Predicting various fragility fractures in women by forearm bone densitometry: a follow-up study

Abstract

This is a follow-up of a previous study on the predictive power of bone mineral measurements; two more observation years have been added. A group of women (n = 1076) had their forearm bone mineral content (BMC) measured from 1970-1976. All fractures that occurred in 1975-1987 (13 years) were recorded. Four hundred sixty-nine fragility fractures occurred during the collection period. Again, it was found that BMC at the distal end of the forearm is a good predictor of future fracture before the age of 70. The measurement at the proximal site (forearm shafts), however, in contrast to our previous study, has a capacity of predicting fracture also in the age group 70-80. BMC measurements were good predictors of vertebral crush fractures and trochanteric hip fracture but lesser predictors of fractures of the distal end of the forearm. In age groups 40-70, BMC was a stronger predictor of fracture than age, and the risk associated with a 1 SD decrease of BMC 6 was 3.2 for a hip fracture as compared with those without any fragility fracture, even when adjusted for age. In addition to BMC, low body weight was a fracture predictor. Body weight 5 kg below age-adjusted mean increased the risk of a trochanteric hip fracture by 30%. The data are used in hypothetical calculations of the effects of screening.