Association between Colles' fracture and low bone mass: age-based differences in postmenopausal women

Colles' fracture (CF) in postmenopausal women has been linked to low bone mass at the lumbar spine and hip. However, the diverse methodological approaches of previous studies make the results difficult to compare and thus the implications of CF in osteoporosis daily clinical practice are not clear. We explored the association between CF and low bone mineral density (BMD) in an incident case-control study in 58 postmenopausal Spanish women aged 45-80 years with recent CF and in 83 population-based controls of the same age range. The BMD of ultradistal distal forearm, lumbar spine and hip was measured by dual-energy X-ray absorptiometry (DXA) and WHO criteria were used to define osteoporosis and osteopenia. BMD was significantly lower in cases for all three areas ( p<0.001). Osteoporosis was more prevalent in cases than controls in the wrist (60% vs. 35%, p<0.001), lumbar spine (47% vs. 20%, p<0.005) and hip (19% vs. 6%, p<0.005). After adjusting for age, menopausal status and body mass index, osteoporosis and osteopenia remained significantly associated with CF only in women aged 65 years or less (ultradistal forearm OR 5.7 (95% CI 1.2-27.2), lumbar spine OR 3.9 (95% CI 1.1-14.3)). We conclude that CF in postmenopausal women aged 65 or less may be used as a sentinel finding to identify patients with generalized osteoporosis. Additionally, 70% of all CF patients regardless of their age had low bone mass ( T-score<-1SD) in any studied site.