Diabetes Mellitus Type 2PoLiFatNCT06895018
Medium-term Effects of a Polyphenol-rich Beverage Based on Red Grape Pomace Extract on Non-alcoholic Fatty Liver Disease, Cardiometabolic Risk Profile and Gut Microbiota in Subjects with Type 2 Diabetes
A study testing Supplementation with Polyphenol Rich Drink in people with Diabetes Mellitus Type 2, run by Federico II University at 1 site in Italy.
Trial summary
Nonalcoholic fatty liver disease (NAFLD) is a liver disease characterized by an abnormal accumulation of fat not due to alcohol or drug consumption that can evolve into steatohepatitis (NASH), fibrosis and cirrhosis. Read more about this study
- Who is it for?
- Ages 35 to 70 years, men only
- Conditions the study is for
- Diabetes Mellitus Type 2
- What is being tested?
- Supplementation with Polyphenol Rich Drink
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 20 participants
- Where
- 1 siteItaly
- Study dates
- 3 May 2024to 31 Oct 2025
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 35 to 70 years
- Men only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Body Mass Index (BMI) >25 and ≤35 kg/m2
- Cholesterolemia ≤ 250 mg/dl and Triglyceridemia ≤ 200 mg/dl.
- type 2 Diabetes in good glycemic control (Hb1Ac ≤7.5%) treated with diet alone or diet + metformin.
Who cannot join
- Cardiovascular events (myocardial infarction and/or stroke)
- Renal insufficiency (serum creatinine >1.5 mg/dl) and liver failure (ALT/AST twice the normal values)
- Anemia (Hb <12 g/dl) or other chronic disease
- Insulin therapy and other hypoglycemic drugs other than metformin
- Habitual intense physical activity
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
About this study
Nonalcoholic fatty liver disease (NAFLD) is a liver disease characterized by an abnormal accumulation of fat not due to alcohol or drug consumption that can evolve into steatohepatitis (NASH), fibrosis and cirrhosis. Its prevalence is high, affecting approximately 20-30% of the general adult population and is also growing in pediatric age. Obesity, insulin resistance and type 2 diabetes (T2DM) are common and well-known risk factors for NAFLD, which is approximately 2-3 times more prevalent among obese and diabetic individuals. Despite the high and increasing prevalence of NAFLD in the population, its pathophysiology is not fully understood and there is currently no pharmacological treatment available.
Recent evidence suggests that dietary polyphenols may have specific beneficial effects on hepatic steatosis and associated sequelae by polyphenol metabolites and their phase II derivatives. Therefore, the aim of our study is to evaluate whether medium-term consumption of a beverage rich in polyphenols extracted from red grape pomace is able to exert beneficial effects on hepatic steatosis, cardiometabolic risk profile and microbiota composition of patients with type 2 diabetes.
Read the detailed description
A randomized, crossover, placebo-controlled study will be conducted. Twenty patients with type 2 diabetes mellitus (T2DM) recruited from the Diabetes Unit of the University Hospital of Naples "Federico II" who meet the inclusion criteria will be studied. After a 2-week run-in period during which they will stabilize their habitual diet, participants will be randomly assigned to receive either 150 ml/day of a polyphenol-rich red grape pomace beverage (RG) or 150 ml/day of a control beverage (Placebo) for a 6-week period each. The two treatments will be separated by a 2-week wash-out period.
At the end of the run-in, wash-out, and both treatment periods, participants will undergo fasting blood samples to evaluate key metabolic parameters. After each treatment period (RG or placebo), a standardized meal (960 kcal, 18% protein, 30% fat, 52% carbohydrates) will be administered along with 150 ml of either the polyphenol-rich beverage or the control beverage, for postprandial metabolic evaluations.
At the end of both treatments, hepatic fat content, fasting and postprandial metabolic parameters, microbiota composition and continuos glucose monitoring will be assessed.
Energy intake and habitual dietary composition will be evaluated at the end of the run-in, and at 6 weeks after the start of each treatment period using a 7-day food diary.
- Conditions
- Diabetes Mellitus Type 2
- Being tested
- Supplementation with Polyphenol Rich Drink, Supplementation with Control Drink (Placebo)
- Keywords
- Polyphenols, NAFLD, Gut microbiota, Glucose metabolism, insulin metabolism, lipid metabolism, glucose variability, sublinical inflammation, grape pomace
- Medical subject headings
- Diabetes Mellitus, Type 2, Non-alcoholic Fatty Liver Disease
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Supplementation with Polyphenol Rich DrinkDietary supplement
Participants were instructed to consume, over a 6-week period, within the context of a Mediterranean diet, a polyphenol-rich drink RGPD (150 mL) containing 1.5 g of polyphenols. After this treatment period, participants underwent a two-week washout period before switching to the alternative treatment with control drink (Placebo) devoid of polyphenols. To evaluate metabolic responses during both fasting and postprandial states, participants participants consumed a standardized test meal at the end of the 6 weeks. This standard meal was preceded by the consumption of the RGPD 60 minutes prior.
Supplementation with Control Drink (Placebo)Dietary supplement
Participants were instructed to consume, over a 6-week period, within the context of a Mediterranean diet, a control drink (Placebo) (150 mL) containing 0 g of polyphenols. After this treatment period, participants underwent a two-week washout period before switching to the alternative treatment with a polyphenol-rich drink RGPD (150 mL) containing 1.5 g of polyphenols. To evaluate metabolic responses during both fasting and postprandial states, participants participants consumed a standardized test meal at the end of the 6 weeks. This standard meal was preceded by the consumption of the Control drink (Placebo) 60 minutes prior.
| Study group | Role | What they receive |
|---|---|---|
| Grape Pomace Polyphenol Rich Drink | Experimental | Participants consume an experimental drink rich in polyphenols extracted from red grape pomace (RGP) containing 1.5 g/150 ml of Gallic Acid Equivalent (GAE) polyphenols and 28 g/150 ml of soluble sugars (14 g of glucose and 14 g of fructose) during the lunch and dinner for 6 weeks Receives: Dietary Supplement: Supplementation with Polyphenol Rich Drink |
| Placebo Drink | Placebo comparator | Participants consume a control drink (Placebo), containing zero polyphenol and 28 g of total sugars (14 g of glucose and 14 g of fructose solubilized in 150 ml of drinking water), quantities equivalent to those contained in the experimental drink, during the lunch and dinner for 6 weeks Receives: Dietary Supplement: Supplementation with Control Drink (Placebo) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Differences in liver fat content
Differences in liver fat content after the intake of polyphenol rich drink (RGPD) for 6 weeks, as compared to Control drink (Placebo). Liver fat content will be assessed by magnetic resonance spectroscopy (MRI).
Measured: At baseline and at the end of 6 weeks of each treatment
Secondary outcomes (8)
Differences in glycemic variability
Differences in glycemic variability after the intake of polyphenol rich drink (RGPD) for 6 weeks, as compared to control drink (placebo). Glycemic variability will be assessed by Continuos Glucose Monitoring (CGM) during the 7 days before the end of each treatment.
Measured: At baseline and at the end of 6 weeks of each treatment
Differences in glucose response
Differences in fasting and postprandial plasma glucose response to a standard test meal at the end of the 6-week treatment with polyphenol rich drink (RGPD) as compared to control drink (placebo). Plasma glucose concentration will be assessed by enzymatic colorimetric methods.
Measured: At the end of 6 weeks of each treatment
Differences in insulin response
Differences in fasting and postprandial plasma insulin response to a standard test meal at the end of the 6-week treatment with polyphenol rich drink (RGPD) as compared to control drink (placebo). Plasma insulin concentration will be assessed by ELISA method.
Measured: At the end of 6 weeks of each treatment
Differences in fasting lipid concentrations
Differences in fasting plasma triglycerides, total cholesterol, HDL-cholesterol and LDL-cholesterol concentration at the end of the 6-week treatment with polyphenol rich drink (RGPD) as compared to control drink (placebo). Plasma lipid concentrations will be assessed by enzymatic colorimetric methods.
Measured: At the end of 6 weeks of each treatment
Differences in postprandial triglyceride response
Differences in postprandial plasma triglycerides concentration at the end of the 6-week treatment with polyphenol rich drink (RGPD) as compared to control drink (placebo). Plasma triglyceride concentrations will be assessed by enzymatic colorimetric methods.
Measured: At the end of 6 weeks of each treatment
Differences in gastrointestinal hormones response
Differences in fasting and postprandial plasma GLP-1, PYY and Ghrelin concentration at the end of the 6-week treatment with polyphenol rich drink (RGPD) as compared to control drink (placebo). Plasma concentrations of GLP-1, PYY and Ghrelin will be assessed by ELISA methods.
Measured: At the end of 6 weeks of each treatment
Differences in inflammatory markers
Differences in fasting and postprandial serum hs-CRP concentration at the end of the 6-week treatment with polyphenol rich drink (RGPD) as compared to control drink (placebo). Serum concentrations of hs-CRP will be assessed by immunoturbidimetric method.
Measured: At the end of 6 weeks of each treatment
Differences in gut microbiota composition
Differences in microbiota composition at the end of the 6-week treatment with polyphenol rich drink (RGPD) as compared to control drink (placebo). Microbiota analysis will be assessed on feacal samples by metagenomics.
Measured: At the end of 6 weeks of each treatment
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 Mar 2025
- Study start3 May 2024
- Primary completion8 Aug 2025 (estimated)
- Study completion31 Oct 2025 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Diabetes Mellitus Type 2Studies of the same condition, open and under way.
- More trials run by Federico II UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Federico II University
- Sponsor type
- University, hospital or other
- Collaborators
- Fondazione C.N.R./Regione Toscana "G. Monasterio", Pisa, Italy
- Responsible party
- Principal investigator, Giuseppina Costabile, Federico II University
- Investigators
- Rosalba Giacco, Senior Researcher, Principal investigator, CNRLuigi Russo, Senior Researcher, Study director, CNRLutgarda Bozzetto, Full Professor, Principal investigator, Federico II Univerisity
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06895018
- Sponsor's protocol ID
- 325/20
- Acronym
- PoLiFat
- Status last verified
- Dec 2024
- First submitted
- 19 Mar 2025
- Last updated
- 26 Mar 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 26 Mar 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Medium-term Effects of a Polyphenol-rich Beverage Based on Red Grape Pomace Extract on Non-alcoholic Fatty Liver Disease, Cardiometabolic Risk Profile and Gut Microbiota in Subjects with Type 2 Diabetes
- ClinicalTrials.gov ID
- NCT06895018
- Acronym / sponsor ID
- PoLiFat / 325/20
- Conditions
- Diabetes Mellitus Type 2
- Keywords
- Polyphenols, NAFLD, Gut microbiota, Glucose metabolism, insulin metabolism, lipid metabolism, glucose variability, sublinical inflammation
- Study type
- Interventional
- Recruitment status
- Enrolling by invitation
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- Federico II UniversityUniversity, hospital or other
- Collaborators
- Fondazione C.N.R./Regione Toscana "G. Monasterio", Pisa, Italy
- Study start
- 3 May 2024 (actual)
- Primary completion
- 8 Aug 2025 (estimated)
- Study completion
- 31 Oct 2025 (estimated)
- First posted
- 26 Mar 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Nonalcoholic fatty liver disease (NAFLD) is a liver disease characterized by an abnormal accumulation of fat not due to alcohol or drug consumption that can evolve into steatohepatitis (NASH), fibrosis and cirrhosis. Its prevalence is high, affecting approximately 20-30% of the general adult population and is also growing in pediatric age. Obesity, insulin resistance and type 2 diabetes (T2DM) are common and well-known risk factors for NAFLD, which is approximately 2-3 times more prevalent among obese and diabetic individuals. Despite the high and increasing prevalence of NAFLD in the population, its pathophysiology is not fully understood and there is currently no pharmacological treatment available.
Recent evidence suggests that dietary polyphenols may have specific beneficial effects on hepatic steatosis and associated sequelae by polyphenol metabolites and their phase II derivatives. Therefore, the aim of our study is to evaluate whether medium-term consumption of a beverage rich in polyphenols extracted from red grape pomace is able to exert beneficial effects on hepatic steatosis, cardiometabolic risk profile and microbiota composition of patients with type 2 diabetes.
Detailed description
A randomized, crossover, placebo-controlled study will be conducted. Twenty patients with type 2 diabetes mellitus (T2DM) recruited from the Diabetes Unit of the University Hospital of Naples "Federico II" who meet the inclusion criteria will be studied. After a 2-week run-in period during which they will stabilize their habitual diet, participants will be randomly assigned to receive either 150 ml/day of a polyphenol-rich red grape pomace beverage (RG) or 150 ml/day of a control beverage (Placebo) for a 6-week period each. The two treatments will be separated by a 2-week wash-out period.
At the end of the run-in, wash-out, and both treatment periods, participants will undergo fasting blood samples to evaluate key metabolic parameters. After each treatment period (RG or placebo), a standardized meal (960 kcal, 18% protein, 30% fat, 52% carbohydrates) will be administered along with 150 ml of either the polyphenol-rich beverage or the control beverage, for postprandial metabolic evaluations.
At the end of both treatments, hepatic fat content, fasting and postprandial metabolic parameters, microbiota composition and continuos glucose monitoring will be assessed.
Energy intake and habitual dietary composition will be evaluated at the end of the run-in, and at 6 weeks after the start of each treatment period using a 7-day food diary.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Grape Pomace Polyphenol Rich Drink | Experimental | Dietary Supplement: Supplementation with Polyphenol Rich DrinkParticipants consume an experimental drink rich in polyphenols extracted from red grape pomace (RGP) containing 1.5 g/150 ml of Gallic Acid Equivalent (GAE) polyphenols and 28 g/150 ml of soluble sugars (14 g of glucose and 14 g of fructose) during the lunch and dinner for 6 weeks |
| Placebo Drink | Placebo comparator | Dietary Supplement: Supplementation with Control Drink (Placebo)Participants consume a control drink (Placebo), containing zero polyphenol and 28 g of total sugars (14 g of glucose and 14 g of fructose solubilized in 150 ml of drinking water), quantities equivalent to those contained in the experimental drink, during the lunch and dinner for 6 weeks |
Who may qualify
- Ages
- 35 to 70 years
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Body Mass Index (BMI) >25 and ≤35 kg/m2
- Cholesterolemia ≤ 250 mg/dl and Triglyceridemia ≤ 200 mg/dl.
- type 2 Diabetes in good glycemic control (Hb1Ac ≤7.5%) treated with diet alone or diet + metformin.
Key exclusion criteria (5 listed)
- Cardiovascular events (myocardial infarction and/or stroke)
- Renal insufficiency (serum creatinine >1.5 mg/dl) and liver failure (ALT/AST twice the normal values)
- Anemia (Hb <12 g/dl) or other chronic disease
- Insulin therapy and other hypoglycemic drugs other than metformin
- Habitual intense physical activity
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Supplementation with Polyphenol Rich DrinkParticipants were instructed to consume, over a 6-week period, within the context of a Mediterranean diet, a polyphenol-rich drink RGPD (150 mL) containing 1.5 g of polyphenols. After this treatment period, participants underwent a two-week washout period before switching to the alternative treatment with control drink (Placebo) devoid of polyphenols. To evaluate metabolic responses during both fasting and postprandial states, participants participants consumed a standardized test meal at the end of the 6 weeks. This standard meal was preceded by the consumption of the RGPD 60 minutes prior. | Dietary supplement | Grape Pomace Polyphenol Rich Drink |
| Supplementation with Control Drink (Placebo)Participants were instructed to consume, over a 6-week period, within the context of a Mediterranean diet, a control drink (Placebo) (150 mL) containing 0 g of polyphenols. After this treatment period, participants underwent a two-week washout period before switching to the alternative treatment with a polyphenol-rich drink RGPD (150 mL) containing 1.5 g of polyphenols. To evaluate metabolic responses during both fasting and postprandial states, participants participants consumed a standardized test meal at the end of the 6 weeks. This standard meal was preceded by the consumption of the Control drink (Placebo) 60 minutes prior. | Dietary supplement | Placebo Drink |
Primary outcome
Differences in liver fat content
Time frame: At baseline and at the end of 6 weeks of each treatment
Differences in liver fat content after the intake of polyphenol rich drink (RGPD) for 6 weeks, as compared to Control drink (Placebo). Liver fat content will be assessed by magnetic resonance spectroscopy (MRI).
8 secondary outcomes
Differences in glycemic variability
Time frame: At baseline and at the end of 6 weeks of each treatment
Differences in glucose response
Time frame: At the end of 6 weeks of each treatment
Differences in insulin response
Time frame: At the end of 6 weeks of each treatment
Differences in fasting lipid concentrations
Time frame: At the end of 6 weeks of each treatment
Differences in postprandial triglyceride response
Time frame: At the end of 6 weeks of each treatment
Differences in gastrointestinal hormones response
Time frame: At the end of 6 weeks of each treatment
Differences in inflammatory markers
Time frame: At the end of 6 weeks of each treatment
Differences in gut microbiota composition
Time frame: At the end of 6 weeks of each treatment
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 26 Mar 2025.
- Individual participant dataSharing planned: Yes
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Rosalba Giacco, Senior Researcher principal investigator
CNR
Luigi Russo, Senior Researcher study director
CNR
Lutgarda Bozzetto, Full Professor principal investigator
Federico II Univerisity
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Supplementation with Polyphenol Rich Drink in people with Diabetes Mellitus Type 2, run by Federico II University at 1 site in Italy.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: enrolling by invitation, as of the sponsor's last update on 26 Mar 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Italy. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Differences in liver fat content (time frame: At baseline and at the end of 6 weeks of each treatment). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 26 Mar 2025.