Background/Purpose:

Osteoporosis is more frequently observed in patients with rheumatoid arthritis (RA) than in general population. Bisphosphonate (BP), which suppresses bone resorption by inhibiting osteoclast activation, has been most commonly used for treatment of osteoporosis. Previous studies demonstrated that anti-TNF therapy has a beneficial effect on bone loss possibly through anti-inflammatory effects as well as its inhibitory effects on osteoclast activation. However, there have been few studies assessing the role of TNF blocker for osteoporosis in RA patients under concomitant treatment with BP. Therefore, we performed a retrospective longitudinal study to investigate the changes in bone loss in RA patients received BP with or without TNF blockers.

Methods:

The study cohort consisted of 107 RA patients who were diagnosed with osteoporosis and treated with BP, at a tertiary referral center from Jan. 2005 to Dec. 2013. The areal bone mineral density (BMD) (g/cm²) of the lumbar spine, femur neck, trochanter and total femur was measured by dual-energy X-ray absorptiometry. Follow-up BMD was obtained at 1.22 ± 0.36 years after initial acquisition of BMD. The rate of change in the BMD was expressed as the annualized percentage change of BMD between initial measurement and subsequent measurement.

Results:

Among RA patients receiving BP with (n = 19) and without TNF blockers (n = 88), 19 (100.0 %) and 80 (90.9 %) were women, respectively. The mean ages at initial BMD for these subjects were 67.4 ± 10.3 years (range, 46 – 84 years) and 66.1 ± 8.3 years (range, 43 – 83 years), respectively (P = 0.569). There was no significant difference in baseline clinical characteristics including laboratory data, baseline BMD and dose of corticosteroid between the two groups. With BP Treatment, follow-up BMD was significantly increased at the area of lumbar spine in RA patients regardless of concomitant use of TNF blockers. Further, there were no statistical significant differences in annualized BMD changes between RA patients receiving BP with or without TNF blockers, although there was a numerical difference in the BMD changes between the two groups (Table 1).

Conclusion:

In RA patients with osteoporosis receiving BP, there was a no significant additional effect of TNF blockers for bone loss. Therefore, administration of BP is still important in treatment of osteoporosis in patients with RA, even in those who were taking TNF blockers. 

Table 1. Comparison of mean annualized changes of BMD between patients with and without TNF-blockers

BMD; Bone Mineral Density

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/the-effect-of-tnf-blockers-on-bone-mineral-density-in-rheumatoid-arthritis-patients-receiving-bisphosphonate/