AgingNCT04812392
Physical Inactivity Impacts on Blood Vessel Health and Glucose Levels in an Aging Population
A study testing Continuous Glucose Monitoring System in people with Aging and Cardiovascular Diseases, run by Leryn Reynolds at 1 site in United States.
Trial summary
Physical inactivity is known to increase post meal blood sugar levels in young, active populations. However, how quickly this may occur in active, older adults is not clear. Further, the relationship between blood vessel health and blood sugar disturbances which occur to acute physical inactivity is not clear. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Aging, Cardiovascular Diseases, Glucose Intolerance
- What is being tested?
- Continuous Glucose Monitoring System
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Apr 2021to 30 Jan 2022
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- 55 years and older, 18-40 years old
- Healthy, physically active, performing at least 90 min/week of physical activity
- Free of physical limitations that may interfere with alterations in daily physical activity levels
Who cannot join
- Physician diagnosed metabolic disease, HIV, hepatitis, or tuberculosis.
- Body weight change of greater than 5% within the previous 2 months
- Smoking within the previous 2 months.
- Taking medications that alter blood glucose levels
Trial locations and contacts
1 site in 1 country.
About this study
Official title: The Impact of 3 Days of Reduced Physical Activity on Endothelial Function and Glycemic Control in Active Older Adults
Physical inactivity is known to increase post meal blood sugar levels in young, active populations. However, how quickly this may occur in active, older adults is not clear. Further, the relationship between blood vessel health and blood sugar disturbances which occur to acute physical inactivity is not clear. It is unknown if impairments in blood vessel function precede increases in blood sugar levels that occurs with inactivity in an aging population. This study aims to determine if short term reductions in physical activity impair blood vessel health and blood glucose control to a greater extent in an aging population compared to a young population. The investigators hypothesize that 3 days of reduced physical activity will result in impaired blood vessel function and glycemic control in an aged population.
Read the detailed description
Subjects will undergo testing in 2 study phases separated by at least 2 weeks: 1) active phase: subjects will have post meal glucose levels measured across 3 days of participating in their normal exercise routines. Blood vessel health will also be measured via flow mediated dilation at the end of the 3 day monitoring period. 2) physically inactive phase: subjects will stop participating in exercise for 3 days while post meal glucose levels are measured. Blood vessel health will also be assessed on days 1, 3 of removal of exercise. The subject will need to come into the lab on these days of inactivity to have blood vessel health measured.
The study procedures are described below.
Continuous Glucose Monitoring The investigators would like to gain more information about how blood sugar levels change over the course of a day in a free living setting. To do this the investigators will use a continuous glucose monitoring system (CGMS). This system is what individuals with diabetes frequently use to monitor their glucose levels over the course of the day. Subjects will be asked to wear the CGMS for 3 consecutive, full days on 2 different occasions. This includes 3 days during their normal regular physical activity, then for 3 days following during the no exercise protocol. The CGMS is worn on the stomach, and it is a tiny glucose sensor which is inserted just under the skin. This device measures and records blood glucose values throughout the day. In addition, subjects will be asked to make at least four finger stick blood glucose readings taken with a standard glucose meter at different times each day and record these numbers on a log sheet. During the continuous glucose monitoring, subjects will need to consume the same type and quantity of foods at the same time each day (i.e. whatever the subjects consumes on day 1 of baseline testing, they need to eat that exact same food, volume of food and at the same time on days 1-3 of the study). Meals and snacks consumed are also entered into a paper-based diary.
Blood Vessel Health Measurement (Flow Mediated Dilation: FMD) Subjects will be asked to perform their normal exercise routines 12-16 hours prior to blood vessel health being measured in the active phase as well as prior to the first blood vessel health measurement in the inactive phase to control for the acute effects of exercise on blood vessel health. Blood vessel health will be measured at the end of the active phase in both groups of subjects. Further blood vessel health will be measured following 1, 3 days of being inactive in both groups of subjects. Blood flow to the leg will be measured by applying blood pressure cuffs around the ankle. Pre flow mediated dilation diameter and velocity are recorded for 3 minutes prior to a blood pressure cuff being inflated for 5 minutes. Following cuff deflation, a 2-minute diameter and velocity recording is collected.
- Conditions
- Aging, Cardiovascular Diseases, Glucose Intolerance
- Being tested
- Continuous Glucose Monitoring System
- Keywords
- diabetes, physical inactivity, vascular function
- Medical subject headings
- Cardiovascular Diseases, Glucose Intolerance, Diabetes Mellitus, Sedentary Behavior
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Continuous Glucose Monitoring SystemDevice
Subjects will wear a continuous glucose monitoring system for 3 days during the 3 day reduced physical activity phase.
| Study group | Role | What they receive |
|---|---|---|
| Acute Physical Inactivity | Experimental | Subjects will undergo 3 days of reduced physical activity. Receives: Device: Continuous Glucose Monitoring System |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in glycemic control during a reduced physical activity state
The change in blood glucose levels measured following consumption of a meal will be assessed before inactivity and following 3 days of inactivity.
Measured: The change of blood glucose values from pre-inactivity and following 3 days of inactivity
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Mar 2021
- Study start1 Apr 2021
- Primary completion30 Jan 2022
- Study completion30 Jan 2022
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for AgingStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 20 participants (actual)
Sponsor and investigators
- Lead sponsor
- Leryn Reynolds
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Leryn Reynolds, Old Dominion University
- Investigators
- Leryn Reynolds, Ph.D., Principal investigator, Old Dominion University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04812392
- Sponsor's protocol ID
- ERP-2021-12576
- Status last verified
- Mar 2026
- First submitted
- 16 Mar 2021
- Last updated
- 4 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 4 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Impact of 3 Days of Reduced Physical Activity on Endothelial Function and Glycemic Control in Active Older Adults
- ClinicalTrials.gov ID
- NCT04812392
- Acronym / sponsor ID
- ERP-2021-12576
- Conditions
- Aging, Cardiovascular Diseases, Glucose Intolerance
- Keywords
- diabetes, physical inactivity, vascular function
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 20 participants (actual)
- Lead sponsor
- Leryn ReynoldsUniversity, hospital or other
- Study start
- 1 Apr 2021 (actual)
- Primary completion
- 30 Jan 2022 (actual)
- Study completion
- 30 Jan 2022 (actual)
- First posted
- 23 Mar 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Physical inactivity is known to increase post meal blood sugar levels in young, active populations. However, how quickly this may occur in active, older adults is not clear. Further, the relationship between blood vessel health and blood sugar disturbances which occur to acute physical inactivity is not clear. It is unknown if impairments in blood vessel function precede increases in blood sugar levels that occurs with inactivity in an aging population. This study aims to determine if short term reductions in physical activity impair blood vessel health and blood glucose control to a greater extent in an aging population compared to a young population. The investigators hypothesize that 3 days of reduced physical activity will result in impaired blood vessel function and glycemic control in an aged population.
Detailed description
Subjects will undergo testing in 2 study phases separated by at least 2 weeks: 1) active phase: subjects will have post meal glucose levels measured across 3 days of participating in their normal exercise routines. Blood vessel health will also be measured via flow mediated dilation at the end of the 3 day monitoring period. 2) physically inactive phase: subjects will stop participating in exercise for 3 days while post meal glucose levels are measured. Blood vessel health will also be assessed on days 1, 3 of removal of exercise. The subject will need to come into the lab on these days of inactivity to have blood vessel health measured.
The study procedures are described below.
Continuous Glucose Monitoring The investigators would like to gain more information about how blood sugar levels change over the course of a day in a free living setting. To do this the investigators will use a continuous glucose monitoring system (CGMS). This system is what individuals with diabetes frequently use to monitor their glucose levels over the course of the day. Subjects will be asked to wear the CGMS for 3 consecutive, full days on 2 different occasions. This includes 3 days during their normal regular physical activity, then for 3 days following during the no exercise protocol. The CGMS is worn on the stomach, and it is a tiny glucose sensor which is inserted just under the skin. This device measures and records blood glucose values throughout the day. In addition, subjects will be asked to make at least four finger stick blood glucose readings taken with a standard glucose meter at different times each day and record these numbers on a log sheet. During the continuous glucose monitoring, subjects will need to consume the same type and quantity of foods at the same time each day (i.e. whatever the subjects consumes on day 1 of baseline testing, they need to eat that exact same food, volume of food and at the same time on days 1-3 of the study). Meals and snacks consumed are also entered into a paper-based diary.
Blood Vessel Health Measurement (Flow Mediated Dilation: FMD) Subjects will be asked to perform their normal exercise routines 12-16 hours prior to blood vessel health being measured in the active phase as well as prior to the first blood vessel health measurement in the inactive phase to control for the acute effects of exercise on blood vessel health. Blood vessel health will be measured at the end of the active phase in both groups of subjects. Further blood vessel health will be measured following 1, 3 days of being inactive in both groups of subjects. Blood flow to the leg will be measured by applying blood pressure cuffs around the ankle. Pre flow mediated dilation diameter and velocity are recorded for 3 minutes prior to a blood pressure cuff being inflated for 5 minutes. Following cuff deflation, a 2-minute diameter and velocity recording is collected.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Acute Physical Inactivity | Experimental | Device: Continuous Glucose Monitoring SystemSubjects will undergo 3 days of reduced physical activity. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- 55 years and older, 18-40 years old
- Healthy, physically active, performing at least 90 min/week of physical activity
- Free of physical limitations that may interfere with alterations in daily physical activity levels
Key exclusion criteria (4 listed)
- Physician diagnosed metabolic disease, HIV, hepatitis, or tuberculosis.
- Body weight change of greater than 5% within the previous 2 months
- Smoking within the previous 2 months.
- Taking medications that alter blood glucose levels
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Continuous Glucose Monitoring SystemSubjects will wear a continuous glucose monitoring system for 3 days during the 3 day reduced physical activity phase. | Device | Acute Physical Inactivity |
Primary outcome
Change in glycemic control during a reduced physical activity state
Time frame: The change of blood glucose values from pre-inactivity and following 3 days of inactivity
The change in blood glucose levels measured following consumption of a meal will be assessed before inactivity and following 3 days of inactivity.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Mar 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Leryn Reynolds, Ph.D. principal investigator
Old Dominion University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Continuous Glucose Monitoring System in people with Aging and Cardiovascular Diseases, run by Leryn Reynolds at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 4 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in glycemic control during a reduced physical activity state (time frame: The change of blood glucose values from pre-inactivity and following 3 days of inactivity). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 Mar 2026.