Lifestyle Control of Postprandial Hyperglycemia

Low-carbohydrate Diet, With or Without Exercise, for Improving Postprandial Glucose Control and Vascular Function in Type 2 Diabetes and Prediabetes.

Large spikes in blood glucose experienced after meals in people with type 2 diabetes are known to damage blood vessels. Low carbohydrate high fat diets and exercise can improve blood glucose control in people with type 2 diabetes but it is unclear how these two strategies interact to affect blood vessel function and inflammation. We will examine how following a short-term low carbohydrate high fat diet (4 days) with or without post-meal walking impacts markers of blood vessel function and inflammation. We will also examine how a single low carbohydrate high fat meal, with or without post-meal walking, impacts blood glucose control and blood vessel function. Findings will help determine the best lifestyle approach for improving cardiovascular health in type 2 diabetes.

Study Overview

• Status: Completed
• Conditions: Type 2 Diabetes
• Intervention / Treatment: Behavioral: High-carbohydrate diet; Behavioral: Low-carbohydrate diet; Behavioral: Low-carbohydrate diet with post-meal walking

• Study Type: Interventional
• Enrollment (Actual): 16
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • British Columbia
    • Kelowna, British Columbia, Canada, V1V 1V7
      • University of British Columbia, Okanagan.

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 40 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Diagnosed with type 2 diabetes (at least 6 months ago)
• Aged 40-75
• Engaging in 2 or less moderate-to-vigorous exercise bouts per week in the last 3 months
• Ability to understand and communicate in English to interact with the personal trainer

Exclusion Criteria:

• Diagnosed coronary artery disease
• Any contraindications to exercise (e.g., musculoskeletal injury)
• Prior history of cardio- or cerebrovascular disease or myocardial infarction
• Hypertension that is not controlled by medication (systolic blood pressure (BP) >160 mmHg and/or diastolic BP >99 mmHg)
• Change in diabetes medications in the previous 6 months
• Diagnosed with peripheral neuropathy
• Taking exogenous insulin

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: High-carbohydrate diet	Behavioral: High-carbohydrate diet; Participants will engage in 4 days of high-carbohydrate low fat diet as recommended by the Canadian Diabetes Association. The macronutrients content will go as follow: 55% carbohydrate, 25% protein and 20% fat. Breakfast, lunch and dinner will be provided to the participants as part of an isoenergetic diet. Between interventions there will be at least a one-week washout, where participants are encouraged to return to their baseline dietary habits.
Experimental: Low-carbohydrate diet	Behavioral: Low-carbohydrate diet; Participants will engage in 4 days of low-carbohydrate high-fat diet. The macronutrients content will go as follow: 10% carbohydrate, 25% protein and 65% fat. Breakfast, lunch and dinner will be provided to the participants as part of an isoenergetic diet. Between interventions there will be at least a one-week washout, where participants are encouraged to return to their baseline dietary habits.
Experimental: Low-carbohydrate diet with post-meal walking	Behavioral: Low-carbohydrate diet; Participants will engage in 4 days of low-carbohydrate high-fat diet. The macronutrients content will go as follow: 10% carbohydrate, 25% protein and 65% fat. Breakfast, lunch and dinner will be provided to the participants as part of an isoenergetic diet. Between interventions there will be at least a one-week washout, where participants are encouraged to return to their baseline dietary habits.; Behavioral: Low-carbohydrate diet with post-meal walking; Participants will follow the same diet as in the low-carbohydrate diet arm but also perform 15 minutes of walking beginning ~15 minutes after breakfast, lunch and dinner. Approximately 70 kcal (individualized) will be added to main meals to account for exercise energy expenditure. Between interventions there will be at least a one-week washout, where participants are encouraged to return to their baseline dietary habits.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Difference in glycemic control assessed by continuous glucose monitoring in low-carbohydrate, low-carbohydrate plus post-meal walking, and high-carbohydrate low-fat arm.	4-day average glucose levels assessed in each arm.

Secondary Outcome Measures

Outcome Measure	Time Frame
Change from baseline in circulating inflammatory cytokines after 4 days of intervention.	Fasting measurements taken on day 1 and day 5.
Change from baseline in toll-like receptors 2 and 4 expression on white blood cells after 4 days of intervention.	Fasting measurements taken on day 1 and day 5.
Change from baseline in flow mediated dilation of brachial artery after 4 days of intervention.	Fasting measurements taken on day 1 and day 5.

Other Outcome Measures

Outcome Measure	Time Frame
Change from baseline in flow-mediated dilation after single breakfast meal on day 1 of the intervention	Baseline and 1, 2, and 3 hours post-breakfast on day 1 in each arm
Change from baseline in plasma glucose after single breakfast meal on day 1 of the intervention	Baseline and 1, 2, and 3 hours post-breakfast on day 1 in each arm
Change from baseline in body weight after a single meal and 4 days of intervention.	Fasting measures on day 1 and day 5.

Collaborators and Investigators

• Sponsor: University of British Columbia
• Collaborators: Medtronic

Study record dates

Study Major Dates

• Study Start: November 1, 2015
• Primary Completion (Actual): June 1, 2017
• Study Completion (Actual): June 1, 2017

Study Registration Dates

• First Submitted: February 11, 2016
• First Submitted That Met QC Criteria: February 11, 2016
• First Posted (Estimate): February 17, 2016

Study Record Updates

• Last Update Posted (Actual): August 3, 2017
• Last Update Submitted That Met QC Criteria: August 1, 2017
• Last Verified: August 1, 2017

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Metabolic Diseases; Endocrine System Diseases; Diabetes Mellitus; Diabetes Mellitus, Type 2
• Other Study ID Numbers: H1501952

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO