Objective: To assess the risk of fracture following onset of Alzheimer's disease.
Design: Retrospective (historical) cohort study.
Setting: Population-based in Rochester, Minnesota.
Participants: All 543 Rochester residents with onset of Alzheimer's disease during the 10-year period, 1975-84, and an equal number of age- and sex-matched controls from the community.
Measurements: Fractures were assessed through review of each subject's complete (inpatient and outpatient) medical records in the community.
Main results: Rochester residents with Alzheimer's disease were no more likely to have a history of fracture prior to onset than were matched controls from the same population. During the year of onset, there was a 2-fold excess of fractures at various sites among those with Alzheimer's disease. The risk ratio for any fracture subsequently was 1.1 (95% CI 0.9, 1.3), and this slight increase was accounted for entirely by a 2.7-fold increase in the risk of hip fracture (95% CI 1.8, 4.2).
Conclusions: Fracture risk was not increased before the onset of Alzheimer's disease, although there was an excess of fractures around the time that Alzheimer's disease came to clinical attention. Fracture risk was not elevated thereafter except for a substantial increase in the risk of hip fracture. This suggests a link with certain falls rather than generalized disuse osteoporosis.