Factors affecting broadband ultrasound attenuation results of the calcaneus using a gel-coupled quantitative ultrasound scanning system

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.

Bone structure and geometry in young men: the influence of smoking, alcohol intake and physical activity

BACKGROUND

The development of osteoporosis is influenced by peak bone mass attained in youth - the influence of lifestyle factors upon which is poorly described, especially amongst males. We sought to address this issue in a large scale study.

METHODS

Hip bone mineral density (dual X-ray absorptiometry, DXA), bone microarchitecture (calcaneal quantitative ultrasound, QUS) and femoral geometry (magnetic resonance imaging, MRI) were characterised in 723 healthy male military recruits (mean ± S.E. age 19.92 ± 0.09 years [range 16-18 years], height 177.67 ± 0.24 cm, weight 73.17 ± 0.37 kg) on entry to UK Army training. Association was sought with prior physical activity, smoking status and alcohol intake.

RESULTS

DXA measures were made in 651, MRI measures in 650, and QUS measures in 572 recruits. Increasing levels of weight-bearing physical activity enhanced periostial bone apposition, increases in both total hip and femoral neck bone mineral density (BMD; p ≤ 0.0001 in both cases), and cortical [p<0.0001] and periostial bone volumes [p=0.016]. Smoking habit was associated with preserved bone geometry, but worse BMD [p=0.0001] and QUS characteristics [p ≤ 0.0005]. Moderate alcohol consumption was associated with greater BMD [p ≤ 0.015].

CONCLUSIONS

Whilst exercise (and perhaps moderate alcohol intake) is beneficial to bone morphometry, smoking is detrimental to bone mineral density in young males notable for the likely short duration of smoking to influence skeletal properties. However, differences in socio-economic status, lifestyle and related environmental factors may to some extent confound our results.

Effects of phase cancellation and receiver aperture size on broadband ultrasonic attenuation for trabecular bone in vitro

Phase cancellation in ultrasound due to large receiver size has been proposed as a contributing factor to the inaccuracy of estimating broadband ultrasound attenuation (BUA), which is used to characterize bone quality. Transducers with aperture size ranging from 2 to 5 mm have been used in previous attempts to study the effect of phase cancellation. However, these receivers themselves are susceptible to phase cancellation because aperture size is close to one center wavelength (about 3 mm at 500 KHz in water). This study uses an ultra small receiver (aperture size: 0.2 mm) in conjunction with a newly developed two-dimensional (2-D) synthetic array system to investigate the effects of phase cancellation and receiver aperture size on BUA estimations of bone tissue. In vitro ultrasound measurements were conducted on 54 trabecular bone samples (harvested from sheep femurs) in a confocal configuration with a focused transmitter and synthesized focused receivers of different aperture sizes. Phase sensitive (PS) and phase insensitive (PI) detections were performed. The results show that phase cancellation does have a significant effect on BUA. The normalized BUA (nBUA) with PS is 8.1% higher than PI nBUA while PI BUA is well correlated with PS BUA. Receiver aperture size also influences the BUA reading for both PI and PS detection and smaller receiver aperture tends to result in higher BUA readings. The results also indicate that the receiver aperture size used in the confocal configuration with PI detection should at least equal the aperture of the transmitter to capture most of the energy redistributed by the interference and diffraction from the trabecular bone.

Influence of Lifestyle Factors on Quantitative Heel Ultrasound Measurements in Middle-Aged and Elderly Men

We examined the distribution of quantitative heel ultrasound (QUS) parameters in population samples of European men and looked at the influence of lifestyle factors on the occurrence of these parameters. Men aged between 40 and 79 years were recruited from eight European centers and invited to attend for an interviewer-assisted questionnaire, assessment of physical performance, and quantitative ultrasound (QUS) of the calcaneus (Hologic; Sahara). The relationships between QUS parameters and lifestyle variables were assessed using linear regression with adjustments for age, center, and weight. Three thousand two hundred fifty-eight men, mean age 60.0 years, were included in the analysis. A higher PASE score (upper vs. lower tertile) was associated with a higher BUA (β coefficient = 2.44 dB/Mhz), SOS (β = 6.83 m/s), and QUI (β = 3.87). Compared to those who were inactive, those who walked or cycled more than an hour per day had a higher BUA (β = 3.71 dB/Mhz), SOS (β = 6.97 m/s), and QUI (β = 4.50). A longer time to walk 50 ft was linked with a lower BUA (β = -0.62 dB/Mhz), SOS (β = -1.06 m/s), and QUI (β = -0.69). Smoking was associated with a reduction in BUA, SOS, and QUI. There was a U-shaped association with frequency of alcohol consumption. Modification of lifestyle, including increasing physical activity and stopping smoking, may help optimize bone strength and reduce the risk of fracture in middle-aged and elderly European men.

Vitamin D status and common risk factors for bone fragility as determinants of quantitative ultrasound variables in a nationally representative population sample

Calcaneal quantitative ultrasound (QUS) can predict bone strength and fracture risk. Bone fragility has no single cause but results from a complex interplay of several etiologic or contributing factors. Vitamin D is essential for bone health even though it is still unclear how much of this vitamin is required to maintain bone strength and prevent fractures. Measurements of serum 25-hydroxyvitamin D [S-25(OH)D] have indicated a high prevalence of inadequate vitamin D status in a number of studies mostly based on selected study populations. The objective of this study was to examine the associations between S-25(OH)D, common risk factors for bone fragility, and QUS variables in a large unselected population sample. The study population consisted of 2736 men and 3299 women from a nationally representative population sample, aged 30 years or over. Information on lifestyle was elicited by means of interviews and questionnaires. Body fat mass was estimated using an impedance-meter. S-25(OH)D was measured by radioimmunoassay. Calcaneal QUS was performed on the Hologic Sahara apparatus recording broadband ultrasound attenuation (BUA) and speed of sound (SOS). The potential determinants of BUA and SOS were analysed using separate multiple linear regression models for men and women. S-25(OH)D proved to be an independent determinant of BUA (P<0.0001 for men, P<0.001 for women) and SOS (P<0.0001 for men, P<0.05 for women). BUA was also independently associated with age, height, weight, alcohol consumption, and postmenopausal status in women, and with weight, alcohol consumption, smoking and physical activity in men. All of the above variables, except for weight in women, were also found to be independent determinants of SOS in both men and women. A reverse association was found between S-25(OH)D and adiposity in spite of higher intakes of vitamin D in those with higher fat mass. In this unselected sample of men and women, vitamin D status, several lifestyle factors and physical characteristics proved to be significant determinants of BUA and SOS. Inadequate vitamin D status was common, and measures ensuring adequate intakes of vitamin D in the population thus deserve continued attention. Obesity should be taken into account in future assessments of vitamin D status in Finland as in other countries.

Accuracy study on "Osteorisk": a new osteoporosis screening clinical tool for women over 50 years old

CONTEXT AND OBJECTIVE

Osteoporosis is the greatest cause of quality-of-life reductions, morbidity and mortality among postmenopausal women, with growing incidence as populations age. Clinical tools like Osteorisk provide an easy-access and low-cost alternative method that helps physicians to reduce the need for dual-energy X-ray absorptiometry (DXA), the expensive gold standard examination for diagnosing osteoporosis. The aim here was to study the accuracy of Osteorisk using heel ultrasonography for bone mineral density (BMD).

DESIGN AND SETTING

Cross-sectional study, at Faculdade de Medicina do ABC.

METHODS

A structured questionnaire was applied to 615 postmenopausal women, with anthropometric measurements, Osteorisk calculations and quantitative ultrasound on the heel using Sonost 2000 equipment.

RESULTS

461 women were included, with mean age 60 +/- 9 years, weight 67.6 +/- 12.9 kg and body mass index (BMI) 28.8 +/- 5.0 kg/m(2). Their Osteorisk classifications were: 61.0% low-risk, 28.4% medium-risk and 10.6% high-risk. Quantitative ultrasound showed 81.3% low-risk, 10.0% medium-risk and 8.7% high-risk regarding osteoporosis. Statistically significant results were observed (p < 0.001) when Osteorisk was correlated with age, years since menopause and BMI. Correlating these same variables with quantitative ultrasound, statistically significant results were observed for age (p < 0.001), years since menopause (p < 0.001) and BMI (p < 0.006). The sensitivity, specificity, negative predictive value and positive predictive value for Osteorisk were 64%, 6.7%, 89% and 30.6%, respectively.

CONCLUSION

Osteorisk is a valid tool for screening for women at low risk of osteoporosis, making it possible for these women not to have to undergo densitometry.

Association of estrogen receptor alpha gene polymorphisms and lifestyle factors with calcaneal quantitative ultrasound and osteoporosis in postmenopausal Vietnamese women

Genetic and lifestyle factors are important in the pathogenesis of osteoporosis. We investigated the relationships of PvuII and XbaI polymorphisms of the estrogen receptor alpha (ER-alpha) gene, lifestyle factors with speed of sound at the calcaneus (calcaneal SOS) and osteoporosis in a population-based study of 140 healthy postmenopausal women. By an analysis of covariates, women with higher copies of P or X alleles had higher calcaneal SOS compared with others (P=0.012, PP vs. pp; P=0.045, Xx vs. xx). Women with lower copies of px or higher copies of PX haplotypes had higher calcaneal SOS compared with others (P=0.021, 0 px vs. 2 px; P=0.011, 1 PX vs. 0 PX). The px and PX haplotypes, age and years since menopause were found to be independent predictors of calcaneal SOS in multiple linear regression models. Using logistic regression, we found an increased osteoporosis risk with evidence for a px haplotype dose effect (OR=2.82, 95% CI=1.50-5.31, P=0.001) and for a PX haplotype dose effect (OR=0.42, 95% CI=0.19-0.93, P=0.033). An increased educational level was associated with a reduced risk of osteoporosis (P=0.035 in the model with px, P=0.044 in the model with PX). In conclusion, the present study suggests that PvuII and XbaI polymorphims of the ER-alpha gene, age, years since menopause and educational level are associated with bone density, as assessed by calcaneal SOS, and osteoporosis in postmenopausal Vietnamese women.

COL1A1 Sp1 polymorphism associates with bone density in early puberty

Optimal acquisition of bone mass in puberty is a key determinant of the lifetime risk of osteoporosis and has a strong genetic basis. We investigated the relationship between the COL1A1 Sp1 polymorphism and BMD in early puberty, and how the genotypes relate to bone size and geometry as well as bone turnover and material properties in 247 10- to 13-year-old girls. Bone properties were measured using DXA, pQCT, and ultrasound. Also, serum P1NP, OC, B-ALP, and TRACP 5b were assessed. Our results showed that girls with the TT genotype had significantly lower BMC and BMD of the total body, lumbar spine, and proximal femur, as well as BUA at the calcaneus, than those with the GT and GG genotype. They also had significantly lower B-ALP, as well as P1NP/TRACP 5b and (OC + B-ALP)/TRACP 5b, compared to the others. These findings indicate that the COL1A1 polymorphism is associated with low bone properties in early puberty and suggest a possible physiological effect on collagen metabolism and bone turnover. This information may contribute to the identification of children at risk for suboptimal acquisition of peak bone mass and may ultimately be of value in the planning of early preventive strategies for osteoporosis.

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

There are many risk factors associated with low bone mineral density. Quantitative ultrasound (QUS) is a generally accepted method for measurement of bone and has been shown to be strongly associated with future fracture risk. The Osteoporosis and Ultrasound Study (OPUS) is a multi-centre European wide study examining 5 different QUS scanners (4 calcaneal, 1 finger device). The aim of this paper was to examine the relationship between risk factors (as assessed by questionnaire) and QUS measurements. 449 younger women (aged 20 to 39 years) and 2283 older women (aged 55 to 79 years) were included in this analysis. As expected, those with a self-reported previous fracture had lower QUS measurements than those without (P < 0.001). However, no significant difference was seen between those reporting a maternal hip fracture and those who did not report such an event. Differences were found for smokers vs. non-smokers for SOS but not for BUA measurements. Weight was positively correlated with all BUA variables but only with some SOS variables. We determined which risk factors were most strongly associated with QUS measurements by using step-wise multiple regression. Models for each QUS measurement were calculated, and the R2 values ranged from 0.18 to 0.28 for SOS, 0.27 to 0.32 for BUA and 0.31 to 0.42 for the finger QUS device. The most common risk factors across all models were age, use of hormone replacement therapy, self-reported previous fracture, self-reported diagnosis of osteoporosis, current weight, pulse rate and self-reported estimated height at age 20 years. We analysed relationships across the 5 centres and detected some geographical differences in the prevalence of the risk factors. In conclusion, similar relationships are seen with QUS measurements as are found for bone mineral density. However, the strength of the association is dependent on the type of QUS device and variable measured.

Association of reduced physical activity and quantitative ultrasound measurements: a 6-year follow-up study of adolescent girls

Sonographic parameters of the heel were recorded in order to investigate the effects of changes in physical activities among 140 healthy growing peripubertal Caucasian girls. Calcaneal quantitative ultrasound measurements (Hologic Sahara) were recorded at baseline and 2- and 6-year follow-up. Broadband ultrasound attenuation, speed of sound (SOS), and T scores were documented. Altogether, 30 girls reduced their physical activity by >50% and 29 girls by 25-50%, whereas 81 girls continued at the present level or increased it. Age and physical activity together accounted for 16.7% of the variation in calcaneal T scores at baseline and for 16.4% at 2-year follow-up, whereas physical activity alone accounted for 11.3% of the variation at 6-year follow-up. The reduction in mean T scores was significant (from 2.0 to 0.8, P < 0.001) among those having discontinued their physical activity by the 6-year measurement. The changes between three groups were statistically significantly different from each other (P = 0.003). The mean SOS values decreased 16.78 meters per second (95% CI -26.9 to -6.7) among those having discontinued their physical activity between the 2- and 6-year follow-up measurements. The SOS value sensitively reacts to changes in physical activity, and consequently, it will help assess changes in bone quality. Because of such an immediate reaction, SOS is a good-quality measure for the physical condition of bone in young people and a suitable tool for detecting changes in calcaneal bone.

Screening for low bone mass with quantitative ultrasonography in a community without dual-energy X-ray absorptiometry: population-based survey

BACKGROUND

Dual-energy x-ray absorptiometry (DXA) is the criterion standard to identify low bone mineral density (BMD), but access to axial DXA may be limited or cost prohibitive. We screened for low bone mass with quantitative ultrasonography (QUS) in a community without DXA, analyzed its reliability and obtained reference values and estimated the prevalence of low QUS values.

METHODS

We enrolled 6493 residents of Kinmen, Taiwan, and a reference group (96 men and 70 women aged 20-29 years) for this cross-sectional, community-based study. All participants completed a questionnaire and underwent ultrasonographic measurements. Reliability and validity of QUS measurements were evaluated. Broadband ultrasound attenuation (BUA) values were obtained and statistically analyzed by age, sex and weight. Annual loss of BUA was determined. Trends in the prevalence of QUS scores were evaluated.

RESULTS

Two QUS were used and had a correlation coefficient of 0.90 (p < 0.001). Calcaneal BUA was significantly correlated with BMD in the femoral neck (r = 0.67, p < 0.001) and BMD of the total lumbar spine (r = 0.59, p < 0.001). BUAs in the reference group were 92.72 +/- 13.36 and 87.90 +/- 10.68 dB/MHz for men and women, respectively. Estimated annual losses of calcaneal BUA were 0.83% per year for women, 0.27% per year for men, and 0.51% per year for the total population. The prevalence of severely low QUS values (T-score = -2.5) tended to increase with aging in both sexes (p < 0.001). Across age strata, moderately low QUS values (-2.5 < T-score < -1.0) were 31.6-41.0% in men and 23.7-38.1% in women; a significant trend with age was observed in men (p < 0.001).

CONCLUSION

Age-related decreases in calcaneal ultrasonometry, which reflected the prevalence of low bone mass, were more obvious in women than in men.

Body composition: gender-specific risk factor of reduced quantitative ultrasound measures in older people

INTRODUCTION

Body composition has been reported as a significant determinant of bone mineral density. However, data regarding the relationship between the body composition and quantitative ultrasound (QUS) are scarce.

METHODS

This cross-sectional study examined risk factors of reduced QUS measures in older men and women. A total of 699 subjects aged 60 years old and over-458 women and 241 men-who lived in rural communities of Thailand were randomly recruited.

RESULTS

By using broadband ultrasound attenuation at the cutoff point of mean -1.0 SD based on young Thai people, the independent factors associated with reduced QUS measures in men were: poor activity of daily living, older age, and low fat mass. As for older women, the independent factors were the number of years since menopause, lack of regular exercise, lower height, and low fat mass. When using the stiffness index at the cutoff point of mean -1.6 SD based on young Thai people, the independent factors associated with reduced QUS measures in men were older age and low fat mass. Meanwhile, the number of years since menopause and low lean body mass were independent risk factors in women.

CONCLUSIONS

Poor activity of daily living in men or lack of regular exercise in women was found to be a modifiable risk factor of reduced QUS measures. Years since menopause and low lean body mass were significant factors determining reduced QUS measures in women. Fat mass was an independent factor associated with reduced QUS measures both in men and women.

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

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

Lifestyle factors affecting heel ultrasound in Greek females across different life stages

The use of quantitative ultrasound (QUS) of the bone is rapidly gaining in popularity, and QUS is widely used worldwide for the assessment of skeletal status. Although much has been learned about the influence of various factors on ultrasonic parameters in various populations, similar information at the local level is not available. This study was carried out to examine the effects of anthropometric, dietary, physical activity, reproductive, and other lifestyle factors on QUS parameters in healthy Greek women, including children (n=217), adults (n=235), and elderly (n=369) subjects. Calcaneal QUS measurements were performed with the SAHARA device, which measures broadband ultrasound attenuation (BUA) and speed of sound (SOS) through the os calcis; a composite parameter, the quantitative ultrasound index (QUI), and an estimate of heel bone mineral density (eBMD) were also derived. All QUS indices were higher in adult women than in girls or elderly women (P<0.05). The latter had a similar BUA to girls, but lower SOS, QUI, and eBMD (P<0.05). Most QUS parameters correlated positively with height, weight, body mass index (BMI), hip circumference, organized physical activity, and activity promoting bone mass, but negatively with the time devoted to sedentary activities and absolute carbohydrate intake (P<0.05). Age of menarche and years since menopause were negatively associated with QUS in the adult and elderly women, respectively (P<0.05). The latter relationship, however, was due to the confounding effect of advancing age. Overweight and obese females had significantly higher BUA and eBMD than normal-weight subjects (P<0.05), but similar SOS and QUI; this held true for all age groups. Likewise, in all ages, individuals spending more than 2 h/week on organized activities had significantly higher QUS indices than those spending less time on exercise (P<0.05). Further, postmenarchial girls had significantly higher age-adjusted BUA, SOS, QUI, and eBMD than premenarchial ones (P<0.05). Similarly, all QUS parameters were significantly higher in adult women with an early onset of menarche (<14 years old) than in those with a late onset (P<0.05), but no effects of menarche were detected among the elderly. No significant effects of calcium intake (which was generally adequate), smoking or alcohol drinking (which were generally low) on QUS indices were observed, in either age group. Available independent variables could explain approximately 16%-24% of the total variance in BUA, SOS, QUI and eBMD. The most important positive predictors of QUS were adulthood, time devoted to organized activities, and weight or BMI, while age and carbohydrate intake per se contributed negatively. In conclusion, age, body size, physical activity, and some aspects of reproductive history and diet appear to variably affect calcaneal QUS indices among otherwise healthy Greek women at different life stages.

Relation of PvuII site polymorphism in the COL1A2 gene to the risk of fractures in prepubertal Finnish girls

Genetic susceptibility to fractures may be detectable in early childhood. We evaluated the associations between the polymorphic PvuII site of the COL1A2 gene and bone properties assessed by different modalities (dual-energy X-ray absorptiometry; peripheral quantitative computed tomography; gel coupling scanning quantitative ultrasonometry; ultrasound bone sonometry), bone turnover markers, and the occurrence of fractures in 244 prepubertal Finnish girls. Tanner stage and physical characteristics did not differ significantly among girls with different COL1A2 genotypes. The polymorphism was not significantly associated with different bone properties or any of the bone turnover markers when girls at Tanner stage I (prepuberty) and stage II (early puberty) were considered together, but there was a significant association with spine bone mineral content (BMC) and bone mineral density (BMD), as well as with speed of sound (SOS) (P < 0.05), when girls at Tanner stage I were considered separately, as a purpose to avoid the confounding effect that the pubertal growth spurt has on skeletal development. The distribution of fractures was different between the three genotype groups (P = 0.023). The P alleles were over-represented in girls who had been fractured at least once; 88% of them had at least one copy of the P allele (either PP or Pp). Girls with the PP genotype had 4.9 times higher relative risk for fractures than girls with the pp genotype (95% CI, 1.4 to 17.4; P = 0.015). No significant difference was found between fractured and nonfractured girls in anthropometric measurements, physical activity, or bone mass. However, BMD of the spine and SOS at the radius and tibia were significantly lower in the fractured girls. We conclude that the COL1A2 polymorphism is associated with nonosteoporotic fractures in prepubertal girls independently of bone density.

Diet in midpuberty and sedentary activity in prepuberty predict peak bone mass

BACKGROUND

An average daily calcium intake of 1300 mg is recommended for North American adolescents aged 9-18 y. However, questions remain about these recommendations.

OBJECTIVE

We assessed whether there is a stage of puberty when dietary calcium is more strongly related to peak bone mass, as indicated by young adult bone mass (YABM); whether dietary calcium intake > 1000 mg/d in adolescence is associated with higher YABM; and whether race affects any of these associations between dietary calcium and YABM. Secondarily, we evaluated relations between sedentariness and YABM.

DESIGN

In a retrospective cohort study, we recruited 693 black and white women aged 21-24 y who had participated in the 10-y National Heart, Lung, and Blood Institute Growth and Health Study and measured YABM with the use of dual-energy X-ray absorptiometry. Dietary calcium and sedentary activity data, gathered through 3-d food records and self-reports of television-video viewing at 8 annual examinations, were averaged over 3 pubertal stages. Complete data were available from 161 black and 180 white females. Multiple regression, controlling for race, weight, and height, was applied to assess diet and activity relations with YABM.

RESULTS

Dietary calcium was most strongly associated with YABM in midpuberty. Calcium intake > 1000 mg/d was associated with higher YABM, but this association was not significant at all skeletal sites. Race did not affect the observed relations between calcium and YABM. Sedentary activity in prepuberty was inversely associated with YABM.

CONCLUSIONS

Interventions should focus on ensuring adequate calcium intake in midpuberty and on minimizing sedentariness in prepuberty.

Community-based survey of low quantitative ultrasound values of calcaneus in Taiwan

This study investigated prevalence and associated-factors of low quantitative ultrasound (QUS) values by screening calcaneal QUS parameters--broadband ultrasound attenuation (BUA) and speed of sound (SOS)--in population samples of three different Taiwanese communities. The study included 6,322 subjects (2,631 male and 3,691 female), aged 31 yr old or more in Shih-Pai (a metropolitan area in northern Taiwan),Yu-Chi (a mountain area in central Taiwan), and A-Lein (a seaside area in southern Taiwan). The overall response rate was 50.2%. The correlation between BUA and SOS was 0.684, p<0.001. From those who responded, we selected 403 subjects aged 31-40 yr as the reference (the young group), and their BUA was 65.34+/-7.91 dB/MHz. The t-score was calculated from the BUA data of our reference group. The percentile of -2.5<t-score<-1.0 and t-score< or =-2.5 in male subjects was 21.4 and 2.9%, respectively, and in female subjects 24.2 and 14.1%, respectively. The BUA of urban area subjects was higher than that of rural area subjects in almost all age-strata, and overweight was noted to be a protective factor. The effect of age-adjusted odds ratio (AOR) on low QUS values in females was significantly increased every 10 yr from 1.55, 5.13, 13.81, 34.29, to 38.14. This survey showed that age-related decreases in calcaneal ultrasonometry, indicating prevalence of low QUS values, were more obvious in female than male subjects. Overall 38.3% of the female Taiwanese had low QUS values, and this is approximately equivalent to the lifetime risk of fracture at the hip, spine, or distal forearm in Caucasian women. The specific t-score designation, as World Health Organization (WHO) criteria, applied to calcaneal QUS are reasonable when the reference group is selected from the same population.

Effects of ethnicity and gender on reliable measurements using the Sahara ultrasonometer

The objectives of this study were to evaluate the relationship between age and ultrasound (US) parameters and to assess the influences of ethnicity, sex, body mass index (BMI), and age on the ability to obtain a reliable measurement as indicated by the Sahara software. Quantitative ultrasound parameters were assessed in 1554 African American and Caucasian men and women between the ages of 18 and 93 using the Sahara ultrasonometer. The relationships among age and broadband ultrasound attenuation, speed of sound (SOS), qualitative ultrasound index, and bone mineral density showed a decline in all US parameters with age. The relationship was linear for males and curvilinear for females for all parameters except SOS, which was also linear for females. The Sahara software indicated that 66% of the measurements for African American men were unreliable, 27% for African American females, 14% for Caucasian males, and 6% for Caucasian females. The factors found to contribute to the likelihood (odds ratio, [95% confidence interval]) of obtaining an unreliable estimate were having a high BMI (1.13, [1.1, 1.16]), being of African American ethnicity (5.29 [3.78, 7.41]), and being male (3.1 [2.8, 4.1]). Our study provides evidence that US results from the Sahara should be interpreted with caution in males, in individuals with African American ancestry, and in individuals with a high BMI.

Relationships among calcaneal backscatter, attenuation, sound speed, hip bone mineral density, and age in normal adult women

The present study was undertaken in order to investigate the use of calcaneal ultrasonic backscatter for the application of diagnosis of osteoporosis. Broadband ultrasonic attenuation (BUA), speed of sound (SOS), the average backscatter coefficient (ABC), and the hip bone mineral density (BMD) were measured in calcanea in 47 women (average age: 58 years, standard deviation: 13 years). All three ultrasound variables had comparable correlations with hip BMD (around 0.5). As reported previously by others, BUA and SOS were rather highly correlated with each other. The logarithm of the ABC was only moderately correlated with the other two. The three ultrasound parameters exhibited similar moderate negative correlations with age. These results taken collectively suggest that the ABC may carry important diagnostic information independent of that contained in BUA and SOS and, therefore, may be useful as an adjunct measurement in the diagnosis of osteoporosis.

Quantitative ultrasound in postmenopausal osteoporosis

Ultrasound has been proposed as a low-cost, radiation-free method for osteoporosis assessment in postmenopausal women. Large prospective studies have shown that ultrasound parameters can be used for fracture risk estimate in this population, providing that adequate quality control is performed. The places of both ultrasound and the current gold standard method for bone assessment, dual energy x-ray absorptiometry, are still to be determined. Further studies are needed on the diagnosis of osteoporosis using ultrasound, because current diagnostic thresholds, designed by the World Health Organization, do not apply to this-new technology. Monitoring of skeletal changes and treatment effects by ultrasound cannot be recommended.