Diabetes, Cardiovascular Diseases, Prediabetes
Conditions
Keywords
Diabetes, Arterial Stiffness, Blood Pressure, Endothelial Function, Body Composition, Glycemic Control, Apples, Functional Foods, Polyphenols, Fiber
Brief summary
The hypothesis of this study is that the daily consumption of 75 g dried apple powder for twelve weeks will improve arterial stiffness and blood pressure by improving endothelial-mediated vasodilation and vascular sympathetic activity and favorably altering biochemical markers associated with cardiovascular risk and glycemic control compared to a macronutrient-matched control powder. 50 men and women between the ages of 45 and 65 with prediabetes or type 2 diabetes who are overweight or obese will be included in the study. After a two-week run-in phase, eligible men and women will be randomly assigned to one of two treatment groups: 1) 75 g dried apple powder; or 2) 75 g placebo powder daily for twelve weeks. After an initial telephone screening, all participants will be requested to report to the study site for their first visit. On the first visit (screening), participants will be provided with verbal and written explanation of the project. They will then be asked to sign an informed consent form, followed by measuring fasting glucose levels and a medical history questionnaire to confirm prediabetes or type 2 diabetes. Baseline assessments will be performed for medical history, medication use, dietary intake, and physical activity. Qualified participants will be scheduled for their second visit two weeks later (actual baseline data collection) and randomly assigned to their treatment group. On the second (baseline) visit between the hours of 6:00-11:00 A.M., blood pressure and vascular function will be measured followed by blood draw and urine collection. Anthropometrics will be measured. Participants will be provided with their assigned treatment and will receive standard instructions on how to fill out daily diaries for their treatment, and for food and physical activity records. Blood pressure, vascular function, blood draw, urine collection, and anthropometric, body composition, diet, and physical activity assessments will be repeated at 6- (third visit), and 12-week (final visit) intervals. All cardiovascular measurements will be performed between 6:00 to 11:00 A.M., in a quiet temperature-controlled room in the supine position after an overnight fast and 12 hours after the abstinence of caffeine and/or 24 hours after the last bout of moderate to heavy physical activity.
Interventions
DIETARY_SUPPLEMENTApple
12 weeks of 75 g dried apple powder taken in 480 ml per day.
DIETARY_SUPPLEMENTPlacebo
12 weeks of 75 g apple-flavored placebo powder taken in 480 ml per day.
Sponsors
U.S. Apple Association
Florida State University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
45 Years to 65 Years
Healthy volunteers
No
Inclusion criteria
* Men and women (1 to 10 years postmenopausal) * Aged 45-65 years * Prediabetes or Type 2 Diabetes (Hemoglobin A1c ≥ 5.7%) * Overweight or obese (body mass index between 25 and 40 kg/m2)
Exclusion criteria
* Diagnosed cardiovascular disease * Uncontrolled hypertension (≥ 160/100 mmHg) * Other active chronic diseases such as cancer, asthma, glaucoma, thyroid, kidney, liver and pancreatic disease * Participating in a weight loss program * Heavy smokers (\> 20 cigarettes per day) * Heavy drinkers (\> 12 alcoholic drinks per week) * Consumption of more than two apples per week * Body mass index less than 25 or greater than 40 kg/m2)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Blood Pressure | 12 weeks | By measuring brachial and aortic blood pressure at rest and during physiological stress (handgrip exercise and post-exercise muscle ischemia). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Autonomic Control of Blood Pressure | 12 weeks | By measuring blood pressure variability and baroreflex sensitivity at rest and during physiological stress. |
| Endothelial-mediated Vasodilation | 12 weeks | By measuring flow-mediated dilation in the brachial artery. |
| Inflammation | 12 weeks | By measuring markers of inflammation. |
| Arterial Stiffness | 12 weeks | By measuring arterial stiffness and augmentation index at rest and during physiological stress (handgrip exercise and post-exercise muscle ischemia). |
| Insulin Sensitivity | 12 weeks | By measuring fasting glucose, insulin, homeostatic model of insulin resistance, and hemoglobin A1C. |
| Atherogenic Markers | 12 weeks | By measuring adhesion factors, lipid profiles, and atherogenic risk ratios. |
| Body Composition | 12 weeks | By measuring fat mass and fat-free mass using dual-energy X-ray absorptiometry and anthropometrics. |
| Oxidative Stress | 12 weeks | By measuring markers of oxidative stress. |
Countries
United States
Outcome results
None listed