Beneficial effect of innovative nutraceutical formulation based on grape pomace polyphenolic extract on serum levels of TMAO, a new biomarker of cardiovascular diseases

ISRCTN	ISRCTN10794277
DOI	https://doi.org/10.1186/ISRCTN10794277
Secondary identifying numbers	18/06/2018 123512

Submission date: 12/09/2018
Registration date: 17/09/2018
Last edited: 06/08/2021

Recruitment status: No longer recruiting
Overall study status: Completed
Condition category: Nutritional, Metabolic, Endocrine

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Plain English summary of protocol

Background and study aim
Cardiovascular diseases (CVD), such as ischemic heart disease (i.e. angina, heart attack) or cerebrovascular diseases (i.e. stroke), are recognised to be the main causes of disability and mortality worldwide. Some risk factors for such diseases cannot be changed i.e. age, sex and family history; however, there are other risk factors that are modifiable, including smoking, alcohol abuse, dietary habits and lifestyle. Monitoring these modifiable risk factors, and associated conditions such as diabetes, obesity, dyslipidaemia and hypertension, is useful and effective in the prevention of CVD.
Research has shown that there is a strong link between the activity of bacteria that live in the intestine (gut microbiota) and CVD risk. Gut microbiota are the main producers of various molecules, which can have positive and negative effects on the body. One of these is TMAO (trimethylamine N-oxide), the presence of which is an indicator of increased risk of CVD. TMAO can promote the development of atherosclerosis, which can then worsen metabolic diseases such as obesity and diabetes. Obesity or prolonged unhealthy dietary habits can change the gut microbiota, leading to a reduction in the presence of beneficial bacteria and an increase in bacteria that produce TMAO. In particular, diets rich in animal-derived protein (meat, eggs and fish) can lead to increased TMAO levels in the blood. Plant-based diets contribute to decreasing TMAO levels through molecules called polyphenols, which are well-known for their antioxidant activity. A polyphenol called resveratrol (RSV), which is found in wine, exerts its effects specifically against increased TMAO levels in the blood. However, polyphenols derived from the diet often have low absorption into the intestine. Therefore, supplements and food additives (nutraceuticals) based on polyphenol may be a way to improve their absorption into the body.
This study aims to assess the effects of a new nutraceutical based on grape pomace polyphenols such as RSV on the levels of TMAO in overweight and obese people.

Who can participate?
Overweight and obese women aged 18-83 years old

What does the study involve?
Participants will be randomly allocated to one of two groups - group A or group B. For 4 weeks, all participants will be given a placebo. After this, there will be an 8 week treatment period, where group A will receive 600 mg grape polyphenol extract (GPE) and group B will receive 600 mg GPE and 600 mg pectin. Both groups will be asked to take this daily. Participants will be asked to maintain their usual patterns of physical activity throughout the study period.
Blood samples will be taken at week 0, 4, 8, 12 and 16 and body measurements will be taken at the start and end of the study. Participants will also be asked to record their dietary habits for one week at the start and end of the study.

What are the possible benefits and risks of participating?
Participants taking part in this study should benefit from the effects of polyphenols, including a positive influence on oxidative stress biomarkers. There are no known risks to participants taking part in this study.

Where is the study run from?
1. Samnium Medical Cooperative (Italy)
2. Department of Pharmacy, University of Naples “Federico II” (Italy)

When is the study starting and how long is it expected to run for?
June 2018 to January 2019

Who is funding the study?
1. Samnium Medical Cooperative (Italy)
2. Department of Pharmacy, University of Naples “Federico II” (Italy)

Who is the main contact?
Prof. Gian Carlo Tenore
giancarlo.tenore@unina.it

Contact information

Prof Gian Carlo Tenore
Public

Via Domenico Montesano 49
Naples
80131
Italy

ORCID ID	0000-0002-0251-9936
Phone	+39081678607
Email	giancarlo.tenore@unina.it

Dr Giuseppe Annunziata
Public

Via Domenico Montesano 49
Naples
80313
Italy

ORCID ID	0000-0002-1922-662X
Phone	+39081678606
Email	giuseppe.annunziata@unina.it

Dr Maria Maisto
Public

Via Domenico Montesano 49
Naples
80131
Italy

ORCID ID	0000-0002-0340-2254
Phone	+39081678606
Email	maria.maisto@unina.it

Study information

Study design	Interventional double-blind placebo-controlled randomised parallel trial
Primary study design	Interventional
Secondary study design	Randomised parallel trial
Study setting(s)	Hospital
Study type	Prevention
Participant information sheet	Not available in web format, please use contact details to request a participant information sheet: Gian Carlo Tenore giancarlo.tenore@unina.it
Scientific title	Effect of grape pomace extract on TMAO serum levels: a monocentric, double-blind, randomised, placebo-controlled parallel-group study
Study acronym	GPE
Study objectives	Grape pomace extract (GPE) is a polyphenol-rich food-derived matrix. Among the GPE polyphenols, resveratrol (RSV) is the most representative. Evidences demonstrated that RSV is a strong antioxidant agent; additionally, a single animal-based study showed the ability of RSV to reduce serum levels of TMAO in mice. Therefore, the aims of this study are: 1. To evaluate the effect of GPE on TMAO serum levels in overweight/obese subjects. 2. To evaluate the effects of GPE on anthropometric and metabolic (plasma glucose, insulin, HOMA-IR, TC, LDL-c, HDL-c, TG) parameters and oxidative stress biomarkers (ox-LDL)
Ethics approval(s)	Azienda Ospedaliera Gaetano Rummo Via dell’Angelo, 1 – 82100 Benevento, 18/06/2018, reference number 57993
Health condition(s) or problem(s) studied	Overweight/obesity
Intervention	Participants are randomly allocated into two groups - group A and group B. Participants will be followed by a 2-arm parallel-group design including 4-week run-in periods and 8-week treatment periods. During the run-in periods, participants will be provided with a placebo supplement. During the treatment period, group A will be given 600 mg grape polyphenol extract (GPE) per day, and group B will be given 600 mg GPE and 600 mg pectin per day. All capsules will be identical. There will be a one month follow-up period for both groups. At the start of the study, participants will be subjected to evaluation of anthropometric parameters and nutritional habits, along with an assessment of metabolic parameters and oxidative stress biomarkers. This will then be repeated at the end of the study. Clinic visits and blood sampling will be performed after 12 hours of fasting at weeks 0, 4, 8, 12 and 16.
Intervention type	Supplement
Primary outcome measure	Trimethylamine N-oxide (TMAO) serum levels, assessed using liquid chromatography/mass spectrometry (LC/MS) analysis of blood samples at weeks 1, 5 and 12 of the study period.
Secondary outcome measures	Unless otherwise stated, the following are assessed at weeks 0, 4, 8, 12 and 16: 1. Clinical history, assessed by interviews and analysis of previous clinical data at the baseline 2. Anthropometric measures, collected by measuring height and weight 3. Nutrient intake and dietary habits, assessed using a seven day food record validated nutritional questionnaire at the baseline and at the end of the study period 4. Blood pressure, assessed using a blood pressure cuff 5. Plasma total cholesterol (TC), measured from blood samples using a Diacron International Free Carpe Diem spectrophotometer (Grosseto, Italy), and commercially available kits from Diacron International 6. HDL-C, measured from blood samples using a Diacron International Free Carpe Diem spectrophotometer (Grosseto, Italy), and commercially available kits from Diacron International 7. LDL-C, measured from blood samples using a Diacron International Free Carpe Diem spectrophotometer (Grosseto, Italy), and commercially available kits from Diacron International 8. Triglyceride levels, measured from blood samples using a Diacron International Free Carpe Diem spectrophotometer (Grosseto, Italy), and commercially available kits from Diacron International 9. Plasma glycaemia, measured from blood samples using a Diacron International Free Carpe Diem spectrophotometer (Grosseto, Italy), and commercially available kits from Diacron International 10. Plasma insulin, measured from blood samples using ELISA 11. ox-LDL, measured from blood samples using a Diacron International Free Carpe Diem spectrophotometer (Grosseto, Italy), and commercially available kits from Diacron International 12. Blood analysis of the following, measured using a Diacron International Free Carpe Diem spectrophotometer (Grosseto, Italy), and commercially available kits from Diacron International: 12.1. Aspartate transaminase (AST) 12.2. Alanine transaminase (ALT) 12.3. Gamma-glutamyltransferase (γ-GTP) 12.4. Alkaline phosphatase (ALP) 12.5. Lactate dehydrogenase (LDH) 12.6. Albumin 12.7. Total bilirubin 12.8. Creatinine
Overall study start date	03/06/2018
Completion date	28/01/2019

Eligibility

Participant type(s)	Patient
Age group	Adult
Lower age limit	18 Years
Upper age limit	83 Years
Sex	Both
Target number of participants	118
Total final enrolment	90
Key inclusion criteria	1. Aged 18-83 years of age 2. Of white race 3. Overweight/obese (BMI >25 kg/m²).
Key exclusion criteria	1. Smokers 2. Hepatic disease 3. Renal disease 4. Heart disease 5. Family history of chronic diseases 6. Drug therapy or supplement intake containing grape polyphenols 7. Heavy physical exercise (over 10 hours per week) 8. Pregnant, suspected of being pregnant or hoping to become pregnant 9. Breastfeeding 10. Birch pollen allergy 11. Use of vitamin or mineral supplements 2 weeks prior to entry into the study 12. Donation of blood less than 3 months prior to the study
Date of first enrolment	19/09/2018
Date of final enrolment	27/09/2018

Locations

Countries of recruitment

Italy

Study participating centres

Department of Pharmacy, University of Naples “Federico II” (lead center)

Via Domenico Montesano, 49
Naples
80131
Italy

Samnium Medical Cooperative (Benevento, Italy)

Viale C. Colombo, 18
Castelvenere (BN)
82037
Italy

Sponsor information

Samnium Medical Cooperative (Benevento, Italy)
Hospital/treatment centre

Viale C. Colombo, 18
Castelvenere (BN)
82037
Italy

"ROR"	https://ror.org/02ww5xj89

Funders

Funder type

Not defined

Samnium

No information available

Results and Publications

Intention to publish date	01/03/2019
Individual participant data (IPD) Intention to share	No
IPD sharing plan summary	Not expected to be made available
Publication and dissemination plan	Planned publication in a high-impact peer reviewed journal
IPD sharing plan	Data of individual patients will be available upon request of patient permission.

Study outputs

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Results article	results	21/05/2019	06/06/2019	Yes	No
Results article		19/07/2021	06/08/2021	Yes	No

Editorial Notes

06/08/2021: Publication reference added.
The following changes were made to the trial record:
1. Publication reference added.
2. The total final enrolment was added.
04/10/2018: The intention to publish date has been changed from 01/03/2018 to 01/03/2019