Objective: The aims of this study were to determine the course of plasma levels of inflammatory mediators (interleukin 6 [IL-6], tumor necrosis factor α [TNF-α], soluble TNF receptor 1 [sTNF-R1]) and the severity of low-back pain (LBP) over 6 to 12 months after an acute episode of LBP in elderly women and to establish an association between inflammatory mediators and LBP recovery.
Design: This was a longitudinal study of a subsample (155 elderly women with acute LBP, aged ≥65 years) of the international Back Complaints in the Elders cohort study. Plasma levels of IL-6, TNF-α, and sTNF-R1 were measured using enzyme-linked immunosorbent assays and pain severity using the numerical pain scale.
Results: There was a decrease in the severity of LBP (P = 0.033) and in the levels of IL-6 and TNF-α (P < 0.001) and an increase in sTNF-R1 (P < 0.001) in the first year after an acute episode of LBP. The probability of occurrence of pain relief at the 12-month follow-up was 2.22 times higher in elderly women who had low levels of IL-6 (<1.58 pg/mL) at baseline.
Conclusions: Our findings showed a relationship between inflammation and LBP by establishing that low IL-6 plasma levels preceded outcome (LBP recovery), supporting the concept that proinflammatory cytokines promote pain.
From the Rehabilitation Sciences Program, Physical Therapy Department, Federal University of Minas Gerais, Belo Horizonte (BZQ, NMBR, RAL, AGPA, RMFVSJ, AAOL, JPS, LSMP); Federal University of Alfenas, Alfenas (DSP); and Federal University of Juiz de Fora, Juiz de Fora (DCF), Minas Gerais, Brazil.
All correspondence and requests for reprints should be addressed to: Bárbara Zille Queiroz, PhD, Av. Antônio Carlos, 6627, CEP 31270-901, Belo Horizonte, Minas Gerais, Brazil.
BZQ reports grants from FAPEMIG, CNPq, CAPES, and Pró Reitoria de Pesquisa da Universidade Federal de Minas Gerais during the conduct of the study.
Financial disclosure statements have been obtained, and no conflicts of interest have been reported by the authors or by any individuals in control of the content of this article.
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