Abstract: Objective To explore the correlations of the levels of serum neurofilament light chain (NfL), homocysteine (Hcy), and meteorin-like protein (Metrnl) with diabetic peripheral neuropathy (DPN) in the elderly with type 2 diabetes mellitus(T2DM), so as to provide new reference indicators for the early diagnosis of DPN in the elderly. Methods From July 2022 to June 2024, 81 elderly patients with T2DM admitted to NO.215 Hospital of Shaanxi Nuclear Industry were divided into DPN group (n=31) and non-DPN group (n=50) according to whether DPN occurred. The general clinical information of all the patients were collected, and enzyme linked immunosorbent assay was used to detect the serum levels of NfL, Hcy, and Metrnl. Multivariate logistic regression was used to analyze the influencing factors for DPN in the elderly T2DM patients. The diagnostic value of each indicator for DPN was analyzed by the receiver operating characteristic(ROC) curve. Results The course of disease in DPN group was significantly longer than that in non-DPN group(P<0.05). The levels of NfL, Hcy and fasting plasma glucose(FPG) in DPN group were higher and the levels of Metrnl and fasting C-peptide were lower than those in non-DPN group (P<0.05). Multivariate logistic regression suggested that long disease duration, high levels of FPG, NfL and Hcy were risk factors for DPN in elderly T2DM patients, while high levels of fasting C-peptide and Metrnl were protective factors for DPN (P<0.05). The area under curve (AUC) of combined diagnosis was 0.968, with a sensitivity and specificity of 93.55% and 90.00%, respectively, which was better than those of individual diagnosis (P<0.05). Conclusions The serum levels of NfL and Hcy are significantly increased, and the Metrnl level is significantly decreased in elderly DPN patients. The three indicators could be used as early diagnostic indicators for DPN, and the combined detection is of great significance to improve the diagnostic efficacy.

Key words: neurofilament light chain, homocysteine, meteorin-like protein, type 2 diabetes mellitus, peripheral neuropathy