Antibiotic exposure prior to rheumatoid arthritis (RA) diagnosis was associated with a higher likelihood of the condition developing, according to a study published in Rheumatology.
Researchers conducted a retrospective case-control study that included 8482 people with RA and 22,661 controls without RA matched based on age, gender, date of diagnosis, and practice. Over 15 years, clinical data were collected from the Royal College of General Practitioners Research and Surveillance Centre database in the United Kingdom. The type and number of antibiotic prescriptions preceding RA diagnosis were used to measure exposure. The analyses were adjusted for several potential confounding factors, including the presence of dyslipidemia, diabetes, prior stroke, and smoking status.
After analysis, the researchers found that antibiotic exposure within 1 year, 5 years, or ever prior to RA diagnosis was associated with a higher risk for RA developing. The team also reported that the association had a strong dose-response relationship.
In addition, patients who received more than 10 antibiotics within a 5-year duration had more than double the risk of being diagnosed with RA compared with controls (adjusted odds ratio, 2.65; 95% CI, 2.40-2.93).
One key limitation of the study was the retrospective design.
“If antibiotics are incriminated in the onset of RA, it remains unclear whether their involvement is through removal of certain bacterial species, allowing overgrowth of others, or whether it is the result of a change in the immune response as mediated by the gut microbiome,” investigators concluded.
Armstrong D, Dregan A, Ashworth M, White P, McGee C, de Lusignan S. Influence of prior antibiotic use on risk of rheumatoid arthritis: case control study in general practice [published online October 3, 2019]. Rheumatology. doi:10.1093/rheumatology/kez452