The impact of transcutaneous auricular vagus nerve stimulation on C-reactive protein in patients with chronic low back pain

Background: The purpose of this study is to evaluate the impact of transcutaneous auricular vagus nerve stimulation (tVNS) as an additional therapy to exercise program on C-reactive protein (CRP) in patients with chronic low back pain. Methods: Twenty-two patients between the ages 18-55 with chronic low back pain (CLBP) were randomly divided into 2 groups. The intervention group was assigned 10 sessions of tVNS and 4 sessions of exercise program (EXC + tVNS), while the control group was assigned 4 sessions of exercise program (EXC). Patients were assessed before and 2 weeks after treatments using C-reactive protein (CRP). Results: Transcutaneous auricular vagus nerve stimulation was well tolerated, and no side effects were reported. The mean CRP was slightly increased in both groups. In the intervention group was from 0.22 +/- 0.13 mg/dl to 0.39 +/- 0.30 mg/dl (P=0.074), and in the control group was from 0.21 +/- 0.18 mg/dl to 0.22 +/- 0.18 mg/dl (P=0,813). The between-group comparison showed no significantly different. Following Cohen's D, the effect size of the intervention group (0.735) was higher than the control group (0.055). Conclusion: Based on the analysis data, we conclude that tVNS therapy did not give additional benefit together with exercise on CRP levels in patients with CLBP. It was determined that additional research is required to study the effect of tVNS and exercise independently in CLBP with longer follow-up times and other tVNS methodological approaches.