The changes of blood-based inflammatory biomarkers after non-pharmacologic interventions for chronic low back pain: a systematic review.

Background: Chronic low back pain (CLBP) is a prevalent and debilitating condition, leading to significant challenges to both patients and the governmental healthcare system. Non-pharmacologic interventions have received increasing attention as potential strategies to alleviate chronic low back pain and improve patient outcomes. The aim of this systematic review was to comprehensively assess the changes in blood inflammatory biomarkers after non-pharmacologic interventions for CLBP patients, thus trying to understand the complex interactions between non-pharmacologic interventions and inflammatory biomarker changes in CLBP.

Methods: A thorough search (from January 1st, 2002 to October 5th, 2022) of PubMed, Medline (platform Web of Science), and the Cochrane Library (platform Wiley Online Library) were conducted, and inclusion criteria as well as exclusion criteria were refined to selection of the studies. Rigorous assessments of study quality were performed using RoB 2 from Cochrane or an adaptation of the Downs and Black checklist. Data synthesis includes alterations in inflammatory biomarkers after various non-pharmacologic interventions, including exercise, acupressure, neuro-emotional technique, and other modalities.

Results: Thirteen primary studies were included in this systematic review, eight randomized controlled trials, one quasi-randomized trial, and four before-after studies. The interventions studied consisted of osteopathic manual treatment (one study), spinal manipulative therapy (SMT) (three studies), exercise (two studies), yoga (two studies) and acupressure (two studies), neuro-emotional technique (one study), mindfulness-based (one study) and balneotherapy study (one study). Four studies reported some changes in the inflammatory biomarkers compared to the control group. Decreased tumor necrosis factor-alpha (TNF-α) after osteopathic manual treatment (OMT), neuro-emotional technique (NET), and yoga. Decreased interleukin (IL)-1, IL-6, IL-10, and c-reactive protein (CRP) after NET, and increased IL-4 after acupressure. Another five studies found changes in inflammatory biomarkers through pre- and post-intervention comparisons, indicating improvement outcomes after intervention. Increased IL-10 after balneotherapy; decreased TNF-α, IL-1β, IL-8, Interferon-gamma, interferon-γ-induced protein 10-γ-induced protein 10 after exercise; decreased IL-6 after exercise and SMT; decreased CRP and chemokine ligand 3 after SMT.

Conclusion: Results suggest a moderation of inflammatory biomarkers due to different non-pharmacologic interventions for CLBP, generally resulting in decreased pro-inflammatory markers such as TNF-α and IL-6 as well as increased anti-inflammatory markers such as IL-4, thus revealing the inhibition of inflammatory processes by different non-pharmacologic interventions. However, a limited number of high-quality studies evaluating similar interventions and similar biomarkers limits the conclusion of this review.