Secondary osteoporosis and the risk of distal forearm fractures in men and women

Secondary osteoporosis plays an important role in the pathogenesis of hip and spine fractures, but relatively little is known about the potential impact of secondary osteoporosis and fall-related disorders on the risk of distal forearm fractures. To address this issue, we conducted a population-based, nested case-control study comparing 496 Rochester, Minnesota, residents with an initial distal forearm fracture to an equal number of age- and gender-matched controls. Potential risk factors were assessed by review of each subject's complete (inpatient and outpatient) medical records in the community (median duration >30 years) and analyzed using multiple logistic regression. Although history of diabetes mellitus in women (odds ratio [OR] 0.34, 95% confidence interval [CI] 0.15-0.75) and long-term anticonvulsant use in both genders (OR 3.58, 95% CI 1.26-10) were independently associated with fracture risk in a multivariate analysis, the conditions linked with secondary osteoporosis had, in aggregate, no statistically significant association with distal forearm fractures. Fall-related conditions altogether were associated with a borderline increase in risk (OR 1.36, 95% CI 0.98-1.91) and might have accounted for 19% of forearm fracture occurrence in the community. Among women (OR 2.72, 95% CI 1.20-6.19), but not men, a history of prior osteoporotic fracture was also associated with an increase in distal forearm fractures. These factors do not appear to account for the discrepancy in forearm fracture incidence in women when compared with men.