Association of Leptin Levels and Disease Activity in Patients with Early Rheumatoid Arthritis

Abstract

Objective: Previous studies have reported a link between metabolic parameters and disease activity in rheumatoid arthritis (RA), although the evidence is limited in early RA. We aimed to investigate the relationship between disease activity and adipocytokine levels in subjects with early RA.

Methods: Forty-seven patients with early RA (symptom duration ≤12 months) were enrolled. Disease activity was determined by DAS28-CRP. Patients were treated with DMARDs according to the EULAR recommendations. Subjects were tested before and five months after treatment.

Results: Early RA patients with high disease activity (DAS28-CRP > 4.9) had greater BMI (31.2 ± 6.8 kg/m² vs. 26.7 ± 4.1 kg/m²; p = 0.006) and higher leptin levels (14.62 ± 15.60 ng/mL vs. 7.82 ± 8.00 ng/mL; p = 0.048). Levels of other adipocytokines were not significantly different. Leptin levels were similar in subjects with mild/moderate disease activity and controls. DAS28-CRP was correlated with leptin (r = 0.303, p = 0.039). Leptin levels decreased significantly after treatment (from 10.86 ± 12.34 ng/mL to 9.22 ± 9.29 ng/mL; p = 0.047) along with insulin levels (from 13.68 ± 21.90 mU/L to 7.09 ± 4.72 mU/L; p = 0.010) and HOMA-IR (from 4.39 ± 9.53 to 1.70 ± 1.38; p = 0.012). HDL cholesterol levels increased (from 41 ± 10 mg/dL48 ± 10 mg/dL; p <0.001).

Conclusion: Leptin levels were associated with disease activity in patients with early RA and these levels decreased after treatment with DMARDs. Further research is needed to elicit leptin's role to regulate disease activity in early RA.

Keywords: RBP4; Rheumatoid arthritis; insulin resistance; leptin; resistin.