Ultrasound, densitometry, and extraskeletal appendicular fracture risk factors: A cross-sectional report on The Saunders County Bone Quality Study

The Saunders County Bone Quality Study was designed to determine the feasibility of ultrasonic bone measurement, at the patella, as a predictor of low-trauma fractures in a runal population-based study. At the first visit of this 4-year longitudinal study, anthropometric and clinical measurements and medical, surgical, and fracture histories were obtained for the 1428 participants (899 women and 529 men). Explored risk factors for low-trauma fractures included age, sex, calcium intake, alcohol and caffeine ingestion, tobacco use, body mass and grip strength, age of menopause, estrogen replacement therapy, propensity to fall, distal radius and ulna bone mineral content, and bone density. Forward multivariate logistic regression analysis showed that lower ultrasound values are more consistently associated with reported low-trauma appendicular fractures than the commonly reported forearm absorptiometry measures of radius mineral content and density. When ultrasound, age, and the extra skeletal risk factors were included in an additional multivariate model, only age and ultrasound were significantly associated with appendicular fracture history in women (P=0.0003), whereas only ultrasound was associated in the men (P=0.001). We conclude that ultrasound is a better measure of association with reported low-trauma fractures than the commonly reported forearm SPA measures. Even after adjustment for many of the extra skeletal risk factors, low AVU is highly associated with low-trauma fracture status for both women and men.