Calcaneal ultrasound reference ranges for Australian men and women: the Geelong Osteoporosis Study

Heel ultrasound is a more portable modality for assessing fracture risk than dual-energy X-ray absorptiometry and does not use ionising radiation. Fracture risk assessment requires appropriate reference data to enable comparisons. This study reports the first heel ultrasound reference ranges for the Australian population. This study aimed to develop calcaneal (heel) ultrasound reference ranges for the Australian adult population using a population-based random sample. Men and women aged a parts per thousand yen20 years were randomly selected from the Barwon Statistical Division in 2001-2006 and 1993-1997, respectively, using the electoral roll. Broadband ultrasound attenuation (BUA), speed of sound (SOS) and stiffness index (SI) were measured at the heel using a Lunar Achilles Ultrasonometer. Gender-specific means and standard deviations for BUA, SOS and SI were calculated for the entire sample (men 20-93 years, n = 1,104; women 20-92 years, n = 914) and for participants aged 20-29 years (men, n = 157; women, n = 151). Associations between ultrasound measures and age were examined using linear regression. For men, mean +/- standard deviation BUA, SOS and SI were 118.7 +/- 15.8 dB/MHz, 1,577.0 +/- 43.7 m/s and 100.5 +/- 20.7, respectively; values for women were consistently lower (111.0 +/- 16.4 dB/MHz, P < 0.001; 1,571.0 +/- 39.0 m/s, P = 0.001; and 93.7 +/- 20.3, P < 0.001, respectively). BUA was higher in young men compared with young women (124.5 +/- 14.4 vs 121.0 +/- 15.1 dB/MHz), but SOS (1,590.1 +/- 43.1 vs 1,592.5 +/- 35.0 m/s) and SI (108.0 +/- 19.9 vs 106.3 +/- 17.7) were not. The relationships between age and each ultrasound measure were linear and negative across the age range in men; associations were also negative in women but non-linear. These data provide reference standards to facilitate the assessment of fracture risk in an Australian population using heel ultrasound.