The Effect of Dietary Nitrate Supplementation on Ability of Individuals With Type 2 Diabetes to Perform Exercise

Study Overview
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Brief Summary
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The investigators are conducting a research study to see if increasing the amount of nitrate (a substance found in large quantities in certain vegetables) in the diet can increase the ability of individuals with Type 2 diabetes (T2D) to perform exercise. Some people with T2D find exercise more uncomfortable than individuals who do not have T2D. This may be explained by the experimental studies showing that T2D can result in reductions in the supply of oxygen to the muscles. Studies have also shown that for a given level of activity, individuals with T2D will be much closer to their maximum exercise capacity than healthy individuals. Dietary nitrate may have two important beneficial effects in individuals with T2D: 1) The effects of dietary nitrate on the responses to exercise may have a significant impact on the ability of individuals with Type 2 diabetes to perform daily tasks and exercise more comfortably and 2) experimental studies suggest that increased nitrate consumption has been shown to reduce the amount of oxygen required for a given level of exercise. The investigators will recruit 60 individuals with T2D. These people will take part in a randomised crossover design study where they will be asked to drink normal beetroot juice (rich in nitrate) and nitrate depleted beetroot juice, prior to performing two different walking exercise tasks (a six minute walk and repeated, low intensity treadmill walking). This study aims to determine if dietary nitrate supplementation reduces the amount of oxygen required for a given level of exercise in individuals with T2D. To test brain function individuals will be asked to perform a standard computerised decision making task following consumption of the nitrate rich and nitrate depleted juices.

Official Title
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The Effect of Dietary Nitrate Supplementation on Ability of Individuals With Type 2 Diabetes to Perform Exercise

Conditions
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Type 2 Diabetes

Intervention / Treatment
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* Dietary Supplement: Beetroot


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients with T2D (as defined by WHO) of at least 5 years duration between the ages of 35-75 will be invited. Exclusion Criteria: patients with significant renal impairment (eGFR<30) uncontrolled hypertension BMI<25 or >35 are taking regular organic nitrates, nicorandil, or thiazolidinidiones, or any medication which may interfere with data interpretation or safety who have had a myocardial infarction or cerebro-vascular event who smoke, or any other serious medical condition which would interfere with data interpretation or safety will be excluded from participation.

Ages Eligible for Study
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Minimum Age: 35 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Health Services Research
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: T2DM<br>Crossover design where participants will start in the Beetroot juice condition, and after a washout period, move into the other condition. | Dietary Supplement: Beetroot<br> <br> * Other names: James Whites Drinks beetroot sports shot;|
| Placebo Comparator: Placebo<br>Crossover design where participants will start in the placebo condition, and after a washout period, move into the other condition. | Dietary Supplement: Beetroot<br> <br> * Other names: James Whites Drinks beetroot sports shot;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pulmonary gas exchange via MedGraphics CardiO2 Cardiopulmonary Diagnostic Systems | Pulmonary gas exchange was measured during treadmill walking exercise (MedGraphics CardiO2 Cardiopulmonary Diagnostic Systems, St. Paul, MN, USA). Prior to each testing session the analysers were calibrated using known concentrations. The volume transducer was calibrated using a 3-litre syringe (Hans Rudolph, Kansas City, MO, USA). When we refer to the oxygen cost of exercise we are referring to end exercise oxygen uptake. | 3 x 6 minutes of gas exchange per participant, twice, 10-14 days apart | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Functional capacity measured by 6-Minute Walking Test (6MWT) |  | 6 minutes walking per participant per visit |