Adipose Tissue Blood Flow in Aging Humans

April 27, 2026 updated by: Kelli A. Lytle, Mayo Clinic

The goal of this basic science clinical trial is to understand whether adipose tissue blood flow changes between younger and older healthy adults.

The main question[s] it aims to answer are:

  • Is basal and nutrient responsive adipose tissue blood flow (ATBF) different between younger and older adults
  • What molecular and systemic signatures related to adipose tissue blood flow are altered between these two groups.

Participants will undergo measurements of adipose tissue blood flow using the xenon washout technique, undergo 2 abdominal subcutaneous adipose tissue biopsies, and drink a sugary drink.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

On Visit 1, volunteers will provide written informed consent (and urine pregnancy test for women of childbearing age), complete a Dual x-ray absorptiometry scan, baseline labs (comprehensive metabolic panel) and a cardiopulmonary exercise test. Participants will arrive fasted at 08:00, and urine pregnancy test for women of childbearing age administered and an intravenous catheter will be placed. Following 30min of supine rest, baseline venous blood samples will be collected. ATBF will be assessed on participants' left abdomen first by measurement of blood flow using 133Xenon washout method. Immediately thereafter, an abdominal adipose tissue biopsy of the left side will be performed but ≥6 cm distant from location of 133Xenon injections. Subjects will them consume 75 gm glucose; because ATBF peaks 30-60 minutes following ingestion of glucose, ATBF measures will start 30 minutes after ingestion on the contralateral side followed immediately by plasma measures and another adipose tissue biopsy. During ATBF measurements, brachial blood pressure will be assessed in two-minute intervals.

Study Type

Interventional

Enrollment (Estimated)

24

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Minnesota
      • Rochester, Minnesota, United States, 55905
        • Recruiting
        • Mayo Clinic Minnesota
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion criteria

  • Within the ages of 18-35 years or 65-80 years at time of study visit
  • BMI between 20-25.0 kg/m2.

Exclusion criteria:

  • Presence of diagnosed cardiometabolic diseases (e.g., Type 2 diabetes, hypertension, Heart Failure)
  • Taking prescription anticoagulants
  • Taking prescriptions or supplements that effect adipose tissue metabolism (i.e., statins, Thiazolidinediones, niacin, atypical antipsychotics, or fish oil)
  • Pregnant or nursing
  • Inability to provide written informed consent
  • Smokers

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: Older Adults
Other: 75 gm oral glucose load
Consumption of 75 gm oral glucose load in order to test nutrient responsiveness
Active Comparator: Younger Adults
Other: 75 gm oral glucose load
Consumption of 75 gm oral glucose load in order to test nutrient responsiveness

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Adipose tissue blood flow
Time Frame: Baseline, pre-intervention fasting and immediately following 75 gm oral glucose load
blood flow will be measured in the upper body subcutaneous adipose tissue using 133 Xenon washout and reported as blood flow in ml/min/100g adipose tissue.
Baseline, pre-intervention fasting and immediately following 75 gm oral glucose load

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Genomic alterations
Time Frame: Baseline, pre-intervention fasting and immediately following 75 gm oral glucose load
RNA-Seq from adipose tissue biopsies
Baseline, pre-intervention fasting and immediately following 75 gm oral glucose load

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Mayo Clinic

Collaborators

National Center for Advancing Translational Sciences (NCATS)

Investigators

  • Principal Investigator: Kelli Lytle, PhD, Mayo Clinic

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 15, 2024

Primary Completion (Estimated)

December 30, 2028

Study Completion (Estimated)

December 30, 2028

Study Registration Dates

First Submitted

September 26, 2023

First Submitted That Met QC Criteria

October 19, 2023

First Posted (Actual)

October 23, 2023

Study Record Updates

Last Update Posted (Actual)

May 1, 2026

Last Update Submitted That Met QC Criteria

April 27, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • 23-004200
  • UL1TR002377 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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