TNFα inhibitors (TNFαI) exert positive effects on disease activity in rheumatoid arthritis (RA). Bone involvement is a major determinant of functional impairment in this disease.
Objectives
Here we investigated the short-term effects of TNFαI therapy on bone metabolism and density.
Methods
We studied 54 patients with RA starting a TNFI biologic drug, in whom any factor known to interfere with bone metabolism was excluded or rigorously accounted for. We measured at baseline and after 6 month therapy bone turnover markers (BTM): N-propeptide of type I collagen (P1NP), and bone alkaline phosphates (bAP) for bone formation and serum C-terminal telopeptide of type I collagen (CTX) for bone resorption. We also evaluated bone mineral density (BMD) at hip and lumbar by dual energy X ray absorptiometry (DEXA).
Results
All bone markers rose significantly and these changes were not dependent on steroids dosage; a significant decrease in femoral neck BMD was also observed (see Table).
Conclusions
These results indicate that TNFαI therapy in RA over 6 months is associated with an early increase in bone turnover and a decline in hip BMD.