Differences in human assumed central sensitization between patients with radiating and non-radiating chronic low back pain: a cross-sectional observational study with special attention to sex.

Abstract

Objectives: Radiating chronic low back pain (CLBP-r) is linked to more pain, more disability, and a lower quality of life than non-radiating chronic low back pain (CLBP-nr). Female patients experience higher pain intensity and greater incidence of pain-related conditions compared to males. The objectives are to compare clinical manifestations potentially associated with human assumed central sensitization (HACS) between: (1) patients with CLBP-r and CLBP-nr and (2) female and male patients.

Methods: In this cross-sectional observational study, 142 patients with CLBP underwent quantitative sensory testing (QST), including mechanical detection thresholds, mechanical pain thresholds, pressure pain thresholds, wind-up ratio, conditioned pain modulation, and the central sensitization inventory (CSI) to assess HACS.

Results: Patients with CLBP-r based on radiculopathy, radicular pain, or segmental pain showed a higher mechanical detection threshold (8.0 [2.0-16.0] vs. 4.0 [1.0-8.0]; p < 0.001) and mechanical pain threshold (64.0 [16.0-128.0] vs.16 [8.0-64.0]; p = 0.001) and lower CSI score (34.2 ± 13.7 vs. 40.6 ± 12.4; p = 0.005) compared to patients with CLBP-nr. Female patients showed lower mechanical pain threshold (32.0 [8.0-64.0]) vs. (96.0 [32.0-128.0]; p < 0.001) and pressure pain threshold (36.0 [24.5-51.8] vs. 65.5 [40.2-83.0]; p < 0.001) than males.

Discussion: Radiating pain and sex appears to influence clinical expressions attributed to HACS. Patients with CLBP-r showed higher mechanical thresholds and female patients presented lower mechanical and pressure pain thresholds. Interpretation should consider the cross-sectional design, the use of two data sets and unresolved clinical relevance.

Clinical trial registration: https://trialsearch.who.int/ identifiers are NL-OMON24108 and NL-OMON24502.