Serum Neuron-Specific Enolase Levels in Patients With Diabetic Peripheral Neuropathy

Abstract

Background: Based on previous reports that elevated NSE levels may predict diabetic neuropathy, we aimed to validate this association in a well-characterized cohort. Using strict exclusion criteria, standardized clinical scales, and nerve conduction studies, we aimed to evaluate the clinical utility of NSE levels in diabetic patients with and without neuropathic pain. Methods: A total of 144 Type 2 diabetic patients were included in this prospective cross-sectional study. Neuropathic pain symptoms were assessed using the Douleur Neuropathique 4 questionnaire (DN4) and the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS). The diagnosis of diabetic peripheral neuropathy (DPNP) was established based on electrophysiological findings. Patients were divided into three groups as follows: those having neuropathic pain with DPNP (Group 1, n = 60) and without DPNP (Group 2, n = 56). The patients without neuropathic pain (n = 28) were defined as Group 3. Serum NSE levels were derived via electrochemiluminescence immunoassay. Results: There was no significant between-group difference in age or gender (both p > 0.05). The disease duration was significantly longer in patients having neuropathic pain, compared to those without neuropathic pain (p = 0.004). The serum levels of NSE (p < 0.001) and the scores on the DN4 (p = 0.001) and LANSS (p = 0.016) instruments were higher in Group 1 than in Group 2. The NSE level was positively correlated with the LANSS score (r = 0.260, p = 0.005) and independently associated with the presence of DPNP in a multivariate model (OR 1.33, 95% confidence interval 1.12–1.58, p = 0.001). On the ROC analysis, an NSE cutoff of 9.51 ng/mL predicted the presence of DPNP. Conclusion: Elevated serum NSE levels were significantly associated with DPNP in diabetic patients, indicating that NSE may serve as a potential biomarker for large-fiber involvement. However, this finding warrants confirmation in larger, multicenter studies. Copyright