Acute Vascular Response To Meals Varying In Glycemic Index And Glycemic Load

Unity Health Toronto21 enrolled

Overview

This study examines the effects of carbohydrate type (high- or low-Glycemic Index (GI)) and amount (high- or low-Glycemic Load (GL)) have on blood glucose levels, blood pressure and arterial stiffness in healthy individuals. It will also determine whether subjective ratings such as test meal palatability and hunger are related to changes in blood glucose. The investigators hypothesize that: (1) High-GI meals, regardless of GL, will increase arterial stiffness; low-GI meals, regardless of GL, will have a neutral or lowering effect on arterial stiffness (augmentation index). (2) High-GI meals, regardless of GL, will have an elevating effect on both central and peripheral blood pressures. (3) The incremental area under the curve for blood glucose will show most significant differences between high-GI, high-GL and low-GI, low-GL meals at 30 and 90 min.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

NONE

Enrollment

Conditions

Healthy

Interventions

Eligibility

Sex: ALLMin age: 18 YearsMax age: 75 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * healthy * age 18 - 75 years * BMI 18 - 25 kg/m2 * brachial systolic blood pressure \< 140 mmHg * brachial diastolic blood pressure \< 90 mmHg Exclusion Criteria: * primary hypertension * diabetes * allergy or sensitivity to any foods to be used in the study * gastrointestinal disorders * chronic kidney disease * liver disease * hepatitis * estrogen-sensitive cancer * heavy alcohol use * sleep apnea * bleeding disorders * planned surgery (within time frame of study) * angina * Congestive Heart Failure * coronary revascularization * peripheral vascular disease and/or coronary/cerebrovascular events within the previous 6 months * positive HIV diagnosis * prescription of anti-depressants, anti-hypertensives, anti-coagulant medications, diuretics, sympathomimetics, herbal therapies, vitamin or K supplementation, medication affecting NO synthesis * chronic use or prescription of NSAIDs * women of childbearing potential must not be pregnant or breastfeeding

Outcomes

Primary Outcomes

To measure postprandial changes in augmentation index (AIx) to determine the acute effect of high- and low-GI and high- and low-GL meals on arterial stiffness.

Time frame: 4 separate mornings, measurements taken at baseline and at 60, 120, 180 and 240 minutes

Secondary Outcomes

To determine the acute effect of high- and low-GI and high- and low- GL meals on central and peripheral blood pressure

Time frame: 4 separate mornings, measurements taken at baseline, 60, 120, 180 and 240 minutes.