Levels of markers of bone resorption are moderately increased in patients with inactive rheumatoid arthritis

OBJECTIVE: Clinical remission occurs in 10-20% of patients with rheumatoid arthritis (RA). However, it is questionable whether clinical remission corresponds to the complete absence of the inflammatory process. To answer this question we measured collagen degradation products (which are known to be increased in active disease) in patients with inactive RA and in healthy controls. PATIENTS AND METHODS: The urinary levels of bone resorption markers (pyridinoline, deoxypyridinoline, N-terminal telopeptide and C-terminal telopeptide) were measured in 184 patients with inactive RA, as defined by the preliminary criteria of clinical remission of the American College of Rheumatology, and in 118 healthy individuals. RESULTS: After adjusting for age, concentrations of all four bone resorption markers were found to be significantly higher in patients with inactive RA than in healthy controls. CONCLUSION: The urinary excretion of bone resorption markers is increased in patients classified as having inactive RA. These results suggest that the inflammatory process is not completely absent.