19 November, 2012:

A total of 2341 postmenopausal women were recruited in five centers in Italy during 2006 and 2007 for quantitative ultrasound (QUS) measurement at the phalanges during a screening program for osteoporosis [1]. Two ultrasound parameters were collected: amplitude-dependent speed of sound (AD-SoS) and ultrasound bone profile index (UBPI). Women were then re-contacted in 2010 (n = 2211) and were asked about fracture occurrence during the period since previous QUS measurement. The mean age of the recruited women was 60.9 ± 10.0 years, the mean age at menopause was 49.3 ± 4.4 years, and the mean body mass index (BMI) was 26.5 ± 4.6 kg/m2. A total number of 108 new major osteoporotic fractures occurred during the 3-year period, of which 23 were hip fractures and 51 were vertebral fractures. The relative risk (RR) per standard deviation (SD) decrease for major fractures was 1.77 (95% confidence interval (CI) 1.59–1.97) for AD-SoS and 2.06 (95% CI 1.78–2.37) for UBPI. When corrected for age, BMI, and age at menopause, the RRs were still significant and equal to 1.44 (95% CI 1.26–1.65) for AD-SoS and 1.67 (95% CI 1.39–2.00) for UBPI. The RR for vertebral fractures was 1.63 (95% CI 1.41–1.88) for AD-SoS and 1.73 (95% CI 1.44–2.08) for UBPI. The RR for hip fractures was 1.92 (95% CI 1.55–2.37) for AD-SoS and 2.68 (95% CI 1.86–3.86) for UBPI. Thus, this study showed that ultrasound parameters AD-SoS and UBPI were able to significantly predict future major fractures in a prospective cohort of more than 2000 postmenopausal women.

Comment

Quantitative ultrasound of the bone provides information not only about bone density but also on architecture and elasticity. It is a radiation-free technique, relatively inexpensive and easily transportable. Measurements at the fingers take only a few minutes. Theoretically, it seems to be the ideal modality for assessing bone strength, yet dual-energy X-ray absorptiometry (DXA), a much more expensive and time-consuming examination, is the gold standard recommended by health authorities and guidelines and is an important component of the FRAX risk assessment tool [2,3]. There could be several reasons for the existing inferiority of QUS versus the traditional DXA measurement. QUS examinations could be performed in several sites, which raises the question whether measurements at various peripheral sites (heel, finger, wrist) are similar in regard to their predictive values for vertebral and hip fractures. Other arguments relate to the accuracy of QUS when tested head-to-head with DXA, and to the efficacy of QUS, both as a screening tool and for monitoring the consequences of treatment, as compared to DXA.

The current study demonstrated good correlations between hip fracture risk and finger QUS [1], whereas a recent meta-analysis reached similar conclusions looking at studies employing heel QUS [4]. Investigating men and women with non-osteoporotic bone density (DXA T-score > -2.5) during a 7-year follow-up showed that baseline calcaneal QUS correlated with future fracture risk [5]. Albanese and colleagues found that phalangeal QUS showed the same ability as lumbar spine BMD in discriminating women with or without vertebral fractures and in the prediction of fracture risk [6]. However, another recent review [7] challenged the use of QUS instead of DXA, stating that 'based on the analysis of seven studies, we conclude that QUS of the calcaneus still cannot be used to confirm diagnosis of osteoporosis by comparing the results to those of patients who had already received such a diagnosis based on DXA.'

All the relevant publications put forward the belief that, with improvement of the QUS technology, the accuracy of these examinations will become much better and potentially will match that of DXA. Perhaps the best description of the current status of QUS, which was embedded in the updated USPSTF statement [2], is that 'quantitative ultrasonography of the calcaneus predicts fractures of the femoral neck, hip, and spine as effectively as DXA. However, current diagnostic and treatment criteria for osteoporosis rely on DXA measurements only, and criteria based on quantitative ultrasonography or a combination of quantitative ultrasonography and DXA have not been defined.'

Amos Pines

Department of Medicine 'T', Ichilov Hospital, Tel-Aviv, Israel

References

1. Guglielmi G, Rossini M, Nicolosi MG, et al. Three-year prospective study on fracture risk in postmenopausal women by quantitative ultrasound at the phalanges. J Clin Densitom 2012 Aug 15. Epub ahead of print.

http://www.ncbi.nlm.nih.gov/pubmed/22901551 

2. US Preventive Services Task Force. Screening for osteoporosis: US preventive services task force recommendation statement. Ann Intern Med 2011;154:356-64.

http://www.ncbi.nlm.nih.gov/pubmed/21242341 

3. McCloskey E, Kanis JA. FRAX updates 2012. Curr Opin Rheumatol 2012;24:554–60.

http://www.ncbi.nlm.nih.gov/pubmed/22820516 

4. Moayyeri A, Adams JE, Adler RA, et al. Quantitative ultrasound of the heel and fracture risk assessment: an updated meta-analysis. Osteoporos Int 2012;23:143-53.

http://www.ncbi.nlm.nih.gov/pubmed/22037972 

5. Chan MY, Nguyen ND, Center JR, Eisman JA, Nguyen TV. Quantitative ultrasound and fracture risk prediction in non-osteoporotic men and women as defined by WHO criteria. Osteoporos Int 2012 Aug 10. Epub ahead of print.

http://www.ncbi.nlm.nih.gov/pubmed/22878531 

6. Flater M, Bittar CK, Zabeu JL, Carneiro AC. Review of comparative studies between bone densitometry and quantitative ultrasound of the calcaneus in osteoporosis. Acta Reumatol Port 2011;36:327-35.

http://www.ncbi.nlm.nih.gov/pubmed/22472924

7. Albanese CV, Cepollaro C, de Terlizzi F, Brandi ML, Passariello R. Performance of five phalangeal QUS parameters in the evaluation of gonadal-status, age and vertebral fracture risk compared with DXA. Ultrasound Med Biol 2009;35:537-44.

http://www.ncbi.nlm.nih.gov/pubmed/19097682 

Content updated 19 November 2012