Abstract # 3121 Longitudinal analysis of inflammatory, psychological, and sleep-related factors following an acute low back pain episode—the good, the bad, and the ugly

Abstract

Systemic inflammation may contribute to the transition from acute to chronic low back pain (LBP). Whether changes present early or develop over time is unclear. This study aimed to determine whether systemic cytokines/CRP during acute LBP were associated with recovery at 6 months. Acute LBP (<2 weeks since onset) and pain-free participants provided blood for assessment of CRP, TNF, IL-6 and IL-1β after completing questionnaires related to pain/disability, sleep and psychological status. LBP participants repeated measurements at 6 months. Biomarkers were compared at baseline between LBP and control participants, and longitudinally (baseline/6 months) between unrecovered (⩾ pain and disability), partially recovered (<pain and/or disability) and recovered (no pain and disability) participants at 6 months. We assessed baseline patterns of inflammatory, psychological, sleep and pain data using hierarchical clustering and related the clusters to recovery (%change in pain) at 6 months. Baseline CRP was higher in acute LBP than controls. In LBP, baseline CRP was higher in the recovered than non-recovered groups. Conversely, TNF was higher at both time-points in the non-recovered than recovered groups. Two subgroups were identified that associated with more (“inflammatory and poor sleep”) or less (“high TNF and depression”) recovery. In summary, high inflammation (CRP/IL-6) was associated with good recovery, but specific elevation of TNF, with or without depressive symptoms, was associated with bad recovery. Depression and TNF may have a two-way relationship.