High incidence of vertebral and non-vertebral fractures in the OSTRA cohort study: a 5-year follow-up study in postmenopausal women with rheumatoid arthritis

SUMMARY: A 5-year follow-up study was performed in female RA patients with established disease looking at vertebral fractures, scored on spinal X-rays, and non-vertebral fractures. We found a high incidence rate of vertebral and non-vertebral fractures in these patients compared to population-based studies. INTRODUCTION: The aim of this study is to investigate the incidence of vertebral and non-vertebral fractures over a 5-year period in a cohort of postmenopausal patients with established rheumatoid arthritis (RA). METHODS: One hundred and fifty female patients with established RA were included into the OSTRA cohort. The cohort was assessed at baseline and at 5 years for incident vertebral and non-vertebral fractures. Spinal X-rays were taken at baseline and at follow-up and scored using the semi-quantitative method according to Genant. RESULTS: At 5 years, 102 patients (68%) were examined and included in the present analysis. At baseline, the mean age was 61 years, disease duration 17 years, body mass index 25.5 kg/m(2) and 65% of the patients were rheumatoid factor positive. Fifteen percent were treated with bisphosphonates, 25% received calcium supplementation and 20% vitamin-D supplementation at baseline. During the 5-year follow-up, a total of 16 patients out of 102 patients (16%) had a new non-vertebral fracture [annual incidence of 3.2 (95% CI 1.8–5.5) per 100 patients/year]. In 18 patients out of 97 patients (19%), new vertebral fractures were identified on spinal X-ray [annual incidence of 3.7 (95% C.I. 2.2–5.8) per 100 patients/year]. CONCLUSIONS: We found a high incidence of vertebral and non-vertebral fractures in a cohort of women with established RA compared to population-based studies.