The association of vitamin D level with diabetic peripheral neuropathy: A comparative cross- sectional study

Abstract

Background & Objective: Diabetic peripheral neuropathy (DPN) is a common complication of type 2 diabetes mellitus (DM). Vitamin D deficiency has been shown to be prevalent among patients with type 2 DM, particularly in those with DPN. This study aimed to look at the association of serum vitamin D level with peripheral neuropathy in patients with type 2 DM. Methods: This was a comparative cross- sectional study conducted in a tertiary hospital in Malaysia. Fifty diabetic patients with DPN and fifty diabetic patients without DPN were recruited. Serum vitamin D level was determined by measuring 25-hydroxyvitamin D [25(OH)D] level. The patients were clinically assessed and screened with Diabetic Neuropathy Symptoms score. Nerve conduction study was performed for patients with DPN. Results: The serum 25(OH)D level was significantly lower in patients with DPN (11.81 [9.09-18.06] vs 18.63 [11.25-22.63] ng/ml; p=0.006). Multiple logistic regression analysis showed that DPN was significantly associated with higher BMI, longer duration of DM, insulin usage and serum 25(OH)D level. The usage of fibrates had negative association with DPN. Subgroup analysis of the DPN group showed that patients with painful DPN had significant lower serum 25(OH)D level (p<0.001) and the clinical severity of DPN negatively correlated with serum 25(OH)D level (p=0.015). Conclusion: Vitamin D deficiency is associated with DPN in patients with type 2 DM. In addition, patients with painful DPN tend to have significantly lower serum 25(OH)D level.