Race-specific associations: inflammatory mediators and chronic low back pain

Chronic low back pain (cLBP) is a global health crisis that disproportionately burdens non-Hispanic Black (NHB) individuals, compared with those who identify as non-Hispanic White (NHW). Despite the growing personal and societal impact of cLBP, its biological underpinnings remain poorly understood. To elucidate the biological factors that underlie the racial disparities in cLBP, this study sought to determine whether inflammatory mediators associated with pain interference (PI), pain at rest (PAR), and movement-evoked pain (MEP) differ as a function of racial identity. Blood samples were collected from 156 individuals with cLBP (n = 98 NHB participants, n = 58 NHW participants). Enzyme-linked immunosorbent assay and multiplex assays were used to quantify concentrations of proinflammatory (fibrinogen, C-reactive protein [CRP], serum amyloid A, tumor necrosis factor α [TNF-α], and interleukin [IL]-1α, IL-1β, and IL-6) and anti-inflammatory markers (IL-4 and IL-13). Spearman rho correlations were used to assess associations among markers of inflammation and PI, PAR, and MEP using the Brief Pain Inventory-Short Form. Analyses revealed that for NHW patients, CRP, serum amyloid A, and IL-6 were positively associated with cLBP outcomes and IL-4 was inversely associated with PAR and MEP. However, for NHB patients, only IL-1α was positively associated with PAR. Our findings suggest that, while there are associations between inflammation and cLBP outcomes, the biomarkers that underlie the inflammation could very well differ as a function of racialized minority group. However, more research with racially inclusive samples is needed to elucidate the mechanisms that may contribute to racial disparities in cLBP.