Sympathetic Activation in Obesity

NCT ID: NCT04946552

Last Updated: 2024-02-16

Study Results

Results available

Outcome measurements, participant flow, baseline characteristics, and adverse events have been published for this study.

View full results

Basic Information

Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.

Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

5 participants

Study Classification

INTERVENTIONAL

Study Start Date

2021-11-23

Study Completion Date

2022-09-30

Brief Summary

Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.

The primary objective of this study is to determine whether sympathetic nervous system (SNS) activity in white adipose tissue (WAT) and brown adipose tissue (BAT), skeletal muscle and brain is altered in individuals with obesity in comparison to individuals with normal weight. Simultaneous multi-organ SNS activation will be obtained with a radiotracer for norepinephrine transporter (NET) for whole-body Positron Emission Tomography (PET) imaging and microneurography (peroneal muscle SNS activity).

The secondary objectives of this study are: 1) to evaluate whether gender differences affect peripheral SNS in healthy normal weight and obese men and women in adipose tissue (WAT and BAT) and muscle (resting/fasting); 2) To investigate the relationship between peripheral and central SNS activity in obesity, by correlating SNS activity in peripheral tissues (WAT, BAT, and muscle) and brain; and 3) To investigate NET CNS and peripheral SNS activity before and after a high carbohydrate mixed meal in lean and obese men and women.

Detailed Description

Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.

Conditions

See the medical conditions and disease areas that this research is targeting or investigating.

Obesity Healthy

Study Design

Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.

Allocation Method

NON_RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

BASIC_SCIENCE

Blinding Strategy

NONE

Study Groups

Review each arm or cohort in the study, along with the interventions and objectives associated with them.

Individuals with normal BMI

(BMI 18-25 kg/m2)

Group Type ACTIVE_COMPARATOR

PET Scan

Intervention Type DIAGNOSTIC_TEST

Participants will come to the PET Center to undergo the whole body \[11C\]MRB PET scan. An intravenous bolus dose of MRB (\~20mCi) will be injected by an infusion pump. PET data will be acquired dynamically for 120 min using the Siemens mCT-X whole-body PET/CT scanner using continuous bed motion to image multiple PET bed acquisitions from the top of the head to the lower abdominal region.

Mixed Meal Test

Intervention Type DIETARY_SUPPLEMENT

High Carbohydrate Mixed Meal Test (MMT): participants will be studied after a 10-hour overnight fast. A nurse will insert an intravenous (IV) catheter and subjects will ingest a liquid meal (65% carbohydrate, 20% fat, and 15% protein, corresponding to 40% of daily energy expenditure, in \~16 ounces) to be prepared by the Hospital Research Unit Metabolic Kitchen. Blood samples will be collected at -10, 0, 15, 30, 60, 90, and 120 min) for measurement of glucose, insulin and C-peptide concentrations. Plasma samples will be drawn at baseline and throughout the MMT for measurement of additional hormones (such as thyroid hormones, and catecholamines) and free fatty acids (FFA) levels.

Muscle sympathetic nerve activity (MSNA)

Intervention Type DIAGNOSTIC_TEST

Recording of multiunit postganglionic muscle sympathetic nerve activity (MSNA) will be made from the common peroneal nerve as it winds around the fibular head with the subject in the supine position with the subject's thigh comfortably supported. This procedure requires to first trace the course of the nerve using small electrical stimuli applied to the surface of the skin over the nerve or use of ultrasound to visually assist.

Oral Glucose Tolerance Test

Intervention Type DIAGNOSTIC_TEST

Following a 10-hour overnight fast, a nurse will insert an intravenous (IV) catheter. Subsequently, subjects will ingest 7.5 oz of Glucola, which contains 75 g of dextrose in orange flavored water. Blood samples will be taken at -15, 0, 10, 20, 30, 60, 90 and 120 minutes (after glucola ingestion) for the measurement of plasma glucose, insulin, and C-peptide concentrations, and calculation of measurements of insulin sensitivity index (Matsuda Index). Approximately 40 mL of blood will be drawn at this visit.

Body Composition, Percent Body Fat & Percent Body Water (Tanita scale)

Intervention Type OTHER

will be assessed using bioelectrical impedance analysis Tanita® scale; which is a special multi frequency segmental body composition analyzer that delivers a very mild electrical current that allows measurement of fat mass, percent body fat, fat free mass, total body water, and percent body water. This test will be performed at screening visit.

CT Scan

Intervention Type DIAGNOSTIC_TEST

A CT scan will be performed for attenuation correction and to help delineate the BAT and other regions of interest (ROIs). Images will be reconstructed with an ordered subset expectation maximization algorithm using point spread function correction and time-of-flight information. To delineate fat (WAT, BAT) and skeletal muscle regions of interests (ROIs), CT images are first resliced to match the resolution and location of PET images. As performed in previous studies 2, a supraclavicular ROI is first manually drawn on the CT images. Within that area, the fat ROI is segmented using the CT images and an intensity window from -200 to -50 HU. Subsequently the fat ROI is segmented into WAT and BAT ROIs by using the 11C-MRB PET images: Standardized Uptake Value (SUV) ≥ 1.25 for BAT, SUV \< 1.25 for WAT.

Body Composition, Percent Body Fat & Percent Body Water (DXA Scan)

Intervention Type OTHER

For better accuracy, measurement of percent fat and percent body water will be obtained with whole body Dual X-Ray Absorptiometry (DXA) scan (Hologic®) on screening-OGTT visit. The scanner arm will move over the participant's body from feet to head. The machine uses a small amount of radiation (one tenth of the amount of radiation from a chest x-ray) to measure body fat, muscle and bone density.

Individuals with obesity

(BMI 30-40 kg/m2)

Group Type ACTIVE_COMPARATOR

PET Scan

Intervention Type DIAGNOSTIC_TEST

Participants will come to the PET Center to undergo the whole body \[11C\]MRB PET scan. An intravenous bolus dose of MRB (\~20mCi) will be injected by an infusion pump. PET data will be acquired dynamically for 120 min using the Siemens mCT-X whole-body PET/CT scanner using continuous bed motion to image multiple PET bed acquisitions from the top of the head to the lower abdominal region.

Mixed Meal Test

Intervention Type DIETARY_SUPPLEMENT

High Carbohydrate Mixed Meal Test (MMT): participants will be studied after a 10-hour overnight fast. A nurse will insert an intravenous (IV) catheter and subjects will ingest a liquid meal (65% carbohydrate, 20% fat, and 15% protein, corresponding to 40% of daily energy expenditure, in \~16 ounces) to be prepared by the Hospital Research Unit Metabolic Kitchen. Blood samples will be collected at -10, 0, 15, 30, 60, 90, and 120 min) for measurement of glucose, insulin and C-peptide concentrations. Plasma samples will be drawn at baseline and throughout the MMT for measurement of additional hormones (such as thyroid hormones, and catecholamines) and free fatty acids (FFA) levels.

Muscle sympathetic nerve activity (MSNA)

Intervention Type DIAGNOSTIC_TEST

Recording of multiunit postganglionic muscle sympathetic nerve activity (MSNA) will be made from the common peroneal nerve as it winds around the fibular head with the subject in the supine position with the subject's thigh comfortably supported. This procedure requires to first trace the course of the nerve using small electrical stimuli applied to the surface of the skin over the nerve or use of ultrasound to visually assist.

Oral Glucose Tolerance Test

Intervention Type DIAGNOSTIC_TEST

Following a 10-hour overnight fast, a nurse will insert an intravenous (IV) catheter. Subsequently, subjects will ingest 7.5 oz of Glucola, which contains 75 g of dextrose in orange flavored water. Blood samples will be taken at -15, 0, 10, 20, 30, 60, 90 and 120 minutes (after glucola ingestion) for the measurement of plasma glucose, insulin, and C-peptide concentrations, and calculation of measurements of insulin sensitivity index (Matsuda Index). Approximately 40 mL of blood will be drawn at this visit.

Body Composition, Percent Body Fat & Percent Body Water (Tanita scale)

Intervention Type OTHER

will be assessed using bioelectrical impedance analysis Tanita® scale; which is a special multi frequency segmental body composition analyzer that delivers a very mild electrical current that allows measurement of fat mass, percent body fat, fat free mass, total body water, and percent body water. This test will be performed at screening visit.

CT Scan

Intervention Type DIAGNOSTIC_TEST

A CT scan will be performed for attenuation correction and to help delineate the BAT and other regions of interest (ROIs). Images will be reconstructed with an ordered subset expectation maximization algorithm using point spread function correction and time-of-flight information. To delineate fat (WAT, BAT) and skeletal muscle regions of interests (ROIs), CT images are first resliced to match the resolution and location of PET images. As performed in previous studies 2, a supraclavicular ROI is first manually drawn on the CT images. Within that area, the fat ROI is segmented using the CT images and an intensity window from -200 to -50 HU. Subsequently the fat ROI is segmented into WAT and BAT ROIs by using the 11C-MRB PET images: Standardized Uptake Value (SUV) ≥ 1.25 for BAT, SUV \< 1.25 for WAT.

Body Composition, Percent Body Fat & Percent Body Water (DXA Scan)

Intervention Type OTHER

For better accuracy, measurement of percent fat and percent body water will be obtained with whole body Dual X-Ray Absorptiometry (DXA) scan (Hologic®) on screening-OGTT visit. The scanner arm will move over the participant's body from feet to head. The machine uses a small amount of radiation (one tenth of the amount of radiation from a chest x-ray) to measure body fat, muscle and bone density.

Interventions

Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.

PET Scan

Participants will come to the PET Center to undergo the whole body \[11C\]MRB PET scan. An intravenous bolus dose of MRB (\~20mCi) will be injected by an infusion pump. PET data will be acquired dynamically for 120 min using the Siemens mCT-X whole-body PET/CT scanner using continuous bed motion to image multiple PET bed acquisitions from the top of the head to the lower abdominal region.

Intervention Type DIAGNOSTIC_TEST

Mixed Meal Test

High Carbohydrate Mixed Meal Test (MMT): participants will be studied after a 10-hour overnight fast. A nurse will insert an intravenous (IV) catheter and subjects will ingest a liquid meal (65% carbohydrate, 20% fat, and 15% protein, corresponding to 40% of daily energy expenditure, in \~16 ounces) to be prepared by the Hospital Research Unit Metabolic Kitchen. Blood samples will be collected at -10, 0, 15, 30, 60, 90, and 120 min) for measurement of glucose, insulin and C-peptide concentrations. Plasma samples will be drawn at baseline and throughout the MMT for measurement of additional hormones (such as thyroid hormones, and catecholamines) and free fatty acids (FFA) levels.

Intervention Type DIETARY_SUPPLEMENT

Muscle sympathetic nerve activity (MSNA)

Recording of multiunit postganglionic muscle sympathetic nerve activity (MSNA) will be made from the common peroneal nerve as it winds around the fibular head with the subject in the supine position with the subject's thigh comfortably supported. This procedure requires to first trace the course of the nerve using small electrical stimuli applied to the surface of the skin over the nerve or use of ultrasound to visually assist.

Intervention Type DIAGNOSTIC_TEST

Oral Glucose Tolerance Test

Following a 10-hour overnight fast, a nurse will insert an intravenous (IV) catheter. Subsequently, subjects will ingest 7.5 oz of Glucola, which contains 75 g of dextrose in orange flavored water. Blood samples will be taken at -15, 0, 10, 20, 30, 60, 90 and 120 minutes (after glucola ingestion) for the measurement of plasma glucose, insulin, and C-peptide concentrations, and calculation of measurements of insulin sensitivity index (Matsuda Index). Approximately 40 mL of blood will be drawn at this visit.

Intervention Type DIAGNOSTIC_TEST

Body Composition, Percent Body Fat & Percent Body Water (Tanita scale)

will be assessed using bioelectrical impedance analysis Tanita® scale; which is a special multi frequency segmental body composition analyzer that delivers a very mild electrical current that allows measurement of fat mass, percent body fat, fat free mass, total body water, and percent body water. This test will be performed at screening visit.

Intervention Type OTHER

CT Scan

A CT scan will be performed for attenuation correction and to help delineate the BAT and other regions of interest (ROIs). Images will be reconstructed with an ordered subset expectation maximization algorithm using point spread function correction and time-of-flight information. To delineate fat (WAT, BAT) and skeletal muscle regions of interests (ROIs), CT images are first resliced to match the resolution and location of PET images. As performed in previous studies 2, a supraclavicular ROI is first manually drawn on the CT images. Within that area, the fat ROI is segmented using the CT images and an intensity window from -200 to -50 HU. Subsequently the fat ROI is segmented into WAT and BAT ROIs by using the 11C-MRB PET images: Standardized Uptake Value (SUV) ≥ 1.25 for BAT, SUV \< 1.25 for WAT.

Intervention Type DIAGNOSTIC_TEST

Body Composition, Percent Body Fat & Percent Body Water (DXA Scan)

For better accuracy, measurement of percent fat and percent body water will be obtained with whole body Dual X-Ray Absorptiometry (DXA) scan (Hologic®) on screening-OGTT visit. The scanner arm will move over the participant's body from feet to head. The machine uses a small amount of radiation (one tenth of the amount of radiation from a chest x-ray) to measure body fat, muscle and bone density.

Intervention Type OTHER

Eligibility Criteria

Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.

Inclusion Criteria

1. Provision of signed and dated informed consent form
2. Stated willingness to comply with all study procedures and availability for the duration of the study
3. Age 18-45 years
4. In good general health as evidenced by medical history and lean (BMI 18.5-24.9 kg/m2) or non-diabetic obese (BMI 30-50 kg/m2) with a fasting plasma glucose (FPG) \<100 mg/dL and a hemoglobin A1c \<5.7%.

Exclusion Criteria

An individual who meets any of the following criteria will be excluded from participation in this study:

1. Hypertension
2. Cardiac or pulmonary disease,
3. Known history of Type 1 or Type 2 diabetes
4. Hepatic disease, swallowing and gastrointestinal disorders
5. Current use of anti-obesity medications, supplements and/or anti-hyperglycemic medications
6. Neurological injury or illness, and psychiatric medications
7. Women who are pregnant or lactating
8. Subjects who suffer from claustrophobia
9. Subjects who have received a diagnostic or therapeutic radiopharmaceutical within 7 days prior to participation in this study
10. Radiation works or participation in other research studies involving ionizing radiation within one year of the PET scans that would cause the subject to exceed the yearly dose limits.
11. Subjects with history of IV drug use which would prevent venous access for PET tracer injection
12. Severe motor problems that prevent the subject from lying still for PET and MR imaging
13. Subjects who complain of chronic pain
14. Blood donation within 8 weeks of the study
Minimum Eligible Age

18 Years

Maximum Eligible Age

45 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

Meet the organizations funding or collaborating on the study and learn about their roles.

National Institutes of Health (NIH)

NIH

Sponsor Role collaborator

Yale University

OTHER

Sponsor Role lead

Responsible Party

Identify the individual or organization who holds primary responsibility for the study information submitted to regulators.

Responsibility Role SPONSOR

Locations

Explore where the study is taking place and check the recruitment status at each participating site.

Church Street Research Unit

New Haven, Connecticut, United States

Site Status

Countries

Review the countries where the study has at least one active or historical site.

United States

Provided Documents

Download supplemental materials such as informed consent forms, study protocols, or participant manuals.

Document Type: Study Protocol and Statistical Analysis Plan

View Document

Document Type: Informed Consent Form

View Document

Other Identifiers

Review additional registry numbers or institutional identifiers associated with this trial.

1R56DK129344-01

Identifier Type: NIH

Identifier Source: secondary_id

View Link

2000030749

Identifier Type: -

Identifier Source: org_study_id

More Related Trials

Additional clinical trials that may be relevant based on similarity analysis.

BATokines as Biomarkers of Brown Fat in Humans
NCT05050240 ACTIVE_NOT_RECRUITING NA
Weight Gain and Adipose Tissue
NCT02703766 COMPLETED NA