Age-associated changes in ultrasound measurements of the calcaneus in men and women: the Rotterdam Study.

Broadband ultrasound attenuation (BUA) and speed of sound (SOS) of the os calcis were measured in a sample of 1405 persons (628 men), aged 55-93 years, from the cohort of the Rotterdam Study, a population-based study of diseases in the elderly. We studied the effect of age, body mass index, age at menopause, current use of thiazides, loop diuretics, and estrogens, smoking, and disability on SOS and BUA. Comparisons were made between ultrasound measurements and bone mineral density (BMD) measurements of the lumbar spine and proximal femur using DXA. We found a significant decline with age in SOS and BUA in men (-0.4 and -0.1 %/year, respectively) and women (-1.3 and -0.4%/year, respectively), which persisted after adjustment for body mass index. Age at menopause was not associated with SOS or BUA. Pack-years of smoking was negatively related to SOS in both sexes and to BUA in men. Severe disability was associated with lower SOS and BUA in men, but not in women. Despite the small number of exposed persons, current corticosteroid use was associated with lower BUA in men. The other risk factors examined did not affect the ultrasound measurements. We observed modest correlations between SOS or BUA, on the one hand, and BMD of the lumbar spine, on the other hand (r = 0.32-0.42). Similar correlations were found between ultrasound measurements and BMD measurements of the proximal femur. We conclude that in persons 55 years or over (1) there is a significant age-related decline of BUA and SOS, which is about three times higher in women compared with men, and (2) ultrasound measurements are not able to predict low BMD in hip or spine.