THERAPEUTIC INSIGHTS OF VITAMIN D IN THE MANAGEMENT OF TYPE 2 DIABETIC NEUROPATHY

Abstract

Background: Diabetes mellitus is derived from the Greek term diabetes, meaning siphon - to pass through, and the Latin word mellitus, meaning sweet. The most common consequence is neuropathy, namely distal symmetric polyneuropathy (referred to as diabetic neuropathy in this primer). Diabetic neuropathy is a loss of sensory function that begins distally in the lower limbs and is accompanied by discomfort and significant morbidity. Over time, at least 50% of diabetics develop diabetic neuropathy. The study aimed to identify the impact of oxidative markers (glutathione (GSH), advanced oxidation protein products (AOPP), advanced glycation end products (AGEs), malondialdehyde (MDA), and inflammatory biomarkers (interleukin-6, IL-6, TNF-α, and myeloperoxidase (MPO)) on the development of diabetic neuropathy along with routinely used biochemical parameters. Materials and Method: This was a case-control study. All the selected patients were screened and enrolled by convenient non-probability sampling technique at the social security hospital Lahore. Written Informed consent was obtained before enrollment of the study subjects. A total of 150 patients enrolled in the study, and they were divided into three groups, 50 subjects with type 2 diabetic neuropathy taking oral antidiabetics only and 50 diagnosed diabetic neuropathy (DN) subjects taking adjunct oral vitamin D therapy, 50 healthy individuals as a control group. Five mL of venous blood sample was taken from the antecubital vein of each participant. Statistical analysis was performed by GraphPad. The results of all variables were evaluated by using one-way ANOVA. Results: The mean value of biochemical parameters (WBCs, platelets, HbA1c, BSF, triglycerides, LDL, HDL, serum creatinine, and liver function tests, were increased in diabetics with neuropathy compared to the control and treated group. There was a significant improvement in these parameters after vitamin D therapy, the mean values of MDA, AGE, and AOPPs in type 2 diabetics with neuropathy were significantly increased compared to the control group and a significant decrease was noticed after vitamin D supplementation in the vitamin D group. GSH level was decreased in type 2 diabetics with DPN patients as compared to the control group. A significant increase in GSH was noticed in the vitamin D group. In addition, IL-6, TNFα, and MPO levels were also increased in the case of diabetic neuropathy as compared to controls. However, a significant decrease in the levels was seen in the vitamin D group. Conclusions: ROS-mediated injuries in type 2 diabetics with neuropathy can be prevented by the restoration of an antioxidant defense system, through the administration of antioxidant agents and micronutrients like vitamin D as an adjunct therapy along with antidiabetics drugs insulin/oral antidiabetics. Moreover, increased levels of inflammatory mediators are responsible for enhancing inflammation in patients with diabetic neuropathy. Vitamin D helps to decrease the levels of inflammatory biomarkers in subjects with diabetic neuropathy.