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Metabolism and Thyroid Hormone Changes During Exposure to Cold Temperatures

NCT00521729 · Status: COMPLETED · Phase: NA · Type: INTERVENTIONAL · Enrollment: 160

Last updated 2019-12-16

No results posted yet for this study

Summary

This study will examine how body metabolism adjusts to small changes in environmental temperature and how it may be related to weight loss.

Healthy, non-obese individuals between 18 and 60 years of age may be eligible for this study. The study consists of one screening visit and one 5-day admission to the NIH Clinical Center for the following procedures:

Diet: Participants follow a proscribed diet consisting of 50% carbohydrates, 20% protein and 30% fat.

DEXA scan to measure body fat. Subjects lie on a table above a source of X-rays while a very small dose of X-rays is passed through the body.

Air displacement plethysmography (Bod-Pod) to study fat composition: Subjects sit in a small booth for 10 minutes wearing a swim suit and breathing normally through a tube. This test measures the person s weight and volume precisely.

Metabolic room: Subjects stay 12 hours in a specialized room designed to measure the amount of oxygen breathed in and the amount of carbon dioxide breathed out. The room contains a private toilet and sink, treadmill, bed, desk, window, telephone and computer with television and internet access. While in this room, subjects undergo the following:

* Continuous heart rate monitor: Subjects wear an EKG monitor to analyze heart rate variability.
* Spontaneous movements: Subjects wear portable accelerometers at the hip and wrist to measure spontaneous physical movements.
* Continuous temperature monitor: Subjects swallow a small capsule that transmits internal body temperature via miniature, wireless sensors. Adhesive patches placed on the skin monitor external body temperature.
* Blood and urine collections: Subjects collect all of their urine during the 12 hours they are in the metabolic room. Blood samples are taken at specified intervals through a catheter that has been placed in a vein.
* Microdialysis: A small needle is placed into fat tissue just under the skin on the abdomen. A solution containing a minimal amount of ethanol is infused and samples of fluid are collected every 20 minutes as it leaves the fat pad. This helps determine the metabolism level. This procedure starts 30 minutes before entering the metabolic room and continues until the subject leaves the room.

Fat tissue biopsy: A small piece of fat tissue is withdrawn through a needle from under the skin on the abdomen. The sample is used to study fat tissue size and ability to store sugar.

Conditions

Interventions

PROCEDURE

Exposure to Cold Temperature

Sponsors & Collaborators

  • National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

    lead NIH

Principal Investigators

  • Kong Y Chen, Ph.D. · National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Study Design

Allocation
RANDOMIZED
Purpose
OTHER
Model
CROSSOVER

Eligibility

Min Age
18 Years
Max Age
60 Years
Sex
ALL
Healthy Volunteers
No

Timeline & Regulatory

Start
2007-08-24
Primary Completion
2015-01-12
Completion
2018-06-26

Countries

  • United States

Study Locations

More Related Trials

Entities

Diseases

Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT00521729 on ClinicalTrials.gov