Association between bone mineral density and vascular health in rheumatoid arthritis.

Introduction: Rheumatoid arthritis (RA) is associated with heightened cardiovascular disease and increased susceptibility to osteoporosis, with shared underlying mechanisms. This study aimed to investigate the association between vascular function and bone mineral density (BMD).

Methods: We conducted a cross-sectional study of 49 patients with RA at Tan Tock Seng Hospital, Singapore. Endothelial function was measured as reactive hyperaemia index (RHI)-endothelial peripheral arterial tonometry and aortic stiffness as carotid-femoral pulse wave velocity (cf-PWV) using SphygmoCor. Univariable and multivariable linear regression analyses were performed to evaluate the associations between BMD and vascular function. We used natural logarithm RHI (lnRHI) and cf-PWV as response variables, and each BMD as covariate, adjusting for body mass index, positive anti-cyclic citrullinated peptide, cumulative prednisolone dose, hydroxychloroquine use and Systematic COronary Risk Evaluation 2.

Results: We recruited 49 patients (mean age 61.08 ± 8.20 years), of whom 44 (89.80%) were women and 39 (81.25%) were Chinese. Significant associations were found between lnRHI and BMD at the lumbar spine (β = 0.4289, P = 0.037) and total hip (β = 0.7544, P = 0.014) in univariable analyses. Multivariable analyses confirmed these associations, showing that lower BMD at the lumbar spine (β = 0.7303, P = 0.001), femoral neck (β = 0.8694, P = 0.030) and total hip (β = 0.8909, P = 0.010) were significantly associated with worse lnRHI. No significant associations were found between BMD and cf-PWV.

Conclusion: Lower BMD is associated with endothelial dysfunction, but not aortic stiffness in patients with RA. Further longitudinal studies are needed to confirm these associations and understand the underlying mechanisms.