Serum levels of TNF-α in peripheral neuropathy patients and its correlation with nerve conduction velocity in type 2 diabetes mellitus

Abstract Objective To compare serum levels of TNF-α in patients of peripheral neuropathy and patients without neuropathy in type 2 diabetes mellitus. Material and methods This cross sectional study was conducted in diagnosed type 2 diabetes mellitus patients. They were divided in groups, Group I ( n  = 37) with clinically detectable diabetic peripheral neuropathy of shorter duration and Group II ( n  = 27) with clinically detectable diabetic peripheral neuropathy of longer duration. They were compared with patients without clinical neuropathy ( n  = 22), clinical diagnosis was based on neuropathy symptom score (NSS) and neuropathy disability score (NDS) for signs. Blood samples were collected for baseline investigations and estimation of serum TNF-α. Nerve conduction velocity was measured in both upper and lower limbs. Median, Ulnar, Common Peroneal and Posterior Tibial nerves were selected for motor nerve conduction study and Median and Sural nerves were selected for sensory nerve conduction study. Results The comparisons were done between various clinical and biochemical parameters in clinically detectable and undetectable peripheral neuropathy groups of type 2 diabetes mellitus. The study showed raised serum levels of TNF-α in peripheral neuropathy patients and significant correlation with nerve conduction velocity. Conclusion High level of TNF-α in serum of T2DM patients with neuropathy shows possible contribution in development of neuropathy. Due to its independent association this cytokine might be used as biomarker for diabetic peripheral neuropathy.