Effect of Disease-related Variables on Bone Mineral Density in Patients with Rheumatoid Arthritis

Abstract

Objective: Rheumatoid arthritis (RA) is a chronic inflammatory disease that affects the bony architecture. Nevertheless, it remains uncertain whether these effects are due to disease progression, limited mobility, or medication. We conducted this study to analyze changes in bone mineral density (BMD) in patients with RA and its relationship with various disease parameters, such as demographic factors, disease activity, functional disability, duration since onset of symptoms, cumulative steroid dose, and titers of rheumatoid factor (RF).

Materials and methods: This cross-sectional study was conducted at the Rheumatology Clinic of the Tertiary Care Hospital of Mumbai. We included 96 consecutive patients diagnosed with RA using the American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) criteria. Demographic, clinical, and biochemical data were also collected. Disease severity was assessed using the Disease Activity Score 28 with Erythrocyte Sedimentation Rate (DAS28-ESR) score, and physical disability was assessed using the Health Assessment Questionnaire (HAQ) score. BMD was calculated using dual-energy X-ray absorptiometry (DEXA). Significant variations among continuous variables were examined using the t-test, while disparities between categorical variables were evaluated using the Chi-squared test. Statistical significance was set at p < 0.05 within the 95% confidence interval (CI) range.

Results: Of the 96 patients, 77 were female, and 19 were male. The mean age of the study population was 45.28 ± 10.15 years. As the age of patients increased, BMD was found to decrease in the total lumbar spine, neck of the femur, and total hip region (p < 0.05). Sex did not seem to affect BMD. In all three regions, a decrease in BMD with increasing duration since the onset of RA symptoms was observed. Disease severity, measured using the DAS28-ESR score, did not decrease BMD. There was an increase in functional disability, calculated using the HAQ score, with a decrease in BMD at all sites. RF positivity was associated with decreased BMD at the neck of the femur and total hip region but not the total lumbar spine. Long-term use of steroids (≥30 days) decreased BMD at all three sites.

Conclusion: Our study reiterates the effect of RA on the BMD of patients. Advanced age, duration since symptom onset, physical disability, RF positivity, and long-term corticosteroid use are disease-related factors affecting BMD in patients with RA.