Impact of Treat-to-Target Therapy on Bone Mineral Density Loss in Patients With Rheumatoid Arthritis: A Prospective Cohort Study

Abstract

BackgroundOsteoporosis is a common comorbidity of rheumatoid arthritis (RA). Although RA disease activity has been demonstrated to be associated with bone loss in previous studies, most of them were cross-sectional studies and not in the context of treat-to-target (T2T) strategies.ObjectivesThis study aimed to evaluate the association of disease activity with bone mineral density (BMD) changes in the context of T2T strategies in a prospective RA cohort.MethodsRA patients were enrolled from a prospective CENTRA cohort of Peking University First Hospital. The follow-ups have been scheduled every 3 to 6 months. BMD was repeated at baseline, 1 year, and then every other year. Demographics, baseline clinical features, laboratory data, and medications at each visit were recorded. Time-adjusted mean disease activity scores were adopted to reflect the overall disease activity during follow-up. The influence of univariable associations between predictors and BMD was investigated using linear regression.ResultsA total of 268 patients were included in our analysis. Their mean age was 50 (12.9) years, and 224 (83.6%) were women. The median (IQR) disease duration was 48.7 (107.6) months. Osteoporosis in the lumbar spine was observed in 23.1% of patients and 9.3% in the femoral neck at enrollment. Older age, higher SDAI score, and lower BMI were associated with osteoporosis at baseline. The proportion of patients who achieved DAS28-ESR, CDAI, and SDAI remission or LDA at the end of the first year was 71.5%, 68.8%, and 67.4%, respectively. Reevaluations of BMD at 1 year were applied to 144 patients. Mean decreases of BMDs were 1.75% at the lumbar spine and 1.40% at the femoral neck at 1 year from baseline, respectively. Patients who achieved remission had less yearly bone loss in the lumbar spine (p = 0.036). Female gender was identified as a risk factor in the multiple linear regression analyses, and lower disease activity and bisphosphonates were protective factors of continuous bone loss.ConclusionDisease activity is associated with bone loss in RA patients in the context of T2T strategies, and those who achieved remission had less yearly bone loss.