Sodium excretion is higher in patients with rheumatoid arthritis than in matched controls.

OBJECTIVE: It was shown that sodium can promote auto-immunity through the activation of the Th17 pathway. We aimed to compare sodium intake in patients with rheumatoid arthritis (RA) vs. matched controls.

METHODS: This case-control study included 24 patients with RA at diagnosis and 24 controls matched by age, gender and body mass index. Sodium intake was evaluated by 24-hr urinary sodium excretion.

RESULTS: Sodium excretion was greater for patients with early RA (2,849±1,350 vs. 2,182±751.7mg/day, p = 0.039) than controls. This difference remained significant after adjustment for smoking and the use of anti-hypertensive and nonsteroidal anti-inflammatory drugs (p = 0.043). Patients with radiographic erosion at the time of diagnosis had a higher sodium excretion than those without (p = 0.028).

CONCLUSION: Patients with early RA showed increased sodium excretion which may have contributed to autoimmunity.