Effect of L-Thyroxine on Lipid Profiles and Atherosclerosis in Subclinical Hypothyroidism

Study Overview
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Brief Summary
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Subclinical hypothyroidism (SCH) is a common condition affecting 3-10% of the general population, especially in women older than 50 years old. It is controversial whether SCH can lead to increased risks of cardiovascular (CV) disease and whether treatment with L-thyroxine reverses these risks. The present study was designed to evaluate the effect of L-thyroxine treatment in SCH on lipid profile, atherosclerosis, endothelial function, serum inflammatory factors and adipocytokines.

Official Title
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The Beneficial Effect of L-Thyroxine Long -Term Replacement on Lipid Profiles and Atherosclerosis in Subclinical Hypothyroidism: A Prospective Study

Conditions
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Hypothyroidism, Thyroid Diseases, Endocrine System Diseases

Intervention / Treatment
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* Drug: L-thyroxine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male and female aged of 18 to 60 years old; Diagnosis was subclinical hypothyroidism(elevated serum thyroid-stimulating hormone levels with normal serum free T4 levels measured at least two times with a three-month interval); untreated. Exclusion Criteria: Pregnancy or lactation women; Presence of pituitary/hypothalamic disorders, diabetes mellitus or other endocrinal and metabolic disorders; Presence of psychological or physical disabilities,acute infection, cerebrovascular or cardiovascular disease, chronic respiratory disease and other illnesses known to alter lipid metabolism; Taking lipid-lowering agents and other drugs that known to influence thyroid function, blood pressure, heart function or bile acids; Obviously poor compliance.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: L-thyroxine<br>Oral administration, starting dose 25 or 50 micrograms once daily. | Drug: L-thyroxine<br> <br> |
| No Intervention: blank<br>no intervention | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| change in lipid profile |  | measured at baseline; 6 month; 12 months and 24 months. | 
| change in thickness of blood vessel wall |  | measured at baseline; 6 months; 12 months and 24 months. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| change in endothelial function |  | measured at baseline; 6 months; 12 months and 24 months. | 
| change of adipocytokines |  | measured at baseline; 6 months; 12 months and 24 months. | 
| Change of Oxidative Stress and Chronic Inflammatory Factors Related with Atherosclerosis |  | measured at baseline; 6 months; 12 months and 24 months. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Subclinical hypothyroidism, L-thyroxine, Lipid, endothelial function, inflammatory factor, adipocytokine