Abstract
Background: It has been demonstrated that a relationship exists between pro-inflammatory cytokine levels and psychological distress. Psychological distress commonly co-exists with back pain and may be detrimental to rehabilitation in such patients undergoing surgery. We aim to establish whether a link exists between psychological distress and increased levels of Interleukin- 6 (IL-6) and it’s soluble receptor (sIL-6r) in patients undergoing surgery for low back pain.
Methods: All individuals selected for spinal fusion or stabilisation surgery, in whom low back pain was the predominant feature, were eligible for inclusion. Participants completed both the Distress and Risk Assessment Method (DRAM) and Hospital Anxiety and Depression Score (HADS) questionnaires pre-operatively. Blood samples for serum IL-6, sIL-6r and high sensitivity C-Reactive Protein (CRP) levels were extracted at recruitment and results were compared with questionnaire findings.
Results: 63 patients were recruited of whom 90.5% had some degree of measurable psychological distress. Patients were divided into two groups based upon the degree of their distress.
Mean IL-6 levels were higher in groups of patients with more distress measured by the DRAM and HADS depression component but were lower in patients with more anxiety. IL-6 receptor levels were higher in patients with raised DRAM and HADS anxiety scores.
No significant correlation between questionnaire responses and cytokine levels was found. A correlation exists between IL-6 and CRP levels even at normal levels of CRP.
Conclusion: There does not appear to be a significant relationship between IL-6 and sIL-6r levels and psychological distress in back pain patients.
Correspondence should be addressed to: Mr John O’ Dowd, SBPR, c/o BOA, The Royal College of Surgeons, 35–43 Lincoln’s Inn Fields, London WC2A 3PE.
