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  • 1
    ISSN: 1433-2965
    Keywords: Bone mineral density ; Broadband ultrasound attenuation ; Speed of sound ; Ultrasound References
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We performed ultrasound measurements in the calcaneus of 512 healthy women. Broadband ultrasonic attenuation (BUA) and speed of sound (SOS) were obtained with a Lunar Achilles ultrasonic instrument. Subjects studied were one group of 67 women working in our hospital (group A) and two groups which are part of two large prospective cohort studies (groups B and C). Group B consisted of 244 women aged 31–79 years randomly selected from a large insurance company, and group C consisted of 201 women aged 74–91 years randomly selected from the electoral rolls. Dual-energy X-ray absorptiometry (DXA) measurements of femoral neck and total body were performed with a Hologic QDR 2000 for group B and with a Lunar DPX Plus for group C. The in vitro precision of the Achilles, estimated by measuring a phantom daily for 45 days, was 0.84% for BUA and 0.12% for SOS. We assessed the in vivo short-term precision in 20 healthy volunteers working at the hospital, measured three times each. The coefficients of variation were 0.93% (±0.21) for BUA and 0.15% (±0.03) for SOS. The precision error was compared with the true variation, to obtain a standardized coefficient of variation. We analysed the three groups pooled together (n=512) and found for BUA an average 20% decrease and for SOS a 5% decrease between the ages of 20 and 90 years. We also performed separate analyses of subjects younger than 50 and older than 50 years, and within each 10-year age group we found that BUA was stable or slightly increased from 20 to 50 years and then decreased after 50. In contrast, SOS did not increase but decreased from the age of 20. We compared DXA measurements of the femoral neck and the total body with ultrasound measurements in groups B and C. In both groups the correlations were better with total body DXA than with femoral neck and spine DXA.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1433-2965
    Keywords: Aging ; Bone loss ; Bone mineral density ; Broadband ultrasound attenuation ; Speed of sound ; Stiffness index ; Ultrasound
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We performed repeated ultrasound measurements approximately 2 years apart (average 23 months ±3 months) on the os calcis of 113 healthy postmeno-pausal women recruited from two large prospective cohort studies named OFELY and EPIDOS. Group A (from OFELY) consisted of 88 women aged 52–72 (63±5) years, randomly selected from a large insurance company, and group B (from EPIDOS) consisted of 25 women aged 75–88 (80±4) years, randomly selected from the voting lists. We obtained broadband ultrasonic attenuation (BUA) and speed of sound (SOS) measurements, as well as the Stiffness index, with a Lunar Achilles ultrasound machine. We performed dual energy X-ray absorptiometry (DXA) measurements of femoral neck bone mineral density (neck BMD) with a Hologic QDR 2000 for group A and with a Lunar DPX Plus for group B. The decrease that we observed over 2 years was on average ±1 SD: −1.01±4.6 dB/MHz (p=0.02) for BUA (which is approximately equal to the long-term precision error in vitro), −11.3±9.2 m/s (p=0.0001) for SOS (approximately 5 times the precision error), −3.8±4.2 %YA (p=0.0001) for Stiffness (2.5 times the precision error) and −0.01±0.03 g/cm2 (p=0.0001) for neck BMD (approximately equal to the precision error). In terms of percentage change this represents: −1.0%±4.3% for BUA, −0.8%±0.6% for SOS and −1.85%±4.4% for neck BMD. At the individual level, most SOS and Stiffness values were consistent with a decrease, whereas BUA and neck BMD values were spread out above and below the zero line of no change. The decreases in SOS and Stiffness were significantly larger in the early postmenopause (⩽20 years since menopause [YSM]) than in the late postmenopause (〉20 YSM). We observed a similar trend for BUA and BMD but this did not reach statistical significance. We found a weak but significant correlation between changes in ultrasound variables and changes in neck BMD. However, the 2-year changes observed in SOS were not significantly correlated with changes in BUA. This study suggests that the heel ultrasound measurements of SOS and Stiffness are valuable indices of postmenopausal bone loss, and could be used for follow-up in therapeutic trials.
    Type of Medium: Electronic Resource
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