Hydroxychloroquine and risk of osteoporosis in patients with rheumatoid arthritis: A population-based retrospective study of 6408 patients.

Aim: Patients with rheumatoid arthritis (RA) are at a higher risk of osteoporotic fractures. Studies have shown that patients with Sjogren's syndrome (SS) and systemic lupus erythematosus (SLE) experienced an increase in bone mineral density (BMD) after receiving hydroxychloroquine (HCQ) treatment, indicating a potential protective effect against osteoporosis. Therefore, this study is to examine the relationship between HCQ usage and the risk of osteoporosis in patients diagnosed with RA.

Methods: The retrospective cohort study used data from Taiwan's National Health Insurance Research Database (NHIRD) covering the period from January 2010 to December 2018, which included 14 050 newly diagnosed RA patients, subsequently divided into two groups: HCQ users and non-users. Propensity score matching (PSM) based on sex, age, urbanization, insured unit type, insured area, and comorbidities was conducted to match the groups. The primary outcome assessed was the evaluation of the risk of osteoporosis by employing a multivariable Cox proportional hazard regression model to calculate the adjusted hazard ratio (aHR).

Results: After PSM, a total of 6408 RA patients were included in the analysis (3204 HCQ users and 3204 non-users). There was no significantly higher risk of osteoporosis in HCQ users compared with non-users, aHR = 0.99 (95% CI: 0.82-1.196). Additionally, different durations of HCQ usage demonstrated a neutral effect on the risk of osteoporosis [HCQ <90 days, aHR = 0.88 (95% CI: 0.585-1.324); HCQ 90-180 days, aHR = 0.941 (95% CI: 0.625-1.418); HCQ >180 days, aHR = 1.019 (95% CI: 0.832-1.249)].

Conclusions: The study indicates that there is no significant association between the use of HCQ and the risk of osteoporosis in patients with RA.