DXA) to assess body composition in children has limitations including expense, lack of portability, and exposure to radiation. The aims of this study were to examine: (1) validity of quantitative ultrasound (QUS) against DXA for measuring bone density and (2) the validity of in-built algorithm of bioelectrical impedance analysis (BIA) for measuring body composition in children (8-13 years) living in New Zealand.

SUBJECTS/METHODS

Total body less head (TBLH), bone mineral content (BMC), bone mineral density (BMD), and body composition were measured with DXA (QDR Discovery A, Hologic, USA); calcaneal BMD and stiffness index (SI) with QUS (Sahara QUS, Hologic, USA), and BIA on the InBody 230 (Biospace Ltd., Seoul, Korea). Relative validity was assessed using Pearson's and Lin's concordance correlation coefficients (CCC), and Bland-Altman plots.

RESULTS

In 124 healthy children, positive correlations between QUS SI and DXA (BMC and BMD) were observed (range = 0.30-0.45, P < 0.01). Results from Lin's CCC test showed almost perfect correlations between BIA and DXA fat free mass (0.96), fat mass (0.92), and substantial correlation for percentage of fat mass (0.75) (P < 0.05).

CONCLUSION

Although BIA results were not as accurate as DXA and DXA remains the gold standard method for clinical assessment, BIA can be an alternative method for investigating body composition among children in large cohort field studies. Calcaneal QUS and DXA are not interchangeable methods for measuring bone density in children similar to our study population.

Impact of physical activity, anthropometric, body composition, and dietary factors on bone stiffness in German university students

BACKGROUND

Bone density in the young-adult life is associated with risk for osteoporosis in later life. Next to genetic factors, lifestyle seems to play an important role for bone health. Aim of the study was to clarify the relationship between various lifestyle factors and bone parameters in university students.

METHODS

In 233 women and 52 men (age: 22.7±3.1 vs. 24.0±3.2 years; BMI: 22.2±2.9 vs. 24.2±3.1 kg∙m^-2) the following parameters were assessed: calcaneal Stiffness Index ([SI]; quantitative ultrasound), body composition (bioelectrical impedance analysis), actual and past physical activity level ([PAL]; standardized questionnaire), and food/nutrient intake (3-day dietary record). Sex differences (Mann-Whitney-U-tests), relationships between SI and lifestyle factors (Spearman's rank correlation), and the influence of the factors on the variance of SI (multiple linear regression) were tested (α=0.05).

RESULTS

6.9% of the women and 5.8% of the men were classified as osteopenic (-2.5< T score <-1). Significant correlations between SI and BMI, absolute fat mass and fat-free mass, actual PAL, and physical activity during adolescence were found in women (r=0.18-0.24, all P<0.05), but not in men. Food/nutrient parameters did not significantly correlate with bone outcomes (P>0.05). In multiple regression analysis physical activity during adolescence, actual PAL, and BMI explained 8% of the variance of SI (P<0.0001): SI=32.2+3.5∙physical activity during adolescence [1: very low, 2: low, 3: medium, 4: high, 5: very high] +28.5∙PAL+0.8∙BMI [kg∙m^-2].

CONCLUSIONS

Parameters of physical activity seem to be more important for bone health than nutrition factors. Therefore, high levels of physical activity during childhood, adolescence, and early-adult life are highly recommended to improve bone parameters.

Association of objectively measured physical activity and sedentary behavior with bone stiffness in peripubertal children

INTRODUCTION

Physical activity (PA) is a key factor of bone mass acquisition in peripubertal children. Sedentary behavior (SB) has been shown to influence bone outcomes. This study aimed to examine the association between objectively measured PA and SB and bone stiffness in Japanese children.

MATERIALS AND METHODS

Participants were fifth-grade children aged 10-11 years from Project Koshu. The stiffness index (SI) of the calcaneus was measured by quantitative ultrasound; PA and SB were evaluated by an accelerometer. Each PA parameter was divided into sex-specific tertile or stratified by recommended PA guideline [≥ 60 min/day of moderate-to-vigorous PA (MVPA)]. The SI was compared among PA and SB through analysis of covariance with Bonferroni correction.

RESULTS

Of 174 children, complete data were obtained from 134 (60 boys and 74 girls). The SI in boys was higher in the highest tertile of MVPA than that in the other groups. A similar association was found in girls but was not significant. Children who met the PA guideline had higher SI than those who did not, but there was no significant difference. A negative relation was observed in girls, with the SI gradually decreasing along with increasing SB (p for trend = 0.038). This association was not observed among boys.

CONCLUSION

This study suggests that MVPA is positively associated with bone stiffness in Japanese schoolchildren in boys and SB is negatively associated with that in girls. Reducing SB might be a brief modifiable factor for preventing lower peak bone mass in girls, in addition to increasing MVPA.

Diagnosis of osteoporotic vertebral fractures in children

Osteoporosis is a generalised disorder of the skeleton with reduced bone density and abnormal bone architecture. It increases bone fragility and renders the individual susceptible to fractures. Fractures of the vertebrae are common osteoporotic fractures. Vertebral fractures may result in scoliosis or kyphosis and, because they may be clinically silent, it is imperative that vertebral fractures are diagnosed in children accurately and at an early stage, so the necessary medical care can be implemented. Traditionally, diagnosis of osteoporotic vertebral fractures has been from lateral spine radiographs; however, a small number of studies have shown that dual energy x-ray absorptiometry is comparable to radiographs for identifying vertebral fractures in children, while allowing reduced radiation exposure. The diagnosis of vertebral fractures from dual energy x-ray absorptiometry is termed vertebral fracture assessment. Existing scoring systems for vertebral fracture assessment in adults have been assessed for use in children, but there is no standardisation and observer reliability is variable. This literature review suggests the need for a semiautomated tool that (compared to the subjective and semiquantitative methods available) will allow more reliable and precise detection of vertebral fractures in children.

Bone modeling, remodeling, and skeletal health in children and adolescents: mineral accrual, assessment and treatment

The modeling and remodeling process of the bone is fundamental to maintaining its integrity and mechanical properties. Many physical and biochemical factors during childhood and adolescence are crucially important for the development of healthy bones. Systemic conditions, such as hormonal status, nutrition, physical inactivity, or many pharmacological treatments, as well as a local variation in the load, can influence bone turnover and, consequently, the attainment of a proper peak bone mass. However, many diseases affecting children and adolescents can be associated with a reduction in bone accrual or a loss of bone mass and quality, which leads to an increased risk of fracture over one's life. In this review, we examine the effects of genetics, physical activity, chronic diseases and pharmacological treatments, and dietary factors on bone integrity in children and adolescents. We also briefly describe the specific tools that are currently used in assessing bone health.

Is calcaneal broadband ultrasound attenuation a valid index of dual-energy x-ray absorptiometry-derived bone mass in children?

Objectives

The aim of the current study was to assess whether calcaneal broadband ultrasound attenuation (BUA) can predict whole body and regional dual-energy x-ray absorptiometry (DXA)-derived bone mass in healthy, Australian children and adolescents at different stages of maturity.

Methods

A total of 389 boys and girls across a wide age range (four to 18 years) volunteered to participate. The estimated age of peak height velocity (APHV) was used to classify children into pre-, peri-, and post-APHV groups. BUA was measured at the non-dominant heel with quantitative ultrasonometry (QUS) (Lunar Achilles Insight, GE), while bone mineral density (BMD) and bone mineral content (BMC) were examined at the femoral neck, lumbar spine and whole body (DXA, XR-800, Norland). Associations between BUA and DXA-derived measures were examined with Pearson correlations and linear regression. Participants were additionally ranked in quartiles for QUS and DXA measures in order to determine agreement in rankings.

Results

For the whole sample, BUA predicted 29% of the study population variance in whole body BMC and BMD, 23% to 24% of the study population variance in lumbar spine BMC and BMD, and 21% to 24% of the variance in femoral neck BMC and BMD (p < 0.001). BUA predictions were strongest for the most mature participants (pre-APHV R² = 0.03 to 0.19; peri-APHV R² = 0.05 to 0.17; post-APHV R² = 0.18 to 0.28) and marginally stronger for girls (R² = 0.25-0.32, p < 0.001) than for boys (R² = 0.21-0.27, p < 0.001). Agreement in quartile rankings between QUS and DXA measures of bone mass was generally poor (27.3% to 38.2%).

Conclusion

Calcaneal BUA has a weak to moderate relationship with DXA measurements of bone mass in children, and has a tendency to misclassify children on the basis of quartile rankings.

Cite this article: B. K. Weeks, R. Hirsch, R. C. Nogueira, B. R. Beck. Is calcaneal broadband ultrasound attenuation a valid index of dual-energy x-ray absorptiometry-derived bone mass in children? Bone Joint Res 2016;5:538–543. DOI: 10.1302/2046-3758.511.BJR-2016-0116.R1.