Modulation of Neurturin Expression by Lumbosacral Spinal Stenosis, Lifestyle Factors, and Glycemic Dysregulation.

Background/Objectives: Lumbosacral spinal stenosis (LSS) is a degenerative condition characterized by narrowing of the spinal canal and associated neuropathic pain. While mechanical compression is well-characterized, the molecular mechanisms contributing to symptom severity remain poorly understood. Neurturin (NRTN), a member of the glial cell line-derived neurotrophic factor family, has emerged as a potential mediator of neural plasticity and nociception, but its role in spinal stenosis is largely unexplored. Methods: We analyzed NRTN mRNA and protein expression in ligamentum flavum samples from 96 patients undergoing surgery for LSS and 85 non-degenerative postmortem controls. Quantification was performed using real-time quantitative polymerase chain reaction (RT-qPCR), enzyme-linked immunosorbent assay (ELISA), Western blotting, and immunohistochemistry. Pain severity Visual Analog Scale (VAS), body mass index (BMI), diabetes, smoking, and alcohol use were assessed as modulators of NRTN expression. Results: NRTN expression was significantly elevated in LSS patients versus controls at both transcript and protein levels (p < 0.05). NRTN levels positively correlated with pain intensity (VAS; ANOVA p = 0.032 for mRNA, p = 0.041 for protein). Multivariate regression identified BMI (β = 0.50, p = 0.015) and diabetes (β = 0.39, p = 0.017) as independent predictors of increased NRTN expression. Alcohol use also showed a positive association (p = 0.046), while smoking showed no significant independent effect. Conclusions: Neurturin is upregulated in ligamentum flavum tissue from LSS patients and correlates with pain severity and metabolic risk factors. These findings suggest NRTN as a potential biomarker and therapeutic target in degenerative spine disease. Further longitudinal and mechanistic studies are warranted to elucidate its role in chronic pain and neuroinflammation.