Hydroxychloroquine therapy and its impact on bone mineral density among systemic lupus erythematosus patients: A cross-sectional study

Abstract

Abstract Background and Objectives Patients with systemic lupus erythematosus (SLE) are at increased risk of osteoporosis due to chronic inflammation, prolonged glucocorticoid (GC) exposure, and treatment-related factors. Hydroxychloroquine (HCQ), a cornerstone of SLE therapy, has shown conflicting effects on bone health. This study examined the association between HCQ use and bone mineral density (BMD) in SLE. Methods A cross-sectional study of 213 SLE patients was conducted at Dr. Soetomo General Academic Hospital. BMD was assessed by dual-energy X-ray absorptiometry (DXA) and classified using WHO criteria. Demographic, clinical, laboratory, and treatment-related variables were collected. Group comparisons employed chi-square and non-parametric tests, while ordinal logistic regression identified independent predictors of reduced BMD. Methods Among 213 patients, 22.5% had normal BMD, 51.2% osteopenia, and 26.3% osteoporosis. Independent predictors of reduced BMD were older age (OR 1.05, 95% CI 1.01–1.09), higher cumulative GC exposure (OR 1.07, 95% CI 1.02–1.12), and lower BMI (OR 0.89, 95% CI 0.80–0.98). Importantly, the use of HCQ has been linked to a protective effect against osteoporosis (OR 0.47, 95% CI 0.22–0.97, P = 0.040). Neither SLEDAI scores nor complement/ESR levels were significantly associated with BMD. Conclusion Low BMD is highly prevalent in SLE and is strongly influenced by age, GC exposure, and BMI. HCQ use was linked to a protective effect on bone health, plausibly mediated by anti-resorptive, antioxidant, and glucocorticoid-sparing properties. Although a causal relationship between these two variables cannot yet be established, this association underscores the need for further well-designed longitudinal or interventional studies.