Effects of Tirzepatide on Muscle and Vascular Health in Obese Older Adults

April 10, 2026 updated by: Shreya Rao, The University of Texas Health Science Center at San Antonio

The Effects of Tirzepatide Use on Muscle and Vascular Function Among Obese Older Adults

Obesity and type 2 diabetes mellitus (T2DM) represent major public health concerns in the aging community. Tirzepatide, a novel dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist recently approved for the treatment of T2DM and obesity has been shown to be effective at reducing weight, improving markers of T2DM control, and improving cardiovascular health. Utilization of tirzepatide among older adults has been on the rise since FDA approval was issued, however the effects of tirzepatide use on functional outcomes in older adults with obesity are not well established. Recent studies show that weight loss caused by tirzepatide may be driven by substantial loss of lean muscle mass, which may contribute to weakness and frailty, particularly among older adults. The proposed pilot study aims to evaluate how treatment with tirzepatide for 6 months affects muscle mass and function among older adults, and if changes in muscle mass are linked to changes in functional status over the same time period.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

This study is a pilot, single-arm, open-label clinical trial to evaluate the effects of Tirzepatide on muscle mass, strength, and vascular health among older adults with obesity. This study is set in South Texas, where rates of obesity and related health issues, including type 2 diabetes and cardiovascular conditions, exceed national averages and where aging-related diseases are on the rise. Tirzepatide is a new FDA approved medication that promotes weight loss and improves health by targeting specific pathways in the body. While it has been shown to be effective in managing weight and blood sugar levels, there is less information about the kind of weight loss it induces, and how weight loss impacts measures of muscle mass, strength and mobility. This is especially concerning for older adults, as losing muscle mass can lead to weakness, falls, and disability.

Study Type

Interventional

Enrollment (Estimated)

20

Phase

  • Phase 2

Contacts and Locations

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

Study Contact

Study Locations

  • United States
    • Texas
      • San Antonio, Texas, United States, 78229
        • Recruiting
        • University of Texas Health Science Center at San Antonio
        • 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

No

Description

Inclusion Criteria

  • Men and postmenopausal women aged 50 years or older.
  • Body Mass Index (BMI) ≥30 kg/m².
  • Untreated HbA1c <6.5% at baseline.
  • Willingness and ability to comply with all study procedures, including fasting requirements for certain visits.
  • Able to provide informed consent and participate in all study assessments.

Exclusion Criteria

  • Active diagnosis of type 2 diabetes mellitus (T2DM), defined by active use of glucose-lowering medications or hemoglobin A1c ≥ 6.5%.
  • Body Mass Index (BMI) ≥ 40 kg/m².
  • Moderate to severe gastroesophageal reflux disease based on patient history.
  • Inability to comply with the treatment protocol or to understand the consent form.
  • Chronic Kidney Disease (CKD) Stage 4.
  • Aspartate aminotransferase (AST) > 33 U/L or alanine aminotransferase (ALT) > 36 U/L.
  • Active pregnancy.
  • Personal or family history of medullary thyroid carcinoma.
  • Personal or family history of multiple endocrine neoplasia type 2 syndrome.
  • Personal history of gastroparesis.
  • Personal history of diabetic retinopathy.
  • Known serious hypersensitivity, including anaphylaxis and angioedema, to Tirzepatide or any of its excipients.
  • Known serious hypersensitivity, including anaphylaxis and angioedema, to any GLP-1 receptor agonist class of therapies.
  • Concomitant treatment with GLP-1 receptor agonist therapy

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: Other
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Tirzepatide
Tirzepatide self-administered once weekly by subcutaneous injection
Drug: Tirzepatide
Once weekly tirzepatide starting at 2.5 mg/weekly, with dose escalation monthly by 2.5 mg to a target dose of 10 mg/weekly or maximum tolerated
Other Names:
  • Zepbound, LY3298176

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Appendicular lean muscle mass
Time Frame: 6 months
Appendicular lean muscle mass assessed at baseline and at 6-month follow-up by dual-energy X-ray absorptiometry (DEXA)
6 months
Muscle Strength
Time Frame: 6 months
Muscle strength assessed by isokinetic and isometric testing using Biodex dynamometry at baseline and at 6-month follow-up.
6 months
Lower Extremity Functional Capacity
Time Frame: 6 months
Functional capacity will be measured using the 6-minute walk test (6MWT) at baseline and 6-month follow up visit.
6 months

Collaborators and Investigators

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

Sponsor

The University of Texas Health Science Center at San Antonio

Investigators

  • Principal Investigator: Elena Volpi, MD, PhD, The University of Texas Health Science Center at San Antonio
  • Principal Investigator: Shreya Rao, MD, MPH, The University of Texas Health Science Center at San Antonio
  • Study Director: Tiffany Cortes, MD, The University of Texas Health Science Center at San Antonio

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.

General Publications

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)

April 1, 2026

Primary Completion (Estimated)

April 1, 2027

Study Completion (Estimated)

June 1, 2027

Study Registration Dates

First Submitted

January 31, 2025

First Submitted That Met QC Criteria

January 31, 2025

First Posted (Actual)

February 6, 2025

Study Record Updates

Last Update Posted (Actual)

April 15, 2026

Last Update Submitted That Met QC Criteria

April 10, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • STUDY00001208

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

De-identified individual participant data that underlie the results reported will be available in accordance with ICMJE policy.

IPD Sharing Time Frame

Data will be available beginning 1 year after the end of the trial and publication of the primary outcomes, and will be available for 24 months.

IPD Sharing Access Criteria

Data will be available to researchers who provide a methodologically sound proposals. Proposals should be directed to the principal investigators. To gain access, data requestors will need to sign a data access agreement.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

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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