Desiccated Thyroid Extract Versus Synthetic T3/T4 Combination (ThyrolarTM) Versus L-T4 Alone in the Therapy of Primary Hypothyroidism With Special Attention to the Gene Polymorphism

May 5, 2015 updated by: Mohamed K.M. Shakir, Walter Reed National Military Medical Center

The proposed study design is a prospective, randomized, double-blind, crossover study. After informed consent is obtained, patients will be randomized to receive either desiccated thyroid in capsules, or L-T4/L-T3 (ThyrolarTM) in capsules, or L-T4 alone capsules. All study participants, physician investigators, those administering the neurocognitive tests and those analyzing test results will be blinded throughout the study.

Subjects will undergo memory testing, a disease specific symptom questionnaire, a general mental health assessment, a complete physical examination, baseline EKG, and biochemical testing consisting of serum TSH, free T4, total T4, total T3, free T3, T3 resin uptake, reverse T3, sex hormone binding globulin (SHBG), serum iodine, a lipid panel, insulin, glucose and leptin. This testing and DXA scan of body composition will be performed at baseline and after each 3 month treatment period. Deiodinase type 2 (DIO2) polymorphisms analyses - will also be performed at the beginning of the study and the results will be blinded to the investigators performing the memory testing.

After 5-6 weeks on the study medication, TSH levels will be checked and the medication adjusted to maintain TSH level between 0.46-4.68 mIU/L. Once the TSH level is in the desired range, subjects will continue the medication for an additional 6 weeks. Subjects will then be crossed-over to the other treatment arm for 3 months. Again, testing will be performed after each treatment period. Finally the subjects will again switched over to the 3rd arm and testing will be performed after treatment period.

A cross-over design is preferred because we are assessing subjective symptoms such as clinical well-being and other parameters. Therefore, we will be able to evaluate the effectiveness of L-T4/T3 (ThyrolarTM) vs DTE vs T4 alone in the same patientssubjects. This is also supported by the previous study by Escobar-Morreale et al.

Additionally, the Wechsler memory scale, DEXA for body composition, measurment of reverse T3, insulin, leptin, and DIO2 polymorphisms analysis will be included for the research portion of this study. Further, the frequency of serum blood draws, for research purposes, will be at intervals of 0, 6, 12, 18, 24, 30 and 36 weeks.

Study Overview

Status

Unknown

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Anticipated)

81

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 65 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Subjects will be between the ages of 18 to 65 and will have been on levothyroxine for primary hypothyroidism for at least 6 months
  • Department of Defense beneficiaries living within 60 miles of Besthesda, MD

Exclusion Criteria:

  • Subjects will be excluded if they have the following problems: pregnancy, plan for pregnancy in the next 12 months, cardiac disease, especially coronary artery disease, chronic obstructive lung disease, malabsorption disorder, gastrointestinal surgeries, significant renal or liver dysfunction, seizure disorders, thyroid and non-thyroid active cancers, uncontrolled psychosis, psychotropic medication use, steroid use, amiodarone, chemotherapy for cancer, iron supplement more than 325mg per day, carafate/ proton pump inhibitor use, cholestyramine use, and those with recent orders who are expected to move out of the geographic area, age less than 18 years old or older than 65 years old. Patients scheduled for deployment will be excluded.
  • Subjects with subclinical hypothyroidism will be excluded. If we include patients with subclinical hypothyroidism, it will be difficult to assess the outcomes. This is because only a very small percentage of patients with subclinical hypothyroidism benefit from thyroid hormone therapy and therefore, a cross-over study as done in this project will not show a difference between the therapies.
  • Females of child-bearing age will be screened with initial assessment for pregnancy as part of standard of care (eg history of amnenorrhea and/or positive pregnancy testing via hCG). There is no experience in using desiccated thyroid extract in pregnant women and there is no published paper in this area. Desiccated thyroid extract is rated Category-A drug in pregnancy which means there are no known risks to the fetus.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Levothyroxine Plus Liothyronine Group
Drug: Levothyroxine Plus Liothyronine
Active Comparator: Levothyroxine Group
Drug: Levothyroxine
Active Comparator: Desiccated Thyroid Extract Group
Drug: Desiccated Thyroid Extract

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Wechsler memory scale, fourth edition (WMS-IV)
Time Frame: 3 months
Pearson, PsychCorp, San Antonio, Texas
3 months
Beck Depression Inventory
Time Frame: 3 months
Pearson, PsychCorp
3 months
Thyroid Symptom Questionnaire (TSQ)
Time Frame: 3 months
Clyde PW, Harari AE, Getka EJ, Shakir KM. Combined levothyroxine plus liothyronine compared with levothyroxine alone in primary hypothyroidism: a randomized controlled trial. JAMA. 2003; 290:2952-2958.
3 months
QOL as measured by General Health Questionnaire (GHQ)-12
Time Frame: 3 months
3 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Walter Reed National Military Medical Center

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

May 1, 2015

Primary Completion (Anticipated)

May 1, 2018

Study Registration Dates

First Submitted

December 8, 2014

First Submitted That Met QC Criteria

December 12, 2014

First Posted (Estimate)

December 17, 2014

Study Record Updates

Last Update Posted (Estimate)

May 6, 2015

Last Update Submitted That Met QC Criteria

May 5, 2015

Last Verified

May 1, 2015

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 397401-1

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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