The Impact of Bariatric Surgery on Adipocyte Metabolism

NCT ID: NCT04242524

Last Updated: 2025-11-24

Basic Information

• Recruitment Status: ACTIVE_NOT_RECRUITING
• Clinical Phase: NA
• Total Enrollment: 82 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2015-03-26
• Study Completion Date: 2025-12-31

Brief Summary

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.

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).

Conditions

Metabolic Syndrome; Obesity

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

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.

Group Type: EXPERIMENTAL

Circadian Clock Alignment

Intervention Type: BEHAVIORAL

Use timed lights and meals to align the circadian clock

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.

Group Type: ACTIVE_COMPARATOR

Circadian Clock Control

Intervention Type: BEHAVIORAL

No circadian clock alignment

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.

Group Type: ACTIVE_COMPARATOR

Circadian Clock Control

Intervention Type: BEHAVIORAL

No circadian clock alignment

Interventions

Circadian Clock Alignment

Use timed lights and meals to align the circadian clock

Intervention Type: BEHAVIORAL

Circadian Clock Control

No circadian clock alignment

Intervention Type: BEHAVIORAL

Eligibility Criteria

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

• 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

Non-Obese Subjects

• 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

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 55 Years
• Eligible Sex: FEMALE
• Accepts Healthy Volunteers: Yes

Sponsors

University of Chicago

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Matthew Brady, PhD

Role: PRINCIPAL_INVESTIGATOR

University of Chicago

Locations

University of Chicago

Chicago, Illinois, United States

Countries

United States

Other Identifiers

IRB14-0984

Identifier Type: -

Identifier Source: org_study_id