Neurocognitive and Metabolic Effects of Mild Hypothyroidism
Public ClinicalTrials.gov record NCT00565864. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
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Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
Patients with hypothyroidism are routinely treated with thyroid hormone (l-thyroxine) for replacement therapy. Physicians monitor the thyroid hormone dose by measuring a thyroid stimulating hormone (TSH) level in the blood, with the goal of a normal level. However, recent data suggest that the "normal" TSH range is too broad, and that patients may still have symptoms if their TSH levels are at the top or bottom part of the normal range. To study this issue, it is useful to address issues such as general health status, psychological symptoms, mood, memory, and metabolic status, since thyroid hormone has major effects on the brain and metabolism, and since patients with treated hypothyroidism often have symptoms related to these areas. In the present study, otherwise healthy subjects with treated hypothyroidism, ages 20-75 years, will be enrolled in a 7-11month study. At baseline, they will have tests of health status, psychological symptoms, mood, memory, body composition, and energy expenditure performed. Following these baseline measurements, subjects will receive either their usual doses of l-thyroxine, or a slightly higher or lower dose. The doses will be chosen to try to achieve either a low-normal TSH level, a high-normal TSH level, or a mildly elevated TSH level. Which target TSH the patient is assigned will be determined randomly, and neither the subject nor the study contacts will know which dose the patient is receiving. Subjects will be seen every 6 weeks during the study for brief visits to make sure they are not having any side effects, and to adjust the l-thyroxine doses if the TSH has not yet reached the target range. At the 24-week visit (end of study), the subjects will undergo the same tests that they had on the baseline visit. Results from the study will be examined to see if minor changes in TSH or other thyroid hormone levels cause changes in any of the outcomes, and if the degree of TSH change correlates with the degree of outcome changes. These results may help physicians caring for patients with thyroid disease better determine the optimal dose of thyroid hormone for each patient.
Study identification
- NCT ID
- NCT00565864
- Recruitment status
- Completed
- Study type
- Interventional
- Phase
- Phase 4
- Enrollment
- 173 participants
Conditions and interventions
Conditions
Eligibility (public fields only)
- Age range
- 20 Years to 75 Years
- Sex
- All
- Healthy volunteers
- Healthy volunteers not accepted
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- Jul 31, 2008
- Primary completion
- Jul 31, 2013
- Completion
- Jul 31, 2013
- Last update posted
- Aug 21, 2018
2008 – 2013
United States locations
- U.S. sites
- 1
- U.S. states
- 1
- U.S. cities
- 1
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| Oregon Health and Science University | Portland | Oregon | 97201 | — |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT00565864, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted Aug 21, 2018 · Synced Sep 6, 2026
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Open the official record
The complete protocol, eligibility criteria, and contact information for NCT00565864 live on ClinicalTrials.gov.