Effects of Quercetin on Blood Sugar and Blood Vessel Function in Type 2 Diabetes.
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| ClinicalTrials.gov Identifier: NCT01839344 |
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Recruitment Status :
Completed
First Posted : April 24, 2013
Last Update Posted : March 18, 2015
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The purpose of this study is to measure the effect of quercetin on glucose tolerance and postprandial endothelial function in comparison to placebo and Acarbose in participants with Type 2 Diabetes.
Primary Hypothesis: We hypothesize that administration of quercetin (2g oral) prior to a 100g maltose tolerance test (MTT) will result in a decrease in postprandial blood glucose at 60 minutes compared to placebo. Acarbose (100mg oral), a pharmaceutical alpha-glucosidase inhibitor, will serve as a positive control.
Secondary Hypothesis: We hypothesize that administration of quercetin (2g oral) will reduce the Area Under the Glucose Curve (AUC) for the 2 hours following a 100g MTT compared to placebo. AUC is hypothesized to be comparable between quercetin and Acarbose.
Tertiary hypothesis: We hypothesize that administration of quercetin (2g oral) prior to a 100g MTT will result in a smaller reduction in flow mediated dilation (FMD) measured as an increase in Reactive Hyperemia Index (RHI) at 90 minutes compared to placebo.
| Condition or disease | Intervention/treatment | Phase |
|---|---|---|
| Diabetes Mellitus, Type 2 | Dietary Supplement: Quercetin Drug: Acarbose Drug: placebo | Phase 2 |
This is a phase II, crossover, double-blinded, controlled trial in 20 participants with type 2 diabetes designed to measure the effect of quercetin on glucose tolerance and postprandial endothelial function in comparison to placebo and Acarbose. Glucose tolerance and insulin excursion will be measured at 0, 30, 60, and 120 minutes following a 100g maltose tolerance test (MTT). Each participant will blindly rotate between three single individual doses of placebo, quercetin (2g oral), and Acarbose (100mg oral) prior to the MTT on 3 separate occasions. Each participant will serve as their own control and comparison for each of the interventions.
Fasting and post-MTT endothelial function will be measured by peripheral tonometry (Itamar EndoPAT (Peripheral Arterial Tone) 2000) and reported as reactive hyperemia index (RHI). EndoPAT testing will be performed prior to the fasting blood collection and then again at 90 minutes following the MTT, during each clinical research visit.
Exploratory data will also be collected on post-MTT increases in gamma-glutamyltransferase (GGT).
| Study Type : | Interventional (Clinical Trial) |
| Actual Enrollment : | 19 participants |
| Allocation: | Randomized |
| Intervention Model: | Crossover Assignment |
| Masking: | Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor) |
| Primary Purpose: | Treatment |
| Official Title: | Evaluation of Quercetin in Type 2 Diabetes: Impact on Glucose Tolerance and Postprandial Endothelial Function. |
| Study Start Date : | May 2013 |
| Actual Primary Completion Date : | March 2014 |
| Actual Study Completion Date : | March 2015 |
| Arm | Intervention/treatment |
|---|---|
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Experimental: Quercetin
Quercetin 250 mg capsules; oral single dose of 2000 mg
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Dietary Supplement: Quercetin
Quercetin 250 mg capsules; oral single dose of 2000 mg |
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Active Comparator: Acarbose
Acarbose 100 mg tablet; oral single dose of 100 mg
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Drug: Acarbose
Acarbose 100 mg tablet; oral single dose of 100 mg
Other Name: Precose |
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Placebo Comparator: Placebo
An oral single dose of a solid, colored empty capsule.
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Drug: placebo
An oral single dose of a solid, colored empty capsule. |
- Glucose tolerance following a maltose tolerance test [ Time Frame: Fasting (i.e., Time 0) and 60 minutes after a 100g maltose tolerance test ]Changes in serum glucose between fasting and 60 minutes after a maltose tolerance test will be calculated for each participant following each randomly assigned treatment. Mean difference in glucose will be calculated for the entire cohort and mean changes secondary to quercetin and Acarbose will be compared to placebo.
- Area under the Glucose Curve (AUC) [ Time Frame: Fasting (i.e., Time 0), 30, 60 and 120 minutes after a 100g maltose tolerance test ]Area Under the Glucose curve (AUC) between 0 minutes and 120 minutes after a maltose tolerance test with intermediate measures at 30 and 60 minutes will be calculated for each participant following each randomly assigned treatment. Mean difference in Area Under the Glucose Curve will be calculated for the entire cohort and mean changes secondary to quercetin and Acarbose will be compared to placebo.
- Reactive Hyperemia Index (RHI) [ Time Frame: Fasting (i.e., Time 0) and 90 minutes after a 100g maltose tolerance test ]Changes in Reactive Hyperemia Index (RHI), measured by peripheral tonometry (Itamar EndoPAT 2000), between fasting and 90 minutes after a maltose tolerance test will be calculated for each participant following each randomly assigned treatment. Mean difference in RHI will be calculated for the entire cohort and mean changes secondary to quercetin and Acarbose will be compared to placebo.
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| Ages Eligible for Study: | 18 Years to 75 Years (Adult, Older Adult) |
| Sexes Eligible for Study: | All |
| Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Adults aged 18-75 years with the International Classification of diseases book 9 (ICD-9) diagnosis of type 2 diabetes (250.XX). As lack of clarity in ICD-9 coding by providers is notorious in type 2 diabetes, we will specify ICD-9 diagnosis 250.XX in order to capture all subtypes of type 2 diabetes (see ICD-9 book for more information on subtypes).
- Patients on a stable dose (consistent dose for one month) of all medications and supplements.
- Hemoglobin A1c (HbA1c) of 6.5-10.5% within the last year. Since quercetin's effect on blood sugar and endothelial function may be related to its anti-oxidant properties, we are interested in looking at is effect on patients with higher levels of oxidative damage associated with higher blood sugars (i.e. elevated HbA1c > 6.5%), yet we will exclude those with severe hyperglycemia.
- Stable exercise and diet for last 1 month.
- Labs (HbA1c, aspartate aminotransferase (AST), Alanine transaminase (ALT), Glomerular filtration rate (GFR), and creatinine) measured within the last year and meet inclusion/exclusion criteria or we will run them.
Exclusion Criteria:
- Current use of insulin or Acarbose (due to possible hypoglycemia); insulin exclusion will ensure exclusion of those with type 1 diabetes.
- Current use of quercetin.
- History of myocardial infarction within the last 6 months, angina, ischemic stroke, uncontrolled hypertension with systolic greater than 180 or diastolic greater than 110.
- Clinical or objective finding suggestive of congestive heart failure Class III or IV or shortness of breath with Activities of Daily Living (ADLs).
- Recent (<14 days) history of infection. During the telephone screening, if patients have had an acute infection in the last 14 days they will be asked if we may recontact them in 3-4 weeks for a second telephone screening to determine qualification (including resolution of their recent infection > 14 days).
- Stage IV or higher kidney disease (eGFR < 30).
- Liver disease (defined as AST or ALT > 2 x high normal (according to lab range)).
- Prior diagnosis of genetic abnormalities of carbohydrate metabolism (e.g. Congenital Sucrase-Isomaltase, Pompe Disease).
- Pregnant or breast feeding.
- Mental illness or other cognitive impairment prohibiting the candidate from making an informed choice (determined at the discretion of the PI in consult with the Research Assistants/Study Coordinator as needed) as assessed throughout telephone screening and informed consent process.
- Hypersensitivity to quercetin or Acarbose; based on past allergic symptoms taken with either drug or drug or supplement.
- Diagnosis of celiac disease/"sprue".
- Contraindications for EndoPAT:
- Participants on anti-platelet medications will be excluded if they have visible bruising (beyond petechiae).
- Participants will be excluded if they are unwilling to fast for 12 hours prior to maltose tolerance test and/or EndoPAT.
- Participants will be excluded if they have taken nitroglycerine, Cialis, or Viagra 12 hrs before test days.
- In order to accommodate the finger probes, participants will be excluded if they are unwilling to clip their fingernails on their index finger short prior to test days. Index finger nail must not extend past their finger on test days.
- Bilateral upper extremity lymphedema.
- Contraindications for Acarbose:
- Current diabetic ketoacidosis.
- Inflammatory bowel disease; colonic ulceration; partial intestinal obstruction, or in patients predisposed to intestinal obstruction; chronic intestinal diseases with marked maldigestion or malabsorption; hernia.
- Cirrhosis
- Renal impairment (serum creatinine > 2 mg/dL).
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): NCT01839344
| United States, Washington | |
| Bastyr Center for Natural Health | |
| Seattle, Washington, United States, 98103 | |
| Principal Investigator: | Ryan Bradley, ND, MPH | Bastyr University |
| Responsible Party: | Bastyr University |
| ClinicalTrials.gov Identifier: | NCT01839344 |
| Other Study ID Numbers: |
13A-1334 |
| First Posted: | April 24, 2013 Key Record Dates |
| Last Update Posted: | March 18, 2015 |
| Last Verified: | February 2014 |
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hyperglycemia Diabetes Mellitus, Type 2 endothelial dysfunction quercetin |
Acarbose glucose tolerance maltose |
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Quercetin Diabetes Mellitus Diabetes Mellitus, Type 2 Glucose Metabolism Disorders Metabolic Diseases Endocrine System Diseases Acarbose |
Glycoside Hydrolase Inhibitors Enzyme Inhibitors Molecular Mechanisms of Pharmacological Action Hypoglycemic Agents Physiological Effects of Drugs Antioxidants Protective Agents |