HyperuricemiaNCT01363869
Effects of Green Tea on Level of Serum Uric Acid in Healthy Individuals
A study testing green tea extracts 2 gm/day, green tea extracts 4 gm/day and green tea extracts 6 gm/day in people with Hyperuricemia and Gout, run by Chiang Mai University at 1 site in Thailand.
Trial summary
Green tea has been extensively investigated for several potential health benefits. Previous studies have suggested that green tea may lower serum uric acid level in human. The purpose of this study is to investigate uric-lowering properties of green tea in healthy individuals. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Hyperuricemia, Gout
- What is being tested?
- green tea extracts 2 gm/day, green tea extracts 4 gm/day and green tea extracts 6 gm/day
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 30 participants
- Where
- 1 siteThailand
- Study dates
- Jun 2011to Mar 2013
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Age 18 years or older
- Healthy individuals
- Normal renal and liver function from blood tests
Who cannot join
- Presence of co-morbidity or currently ill
- Currently using any medication or nutritional supplement product that may affect serum uric acid level
- Serum creatinine higher than 1.5 mg/dl
- Abnormal serum Aspartate aminotransferase (AST) and/or Alanine transaminase (ALT)
- Greater than 15% change in serum uric acid during control period
Trial locations and contacts
1 site in 1 country.
Thailand1 site
Department of Internal Medicine, Faculty of Medicine, Chiang Mai University
Chiang Mai, Chiang Mai, 50200
About this study
Green tea has been extensively investigated for several potential health benefits. Previous studies have suggested that green tea may lower serum uric acid level in human. The purpose of this study is to investigate uric-lowering properties of green tea in healthy individuals.
Read the detailed description
Elevated serum uric acid is related to the risk of development of gout, the most common inflammatory arthritis in men. Allopurinol, a xanthine oxidase inhibitor, is one of the uric-lowering agents commonly used in patients suffering from recurrent and chronic gout. Nevertheless, its use is limited by adverse effects and serious allergic reaction in some patients.
Green tea is one of the most frequently consumed beverages, particularly in Japan. Green tea contains high level of catechins, in which Epigallocatechin gallate (EGCG) is the most abundant compound among other types of catechins. Antioxidant effect contributes to various potential health benefits of green tea. Several in-vitro studies have found that green tea inhibits xanthine oxidase activity and subsequently decreases reactive oxygen species (ROS) and uric acid production. We therefore would like to investigate the hypouricemic effects of green tea.
The study consists of three periods with a total duration of four weeks. The first week is the control period. The following two weeks is the interventional period and the last week is the follow up period. Thirty healthy participants will be randomly assigned into three experimental groups, receiving 2 gm/day, 4 gm/day and 6 gm/day (in capsule, two times after meal) of green tea extract during interventional period. Blood and urine samples will be taken at the beginning and at the end of each study period.
- Conditions
- Hyperuricemia, Gout
- Being tested
- green tea extracts 2 gm/day, green tea extracts 4 gm/day, green tea extracts 6 gm/day
- Keywords
- hyperuricemia, gout, uric acid, xanthine oxidase inhibitor, green tea, catechins, antioxidant
- Medical subject headings
- Hyperuricemia, Gout
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
green tea extracts 2 gm/dayDietary supplement
Green tea extracts capsule (1 gm per capsule), taken after meal, twice daily for 14 days.
Total dosage is 2 grams per day.
green tea extracts 4 gm/dayDietary supplement
Green tea extracts capsule (1 gm per capsule), taken after meal, twice daily for 14 days.
Total dosage is 4 grams per day.
green tea extracts 6 gm/dayDietary supplement
Green tea extracts capsule (1 gm per capsule), taken after meal, twice daily for 14 days.
Total dosage is 6 grams per day.
| Study group | Role | What they receive |
|---|---|---|
| Green tea extracts 2 gm/day | Experimental | Green tea extracts 2 gm/day for 14 days Receives: Dietary Supplement: green tea extracts 2 gm/day |
| Green tea extracts 4 gm/day | Experimental | Green tea extracts 4 gm/day for 14 days Receives: Dietary Supplement: green tea extracts 4 gm/day |
| Green tea extracts 6 gm/day | Experimental | Green tea extracts 6 gm/day for 14 days Receives: Dietary Supplement: green tea extracts 6 gm/day |
What is being measured
The primary outcome is the main question the study is designed to answer.
serum uric acid
Measured: 4 weeks (prior to, immediately after and 7 days after intervention)
Secondary outcomes (4)
urinary uric acid excretion
Measured: 4 weeks (prior to, immediately after and 7 days after intervention)
serum antioxidant activity
Measured: 4 weeks (prior to, immediately after and 7 days after intervention)
serum EGCG level
Measurements of serum level of epigallocatechin gallate (EGCG)
Measured: 1 week (immediately after and 7 days after intervention)
Adverse events
Adverse events during 4-week study
Measured: 4 week (prior to, immediately after and 7 days after intervention)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Jun 2011 (estimated)
- Study startJun 2011
- Primary completionSep 2012
- Study completionMar 2013
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HyperuricemiaStudies of the same condition, open and under way.
- 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
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 30 participants (actual)
Sponsor and investigators
- Lead sponsor
- Chiang Mai University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Kanon Jatuworapruk, Chiang Mai University
- Investigators
- Kanon Jatuworapruk, M.D, Principal investigator, Department of Internal medicine, Faculty of Medicine, Chiang Mai University, Thailand
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01363869
- Sponsor's protocol ID
- MED-11-02-07-13-X
- Status last verified
- Apr 2013
- First submitted
- 31 May 2011
- Last updated
- 25 Apr 2013
- Results posted
- No
- Data monitoring committee
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 25 Apr 2013. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Green Tea on Level of Serum Uric Acid in Healthy Individuals
- ClinicalTrials.gov ID
- NCT01363869
- Acronym / sponsor ID
- MED-11-02-07-13-X
- Conditions
- Hyperuricemia, Gout
- Keywords
- hyperuricemia, gout, uric acid, xanthine oxidase inhibitor, green tea, catechins, antioxidant
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 30 participants (actual)
- Lead sponsor
- Chiang Mai UniversityUniversity, hospital or other
- Study start
- Jun 2011
- Primary completion
- Sep 2012 (actual)
- Study completion
- Mar 2013 (actual)
- First posted
- 2 Jun 2011 (estimated)
- 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.
Green tea has been extensively investigated for several potential health benefits. Previous studies have suggested that green tea may lower serum uric acid level in human. The purpose of this study is to investigate uric-lowering properties of green tea in healthy individuals.
Detailed description
Elevated serum uric acid is related to the risk of development of gout, the most common inflammatory arthritis in men. Allopurinol, a xanthine oxidase inhibitor, is one of the uric-lowering agents commonly used in patients suffering from recurrent and chronic gout. Nevertheless, its use is limited by adverse effects and serious allergic reaction in some patients.
Green tea is one of the most frequently consumed beverages, particularly in Japan. Green tea contains high level of catechins, in which Epigallocatechin gallate (EGCG) is the most abundant compound among other types of catechins. Antioxidant effect contributes to various potential health benefits of green tea. Several in-vitro studies have found that green tea inhibits xanthine oxidase activity and subsequently decreases reactive oxygen species (ROS) and uric acid production. We therefore would like to investigate the hypouricemic effects of green tea.
The study consists of three periods with a total duration of four weeks. The first week is the control period. The following two weeks is the interventional period and the last week is the follow up period. Thirty healthy participants will be randomly assigned into three experimental groups, receiving 2 gm/day, 4 gm/day and 6 gm/day (in capsule, two times after meal) of green tea extract during interventional period. Blood and urine samples will be taken at the beginning and at the end of each study period.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Green tea extracts 2 gm/day | Experimental | Dietary Supplement: green tea extracts 2 gm/dayGreen tea extracts 2 gm/day for 14 days |
| Green tea extracts 4 gm/day | Experimental | Dietary Supplement: green tea extracts 4 gm/dayGreen tea extracts 4 gm/day for 14 days |
| Green tea extracts 6 gm/day | Experimental | Dietary Supplement: green tea extracts 6 gm/dayGreen tea extracts 6 gm/day for 14 days |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Age 18 years or older
- Healthy individuals
- Normal renal and liver function from blood tests
Key exclusion criteria (5 listed)
- Presence of co-morbidity or currently ill
- Currently using any medication or nutritional supplement product that may affect serum uric acid level
- Serum creatinine higher than 1.5 mg/dl
- Abnormal serum Aspartate aminotransferase (AST) and/or Alanine transaminase (ALT)
- Greater than 15% change in serum uric acid during control period
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 |
|---|---|---|
| green tea extracts 2 gm/dayGreen tea extracts capsule (1 gm per capsule), taken after meal, twice daily for 14 days. Total dosage is 2 grams per day. | Dietary supplement | Green tea extracts 2 gm/day |
| green tea extracts 4 gm/dayGreen tea extracts capsule (1 gm per capsule), taken after meal, twice daily for 14 days. Total dosage is 4 grams per day. | Dietary supplement | Green tea extracts 4 gm/day |
| green tea extracts 6 gm/dayGreen tea extracts capsule (1 gm per capsule), taken after meal, twice daily for 14 days. Total dosage is 6 grams per day. | Dietary supplement | Green tea extracts 6 gm/day |
Primary outcome
serum uric acid
Time frame: 4 weeks (prior to, immediately after and 7 days after intervention)
4 secondary outcomes
urinary uric acid excretion
Time frame: 4 weeks (prior to, immediately after and 7 days after intervention)
serum antioxidant activity
Time frame: 4 weeks (prior to, immediately after and 7 days after intervention)
serum EGCG level
Time frame: 1 week (immediately after and 7 days after intervention)
Adverse events
Time frame: 4 week (prior to, immediately after and 7 days after intervention)
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 25 Apr 2013.
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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. This study is not recruiting at the moment.
Kanon Jatuworapruk, M.D principal investigator
Department of Internal medicine, Faculty of Medicine, Chiang Mai University, Thailand
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing green tea extracts 2 gm/day, green tea extracts 4 gm/day and green tea extracts 6 gm/day in people with Hyperuricemia and Gout, run by Chiang Mai University at 1 site in Thailand.
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: finished, as of the sponsor's last update on 25 Apr 2013. 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 Thailand. 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. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
serum uric acid (time frame: 4 weeks (prior to, immediately after and 7 days after intervention)). 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 25 Apr 2013.