Relationship between autoantibody associated with rheumatoid arthritis and tooth loss.

INTRODUCTION: This study evaluated the relationship between serum Rheumatoid Factor (RF) levels and tooth loss in a community-dwelling elderly Japanese women. It was hypothesised that women with high baseline RF levels would experience greater tooth loss over 10 years than age-matched women with lower baseline serum RF levels.

MATERIALS AND METHODS: The study population consisted of 197 women aged 70 years with ≥12 teeth at baseline. One hundred and twenty-four participants completed a 10-year follow-up and were divided into 2 groups according to their baseline serum RF levels as follows: RF negative (<15 U/mL; n = 114) and RF positive (>15 U/mL; n = 10). Negative binomial regression was used to investigate the relationship between baseline RFs and tooth lost over the 10-year period. RF and its interaction with the baseline number of teeth were independent variables, with 9 other adjustment covariates.

RESULTS: Baseline RFs were significantly associated with tooth loss (P = .035). In addition, a statistical interaction between baseline RFs and baseline number of teeth was identified (P = .023), modifying the association between RFs and tooth loss. The adjusted incidence rate ratio (IRR) for RF-positive participants with 21 baseline teeth was 1.88 (95% confidence interval (95% CI): 0.76, 4.65). IRRs obtained for participants who had 25 baseline teeth (3.02; 95% CI: 1.03, 8.83) or 30 baseline teeth (5.47; 95% CI: 1.29, 23.13) suggested that RF-positive participants with a high number of baseline teeth would exhibit greater tooth loss than RF-negative participants.

CONCLUSION: High serum RF levels were associated with a greater IRR for future tooth loss in elderly Japanese women.