Neuroinflammation and metabolic dysfunction drive nerve conduction deficits in diabetic neuropathy: Clinical and in...

Diabetic neuropathy is a debilitating complication of type 2 diabetes mellitus (T2DM), largely driven by systemic inflammation and metabolic disturbances. This cross-sectional study assessed the relationship between interleukin-6 (IL-6), vitamin B12, lipid profile, and nerve conduction parameters in T2DM patients with and without neuropathy. Sixty participants were divided evenly into two groups: T2DM without neuropathy (control) and T2DM with confirmed neuropathy (case). Biochemical parameters measured included fasting and postprandial glucose, glycated hemoglobin (HbA1c), vitamin B12, IL-6, renal function, and detailed lipid profiling. Nerve conduction studies assessed sensory and motor nerves in upper and lower limbs. The neuropathy group showed higher IL-6 levels, lower vitamin B12 concentrations, and an atherogenic lipid profile characterised by increased triglycerides, VLDL, and non-HDL cholesterol. Marked reductions in nerve conduction velocities were evident in both sensory and motor nerves, especially in the common peroneal and posterior tibial nerves, which had high diagnostic accuracy with AUC values of 0.88 and 0.84, respectively. Univariate regression identified IL-6 as significantly associated with decreased conduction velocity in radial sensory and posterior tibial nerves. Supporting these clinical findings, in silico pathway enrichment analyses highlighted key roles for IL-6 signalling, vitamin B12 metabolism, lipid pathways, and myelination in diabetic neuropathy pathogenesis. These integrated data underscore inflammation and metabolic dysfunction as pivotal drivers, with IL-6 and nerve conduction studies serving as promising early biomarkers and therapeutic targets.