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Ultrasound Attenuation (ultrasound + attenuation)

Distribution by Scientific Domains
Medical Sciences100%

Kinds of Ultrasound Attenuation

  • broadband ultrasound attenuation
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    Selected Abstracts

    Association with replication between estrogen-related receptor , (ESRR,) Polymorphisms and bone phenotypes in women of European ancestry

    JOURNAL OF BONE AND MINERAL RESEARCH, Issue 4 2010
    Latifa Elfassihi
    Abstract Osteoporosis is a bone disease characterized by low bone mineral density (BMD), a highly heritable polygenic trait. Women are more prone than men to develop osteoporosis owing to a lower peak bone mass and accelerated bone loss at menopause. Lack of estrogen thus is a major risk factor for osteoporosis. In addition to having strong similarity to the estrogen receptor 1 (ESR1), the orphan nuclear estrogen-related receptor , (ESRR,) is widely expressed and shows overlap with ESR1 expression in tissues where estrogen has important physiologic functions. For these reasons, we have undertaken a study of ESRR, sequence variants in association with bone measurements [heel quantitative ultrasound (QUS) by measurements of broadband ultrasound attenuation (BUA), speed of sound (SOS), and stiffness index (SI) and dual-energy X-ray absorptiometry (DXA) at the femoral neck (FN) and lumbar spine (LS)]. A silent variant was found to be associated with multiple bone measurements (LS, BUA, SOS, and SI), the p values ranging from .006 to .04 in a sample of 5144 Quebec women. The region of this variant was analyzed using the HapMap database and the Gabriel method to define a block of 20,kb. Using the Tagger method, eight TagSNPs were identified and genotyped in a sample of 1335 women. Four of these SNPs capture the five major block haplotypes. One SNP (rs2818964) and one haplotype were significantly associated with multiple bone measures. All SNPs involved in the associations were analyzed in two other sample sets with significant results in the same direction. These results suggest involvement of ESRR, in the determination of bone density in women. © 2010 American Society for Bone and Mineral Research [source]

    Respiratory Function as a Marker of Bone Health and Fracture Risk in an Older Population,

    JOURNAL OF BONE AND MINERAL RESEARCH, Issue 5 2009
    Alireza Moayyeri
    Abstract Identification of those at high risk of osteoporosis and fractures using clinically available tests beyond BMD measures is a major clinical challenge. We examined forced expiratory volume in 1 s (FEV1), an easily obtainable measure of respiratory function, as a clinical measure for fracture prediction. In the context of the European Prospective Investigation into Cancer-Norfolk Study, 8304 women and 6496 men 42,81 yr of age underwent a health check including spirometry and heel quantitative ultrasonography between 1997 and 2000 and were followed up for incident hip fractures until 2007. The main outcome measures were broadband ultrasound attenuation (BUA) of the heel (cross-sectional analysis) and hip fracture risk (prospective analysis). In multivariate regression models, a 1-liter increase in FEV1 was associated with a statistically significant 2.2-dB/MHz increase in BUA, independent of age, smoking, height, body mass index, history of fracture, and use of corticosteroids. Mean FEV1 was significantly lower among 84 women and 36 men with hip fracture compared with other participants. In multivariate proportional-hazard regression models, the relative risk (RR) of hip fracture associated with a 1-liter increase in FEV1 was 0.5 (95% CI, 0.3,0.9; p < 0.001) for both men and women. RR of hip fracture for a 1 SD increase in FEV1 was approximately equivalent to a 0.5 SD increase in BUA among women (1 SD among men) and an ,5-yr decrease in age among both men and women. Middle-aged and older people with low respiratory function are at increased risk of osteoporosis and hip fracture. FEV1, an easy, low-cost, and feasible clinical measure, may help improve the identification of high-risk groups. [source]

    Long-Term Fracture Prediction by DXA and QUS: A 10-Year Prospective Study,

    JOURNAL OF BONE AND MINERAL RESEARCH, Issue 3 2006
    Alison Stewart PhD
    Abstract This study investigated the ability of DXA and QUS to predict fractures long term when measured around the time of the menopause. We found both DXA and QUS are able to predict both any fracture and "osteoporotic" fractures and that QUS can predict independently of BMD. Introduction: There are now many treatments available for prevention of osteoporotic fracture. To be cost-effective, we need to target those most at risk. This study examines the ability of DXA and QUS to predict fractures in an early postmenopausal population of women. Materials and Methods: We prospectively measured 3883 women who had been randomly selected from a community-based register. At baseline, they were measured using DXA of spine and hip (Norland XR-26) and QUS of the heel (Walker Sonix UBA 575). Follow-up had a mean of 9.7 ± 1.1 (SD) years. All incident fractures were identified and validated by examination of X-ray reports, and these were compared with those without fracture in a Cox-regression model to calculate hazard ratios (HRs). Results: We found adjusted HRs for any fracture per 1 SD reduction in spine BMD to be 1.61 (1.42-1.83), whereas neck of femur BMD was 1.54 (1.34-1.75). Areas under the curve (AUC) for a receiver operator characteristic (ROC) analysis were 0.62 for spine BMD and 0.59 for neck BMD. In a subgroup where QUS was also measured, the HR for a 1 SD reduction in BMD was 1.69 (1.29-2.22) for spine BMD and 1.55 (1.17-2.06) for neck BMD. The HR for a 1 SD reduction in broadband ultrasound attenuation (BUA) was 1.53 (1.19-1.96), and 1.44 (1.12-1.86) when further adjusted for neck BMD. The AUCs were 0.63 for spine BMD, 0.59 for neck BMD, and 0.62 for BUA. When only osteoporotic fractures were examined, the HRs increased in all situations. BUA showed the highest HR of 2.25 (1.51-3.34), and when further adjusted for neck BMD was 2.12 (1.38-3.28). Conclusions: In conclusion, it may be possible to scan women around the time of the menopause to predict future fractures. It seems that, for "osteoporotic" fractures, BUA may be an improved predictor of fractures in comparison with DXA, because the relative risk is highest for BUA, and independent of BMD. [source]

    Serum fasting cortisol in relation to bone, and the role of genetic variations in the glucocorticoid receptor

    CLINICAL ENDOCRINOLOGY, Issue 6 2007
    N. M. Van Schoor
    Summary Objective, To examine the relationship between endogenous cortisol and bone, and the role of genetic variations in the glucocorticoid receptor (GR). Design and patients, The Longitudinal Ageing Study Amsterdam (LASA), a population-based cohort study in older men and women. Measurements, Serum fasting cortisol was assessed by competitive immunoassay (n = 1214); bone mineral density (BMD) by dual X-ray absorptiometry (DXA) (n = 502); broadband ultrasound attenuation (BUA) by ultrasound (n = 1209); fractures by self-report (n = 1211); and GR gene polymorphisms (ER22/23EK, N363S, 9beta, BclI) were genotyped by Taqman (n = 858). Results, Higher serum fasting cortisol was significantly associated with lower BMD at all sites and BUA at the heel in women, although most relationships were attenuated by age and body mass index (BMI). The effect on femoral neck BMD remained statistically significant in the fully adjusted model (r = ,0·135, P = 0·04). No significant associations in men were found. Female 9beta G-allele carriers had 50·2 nmol/l lower cortisol and 1·2 lower free cortisol levels than AA homozygotes [P = 0·01 for (free) cortisol]. Furthermore, female BclI GG homozygotes had 54·8 nmol/l higher cortisol levels than C-carriers (P = 0·03). In the total population, BclI GG homozygotes had 0·05 g/cm2 lower trochanteric region BMD (P = 0·03). For the other GR gene polymorphisms, no significant associations were found. Conclusions, Higher cortisol levels are associated with lower femoral neck BMD in elderly women. The G allele of the 9beta polymorphism was associated with lower serum cortisol levels in women. Female BclI GG homozygotes had higher serum cortisol levels, and BclI GG homozygotes had lower trochanteric region BMD in the total population. [source]