Working…
COVID-19 is an emerging, rapidly evolving situation.
Get the latest public health information from CDC: https://www.coronavirus.gov.

Get the latest research information from NIH: https://www.nih.gov/coronavirus.
ClinicalTrials.gov
ClinicalTrials.gov Menu

The Effects of an 8-week Vegan Diet on TMAO Levels and Post-challenge Glucose Levels in Individuals With Dysglycaemia (PYH)

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: NCT03315988
Recruitment Status : Completed
First Posted : October 20, 2017
Last Update Posted : January 30, 2020
Sponsor:
Collaborator:
University Hospitals, Leicester
Information provided by (Responsible Party):
University of Leicester

Brief Summary:

The amount of people with diabetes mellitus has now reached over 4 million in the United Kingdom. Type 2 diabetes accounts for the majority of all cases of diabetes and increases the risk of many other diseases such as heart problems. Plant based diets are thought to be an effective way to improve markers of health related to type 2 diabetes and heart disease. One way that a plant based diet improves health could be through reducing waste products that are generated in the gut by the bacteria that break down food as part of the digestion process. For example, the digestion of some meats, fish and eggs results in the creation of a substance called Trimethylamine-N-Oxide (TMAO) which has been linked to worse health outcomes in several studies. However, the full impact on TMAO and blood glucose levels of swapping regular meat consumption for a plant based vegan diet is not fully understood and requires further research. Therefore, the aim of this study will be to develop and undertake a clinical trial to investigate the effects of an 8-week vegan diet on TMAO levels and post challenge glucose levels in individuals with dysglycaemia (drug naïve).

The study will be interventional single group prospective trial of adults aged 18-75 years of age from a multi-ethnic population with dysglycaemia (drug naïve). A sample of 29 people will be sought. The dietary intervention (vegan diet) will last 8 weeks. Then, the participants will go back to their normal diet and come for their final visit after a four week follow-up period (week 12). To assess the effectiveness of the intervention, primary and secondary outcome data collected at baseline will be compared with data collected at 1 week, 8 weeks and 12 weeks.


Condition or disease Intervention/treatment Phase
Diabetes Mellitus, Type 2 Heart Diseases Other: Adoption of a vegan diet Not Applicable

Detailed Description:

Study Design

Interventional single group prospective trial in a patient population with identified dysglycaemia within the past 36 months defined as 2h post-challenge glucose ≥7.8 mmol/L after a standard oral glucose tolerance test or HbA1c ≥5.7% (39-46 mmol/mol). This phase clinical trial will evaluate the efficacy and underlining mechanisms of a vegan diet in promoting cardiometabolic health in those with dysglycaemia. Specifically, this trial will aim to investigate the effect of an 8-week vegan diet with follow-up at 1, 8 and 12 weeks.

Study Setting

The study will be co-ordinated within the Leicester Biomedical Research Centre (Leicester Diabetes Centre) at the Leicester General Hospital. Clinical measurement sessions will be carried out by the appointed research team. Participants will be asked to visit the study centre on five occasions.

Intervention Description and Definition

The participants will be asked to follow a diet that excludes foods hypothesised to support the syntheses of TMAO, particularly meat (any), eggs and fish (any). A number of studies suggest that dairy products may also have an effect in modulating TMAO production whereas other studies do not. Therefore, in order to avoid any potential contaminating or confounding effect, dairy products will also be avoided.

The diet employed in this study is broadly aligned to a vegan diet. The term vegan will be used to aid behaviour change and food choice. For example, an increasing array of products are now pack marked as vegan. The participants will be asked to keep their diet similar to their original and the Registered Dietitian involved in this study will plan their weekly menus accordingly.

Layout table for study information
Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 28 participants
Allocation: N/A
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Prevention
Official Title: The Effects of an 8-week Vegan Diet on Trimethylamine-N-Oxide (TMAO) Levels and Post-challenge Glucose Levels in Individuals With Dysglycaemia (The Plant Your Health Study)
Actual Study Start Date : October 4, 2017
Actual Primary Completion Date : January 7, 2019
Actual Study Completion Date : January 7, 2019

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Adoption

Arm Intervention/treatment
Experimental: Vegan diet

Intervention Description and Definition The participants will be asked to follow a diet that excludes foods hypothesised to support the syntheses of TMAO, particularly meat (any), eggs and fish (any). A number of studies suggest that dairy products may also have an effect in modulating TMAO production whereas other studies do not. Therefore, in order to avoid any potential contaminating or confounding effect, dairy products will also be avoided.

The diet employed in this study is broadly aligned to a vegan diet. The term vegan will be used to aid behaviour change and food choice. For example, an increasing array of products are now pack marked as vegan. The participants will be asked to keep their diet similar to their original and the Registered Dietitian involved in this study will plan their weekly menus accordingly.

Other: Adoption of a vegan diet
Adoption of a vegan diet The participants of this study wil be asked to adopt a vegan diet under the supervision of a Registered Dietitian.




Primary Outcome Measures :
  1. Change from Baseline TMAO plasma levels at 1, 8 and 12 weeks. [ Time Frame: at 1 (+ 5 days) week , 8 (+/- 5 days) weeks and 12 weeks (+/- 5 days) ]
    urine and plasma samples for TMAO (μM)

  2. Change from Baseline 3-hour post-challenge glucose levels at 1, 8 and 12 weeks. [ Time Frame: at 1 (+ 5 days) week , 8 (+/- 5 days) weeks and 12 weeks (+/- 5 days) ]
    blood samples (mmol/l)


Secondary Outcome Measures :
  1. TMAO (μM) urine levels at baseline. [ Time Frame: at baseline ]
    urine samples

  2. Change from Baseline in TMAO urine/plasma levels at 1 week following a vegan diet. [ Time Frame: at 1 week (+ 5 days) ]
    urine and plasma samples; TMAO (μM)

  3. Change from Baseline 3-hour post-challenge glucose levels at 1 week following a vegan diet. [ Time Frame: at 1 week (+ 5 days) ]
    blood samples for glucose (mmol/l)

  4. Change from week 8 in TMAO urine/plasma levels at 4 weeks after diet has returned to normal (week 12). [ Time Frame: at 12 weeks (+/- 5 days) ]
    urine and plasma samples for TMAO (μM)

  5. Change from week 8 in 3-hour post-challenge glucose levels at 4 weeks after diet has returned to normal (week 12). [ Time Frame: at 12 weeks (+/- 5 days) ]
    blood samples for glucose (mmol/l)

  6. Change from Baseline in body composition using dual energy X-ray absorptiometry (DXA) scan at 8 weeks following a vegan diet. [ Time Frame: at baseline and week 8 (+/- 5 days) ]
    DXA Scan

  7. Change from Baseline in biochemical measures of cardiometabolic health including post-challenge insulin at 1 week. [ Time Frame: 1 week (+5 days) ]
    blood samples (mmol/l)

  8. Change from Baseline in biochemical measures of cardiometabolic health including post-challenge insulin at 8 weeks. [ Time Frame: 8 weeks (+/- 5 days) ]
    blood samples (mmol/l)

  9. Change from Baseline in biochemical measures of cardiometabolic health including post-challenge insulin at 12 weeks. [ Time Frame: 12 weeks (+/- 5 days) ]
    blood samples (mmol/l)

  10. Change from Baseline in biochemical measures of cardiometabolic health including fasting lipids and at 1 week. [ Time Frame: 1 week (+5 days) ]
    blood samples (mmol/l)

  11. Change from Baseline in biochemical measures of cardiometabolic health including fasting lipids and inflammatory markers at 8 weeks. [ Time Frame: 8 weeks (+/- 5 days) ]
    blood samples (mmol/l)

  12. Change from Baseline in biochemical measures of cardiometabolic health including fasting lipids at 12 weeks. [ Time Frame: 12 weeks (+/- 5 days) ]
    blood samples (mmol/l)

  13. Change from Baseline in biochemical measures of cardiometabolic health including inflammatory markers at 1 week. [ Time Frame: 1 week (+5 days) ]
    blood samples (mmol/l)

  14. Change from Baseline in biochemical measures of cardiometabolic health including inflammatory markers at 8 weeks. [ Time Frame: 8 weeks (+/- 5 days) ]
    blood samples (mmol/l)

  15. Change from Baseline in biochemical measures of cardiometabolic health including inflammatory markers at 12 weeks. [ Time Frame: 12 weeks (+/- 5 days) ]
    blood samples (mmol/l)

  16. The extent to which changes in the primary outcomes are mediated by, or independent of, changes to body composition. [ Time Frame: baseline ]
    DXA scan

  17. The extent to which changes in the primary outcomes are mediated by, or independent of, changes to body composition. [ Time Frame: week 8 (+/- 5 days) ]
    DXA scan

  18. The extent to which changes in the primary outcomes are mediated by, or independent of, changes to lifestyle factors. [ Time Frame: baseline ]
    3-day diet diaries

  19. The extent to which changes in the primary outcomes are mediated by, or independent of, changes to lifestyle factors. [ Time Frame: counselling visit (+5 days) ]
    3-day diet diaries

  20. The extent to which changes in the primary outcomes are mediated by, or independent of, changes to lifestyle factors. [ Time Frame: week 1 (+5 days) ]
    3-day diet diaries

  21. The extent to which changes in the primary outcomes are mediated by, or independent of, changes to lifestyle factors. [ Time Frame: week 8 (+/- 5 days) ]
    3-day diet diaries

  22. The extent to which changes in the primary outcomes are mediated by, or independent of, changes to lifestyle factors. [ Time Frame: week 12 (+/- 5 days) ]
    3-day diet diaries

  23. The extent to which changes in the primary outcomes are mediated by, or independent of, changes to lifestyle factors. [ Time Frame: weeks 1-12 ]
    accelerometers

  24. Semi-structured interviews with the completers, at the end of the study, to investigate perception responses having been on a vegan diet. [ Time Frame: at week 12 (+/- 5 days) ]
    semi-structured interviews



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:   18 Years to 75 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Participant is willing and able to give informed consent for participation in the study
  • And either:

    • Overweight (White: BMI>25 - <30, South Asian/ Black and minority ethnic group <27.5) with HbA1c between HbA1c ≥5.7% and ≤ 8% (39-64 mmol/mol) identified within the last 36 months
    • Obese: (White: BMI ≥30, South Asian/ Black and minority ethnic group: ≥27.5)
  • Male or Female
  • Aged 18 - 75 years inclusive
  • Able to understand, read and speak the English language to a sufficient level to understand and take part to the study in the investigators opinion
  • Have access to a phone, and willing to use it as part of the study
  • Regular meat and/or fish eater (at least 3 times per week)-self reported

Exclusion Criteria:

Participant is unwilling or unable to give informed consent

  • Non-English speakers
  • HbA1c above 8% (64 mmol/mol)
  • Taking any form of glucose lowering medication currently or within the last 60 days
  • Current smokers
  • Current use of vegan or vegetarian diet
  • Recent significant weight change (10% or more) over the last 3 months
  • Pregnancy/lactation
  • Clinical eating disorder as detected by their GP or relevant health professional (e.g. dietitian)
  • Have a terminal illness
  • Current or recent (within 6 months) oral antibiotics or steroid use as their usage could impact on the gut bacteria profile
  • Ongoing CVD (e.g. angina) *

    • In the circumstance that an individual is not sure whether they meet the inclusion/ exclusion criteria, (i.e. they are not sure if they have ongoing CVD) this will be reviewed by a named medic on the delegation of authority log for a clinical decision to be made during baseline.

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): NCT03315988


Locations
Layout table for location information
United Kingdom
Leicester Diabetes Centre
Leicester, United Kingdom, LE3 4PW
Sponsors and Collaborators
University of Leicester
University Hospitals, Leicester
Layout table for additonal information
Responsible Party: University of Leicester
ClinicalTrials.gov Identifier: NCT03315988    
Other Study ID Numbers: 0625
First Posted: October 20, 2017    Key Record Dates
Last Update Posted: January 30, 2020
Last Verified: September 2018
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No
Plan Description: There is no plan to make individual participant data (IPD) available to other researchers.

Layout table for additional information
Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by University of Leicester:
type 2 diabetes
vegan diet
TMAO
cardiovascular disease
Additional relevant MeSH terms:
Layout table for MeSH terms
Heart Diseases
Diabetes Mellitus, Type 2
Cardiovascular Diseases
Diabetes Mellitus
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases