Back to resultsThe Effects of an 8-week Vegan Diet on TMAO Levels and Post-challenge Glucose Levels in Individuals With Dysglycaemia (PYH)
Primary Purpose
Diabetes Mellitus, Type 2, Heart Diseases
Status
Completed
Phase
Not Applicable
Locations
United Kingdom
Study Type
Interventional
Intervention
Adoption of a vegan diet
Sponsored by
About this trial
This is an interventional prevention trial for Diabetes Mellitus, Type 2 focused on measuring type 2 diabetes, vegan diet, TMAO, cardiovascular disease
Eligibility 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.
Sites / Locations
- Leicester Diabetes Centre
Arms of the Study
Arm 1
Arm Type
Experimental
Arm Label
Vegan diet
Arm Description
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.
Outcomes
Primary Outcome Measures
Change from Baseline TMAO plasma levels at 1, 8 and 12 weeks.
urine and plasma samples for TMAO (μM)
Change from Baseline 3-hour post-challenge glucose levels at 1, 8 and 12 weeks.
blood samples (mmol/l)
Secondary Outcome Measures
TMAO (μM) urine levels at baseline.
urine samples
Change from Baseline in TMAO urine/plasma levels at 1 week following a vegan diet.
urine and plasma samples; TMAO (μM)
Change from Baseline 3-hour post-challenge glucose levels at 1 week following a vegan diet.
blood samples for glucose (mmol/l)
Change from week 8 in TMAO urine/plasma levels at 4 weeks after diet has returned to normal (week 12).
urine and plasma samples for TMAO (μM)
Change from week 8 in 3-hour post-challenge glucose levels at 4 weeks after diet has returned to normal (week 12).
blood samples for glucose (mmol/l)
Change from Baseline in body composition using dual energy X-ray absorptiometry (DXA) scan at 8 weeks following a vegan diet.
DXA Scan
Change from Baseline in biochemical measures of cardiometabolic health including post-challenge insulin at 1 week.
blood samples (mmol/l)
Change from Baseline in biochemical measures of cardiometabolic health including post-challenge insulin at 8 weeks.
blood samples (mmol/l)
Change from Baseline in biochemical measures of cardiometabolic health including post-challenge insulin at 12 weeks.
blood samples (mmol/l)
Change from Baseline in biochemical measures of cardiometabolic health including fasting lipids and at 1 week.
blood samples (mmol/l)
Change from Baseline in biochemical measures of cardiometabolic health including fasting lipids and inflammatory markers at 8 weeks.
blood samples (mmol/l)
Change from Baseline in biochemical measures of cardiometabolic health including fasting lipids at 12 weeks.
blood samples (mmol/l)
Change from Baseline in biochemical measures of cardiometabolic health including inflammatory markers at 1 week.
blood samples (mmol/l)
Change from Baseline in biochemical measures of cardiometabolic health including inflammatory markers at 8 weeks.
blood samples (mmol/l)
Change from Baseline in biochemical measures of cardiometabolic health including inflammatory markers at 12 weeks.
blood samples (mmol/l)
The extent to which changes in the primary outcomes are mediated by, or independent of, changes to body composition.
DXA scan
The extent to which changes in the primary outcomes are mediated by, or independent of, changes to body composition.
DXA scan
The extent to which changes in the primary outcomes are mediated by, or independent of, changes to lifestyle factors.
3-day diet diaries
The extent to which changes in the primary outcomes are mediated by, or independent of, changes to lifestyle factors.
3-day diet diaries
The extent to which changes in the primary outcomes are mediated by, or independent of, changes to lifestyle factors.
3-day diet diaries
The extent to which changes in the primary outcomes are mediated by, or independent of, changes to lifestyle factors.
3-day diet diaries
The extent to which changes in the primary outcomes are mediated by, or independent of, changes to lifestyle factors.
3-day diet diaries
The extent to which changes in the primary outcomes are mediated by, or independent of, changes to lifestyle factors.
accelerometers
Semi-structured interviews with the completers, at the end of the study, to investigate perception responses having been on a vegan diet.
semi-structured interviews
Full Information
NCT ID
NCT03315988
First Posted
October 4, 2017
Last Updated
January 29, 2020
Sponsor
University of Leicester
Collaborators
University Hospitals, Leicester
1. Study Identification
Unique Protocol Identification Number
NCT03315988
Brief Title
The Effects of an 8-week Vegan Diet on TMAO Levels and Post-challenge Glucose Levels in Individuals With Dysglycaemia
Acronym
PYH
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)
Study Type
Interventional
2. Study Status
Record Verification Date
September 2018
Overall Recruitment Status
Completed
Study Start Date
October 4, 2017 (Actual)
Primary Completion Date
January 7, 2019 (Actual)
Study Completion Date
January 7, 2019 (Actual)
3. Sponsor/Collaborators
Responsible Party, by Official Title
Sponsor
Name of the Sponsor
University of Leicester
Collaborators
University Hospitals, Leicester
4. Oversight
Studies a U.S. FDA-regulated Drug Product
No
Studies a U.S. FDA-regulated Device Product
No
Data Monitoring Committee
No
5. Study Description
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.
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.
6. Conditions and Keywords
Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Diabetes Mellitus, Type 2, Heart Diseases
Keywords
type 2 diabetes, vegan diet, TMAO, cardiovascular disease
7. Study Design
Primary Purpose
Prevention
Study Phase
Not Applicable
Interventional Study Model
Single Group Assignment
Masking
None (Open Label)
Allocation
N/A
Enrollment
28 (Actual)
8. Arms, Groups, and Interventions
Arm Title
Vegan diet
Arm Type
Experimental
Arm Description
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.
Intervention Type
Other
Intervention Name(s)
Adoption of a vegan diet
Intervention Description
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 Measure Information:
Title
Change from Baseline TMAO plasma levels at 1, 8 and 12 weeks.
Description
urine and plasma samples for TMAO (μM)
Time Frame
at 1 (+ 5 days) week , 8 (+/- 5 days) weeks and 12 weeks (+/- 5 days)
Title
Change from Baseline 3-hour post-challenge glucose levels at 1, 8 and 12 weeks.
Description
blood samples (mmol/l)
Time Frame
at 1 (+ 5 days) week , 8 (+/- 5 days) weeks and 12 weeks (+/- 5 days)
Secondary Outcome Measure Information:
Title
TMAO (μM) urine levels at baseline.
Description
urine samples
Time Frame
at baseline
Title
Change from Baseline in TMAO urine/plasma levels at 1 week following a vegan diet.
Description
urine and plasma samples; TMAO (μM)
Time Frame
at 1 week (+ 5 days)
Title
Change from Baseline 3-hour post-challenge glucose levels at 1 week following a vegan diet.
Description
blood samples for glucose (mmol/l)
Time Frame
at 1 week (+ 5 days)
Title
Change from week 8 in TMAO urine/plasma levels at 4 weeks after diet has returned to normal (week 12).
Description
urine and plasma samples for TMAO (μM)
Time Frame
at 12 weeks (+/- 5 days)
Title
Change from week 8 in 3-hour post-challenge glucose levels at 4 weeks after diet has returned to normal (week 12).
Description
blood samples for glucose (mmol/l)
Time Frame
at 12 weeks (+/- 5 days)
Title
Change from Baseline in body composition using dual energy X-ray absorptiometry (DXA) scan at 8 weeks following a vegan diet.
Description
DXA Scan
Time Frame
at baseline and week 8 (+/- 5 days)
Title
Change from Baseline in biochemical measures of cardiometabolic health including post-challenge insulin at 1 week.
Description
blood samples (mmol/l)
Time Frame
1 week (+5 days)
Title
Change from Baseline in biochemical measures of cardiometabolic health including post-challenge insulin at 8 weeks.
Description
blood samples (mmol/l)
Time Frame
8 weeks (+/- 5 days)
Title
Change from Baseline in biochemical measures of cardiometabolic health including post-challenge insulin at 12 weeks.
Description
blood samples (mmol/l)
Time Frame
12 weeks (+/- 5 days)
Title
Change from Baseline in biochemical measures of cardiometabolic health including fasting lipids and at 1 week.
Description
blood samples (mmol/l)
Time Frame
1 week (+5 days)
Title
Change from Baseline in biochemical measures of cardiometabolic health including fasting lipids and inflammatory markers at 8 weeks.
Description
blood samples (mmol/l)
Time Frame
8 weeks (+/- 5 days)
Title
Change from Baseline in biochemical measures of cardiometabolic health including fasting lipids at 12 weeks.
Description
blood samples (mmol/l)
Time Frame
12 weeks (+/- 5 days)
Title
Change from Baseline in biochemical measures of cardiometabolic health including inflammatory markers at 1 week.
Description
blood samples (mmol/l)
Time Frame
1 week (+5 days)
Title
Change from Baseline in biochemical measures of cardiometabolic health including inflammatory markers at 8 weeks.
Description
blood samples (mmol/l)
Time Frame
8 weeks (+/- 5 days)
Title
Change from Baseline in biochemical measures of cardiometabolic health including inflammatory markers at 12 weeks.
Description
blood samples (mmol/l)
Time Frame
12 weeks (+/- 5 days)
Title
The extent to which changes in the primary outcomes are mediated by, or independent of, changes to body composition.
Description
DXA scan
Time Frame
baseline
Title
The extent to which changes in the primary outcomes are mediated by, or independent of, changes to body composition.
Description
DXA scan
Time Frame
week 8 (+/- 5 days)
Title
The extent to which changes in the primary outcomes are mediated by, or independent of, changes to lifestyle factors.
Description
3-day diet diaries
Time Frame
baseline
Title
The extent to which changes in the primary outcomes are mediated by, or independent of, changes to lifestyle factors.
Description
3-day diet diaries
Time Frame
counselling visit (+5 days)
Title
The extent to which changes in the primary outcomes are mediated by, or independent of, changes to lifestyle factors.
Description
3-day diet diaries
Time Frame
week 1 (+5 days)
Title
The extent to which changes in the primary outcomes are mediated by, or independent of, changes to lifestyle factors.
Description
3-day diet diaries
Time Frame
week 8 (+/- 5 days)
Title
The extent to which changes in the primary outcomes are mediated by, or independent of, changes to lifestyle factors.
Description
3-day diet diaries
Time Frame
week 12 (+/- 5 days)
Title
The extent to which changes in the primary outcomes are mediated by, or independent of, changes to lifestyle factors.
Description
accelerometers
Time Frame
weeks 1-12
Title
Semi-structured interviews with the completers, at the end of the study, to investigate perception responses having been on a vegan diet.
Description
semi-structured interviews
Time Frame
at week 12 (+/- 5 days)
10. Eligibility
Sex
All
Minimum Age & Unit of Time
18 Years
Maximum Age & Unit of Time
75 Years
Accepts Healthy Volunteers
No
Eligibility 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.
Facility Information:
Facility Name
Leicester Diabetes Centre
City
Leicester
ZIP/Postal Code
LE3 4PW
Country
United Kingdom
12. IPD Sharing Statement
Plan to Share IPD
No
IPD Sharing Plan Description
There is no plan to make individual participant data (IPD) available to other researchers.
Citations:
PubMed Identifier
33784394
Citation
Argyridou S, Davies MJ, Biddle GJH, Bernieh D, Suzuki T, Dawkins NP, Rowlands AV, Khunti K, Smith AC, Yates T. Evaluation of an 8-Week Vegan Diet on Plasma Trimethylamine-N-Oxide and Postchallenge Glucose in Adults with Dysglycemia or Obesity. J Nutr. 2021 Jul 1;151(7):1844-1853. doi: 10.1093/jn/nxab046.
Results Reference
derived
Learn more about this trial
The Effects of an 8-week Vegan Diet on TMAO Levels and Post-challenge Glucose Levels in Individuals With Dysglycaemia
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