Cardiovascular Disease, Hyperglycemia
Conditions
Keywords
green tea, catechins, vascular endothelial function, postprandial hyperglycemia, oxidative stress
Brief summary
The objective of this study is to formulate and validate a green tea confection (i.e. gummy candy) as a strategy to attenuate postprandial hyperglycemia-induced impairments in vascular function. The central hypothesis is that a green tea confection will protect against vascular endothelial dysfunction by suppressing postprandial hyperglycemia. The central hypothesis of this application will be assessed by developing a green tea-containing confection, examining its physiochemical properties and its inhibition of starch digestion, and then validating its vasoprotective activities in healthy humans by assessing its blood glucose-regulating activities.
Detailed description
The study involves validating a green tea confection (i.e. gummy candy) as a dietary strategy to attenuate postprandial hyperglycemia-induced impairments in vascular function. The central hypothesis is that a green tea confection will protect against vascular endothelial dysfunction by suppressing postprandial hyperglycemia. The central hypothesis of this application will be assessed by providing research participants 75 grams of carbohydrate in the form of a confection that contains no green tea concentrate or green tea concentrate at a level equivalent to approximately 3 cups of freshly brewed tea. Blood glucose and brachial artery flow-mediated dilation will be assessed at regular intervals during the 3 hour postprandial period to define the extent to which green tea attenuates postprandial increases in blood glucose and decreases in vascular function that otherwise occur in a hyperglycemia-dependent manner.
Interventions
DIETARY_SUPPLEMENTGreen Tea Concentrate
Green tea concentrate is being examined as a dietary supplement that can regulate postprandial excursions in blood glucose
Sponsors
Ohio State University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
PREVENTION
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
MALE
Age
18 Years to 30 Years
Healthy volunteers
Yes
Inclusion criteria
* Plasma glucose \<100 mg/dL * Plasma total cholesterol \<200 mg/dL * Plasma triglycerides \<140 mg/dL * Blood pressure \<140/90 * non-dietary supplement user for \>2 months * no use of medications known to affect carbohydrate metabolism, * nonsmoker / never smoker * no history of cardiovascular disease or gastrointestinal disorders
Exclusion criteria
* allergies or aversions to green tea and/or corn starch, * excessive alcohol consumption (\>3 drinks/d), * \>5 h/wk of aerobic activity
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Area Under the Curve of Blood Glucose | Area under the Curve, 0, 30, 60, 90, 120, 150, 180 minutes post-dose | Blood glucose will be measured at 0, 30, 60, 90, 120, 150 and 180 minutes following the ingestion of a confection to calculate area under the concentration-time curve. |
| Area Under the Curve of Brachial Artery Flow Mediated Dilatiion | Area under the Curve, 0, 30, 60, 90, 120, 150, 180 minutes post-dose | Brachial artery flow-mediated dilation will be measured at 0, 30, 60, 90, 120, 150, and 180 minutes following the ingestion of a confection. |
| Brachial Artery Flow-mediated Dilation | 0 min (baseline) | — |
Secondary
| Measure | Time frame |
|---|---|
| Malondialdehyde (0 Min) | Baseline (0 min) |
| Malondialdehyde | 60 min postprandially |
| Ratio of Asymmetric Dimethylarginine Relative to Arginine | 0 min (baseline) |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Baseline Participant Characteristics All participants completed both arms of the cross-over study | 15 |
| Total | 15 |
Baseline characteristics
| Characteristic | Baseline Participant Characteristics |
|---|---|
| Age, Continuous | 25.3 years STANDARD_DEVIATION 3.9 |
| Body Mass Index | 22.4 kg/m^2 STANDARD_DEVIATION 1.8 |
| Fasting Glucose | 88.9 mg/dL STANDARD_DEVIATION 5.2 |
| Region of Enrollment United States | 15 participants |
| Sex: Female, Male Female | 0 Participants |
| Sex: Female, Male Male | 15 Participants |
| Total Cholesterol | 160.5 mg/dL STANDARD_DEVIATION 21.44 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 0 / 8 | 0 / 7 |
| serious Total, serious adverse events | 0 / 8 | 0 / 7 |
Outcome results
Primary
Area Under the Curve of Blood Glucose
Blood glucose will be measured at 0, 30, 60, 90, 120, 150 and 180 minutes following the ingestion of a confection to calculate area under the concentration-time curve.
Time frame: Area under the Curve, 0, 30, 60, 90, 120, 150, 180 minutes post-dose
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Green Tea | Area Under the Curve of Blood Glucose | 998 mmol/L * min | Standard Error 29 |
| Control | Area Under the Curve of Blood Glucose | 981 mmol/L * min | Standard Error 28 |
Primary
Area Under the Curve of Brachial Artery Flow Mediated Dilatiion
Brachial artery flow-mediated dilation will be measured at 0, 30, 60, 90, 120, 150, and 180 minutes following the ingestion of a confection.
Time frame: Area under the Curve, 0, 30, 60, 90, 120, 150, 180 minutes post-dose
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Green Tea | Area Under the Curve of Brachial Artery Flow Mediated Dilatiion | 614 %FMD * min | Standard Error 65 |
| Control | Area Under the Curve of Brachial Artery Flow Mediated Dilatiion | 653 %FMD * min | Standard Error 66 |
Primary
Brachial Artery Flow-mediated Dilation
Time frame: 0 min (baseline)
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Green Tea | Brachial Artery Flow-mediated Dilation | 3.71 % dilation | Standard Error 0.42 |
| Control | Brachial Artery Flow-mediated Dilation | 3.54 % dilation | Standard Error 0.42 |
Primary
Brachial Artery Flow-mediated Dilation
Time frame: 60 min
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Green Tea | Brachial Artery Flow-mediated Dilation | 3.23 % dilation | Standard Error 0.44 |
| Control | Brachial Artery Flow-mediated Dilation | 3.04 % dilation | Standard Error 0.35 |
Secondary
Malondialdehyde
Time frame: 60 min postprandially
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Green Tea | Malondialdehyde | 1.44 uM | Standard Error 0.15 |
| Control | Malondialdehyde | 1.47 uM | Standard Error 0.14 |
Secondary
Malondialdehyde (0 Min)
Time frame: Baseline (0 min)
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Green Tea | Malondialdehyde (0 Min) | 1.18 uM | Standard Error 0.15 |
| Control | Malondialdehyde (0 Min) | 1.18 uM | Standard Error 0.16 |
Secondary
Ratio of Asymmetric Dimethylarginine Relative to Arginine
Time frame: 0 min (baseline)
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Green Tea | Ratio of Asymmetric Dimethylarginine Relative to Arginine | 5.75 nmol/umol | Standard Error 0.26 |
| Control | Ratio of Asymmetric Dimethylarginine Relative to Arginine | 6.24 nmol/umol | Standard Error 0.42 |
Secondary
Ratio of Asymmetric Dimethylarginine Relative to Arginine
Time frame: 60 min (baseline)
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Green Tea | Ratio of Asymmetric Dimethylarginine Relative to Arginine | 6.96 nmol/umol | Standard Error 0.51 |
| Control | Ratio of Asymmetric Dimethylarginine Relative to Arginine | 7.18 nmol/umol | Standard Error 0.53 |