Aspirin and nonsteroidal antiinflammatory drug use in elderly women: effects on a marker of bone resorption. The Study of Osteoporotic Fractures Research Group.

OBJECTIVE: Epidemiological studies suggest nonsteroidal antiinflammatory drug (NSAID) and aspirin use is associated with a modest increase in bone mineral density of the hip and lumbar spine. The ability of NSAID to block prostaglandin E2 production has been shown to impair osteoclast activity in animal models. To determine if regular use of these compounds inhibits bone resorption, we assessed NSAID or aspirin use and N-telopeptide crosslink excretion in elderly postmenopausal women.
METHODS: N-telopeptide crosslink excretion was assessed from a consecutive sample of 499 women from the Study of Osteoporotic Fractures, age > 65 years, who provided a morning urine sample. Questionnaire, examination, and bone mineral density data were obtained at the same visit.
RESULTS: In unadjusted models, daily use of NSAID or aspirin was associated with a reduction of 12.5% (95% CI 0.5, 24.5) in N-telopeptide crosslink excretion (p < 0.05). After adjustment for potential confounders, N-telopeptide crosslink excretion was -4.8% (95% CI -24.4, 14.8) in NSAID users and +7.6% (-9.3, 24.5) in aspirin users compared to nonusers.
CONCLUSION: Regular use of either NSAID or aspirin by elderly women was not associated with reduction in N-telopeptide crosslink excretion compared to nonusers.