The Effect of Sitting and Moderate Exercise on Plasma Insulin and Glucose Responses to an Oral Glucose Tolerance Test

NCT ID: NCT04195165

Last Updated: 2019-12-11

Basic Information

• Recruitment Status: UNKNOWN
• Clinical Phase: NA
• Total Enrollment: 12 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2019-09-23
• Study Completion Date: 2020-09-23

Brief Summary

The investigators hypothesize that cycling for 1 hour of exercise at 65% peak oxygen consumption (VO2peak) after sitting >13 hr/day (SIT+EX) will not be different in postprandial plasma insulin responses compared to the control of only sitting (SIT). Furthermore, the investigators hypothesize that the SIT and SIT+EX groups will have a less favorble insulin response compared to the physically active group after performing the same 1-hour exercise bout (ACTIVE+EX).

Detailed Description

Twelve healthy, untrained male and female participants will complete three different trials in a randomized, crossover design, each occurring over 4 days with a 3-4 day interval between the trials. Each trial consists of 3 phases. The first two days will serve as a control phase (C1) that will allow for familiarization, followed by a 2-day intervention phase consisting of 2 days of sitting 13 h/d for both groups (D1- D2) (SIT+EX and ACTIVE+EX). On the evening of Day 2 the SIT+EX and ACTIVE+EX groups will cycle for 1 hour at 65% of VO2peak. On the morning of Day 3 participants in all conditions will ingest a drink containing 75-g of glucose and undergo a two-hour oral glucose tolerance test (OGTT). For all trials, participants will refrain from any exercise other than that described for the study.

One week prior to the initiation of the first trial, participants will visit the Human Performance Laboratory (HPL) for a 10 min exercise test to measure peak oxygen uptake while cycling (VO2peak). On the same day, participants will be instrumented with an activity monitor worn on their thigh to record time sitting, standing and lying as well as step count (activPal). During the two control day (C1), participants will be asked to refrain from any planned exercise but will be asked to walk or move between 6,000 - 7,500 steps per day, which is considered to be 'low level of physical activity'(31). During the intervention days (D1-D2), those completing SIT and SIT+EX conditions will be asked to remain seated throughout much of the day and achieve <3,000 steps, while those completing the ACTIVE+EX condition will be asked to break up their sitting with low-intensity physical activity, not exercise, and achieve >10,000 steps. However, the only difference between trials is that at 18:00 h during SIT+EX and ACTIVE+EX they will cycle for 1-hr at 65% VO2peak.

On the day of the OGTT (D3), participants will report to the laboratory at 07:00 h. Body weight will be measured. They will lay down for 5 minutes and a catheter will be inserted into an antecubital vein and a fasting blood sample will then be collected 10 min before consumption of high-glucose drink (75 g) composed of water and glucose monohydrate. Approximately 5 ml of blood will be collected at 10, 20, 30, 60, 90 and 120 min after ingestion. Approximately 60 ml of blood will be sampled during each of the three trials and thus the total will amount to approximately 180 ml (6 ounces, 12 tablespoons). This amounts to approximately 2-4% of a person's total blood volume.

All blood samples collected will be transferred to K2 EDTA collection tubes, centrifuged at 2,000 g for 15 minutes at 4◦C and then stored in -80◦C freezer until later analysis. During OGTT, participants will sit quietly reading, watching movies, and/or surfing the Internet. Participants will also be asked to keep a consistent sleep/wake cycle during the trials.

Conditions

Sedentary Behavior; Insulin Sensitivity; Sedentary Lifestyle

Keywords

glucose tolerance; exercise; insulin sensitivity

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

SIT

Subject will be asked to take \<3,000 steps for two intervention days prior to an oral glucose tolerance test on the third day.

Group Type: EXPERIMENTAL

SIT

Intervention Type: BEHAVIORAL

For the SIT and SIT+EX conditions, the subject will be asked to take \<3,000 steps. This is meant to achieve \~12-13 hours of sitting per day, are the investigators are measuring the effect of inactivity and exercise on insulin sensitivity.

SIT+EX

Subject will be asked to take \<3,000 steps for two intervention days. On the evening of the second intervention day, the subject will cycle for one hour at 65% of VO2peak. The subject will undergo an oral glucose tolerance test on the morning of the third day.

Group Type: EXPERIMENTAL

SIT

Intervention Type: BEHAVIORAL

For the SIT and SIT+EX conditions, the subject will be asked to take \<3,000 steps. This is meant to achieve \~12-13 hours of sitting per day, are the investigators are measuring the effect of inactivity and exercise on insulin sensitivity.

EX

Intervention Type: BEHAVIORAL

The SIT+EX and ACTIVE+EX conditions will include an exercise bout on the evening of the second intervention day, and have the oral glucose tolerance test the next morning.

ACTIVE+EX

Subject will be asked to take \>10,000 steps for two intervention days. On the evening of the second intervention day, the subject will cycle for one hour at 65% of VO2peak. The subject will undergo an oral glucose tolerance test on the morning of the third day.

Group Type: EXPERIMENTAL

ACTIVE

Intervention Type: BEHAVIORAL

For the ACTIVE+EX condition, the subject will be asked to take \>10,000 steps for the two intervention days. This is meant to simulate an active lifestyle.

EX

Intervention Type: BEHAVIORAL

The SIT+EX and ACTIVE+EX conditions will include an exercise bout on the evening of the second intervention day, and have the oral glucose tolerance test the next morning.

Interventions

SIT

For the SIT and SIT+EX conditions, the subject will be asked to take \<3,000 steps. This is meant to achieve \~12-13 hours of sitting per day, are the investigators are measuring the effect of inactivity and exercise on insulin sensitivity.

Intervention Type: BEHAVIORAL

ACTIVE

For the ACTIVE+EX condition, the subject will be asked to take \>10,000 steps for the two intervention days. This is meant to simulate an active lifestyle.

Intervention Type: BEHAVIORAL

EX

The SIT+EX and ACTIVE+EX conditions will include an exercise bout on the evening of the second intervention day, and have the oral glucose tolerance test the next morning.

Intervention Type: BEHAVIORAL

Other Intervention Names

Exercise

Eligibility Criteria

Inclusion Criteria

• Healthy, untrained/recreationally active men and women.
• Women must not be pregnant or post-menopausal.

Exclusion Criteria

• Heart problems or coronary artery disease
• Hypertension
• Lung or respiratory problems
• Chest pain, fainting, or heart palpitations during exercise, or told to give up sports because of health problems.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 40 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

University of Texas at Austin

OTHER

Sponsor Role: lead

Responsible Party

Michael B. Dial

Graduate Student

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Michael B Dial

Role: PRINCIPAL_INVESTIGATOR

University of Texas at Austin

Locations

University of Texas at Austin

Austin, Texas, United States

Site Status: RECRUITING

Countries

United States

Central Contacts

Michael B Dial

Role: CONTACT

Phone: 8018915699

Email: Michael.dial@utexas.edu

Facility Contacts

Michael B Dial

Role: primary

Other Identifiers

2019-08-0011

Identifier Type: -

Identifier Source: org_study_id