Quantitative ultrasound normative reference data for community-dwelling white and black females in the United States

TDF and quantitative ultrasound bone quality in African patients on second line ART, ANRS 12169 2LADY sub-study

BACKGROUND

Bone demineralization, which leads to osteoporosis and increased fracture risk, is a common metabolic disorder in HIV-infected individuals. In this study, we aimed to assess the change in bone quality using quantitative ultrasound (QUS) over 96 weeks of follow-up after initiation of second-line treatment, and to identify factors associated with change in bone quality.

METHODS AND FINDINGS

In a randomized trial (ANRS 12169), TDF and PI-naïve participants failing standard first-line treatment, from Burkina Faso, Cameroon, and Senegal were randomized to receive either TDF/FTC/LPVr, ABC/ddI/LPVr or TDF/FTC/DRVr. Their bone quality was assessed using calcaneal QUS at baseline and every 24 weeks until week 96. Stiffness index (SI) was used to measure bone quality. Out of 228 participants, 168 (74%) were women. At baseline, median age was 37 years (IQR: 33-46 years) and median T-CD4 count was 199 cells/μl (IQR: 113-319 cells/μl). The median duration of first-line antiretroviral treatment (ART) was 52 months (IQR: 36-72 months) and the median baseline SI was 101 (IQR: 87-116). In multivariable analysis, factors associated with baseline SI were sex (β = -10.8 [-18.1,-3.5] for women), age (β = -8.7 [-12.4,-5.1] per 10 years), body mass index (BMI) (β = +0.8 [0.1,1.5] per unit of BMI), and study site (β = +12.8 [6.5,19.1] for Cameroon). After 96 weeks of second-line therapy, a reduction of 7.1% in mean SI was observed, as compared with baseline. Factors associated with SI during the follow-up were similar to those found at baseline. Exposure to TDF was not associated with a greater loss of bone quality over time.

CONCLUSION

Bone quality decreased after second-line ART initiation in African patients independently of TDF exposure. Factors associated with bone quality include age, sex, baseline BMI, study site, and duration of follow-up.

Peak Bone Mass and Quantitative Ultrasound Bone Properties in Young Adulthood: A Study in the PEAK-25 Cohort of Women

Peak bone mass is normally reached in the third decade of life. Previously, in the population-based PEAK-25 cohort (n = 1061, age 25.5 ± 0.2), we demonstrated that bone mineral density in the population-based PEAK-25 cohort is comparatively high; therefore, this study aimed to determine if the calcaneus microarchitecture mirrored this. In the process, we describe normative quantitative ultrasound (QUS) values for 25-yr-old women and the relationship between QUS values and extremes of body weight. QUS variables speed of sound (SOS), broadband ultrasound attenuation (BUA), and stiffness index were measured. Young adult values were based on the manufacturer-supplied QUS reference values. Analyses were performed in the cohort as a whole, and additionally, to understand the relationship between body weight and QUS values in young women, the variables were categorized into octiles for weight or body mass index (BMI) and the lowest and highest octiles were compared. In the cohort, SOS values, reflecting bone density, were higher (108 ± 18%), whereas BUA values, reflecting bone complexity, were lower (90 ± 14%) compared to the young adult reference population. SOS did not correlate with body weight or BMI. In the cohort, overall correlations between BUA weight, and BMI were small and positive (Pearson's r coefficients 0.261 and 0.197, respectively; p < 0.001), although in the low-weight group, r coefficients were higher (r = 0.313 and 0.268; p < 0.05). In contrast, in the high-weight group, correlation with BUA values tended to be small, negative, and nonsignificant. Correlation between QUS and dual-energy X-ray absorptiometry-measured bone mineral density was low to moderate and significant at all skeletal sites (r = 0.37-0.52). Whereas coefficients tended to be higher in the low-weight group, the reverse was apparent for the low-BMI group. In these 25-yr-old women, a comparatively high dual-energy X-ray absorptiometry-measured bone mass is offset by less complex bone structures assessed by QUS. This may have implications for later osteoporosis assessment and future fracture risk.

Calcaneal quantitative ultrasound as a determinant of bone health status: what properties of bone does it reflect?

Quantitative ultrasound (QUS) has emerged as a convenient and popular screening tool for osteoporosis. This review aimed to provide basic information on the principle of QUS measurement and discuss the properties of bone reflected by QUS indices. QUS employed high frequency sound waves generated by the device to determine bone health status in humans. In vitro studies showed that QUS indices were significantly associated with bone mineral density (BMD), bone microarchitecture and mechanical parameters. In humans, QUS indices were found to be associated with BMD as well. In addition, QUS could discriminate subjects with and without fracture history and predict risk for future fracture. In conclusion, QUS is able to reflect bone quality and should be used in the screening of osteoporosis, especially in developing countries where dual-X-ray absorptiometry devices are less accessible to the general population.