Working…
ClinicalTrials.gov
ClinicalTrials.gov Menu

The Effect of Dietary Nitrate on Blood Pressure, Insulin Sensitivity, and Vascular Function in Type 2 Diabetes

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
 
ClinicalTrials.gov Identifier: NCT04076007
Recruitment Status : Completed
First Posted : September 2, 2019
Last Update Posted : September 2, 2019
Sponsor:
Information provided by (Responsible Party):
University of Exeter

Brief Summary:
Dietary nitrate supplementation has previously been shown to reduce blood pressure in healthy volunteers. The investigators wished to see whether this would be replicated in subjects with type 2 diabetes and age matched healthy controls.

Condition or disease Intervention/treatment Phase
Diabetes Hypertension Dietary Supplement: Beetroot juice Dietary Supplement: Nitrate depleted beetroot juice Not Applicable

  Show Detailed Description

Layout table for study information
Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 44 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: The Effect of Dietary Nitrate on Blood Pressure, Insulin Resistance and Vascular Function in Type 2 Diabetes
Study Start Date : December 2009
Actual Primary Completion Date : August 2012
Actual Study Completion Date : February 2015

Resource links provided by the National Library of Medicine


Arm Intervention/treatment
Active Comparator: Active
Nitrate rich beetroot juice (7.5 mmol nitrate in 250mls beetroot juice) once daily.
Dietary Supplement: Beetroot juice
Placebo Comparator: Placebo
Nitrate depleted beetroot juice (0.002 mmol nitrate in 250 ml beetroot juice) once daily.
Dietary Supplement: Nitrate depleted beetroot juice



Primary Outcome Measures :
  1. 24 hour Ambulatory Blood Pressure monitoring after 2 weeks active juice [ Time Frame: 2 weeks ]
    24 hour average systolic, diastolic blood pressure in mm Hg

  2. 24 hour Ambulatory Blood Pressure monitoring after 2 weeks placebo juice [ Time Frame: 2 weeks ]
    24 hour average systolic, diastolic blood pressure in mm Hg


Secondary Outcome Measures :
  1. Brachial artery Flow mediated vasodilation [ Time Frame: After 2 weeks active juice and after 2 weeks placebo juice ]
    Following release of a downstream occlusive cuff the percentage change from baseline in the diameter of the brachial artery is recorded.

  2. Microvascular response to Iontophoresis of Acetylcholine and Sodium Nitroprusside [ Time Frame: After 2 weeks active juice and after 2 weeks placebo juice ]
    Skin blood flux will be measured following iontophoresis of the vasodilators acetylcholine and sodium nitroprusside. Peak flux and area under the curve measured in arbitrary units of flux.

  3. Peak reactive hyperemia [ Time Frame: After 2 weeks active juice and after 2 weeks placebo juice ]
    Assessment of morphology of peak blood flow following release of occlusion of lower limb arterial supply. Measurements include time to peak blood flow (seconds), time to return to base line flow (seconds) and categorisation of peak shape.

  4. Maximum hyperemia in response to heating [ Time Frame: After 2 weeks active juice and after 2 weeks placebo juice ]
    Peak blood flux in skin in response to localised heating to 42 degrees C

  5. Cognitive function [ Time Frame: After 2 weeks active juice and after 2 weeks placebo juice ]
    E-prime software will be used to determine the percentage accuracy and response time in seconds to a six separate cognitive challenges

  6. Insulin sensitivity [ Time Frame: After 2 weeks active juice and after 2 weeks placebo juice ]
    A hyperinsulinemic isoglycaemic clamp will be used to determine the amount of glucose required to maintain isoglycaemia (mg/kg/min)



Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.


Layout table for eligibility information
Ages Eligible for Study:   35 Years to 75 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Patients with type II diabetes (as defined by WHO) of at least 5 years duration between the ages of 35-75 known to have blood pressure above 125mmHg systolic and/or 85mmHg diastolic, or who are taking one or two antihypertensive drugs will be invited.

Healthy Control inclusion/exclusion criteria

Inclusion criteria

  • Age and sex matched for participants with diabetes
  • Not on any regular medication, excluding the oral contraceptive pill
  • Able to give informed consent

Exclusion Criteria:

  • Patients with significant renal impairment (eGFR<30), uncontrolled hypertension, BMI<25 or >35, are taking regular organic nitrates, nicorandil, glitazones, phosphodiesterase inhibitors, 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

Exclusion Criteria

  • Antibiotic therapy within the preceding two weeks
  • Myocardial infarction or cerebro-vascular event within the preceding three months
  • Current smoker
  • Any other medical condition which would interfere with data interpretation or safety.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04076007


Locations
Layout table for location information
United Kingdom
NIHR Exeter Clinical Research Facility
Exeter, Devon, United Kingdom, EX2 5DW
Sponsors and Collaborators
University of Exeter
Investigators
Layout table for investigator information
Principal Investigator: Mark Gilchrist, MB ChB, PhD University of Exeter

Layout table for additonal information
Responsible Party: University of Exeter
ClinicalTrials.gov Identifier: NCT04076007     History of Changes
Other Study ID Numbers: CRF035
First Posted: September 2, 2019    Key Record Dates
Last Update Posted: September 2, 2019
Last Verified: August 2019
Keywords provided by University of Exeter:
nitrate
nitrite
nitric oxide
diabetes
hypertension
Additional relevant MeSH terms:
Layout table for MeSH terms
Hypertension
Diabetes Mellitus
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases
Vascular Diseases
Cardiovascular Diseases
Insulin
Hypoglycemic Agents
Physiological Effects of Drugs