Background Osteoporosis is a well-known comorbidity in patients with rheumatoid arthritis (RA). A high percentage of patients with RA have low bone mineral density in axial and peripheral skeleton, which confers an increased fracture risk. In its further development, other risk factors such as age, menopause, disease activity and, especially, some of the drugs used for RA treatment, are involved.
Objectives To study the prevalence of morphometric vertebral fractures (MVF) in a cohort of patients with RA and to identify demographic, analytical, densitometric and RA-related risk markers for vertebral fractures.
Methods A cross-sectional cohort study in routine clinical practice conditions was designed. All patients fulfilled the ACR 2010 classification criteria for RA. We performed a questionnaire of fracture risk factors, an analytical study including serological bone markers (Procollagen Type I Intact N-terminal Propedtide and b-Cross Laps) and a hip and thoracolumbar spine bone densitometry. Patients filled out the Health Assessment Questionnaire (HAQ) and DAS28 was calculated. MVF was defined as a reduction of at least 20% in vertebral body height. A univariate analysis was performed using the presence of MVF as the dependent variable. Statistical significance was established by t-Student (parametric variables) and Mann-Whitney (nonparametric variables) tests. We considered significant a p <0.05.
Results We included 78 patients (77% women, mean age 59 years, duration of RA: 10 years). Vertebral fractures were found in 11 patients (14%). The presence of MVF was associated with a higher mean age (74 vs. 56, p <0.05) and a long-term disease (17 vs. 9 years, P = 0.013). Bisphosphonate therapy was associated with MVF, probably reflecting an indication bias. No association with HAQ score, DAS28 or its individual components was found. We did not find any association with serological bone markers. however, vitamin D levels were significantly higher among patients with fracture (60 nm / l vs. 47 nm / l, P = 0.032) and in patients who were receiving vitamin D supplements (23% vs. 6%, p <0.05). Densitometric osteopenia and osteoporosis at lumbar spine or femoral neck were significantly associated with vertebral fracture.
Conclusions Around 15% of patients with RA may develop MVF. Age, duration of RA, densitometric osteoporosis, vitamin D levels, vitamin D supplements and bisphosphonates are associated with such fractures.
Disclosure of Interest None Declared