Association of Nociplastic Pain Features with Function in Aging Veterans with Chronic Low Back Pain

Chronic low back pain (CLBP) affects nearly one million Veterans and is a leading cause of disability. Nociplastic pain, characterized by altered central nervous system processing, widespread pain and sleep disturbance, may negatively impact treatment response in this population, yet remains underrecognized.

Determine the prevalence and association of nociplastic features with function among aging Veterans with CLBP.

Cross-sectional survey of Veterans aged 50-89 years with CLBP identified through VA administrative data. A stratified random sampling design oversampled women and Black/African-American veterans.

Of 800 invited, 361 responded (45.1% response rate); after excluding those without CLBP, 342 participants were included (mean age 69.2 years, 19.2% women, 17.8% Black/African-American).

Nociplastic features were assessed using the Fibromyalgia Survey Questionnaire to calculate a fibromyalgia severity score. Function was assessed via the Veterans RAND 12-Item Health Survey (VR-12) Physical (PCS) and Mental Component Summary (MCS) scores. Regression models adjusted for sociodemographics, comorbidities, opioid use, pain intensity, and surgical history.

Nociplastic characteristics were highly prevalent (fibromyalgia severity score mean 11.3, SD 5.9). Overall, 36% screened positive for fibromyalgia via American College of Rheumatology criteria, however, over half of respondents aged 50-64 years met criteria. Widespread pain was common; on average, pain was experienced in six discrete locations. Physical function was severely impaired (mean VR-12 PCS 30.2, nearly 2 SD below population norms); psychological function was moderately impaired (mean MCS 45). Higher fibromyalgia severity scores independently associated with poorer physical function (β= -0.30 per point increase, 95% CI -0.49, -0.12; p = 0.0014) and psychological function (β= -0.64, 95% CI -0.93, -0.35; p < 0.001) after adjustment. Gender, BMI, comorbidities, and back surgery were also associated with poorer function.

Nociplastic features are highly prevalent in aging Veterans with CLBP and demonstrate a dose-response relationship with impaired functioning. Recognition may guide more effective, mechanism-based treatment approaches and reduce harm.