Correlation of peripheral neuropathy with serum vitamin D levels and HbA1C variations in type 2 diabetes mellitus patients

Introduction and Aim: The burden of diagnosed and undiagnosed diabetes will increase in the coming decade. Vitamin D deficiency and HbA1C variability are risk factors for diabetic neuropathy, and the association was studied in the present study. Materials and Methods: Data from 346 Type II diabetes patients reporting in a tertiary care Hospital in North India after approval of the ethics committee was analyzed. Michigan Neuropathy Screening Instrument (MNSI) was used to screen the patients for neuropathy. Vitamin D levels were measured. Four HbA1C levels (once every three months) done at least one-year preceding enrolment in the study were analyzed. A nerve conduction study was performed in the Neurophysiology lab. Data were analyzed using SPSS 21.0. Results: Diabetic peripheral neuropathy (DPN) was present in 54.91% of patients. They had a higher BMI, HbA1C %, fasting blood glucose, and low Vitamin D levels. Nerve conduction studies showed more pronounced changes in patients with severe DPN grades. Variability of HbA1C% correlated positively with the duration of diabetes and BMI, and the relation was negative with vitamin D levels. Vitamin D correlated negatively with duration, Hb A1C variability, and BMI. The correlation of HbA1C variability with motor and sensory conduction velocity and amplitude was negative, and with latency, it was positive. Vitamin D correlated positively with amplitude and conduction velocity and negatively with latency. Conclusion: Nerve conduction study, variability in HBA1C, and Vitamin D levels can act as tools to detect DPN. Vitamin D is a modifiable risk factor that needs monitoring in people with diabetes.