Effects of Diet and Exercise on Circadian Glycemia

Glucose Intolerance Clinical Trial

— GLYCEMIA  

Official title:

Control of Postprandial Glycemia: the Roles of Diet and Exercise

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03922685
• Other study ID #: HUM00110793
• Status: Completed
• Phase: N/A
• Start date: September 1, 2016
• Est. completion date: April 2019

Study information

• Verified date: April 2019
• Source: University of Michigan
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Specific aims of the study are:

1. to evaluate whether a 24-h exposure to a 25%-carbohydrate diet will reduce postprandial glycemia to the same extent in the evening (19 h) as in the morning (7 h),. and

2. to determine whether one hour of post-meal moderate intensity exercise (at 50% of maximal effort) will further reduce postprandial glycemia.

The outcome measures are: plasma concentrations of glucose, insulin, glucose-dependent-insulinotropic peptide (GIP), leptin, and the ketone body beta-hydroxybutyrate.

Description:

The two hypotheses in this study are:

1. A 24-h exposure to a 25%-carbohydrate diet will reduce postprandial glycemia to the same extent in the evening (19 h) as in the morning (7 h), and

2. One hour of moderate-intensity exercise (at 50% of maximal effort) will further reduce postprandial glycemia to the same extent in the evening (19 h) as in the morning (7 h).

Eight postmenopausal subjects (age 58.5 years, BMI 25.6 kg/m2) participated in 4 24-h long crossover trials, two terminating at 7h and the other 2 at 19h. At each circadian time one trial required 60 minutes of moderate-intensity exercise (50% of maximal effort), and the other two involved no exercise.

Three 25%-carbohydrate meals prepared by the Michigan Clinical Research Unit (MCRU) kitchen, were eaten at subjects' home, and the fourth was eaten 20 minutes after subjects' arrival at MCRU at either 19 h or 7 h. Blood was collected from antecubital catheter at 10-minute intervals until 23:20 h or 11:20 h, respectively.Plasma was treated with protease inhibitor to preserve GIP, frozen at -80o C until glucose measurements by glucose oxidase, hormone measurements by chemiluminescence, and ketone measurements by Abbott meter strips.

Exercise intensity was determined before the exercise trials on a treadmill from oxygen consumption (VO2) and carbon dioxide production (VCO2) by subjects walking on a treadmill at 3 mph with the treadmill slope increased by 2% every 3 minutes. Maximal effort was established when respiratory exchange ratio (VCO2/VO2) reached or exceeded 1. The treadmill speed and slope at half maximal effort was used during the one-hour exercise bout which was initiated 40 minutes after the start of the meal.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 8
• Est. completion date: April 2019
• Est. primary completion date: August 31, 2017
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Female
• Age group: 50 Years to 65 Years

Eligibility

Inclusion Criteria:

• postmenopausal

• normal blood glucose

• no cholesterol medication

• age between 50 an 65 years

• overweight but not obese

• BMI between 25 and 30 kg/m2

• weight-stable during past 6 months

• exercise less than 20 minutes three times a week

Exclusion Criteria:

• metabolic disease other than hormonally-corrected hypothyroidism

• musculo-skeletal disability that would preclude exercise

• smoker

• do not meet inclusion criteria

Related Conditions & MeSH terms

• Glucose Intolerance

Intervention

Combination Product:
• Dietary manipulation (25% carbohydrate diet) and behavioral (exercise)
The 25% carbohydrate diet consisted of Pulmocare-vanilla liquid, white roll, butter, and string cheese in proportions to achieve 33% of weigh-maintenance diet containing 25% carbohydrate, 20% protein, and 55% fat. Exercise was walking 1 hour on level treadmill at 50% of maximal effort starting 40 minutes after the beginning of the meal
• Dietary manipulation (25% carbohydrate diet) and behavioral (sedentary)
The 25% carbohydrate diet consisted of Pulmocare-vanilla liquid, white roll, butter, and string cheese in proportions to achieve 33% of weigh-maintenance diet containing 25% carbohydrate, 20% protein, and 55% fat. There was no exercise during this trial.

Locations

Country	Name	City	State
n/a

Sponsors (2)

Lead Sponsor	Collaborator
University of Michigan	Northern Michigan University

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Postprandial glucose concentration	The area under the postprandial glucose curve	Four hours: 19:20 to 23:20 in the evening trials; 7:20 to 11:20 in the morning trials
Primary	Postprandial insulin concentration	The area under the postprandial insulin curve	Four hours: 19:20 to 23:20 in the evening trials; 7:20 to 11:20 in the morning trials
Secondary	Postprandial glucose-dependent insulinotropic peptide (GIP) concentration	The area under the postprandial GIP curve	Four hours: 19:20 to 23:20 in the evening trials; 7:20 to 11:20 in the morning trials
Secondary	Postprandial beta-hydroxybutyrate concentration	The area under the beta-hydroxybutyrate postprandial curve	Four hours: 19:20 to 23:20 in the evening trials; 7:20 to 11:20 in the morning trials
Secondary	Postprandial leptin concentration	The area under the leptin postprandial curve	Four hours: 19:20 to 23:20 in the evening trials; 7:20 to 11:20 in the morning trials