Correlation of Vitamin B12 Status, Glycemic Control, and Metabolic Profile with Nerve Conduction Velocity in Type 2 Diabetes Mellitus

Abstract

Introduction: The neurological consequences of type 2 diabetes mellitus develops insidiously, with abnormalities in peripheral nerve function preceding the appearance of overt clinical symptoms. Nerve conduction studies provide an objective, quantifiable measure of peripheral nerve function that may detect nerve dysfunction before symptoms appear. This study examined how vitamin B12, glycemic control, and lipid profile relate to nerve conduction velocity in patients with type 2 diabetes. Methods: Patients with and without type 2 diabetes were recruited in a cross-sectional study. Anthropometric data, fasting lipid profile, glycated haemoglobin, serum vitamin B12, and nerve conduction velocity were recorded for all participants, and Pearson correlation coefficients were calculated between nerve conduction velocity and each biochemical parameter. Results: Patients with diabetes had significantly higher body mass index, poorer glycemic control, lower serum vitamin B12, a more atherogenic lipid profile, and slower sural nerve conduction velocity than controls. Nerve conduction velocity correlated positively with vitamin B12 and negatively with glycated haemoglobin, triglycerides, very-low-density lipoprotein, and total cholesterol, while high-density and low-density lipoprotein showed no significant correlation. Discussion: Glycemic control showed the strongest association with nerve conduction, followed by vitamin B12 and triglyceride-rich lipoproteins, supporting a model in which hyperglycaemia, dyslipidemia, and B12 status act together, rather than glycaemia alone, to influence peripheral nerve function. Conclusion: Assessing vitamin B12 status and lipid profile alongside glycated haemoglobin may help identify patients with type 2 diabetes at greater risk of nerve dysfunction and highlights additional, correctable targets for preserving nerve function, over and above glycemic control alone.

Keywords: Type 2 diabetes mellitus, diabetic peripheral neuropathy, nerve conduction velocity, vitamin B12, dyslipidemia.