The Effects of Inorganic Nitrate on Carbohydrate and Lipid Metabolism in Type 2 Diabetes: The Protocol of a Randomized Placebo-Controlled Clinical Trial

Abstract

Background and Aim: Decreased bioavailability of nitric oxide (NO) in type 2 diabetes contributes to disrupted pathways of glucose/insulin homeostasis and progression of long-term complications. Due to its ability to convert to NO, inorganic nitrate (NO3) has been recently highlighted as a potential therapeutic agent in type 2 diabetes. Materials and Methods: This research entails a double-blind, randomized, placebo-controlled, phase II clinical trial that will be conducted on 62 type 2 diabetic patients. The patients will be randomized to receive a 6-month daily dose of NO3-rich beetroot powder (5 g/d, contains ~250 mg NO3) or placebo (5 g/d, contains <25 mg NO3). The primary outcome is glycosylated hemoglobin A1c (HbA1c). The study is powered to detect a 0.75% reduction in HbA1c levels between the groups. Fasting serum glucose, serum insulin, lipid parameters, liver enzymes, thyroid function tests and complete blood count will be measured as secondary outcomes. The measurements will be done at baseline, and will be repeated in the fourth, twelfth and twenty-fourth weeks. Protocol of the study was approved by the ethical committee of the Research Institute for Endocrine Sciences of Shahid Beheshti University of Medical Sciences (IR.SBMU.ENDOCRINE.REC.1395.322). The trial was registered in the Iranian Registry of Clinical Trials with the following identification: IRCT20180409039246N1.