Tumor necrosis factor alpha in peripheral neuropathy in type 2 diabetes mellitus

Abstract Objective To compare serum levels of tumor necrosis factor alpha (TNF-α) between type 2 diabetes mellitus patients with and without peripheral neuropathy (PN). Also, to study the relation between peripheral nerves conduction velocity and serum level of TNF-α in those patients. Patients and methods This study included three groups with 40 patients in each group. Diabetic PN patients (groups I and II) were compared with diabetic patients without PN (group III). Groups I and II differed in the duration of clinical neuropathy with less than 5 years in group I and more than 5 years in group II. All patients were subjected to general and neurological examination, neuropathy symptom score (NSS), neuropathy disability score (NDS), glycosylated hemoglobin (HbA1c), serum level of TNF-α and both sensory and motor nerve conduction study. Results This study showed raised serum levels of TNF-α in diabetic patients with PN, more with increased duration of neuropathy. TNF-α levels showed statistically significant negative correlation with nerve conduction velocity but positive correlations with each of neuropathy disability score, neuropathy symptom score, and glycosylated hemoglobin. Conclusion TNF-α might be involved in the pathogenesis of diabetic PN, and its serum level might be used as a biomarker for the severity of diabetic PN.