Lower calcaneal bone mineral density and broadband ultrasonic attenuation, but not speed of sound, in South Asian than white European women

Abstract

Background: Quantitative ultrasound (QUS) measures of bone predict fracture risk in older white women. South Asian women have low bone mineral density (BMD), perhaps related to smaller body size or vitamin D insufficiency, but it is unknown whether this is accompanied by lower QUS.

Aim: The study compared QUS, BMD and vitamin D status between South Asian and white European women.

Subjects and methods: Participants were 47 postmenopausal women (23 white European, 24 South Asian) aged 55–65 years. BMD was measured at the calcaneus and radius by dual X-ray absorptiometry. The QUS measurements were broadband ultrasound attenuation (BUA) at the calcaneus and speed of sound (SOS) at the calcaneus, radius and tibia. Serum 25-hydroxy vitamin D was determined in late summer.

Results: South Asian women had significantly lower serum 25-hydroxyvitamin D than white Europeans (13.0 ± 5.1 versus 30.3 ± 7.1 ng mL^–1; p < 0.001). Calcaneal BMD and BUA were 14% and 10% lower (p = 0.016 and 0.045), respectively, in South Asian women. Radial BMD, and SOS at all sites, did not differ significantly between groups.

Conclusion: In this study, postmenopausal South Asian women living in the UK had a high prevalence of vitamin D insufficiency and lower calcaneal BMD than white European women, consistent with previous findings. Differences were detected in calcaneal BUA but not SOS. Further research is needed to evaluate fracture risk and its detection in South Asian women.

• Quantitative ultrasound
• bone mineral density
• ethnicity
• vitamin D