Ignite Creation Date:
2024-05-05 @ 4:48 PM
Last Modification Date:
2024-10-26 @ 9:24 AM
Study NCT ID:
NCT00312715
Status:
COMPLETED
Last Update Posted:
2017-10-06
First Post:
2006-04-08
Brief Title:
Thyroid and Fat Tissue Metabolism
Sponsor:
National Institute of Diabetes and Digestive and Kidney Diseases NIDDK
Organization:
National Institutes of Health Clinical Center CC
Study Overview
Official Title:
Thyroid Hormone-Induced Lipolysis An In Vivo Microdialysis Study
Status:
COMPLETED
Status Verified Date:
2014-07-08
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
This study will use a technique called microperfusion to examine how thyroid hormones are involved in fat metabolism The thyroid gland produces two kinds of hormones T3 and T4 Some of the T4 is changed to T3 in various organs after leaving the thyroid The T3 stimulates the body to burn fat People have different rates at which they can change T4 to T3 and this may lead to differences in body fat among different people
Microperfusion is based on the exchange of substances across tiny holes of a small plastic tube called a probe which is inserted after numbing the skin over a fat pad Through these openings the fat pad is continuously rinsed with small amounts of fluid and an exchange of substances occurs The fluid drips from the other opening of the probe and is collected in a vial Small amounts of study drugs are infused and the amount of substances released by the fat pad in response to them are measured
Healthy normal volunteers 18 years of age and older may be eligible for this study Candidates are screened with a medical history physical examination and blood tests
Participants undergo microperfusion A needle is placed in an arm vein for collecting blood samples before and at the end of the experiment for measuring thyroid hormones and other substances in the blood The skin over the fat pad next to the umbilicus navel is numbed and two microperfusion probes are inserted A salt water solution is infused into the fat pad for one hour and the substances in the fluid are measured as the fluid leaves the fat pad After 1 hour isoproterenol a drug that aids in energy production by fat is added to help determine the level of fat metabolism After an additional hour small amounts of thyroid hormone are added to the fluid and samples are collected as they leave the body Two catheters are inserted during each experiment Small volumes of sterile fluid are circulated continuously in the tubing and samples are collected at regular intervals
Microperfusion is based on the exchange of substances across tiny holes of a small plastic tube called a probe which is inserted after numbing the skin over a fat pad Through these openings the fat pad is continuously rinsed with small amounts of fluid and an exchange of substances occurs The fluid drips from the other opening of the probe and is collected in a vial Small amounts of study drugs are infused and the amount of substances released by the fat pad in response to them are measured
Healthy normal volunteers 18 years of age and older may be eligible for this study Candidates are screened with a medical history physical examination and blood tests
Participants undergo microperfusion A needle is placed in an arm vein for collecting blood samples before and at the end of the experiment for measuring thyroid hormones and other substances in the blood The skin over the fat pad next to the umbilicus navel is numbed and two microperfusion probes are inserted A salt water solution is infused into the fat pad for one hour and the substances in the fluid are measured as the fluid leaves the fat pad After 1 hour isoproterenol a drug that aids in energy production by fat is added to help determine the level of fat metabolism After an additional hour small amounts of thyroid hormone are added to the fluid and samples are collected as they leave the body Two catheters are inserted during each experiment Small volumes of sterile fluid are circulated continuously in the tubing and samples are collected at regular intervals
Detailed Description:
This study will examine how two thyroid preparations levothyroxine T4 and liothyronine T3 affect subcutaneous adipose tissue in normal subjects Thyroid hormone plays an important role in the maintenance of energy metabolism Specifically hyperthyroidism is associated with weight loss via an increase in metabolic rate and lipolysis While this phenomenon has been studied in vitro quite extensively very little information is available on the local action of thyroid hormone on adipose tissue in vivo and in particular at the present no information is available on the role of peripheral conversion of thyroid hormone in subcutaneous adipose tissue We thus propose to study the local action of thyroid hormones on adipose tissue using microdialysis a minimally invasive technique that allows the serial determination of components of the extracellular fluid The measurement of glycerol after correction for changes in blood flow will be used to evaluate the effects of the thyroid hormones on local lipolysis
Healthy volunteers 18 years of age and older may be eligible for this study Candidates are screened with a medical history physical examination and blood tests Subjects with hyperlipidemia impaired glucose tolerance or diabetes and thyroid disease are not eligible for the participation in this study Qualifying study participants undergo subcutaneous fat tissue microdialysis to assess the effects of T3 and T4 on the activity of fat tissue The medications isoproterenol and T3 or T4 are injected in fat tissue under the skin of the abdomen and fluid samples are collected from the area over a 6-12 hour period using the same small needle Glycerol is then measured to study how the thyroid hormones affect fat metabolism During this procedure a 10 glucose solution is infused through the catheter in the arm to limit lipolysis due to fasting Four different sets of experiments are performed with different thyroid hormone doses andor durations
These experiments will provide new information on the role of thyroid hormone in the regulation of adipose tissue metabolism and will help in identifying new treatments for the management of obesity
Healthy volunteers 18 years of age and older may be eligible for this study Candidates are screened with a medical history physical examination and blood tests Subjects with hyperlipidemia impaired glucose tolerance or diabetes and thyroid disease are not eligible for the participation in this study Qualifying study participants undergo subcutaneous fat tissue microdialysis to assess the effects of T3 and T4 on the activity of fat tissue The medications isoproterenol and T3 or T4 are injected in fat tissue under the skin of the abdomen and fluid samples are collected from the area over a 6-12 hour period using the same small needle Glycerol is then measured to study how the thyroid hormones affect fat metabolism During this procedure a 10 glucose solution is infused through the catheter in the arm to limit lipolysis due to fasting Four different sets of experiments are performed with different thyroid hormone doses andor durations
These experiments will provide new information on the role of thyroid hormone in the regulation of adipose tissue metabolism and will help in identifying new treatments for the management of obesity
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None
Secondary IDs
| Secondary ID | Type | Domain | Link |
|---|---|---|---|
| 06-DK-0133 | None | None | None |