Low-dose oral glucocorticoid therapy and risk of osteoporotic fractures in patients with rheumatoid arthritis: a cohort study using the Clinical Practice Research Datalink

Abstract

OBJECTIVES: Clinical trials have shown that low-dose glucocorticoid therapy in patients with rheumatoid arthritis (RA) reduces bone loss in hands or hip, but the effect on osteoporotic fractures is not yet clear. Therefore, we investigated the use of low-dose oral glucocorticoids and risk of osteoporotic fractures among patients with RA. METHODS: This was a cohort study including patients with RA aged 50+ years from the Clinical Practice Research Datalink between 1997-2017. Exposure to oral glucocorticoids was stratified by the most recent prescription in current (<6 months), recent (7-12 months), and past (>1 year) use, and average daily and cumulative doses. Risk of incident osteoporotic fractures (including hip, vertebrae, humerus, forearm, pelvis, and ribs) were estimated by time-dependent Cox proportional-hazards models, adjusted for life-style parameters, comorbidities, and comedications. Secondary analyses assessed osteoporotic fracture risk with a combination of average daily and cumulative doses of oral glucocorticoids. RESULTS: Among 15 123 patients with RA (mean age 68.8 years, 68% females), 1640 osteoporotic fractures occurred. Current low-dose oral glucocorticoid therapy (≤7.5 mg prednisolone equivalent/day) in patients with RA was not associated with overall risk of osteoporotic fractures (adjusted hazard ratio 1.14, 95% CI 0.98-1.33) compared with past glucocorticoid use, but was associated with an increased risk of clinical vertebral fracture (adjusted hazard ratio 1.59, 95% CI 1.11-2.29). Results remained unchanged regardless of a short-term or a long-term use of oral glucocorticoids. CONCLUSION: Clinicians should be aware that even in RA patients who receive low daily glucocorticoid doses, the risk of clinical vertebral fracture is increased.