Prevalence of fractures in women with rheumatoid arthritis and/or systemic lupus erythematosus on chronic glucocorticoid therapy

Maria Luz Rentero, Encarna Amigo, Nicolas Chozas, Manuel Fernández Prada, Lucia Silva-Fernández, Miguel Angel Abad Hernandez, Jose Maria Rodriguez Barrera, Javier del Pino-Montes, on behalf of the GHDP study group

Glucocorticoid (GC) therapy is associated with an increased risk of fractures. The main objective of this study was to determine the prevalence of undiagnosed vertebral fractures in women chronically using GC therapy for autoimmune disorders. We also determined the prevalence of non-vertebral fractures, and investigated whether factors such as quality-of-life and future fracture risk are associated with vertebral/non-vertebral fractures. This was a multicenter cross-sectional study conducted in Spain. All women had rheumatoid arthritis (RA) and/or systemic lupus erythematosus (SLE). Radiological morphometric vertebral fractures were evaluated centrally (Genant semiquantitative method), whereas non-vertebral fractures were not assessed by radiography. Before radiography, patients were asked whether they had vertebral/non-vertebral fractures, hereafter referred to as 'self-reported' fractures. Assessment tools included the Disease Activity Score (DAS28), the SF-36 questionnaire, and FRAX®. Complete data were obtained for 576 outpatients with RA and/or SLE (83.3 % had RA); mean [SD] age 59.6 [15] years. Of all patients, 6.4 % had self-reported vertebral fractures, whereas 18.9 % had morphometric vertebral fractures (RA: 7.1 % self-reported vs. 20.0 % morphometric; SLE: 3.2 % self-reported vs. 13.7 % morphometric). Non-vertebral fractures were self-reported by 9.8 % of RA and 5.3 % of SLE patients. Low physical functioning was associated with morphometric vertebral fractures (mean [SD] SF-36 score 18.8 [6.0] when present vs. 20.1 [5.9] when absent; p = 0.028) and self-reported non-vertebral fractures (16.7 [5.2] when present vs. 20.1 [5.9] when absent; p < 0.001). Mean [SD] DAS28 was higher (p = 0.013) when any self-reported fractures were present (4.0 [1.3]) than absent (3.6 [1.3]). Based on FRAX® analysis, patients with vs. without morphometric vertebral fractures had higher 10-year probabilities of major osteoporotic fractures (mean [SD] 17.9 [12.9]% vs. 9.9 [9.6]%; p < 0.001) and hip fractures (11.0 [11.7]% vs. 4.6 [8.1]%; p < 0.001). Morphometric vertebral fractures were detected in 18.9 % of patients, i.e. 3-times more frequently than verbally reported by patients. Patients with vs. without fractures had worse quality-of-life and increased fracture risk. Accordingly, it is of utmost importance that women chronically using GCs are assessed for fractures, including morphometric vertebral fractures.