TNF Inhibitors Associated with Lower Fracture Risk in Axial Spondyloarthritis

A large case-control study published in Arthritis & Rheumatology using US insurance claims data has found that tumor necrosis factor inhibitors (TNFis) are associated with a significantly lower risk of hip and spine fractures in patients with axial spondyloarthritis (axSpA) compared to those receiving nonsteroidal anti-inflammatory drugs (NSAIDs). These findings highlight a potential role for TNFis in reducing bone fragility and fracture risk in patients with axSpA. 

The study analyzed 13,519 adults with axSpA, including 1,229 patients with fractures and 12,290 controls. Patients were identified from the Merative MarketScan Database (2006–2021) using ICD-9 and ICD-10 codes. Medication exposure was categorized as TNFis, conventional synthetic disease-modifying antirheumatic drugs (csDMARDs), NSAIDs (reference group), or no treatment, based on pharmacy claims and procedure codes. 

In the primary analysis, patients receiving TNFis had 29% lower odds of fracture compared to those on NSAIDs (odds ratio [OR] 0.71, 95% confidence interval [CI] 0.59–0.85), adjusting for age, sex, and diagnosis year. The fully adjusted model confirmed this protective association (OR 0.75, 95% CI 0.62–0.91). These results remained consistent when stratified by sex. 

"We found evidence for a protective effect of receiving TNFis on fracture risk in patients with axSpA, underscoring a potential impact of TNFis in diminishing comorbidities linked with axSpA," the study stated. 

The findings are particularly relevant for patients with axSpA, who face an increased risk of fractures due to chronic inflammation, reduced bone mineral density, and structural changes in the spine. While NSAIDs remain a cornerstone of symptom management, this study suggests that TNFis may provide an added benefit in preserving bone integrity. 

These results support the consideration of TNFi therapy in patients at higher risk for fractures and emphasize the importance of comprehensive bone health assessment in axSpA management.

Reference
Driscoll D, George N, Peloquin C, Jafarzadeh SR, Liew JW, Dubreuil M. Association of therapies for axial spondyloarthritis on the risk of hip and spine fractures. Arthritis Rheumatol. Published online December 16, 2024. doi:10.1002/art.43082