Diabetes Mellitus, Type 2
Conditions
Keywords
hyperglycemia, Diabetes Mellitus, Type 2, endothelial dysfunction, quercetin, Acarbose, glucose tolerance, maltose
Brief summary
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.
Detailed description
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).
Interventions
DIETARY_SUPPLEMENTQuercetin
Quercetin 250 mg capsules; oral single dose of 2000 mg
DRUGAcarbose
Acarbose 100 mg tablet; oral single dose of 100 mg
DRUGplacebo
An oral single dose of a solid, colored empty capsule.
Sponsors
Bastyr University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 75 Years
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Glucose tolerance following a maltose tolerance test | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Area under the Glucose Curve (AUC) | 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. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Reactive Hyperemia Index (RHI) | 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. |
Countries
United States
Outcome results
None listed