It is also useful to mention that the LF/HF ratio in patients with active disease was higher than in controls and in patients with a CRP ≤ 5 mg/L (4.01 ± 2.34 vs. 3.90 ± 2.03 vs. 3.19 ± 1.49), suggesting an excess of sympathetic activity associated with the inflammatory status of the RA patient, even though this increase was not statistically significant. This evidence concerns the gene CRP and rheumatoid arthritis.