Effects of inorganic nitrate on glucose levels in obese subjects
Research type
Research Study
Full title
Effects of inorganic nitrate administration on glycaemic control and oxidative stress in young and older-aged obese subjects: a cross-over, double-blind randomised clinical trial
IRAS ID
129696
Contact name
Mario Siervo
Contact email
Sponsor organisation
The Newcastle upon Tyne Hospitals NHS Foundation Trust
ISRCTN Number
ISRCTN42776917
Research summary
The problem of obesity and diabetes is increasing worldwide. Diabetes seems to be caused by a metabolic defect in the insulin action in various organs (liver, muscle, pancreas) called insulin resistance. A small molecule in the body called Nitric Oxide is continuously produced by cells in the arteries. This molecule controls blood pressure but is also involved in the regulation of sugar levels. Nutrition is important for the prevention and treatment of diabetes. Dietary factors known to have an effect on sugar levels are for example whole-grains, fish oils and vegetables. Inorganic nitrate is a dietary component present at higher concentration in green leafy vegetables and beetroot. Recent research has showed that inorganic nitrate is associated with a decrease in blood pressure (BP). The effect seems to be mediated by an increase in nitric oxide in the body. Whether inorganic nitrate will also have an effect on sugar levels in obese subjects is currently not known. The primary aim of this study is to investigate the effects of inorganic nitrate intake on blood glucose and insulin concentrations in young and older-aged obese subjects. We will also test the association between changes in blood glucose with other biological parameters such as oxidative stress and arterial health. We will recruit twenty obese subjects in total who will be divided according to their age in young (20-35 years) and older (55-70 years). Subjects will attend two three-hour visits. They will receive a glucose drink and then in randomised order a solution of either inorganic nitrate or placebo. Measurements will be performed before the oral doses and then take repeated measurements afterwards. We will measure BP, heart rate and endothelial function. We will take a number of blood samples (7 in total for each visit) to measure glucose, insulin, oxidative stress and telomerase activity.
REC name
Yorkshire & The Humber - South Yorkshire Research Ethics Committee
REC reference
13/YH/0253
Date of REC Opinion
13 Aug 2013
REC opinion
Favourable Opinion