The Effects of Apple Consumption on Cardiovascular Health in Prediabetics and Type 2 Diabetics

Regular Apple Consumption Improves Cardiovascular Risk Factors and Glycemic Control in Overweight and Obese Prediabetics and Type 2 Diabetics

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.

Study Overview

• Status: Completed
• Conditions: Cardiovascular Diseases; Diabetes; Prediabetes
• Intervention / Treatment: Dietary supplement: Apple; Dietary supplement: Placebo

• Study Type: Interventional
• Enrollment (Actual): 50
• Phase: Phase 2

Contacts and Locations

Study Locations

• United States
  • Florida
    • Tallahassee, Florida, United States, 32306
      • Department of Nutrition, Food and Exercise Sciences, Center for Advancing Exercise and Nutrition Research on Aging, Florida State University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 45 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Apple; 12 weeks of 75 g dried apple powder taken in 480 ml per day.	Dietary supplement: Apple; 12 weeks of 75 g dried apple powder taken in 480 ml per day.
Placebo Comparator: Placebo; 12 weeks of 75 g apple-flavored placebo powder taken in 480 ml per day.	Dietary supplement: Placebo; 12 weeks of 75 g apple-flavored placebo powder taken in 480 ml per day.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blood Pressure	By measuring brachial and aortic blood pressure at rest and during physiological stress (handgrip exercise and post-exercise muscle ischemia).	12 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Inflammation	By measuring markers of inflammation.	12 weeks
Oxidative Stress	By measuring markers of oxidative stress.	12 weeks
Insulin Sensitivity	By measuring fasting glucose, insulin, homeostatic model of insulin resistance, and hemoglobin A1C.	12 weeks
Body Composition	By measuring fat mass and fat-free mass using dual-energy X-ray absorptiometry and anthropometrics.	12 weeks
Arterial Stiffness	By measuring arterial stiffness and augmentation index at rest and during physiological stress (handgrip exercise and post-exercise muscle ischemia).	12 weeks
Autonomic Control of Blood Pressure	By measuring blood pressure variability and baroreflex sensitivity at rest and during physiological stress.	12 weeks
Endothelial-mediated Vasodilation	By measuring flow-mediated dilation in the brachial artery.	12 weeks
Atherogenic Markers	By measuring adhesion factors, lipid profiles, and atherogenic risk ratios.	12 weeks

Collaborators and Investigators

• Sponsor: Florida State University
• Collaborators: U.S. Apple Association
• Investigators: Principal Investigator: Sarah A. Johnson, PhD, RDN, Department of Food Science and Human Nutrition, Colorado State University; Principal Investigator: Bahram H. Arjmandi, PhD, RD, Department of Nutrition, Food and Exercise Sciences, Center for Advancing Exercise and Nutrition Research on Aging, Florida State University; Principal Investigator: Arturo Figueroa, MD, PhD, Department of Nutrition, Food and Exercise Sciences, Florida State University

Study record dates

Study Major Dates

• Study Start: August 1, 2014
• Primary Completion (Actual): December 1, 2016
• Study Completion (Actual): December 1, 2016

Study Registration Dates

• First Submitted: August 21, 2014
• First Submitted That Met QC Criteria: August 21, 2014
• First Posted (Estimate): August 25, 2014

Study Record Updates

• Last Update Posted (Estimate): December 8, 2016
• Last Update Submitted That Met QC Criteria: December 6, 2016
• Last Verified: December 1, 2016

More Information

Terms related to this study

• Keywords: Diabetes; Endothelial Function; Fiber; Arterial Stiffness; Body Composition; Blood Pressure; Polyphenols; Glycemic Control; Apples; Functional Foods
• Additional Relevant MeSH Terms: Cardiovascular Diseases
• Other Study ID Numbers: RF02435; 2015.14930 (Other Identifier: FSU IRB)