The Impact of Bariatric Surgery on Adipocyte Metabolism

February 11, 2026 updated by: University of Chicago
The purpose of this study is to understand how daily rhythms of behavior affect the expression of genes in fat cells, and how these daily cycles affect the way fat cells respond to insulin (a hormone that controls blood sugar levels) before and after bariatric surgery.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Bariatric surgery as a means of weight loss has become increasingly popular over the last 10-15 years. In addition to promoting weight loss, bariatric surgery has become increasingly recognized for use in the management of diabetes. Recent studies have indicated that bariatric surgery can result in a marked improvement in insulin sensitivity before long term weight loss is attained. The goal of this project is to delineate the changes in the insulin responsiveness of subcutaneous adipocytes obtained by needle biopsy 2 weeks prior to surgery vs. 12 weeks after bariatric surgery, which could account for improvements in overall insulin sensitivity seen before any long-term sustained weight loss has occurred. The investigators will also examine gene expression in adipocytes (fat cells).

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
28

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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 Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United States
    • Illinois
      • Chicago, Illinois, United States, 60637
        • University of Chicago

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 55 years (Adult)

Accepts Healthy Volunteers

Yes

Description

Obese Subjects

Inclusion Criteria:

  • 18-55 years old
  • Female
  • BMI greater than 40 kg/m2
  • Scheduled for bariatric surgery at the Center for the Surgical Treatment of Obesity at the University of Chicago
  • Signed informed consent

Exclusion Criteria:

  • Male
  • Diagnosed with a systemic illnesses, including heart, renal, liver, or malignant disease
  • Uncontrolled hypertension (blood pressure greater than 140 mmHg systolic and 90 mmHg diastolic without medication)
  • use of beta blockers
  • hemoglobin less than 11.5g/dL
  • known allergy to lidocaine
  • pregnancy
  • lactation
  • Subjects will not have undergone surgery, donated a unit of blood, or participated in another clinical study within the last 4 weeks prior to consent.
  • Post-menopausal

Non-Obese Subjects

Inclusion Criteria:

  • 18-55 years old
  • Female
  • BMI less than 30 kg/m2
  • Signed informed consent

Exclusion Criteria:

  • Male
  • Diagnosed with a systemic illnesses, including heart, renal, liver, or malignant disease
  • Uncontrolled hypertension (blood pressure greater than 140 mmHg systolic and 90 mmHg diastolic without medication)
  • use of beta blockers
  • hemoglobin less than 11.5g/dL
  • known allergy to lidocaine
  • pregnancy
  • lactation
  • Subjects will not have undergone surgery, donated a unit of blood, or participated in another clinical study within the last 4 weeks prior to consent.
  • Post-menopausal

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: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Circadian Clock Alignment - High BMI
Subjects will come to the Sleep Lab three nights before their bariatric surgery procedure for an intervention that will align their central circadian clock. The intervention includes eating meals and snacks at fixed times and having lights off at a specific time at night and lights on at a specific time in the morning.
Behavioral: Circadian Clock Alignment
Use timed lights and meals to align the circadian clock
Active Comparator: Circadian Clock Control - High BMI
Subjects will not come to the Sleep Lab and will live normally at home with no changes to their meal, sleep or wake times.
Behavioral: Circadian Clock Control
No circadian clock alignment
Active Comparator: Circadian Clock Control - Low BMI
Subjects will not come to the Sleep Lab and will live normally at home with no changes to their meal, sleep or wake times.
Behavioral: Circadian Clock Control
No circadian clock alignment

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in insulin sensitivity
Time Frame: 12 weeks
Insulin sensitivity will be measured as the by the phosphorylation level of Akt in adipocytes (fat cells) at baseline and 12 weeks post bariatric surgery
12 weeks

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Chicago

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Matthew Brady, PhD, University of Chicago

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
March 26, 2015

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 15, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 15, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
January 23, 2020

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 23, 2020

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
January 27, 2020

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
February 13, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 11, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • IRB14-0984

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

There is currently no IRB approval or plan to make IPD available to other researchers.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

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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