Association Between FAM134B and Diabetic Peripheral Neuropathy in Type 2 Diabetes: A Double-Center Case-Control Study

Purpose: The role of FAM134B in neurological diseases has received significant attention; however, its role in diabetic peripheral neuropathy (DPN) remains unexplored. This study investigated the association between plasma FAM134B levels and DPN while assessing its diagnostic value. Methods: The study included 128 inpatients with type 2 diabetes divided into DPN (n = 68) and non-DPN (n = 60) groups. FAM134B expression was determined via qRT-PCR analysis of plasma FAM134B mRNA level. All clinical data were retrieved from the Hospital Information System. SPSS and R were used for statistical analyses. Results: Plasma FAM134B mRNA levels were significantly higher in the DPN than in the non-DPN group (p < 0.001). Increased FAM134B mRNA levels were strongly linked to increased odds of DPN, with the highest quartile showing a significant risk elevation (Odds Ratio [OR] = 21.42, 95% Confidence Interval: 4.86-96.46, p < 0.001). Restricted cubic spline analysis confirmed a non-linear relationship, thereby identifying a critical threshold of FAM134B mRNA levels at 2.53, above which the risk sharply increased (adjusted OR = 3.11, p = 0.006). Subgroup analysis showed consistent associations across most subgroups, with a notable difference in males (p = 0.038). The diagnostic performance was moderate (Area Under the Curve [AUC] = 0.756). While adding FAM134B mRNA to the model did not dramatically improve the AUC, it significantly enhanced reclassification metrics (Net Reclassification Improvement = 0.165, Integrated Discrimination Improvement = 0.095, p < 0.05), thereby highlighting its clinical value. Conclusion: Increased FAM134B expression positively correlated with the odds of DPN, and may act as a promising target for diagnostic and therapeutic interventions.