Screening and Assessment of Polyneuropathy in Diabetic Patients and the Effect of Vitamin B12 Administration on the Course of Neuropathy

Abstract

Introduction: Diabetic polyneuropathy is a specific form of axonal neuropathy that includes peripheral neuropathy of sensory nerve fibers with eventual autonomic and motor involvement. Screening and identification of polyneuropathy offers a crucial opportunity to prevent further complications by using vitamin B12. Aim: To assess the occurrence of polyneuropathy in patients with type I and type II diabetes mellitus and evaluate the effect of vitamin B12 administration on the course of polyneuropathy. Materials and Methods: This prospective open label study was carried out in 50 patients in medicine Outpatient Department (OPD) at Smt. Kashibai Navale Medical College and General Hospital, tertiary care hospital in Pune, Maharashtra, India. Fifty patients, aged 18-60 years of type I and type II diabetes mellitus were screened for polyneuropathy from June 2016 to June 2017. Thirty two out of 50 patients showed evidence of neuropathy based on either of the parameters including Diabetic Neuropathy Symptom (DNS) questionnaire; Survey of Autonomic Symptoms (SAS) questionnaire; standardized nerve conduction studies and peripheral neuropathy testing {ankle reflex and Diabetic Neuropathy Examination (DNE)}. These 32 patients were given a tablet methylcobalamin 1.5 mg daily for three months after which all the above parameters were repeated to evaluate the course of neuropathy by paired t-test. Results: Mean baseline DNS score was 1.63±0.75 which improved significantly (p=0.032) to 1.41±0.80 after three month methylcobalamin treatment. Mean baseline SAS score was 4.94±2.60 while post methylcobalamin therapy it was 4.59±2.39, suggesting significant improvement (p=0.009). Nerve conduction velocity of ulnar nerve in every patient was normal before and after methylcobalamin therapy. Mean baseline DNE score (3.34±1.73) improved significantly (p=0.027) to 3.06±1.54 after completing three months of methylcobalamin therapy. Conclusion: Strong positive association was found between diabetes-Vitamin B12 deficiency and polyneuropathy. Administration of methylcobalamin therapy is warranted as it significantly improves symptoms of polyneuropathy in diabetic patients.

Keywords

• diabetic neuropathy
• methylcobalamine
• survey of autonomic symptoms