Evaluation of the Effects of Vitamin D Supplementation on Glycemic Control and Lipid Profile in Normoglycemic and STZ-Induced Type-2 Diabetic Rats

Abstract

The term diabetes mellitus describes a metabolic disorder of multiple aetiologies and is characterized by chronic hyperglycemia with disturbances of carbohydrate, fat and protein metabolism resulting from defects in insulin secretion, insulin action, or both. The current approaches for treatment of diabetes are mostly dependent on insulin and other oral standard drugs, which have their own drawbacks. Thus, micronutrients supplementation is gaining momentum as the quest for management of diabetes continues. Certain micronutrients increase insulin synthesis, secretion and insulin sensitivity thereby improving glycemic control and dyslipidemia. The main objective of this study was to assess the effect of oral vitamin D supplementation on glycemic control and lipid profile in normoglycemic and STZ-induced type 2 diabetic rats. Measurements of biochemical parameters such as intraperitoneal glucose tolerance test, fasting blood glucose level, and serum lipid profile (HDL-c, LDL-c, TC, and TG) were carried out. Glucometer was used to analyze the intraperitoneal glucose tolerance test and interventional (daily) blood glucose levels over time course. At the end of the experiment, Cobasintegra 400 plus was used to analyze the blood glucose levels and lipid profile. The data were analyzed by one-way ANOVA and paired sample students T-test statistical methods. Diabetic rats treated with 400 IU/kg vitamin D had low blood glucose levels (P<0.001 at 6 h vs. day 30) compared with the initial blood glucose level, over time course; and had low blood glucose levels (P<0.001 in all measurement hours vs. day 30) compared with diabetic control group. Diabetic rats treated with 400 IU/kg vitamin D had significant differences of lipid profile (P<0.05 vs. HDL-c, and P<0.01 vs. LDL-c, TG and TC) compared with the control group. This study showed that vitamin D supplement had hypoglycemic effects in normoglycemic rats, but had no effect on their lipid profile. The supplement had pronounced effect in improving glycemic control and dyslipidemia of the diabetic rats. The results from this study can be applied to identify the effect of zinc supplementation in normoglycemic and type-2 diabetics. Besides, this study is significant to know for how much time vitamin D prolongs the action of insulin over time course, thereby to maintain glycemic control and lipid profile in T2DM.

Keywords: Vitamin D, T2DM, insulin sensitivity, IPGTT, fasting blood glucose level, serum lipid profile

Cite this Article

Gidey Gebremeskel, Daniel Seifu. Evaluation of the Effects of Vitamin D Supplementation on Glycemic Control and Lipid Profile in Normoglycemic and STZ-Induced Type-2 Diabetic Rats. Research & Reviews: A Journal of Pharmacology. 2016; 6(2): 24–34p.