Long Term Antibiotics Increase Risk of RA Save

JAMA has published a population-based retrospective cohort study showing a possible association between the long-term use of antibiotics and the risk of rheumatoid arthritis (RA).

A retrospective study of adults (> 40 years) from the Korean National Health Insurance Service database looked at antibiotic exposure from 2003 to 2007. Incident RA was assessed from claims data.

From 3.3 million person-years of follow-up, 29 274 RA patients were identified. The risk of RA was increased by: 

• Antibiotics > 90 days (aHR, 1.79; 95% CI, 1.67–1.92) (vs non-users)
• Use of >3 antibiotic classes (aHR, 1.61; 95% CI, 1.51–1.71) (vs non-users)

These data conform to other reports showing:

• Danish study showing new cases of inflammatory arthritis were more likely to have received Abx in the one-year before (compared to the general population(PRR 1.48 - 1.72)
• Antibiotics were associated with a dose related risk of an RA diagnosis. Patients receiving >10 antibiotics in a 5 year period were twice as likely to receive an RA vs controls [adjusted odds ratio 2.65 (CI 2.40, 2.93)]
• Another UK Clinical Practice Research study showed a 60% increased risk of RA (OR 1.60; 95% CI 1.51–1.68) with antibiotic exposure. 
• Swedish study showed that antibiotics during the first 3 years of life resulted in a 3 fold future risk of JIA (aOR 3.17; 95% CI 1.11–9.03, p = 0.031).
• UK study of the THIN network found a 2 fold increased risk of developing JIA with exposure to antibiotics (adjusted odds ratio 2.1 [95% confidence interval: 1.2–3.5]). The more courses of antibiotics prescribed, the higher the risk.