Ignite Creation Date:
2024-05-05 @ 11:41 AM
Last Modification Date:
2024-10-26 @ 9:11 AM
Study NCT ID:
NCT00106119
Status:
COMPLETED
Last Update Posted:
2015-02-23
First Post:
2005-03-19
Brief Title:
Thyroid and Glucose and Energy Metabolism
Sponsor:
National Institute of Diabetes and Digestive and Kidney Diseases NIDDK
Organization:
National Institutes of Health Clinical Center CC
Study Overview
Official Title:
Peripheral Thyroid Hormone Conversion and Glucose and Energy Metabolism
Status:
COMPLETED
Status Verified Date:
2015-02
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 examine how two thyroid preparations-levothyroxine T4 and liothyronine T3-affect fat and cholesterol metabolism blood sugar regulation and thyrotropin secretion in patients who have had their thyroid gland removed Results of the study may help in the development of better therapies to optimize blood sugar and cholesterol levels in some patients
Patients 18 years of age or older who have had most or all of their thyroid gland removed and are taking long-term thyroid hormone medication may be eligible for this study after screening
Patients 18 years of age or older who have had most or all of their thyroid gland removed and are taking long-term thyroid hormone medication may be eligible for this study after screening
Detailed Description:
Thyroid hormone action plays an important role in the regulation of many physiologic processes among them glucose and lipid metabolism Interestingly the clinical presentation of thyroid dysfunction is extremely variable with relatively poor correlation between circulating hormone levels and clinical features This finding suggests that the local intracellular concentration of the active hormone liothyronine T3 regulated by peripheral conversion of the pro-hormone levothyroxine T4 is an important determinant in the maintenance of the thyroidal homeostasis
The aim of the present study is the evaluation of the role of peripheral thyroid hormone conversion in the regulation of glucose and lipid metabolism by assessing the differential response to T4 or T3 treatment in subjects devoid of endogenous thyroid hormone production T3 administration bypasses peripheral metabolism and therefore will allow us to assess the role of the peripheral thyroid hormone conversion in the regulation of the hormone action at the end-organ level
Fifty hypothyroid subjects will be initially randomized to either of the thyroid hormone replacements liothyronine T3 or levothyroxine T4 treatment period one arm cross-over design with treatment sequence randomized aimed to maintain serum TSH levels greater than or equal to 05 less than or equal to 15 mUL indicating full replacement After a 30-day period of steady-state replacement the study subjects will be admitted to the Clinical Center and after a three-day period of stabilization and an overnight fast will undergo the following tests escalating dose TRH stimulation test indirect calorimetry graded exercise tolerance test DEXA scan and echocardiogram
Patients will also undergo skeletal muscle biopsy and subcutaneous adipose tissue biopsy and microdialysis as well as a two-step euglycemic hyperinsulinemic clamp with measurement of splanchnic gluconeogenesis Fasting venous blood samples will be collected for the determination of the parameters of lipid glucose and energy metabolism
After discharge the patients will switch to the other form of thyroid hormone replacement therapy second period The therapy will be adjusted in order to achieve the same therapeutic goal for TSH concentrations greater than or equal to 05 less than or equal to 15 mUL analogous to that achieved during the first phase of the study TSH less than or equal to 05 mUL difference between T3 and T4 phases After reaching a 30-day period of steady-state replacement study subjects will be re-admitted to the Clinical Center and the previously described evaluation procedures will be repeated
The aim of the present study is the evaluation of the role of peripheral thyroid hormone conversion in the regulation of glucose and lipid metabolism by assessing the differential response to T4 or T3 treatment in subjects devoid of endogenous thyroid hormone production T3 administration bypasses peripheral metabolism and therefore will allow us to assess the role of the peripheral thyroid hormone conversion in the regulation of the hormone action at the end-organ level
Fifty hypothyroid subjects will be initially randomized to either of the thyroid hormone replacements liothyronine T3 or levothyroxine T4 treatment period one arm cross-over design with treatment sequence randomized aimed to maintain serum TSH levels greater than or equal to 05 less than or equal to 15 mUL indicating full replacement After a 30-day period of steady-state replacement the study subjects will be admitted to the Clinical Center and after a three-day period of stabilization and an overnight fast will undergo the following tests escalating dose TRH stimulation test indirect calorimetry graded exercise tolerance test DEXA scan and echocardiogram
Patients will also undergo skeletal muscle biopsy and subcutaneous adipose tissue biopsy and microdialysis as well as a two-step euglycemic hyperinsulinemic clamp with measurement of splanchnic gluconeogenesis Fasting venous blood samples will be collected for the determination of the parameters of lipid glucose and energy metabolism
After discharge the patients will switch to the other form of thyroid hormone replacement therapy second period The therapy will be adjusted in order to achieve the same therapeutic goal for TSH concentrations greater than or equal to 05 less than or equal to 15 mUL analogous to that achieved during the first phase of the study TSH less than or equal to 05 mUL difference between T3 and T4 phases After reaching a 30-day period of steady-state replacement study subjects will be re-admitted to the Clinical Center and the previously described evaluation procedures will be repeated
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 |
|---|---|---|---|
| 05-DK-0119 | OTHER | NIH | None |