Actively Recruiting

Age: 18Years - 100Years
All Genders
Healthy Volunteers
ID06083636

Improvement of Laboratory Diagnostics in Hypothyroid Patients Using Levothyroxine

Led by Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA) · Updated on 2025-10-03

500

Participants Needed

1

Research Sites

N/A

Total Duration

On this page

AI-Summary

What this Trial Is About

Hypothyroidism is a common thyroid disorder caused by insufficient thyroid hormone production. This research aims to improve laboratory tests that assess thyroid hormone levels in hypothyroid patients treated with levothyroxine (L-T4), especially when the usual test, TSH, cannot reliably indicate hormone status. The study includes patients with various forms of hypothyroidism, such as Hashimoto's disease, central hypothyroidism, hypothyroidism after thyroidectomy due to thyroid cancer, and hypothyroidism from Graves' disease treatment. It evaluates whether measuring free triiodothyronine (fT3) and the fT3/fT4 ratio can better reflect thyroid hormone status than traditional tests in some patients. Participants are divided into groups based on their hypothyroidism type and also include healthy controls. All will have a single blood draw to measure thyroid hormone markers including TSH, free T4 (fT4), free T3 (fT3), and their ratio, as well as other markers like total T4, total T3, reverse T3, sex hormone-binding globulin, acylcarnitines, and amino acids. They will also complete a brief questionnaire about their thyroid-related quality of life. Blood draws for patients coincide with their regular clinical appointments, while healthy controls will have one standalone blood draw. During the study, researchers will analyze these blood samples and questionnaire responses to compare hormone levels and markers across groups. The main outcome measures include TSH, fT4, fT3, and the fT3/fT4 ratio from single blood samples collected over approximately four years. Secondary measures include other thyroid hormone markers and metabolites. Data will be stored securely, and participation involves minimal burden with just one blood draw and one questionnaire, aiming to improve future monitoring of thyroid hormone status in patients where current tests are limited.

CONDITIONS

Brief Title

Improvement of Laboratory Diagnostics in Hypothyroid Patients Using Levothyroxine

Who Can Participate

Age: 18Years - 100Years
All Genders
Healthy Volunteers

Eligibility Criteria

Eligible

You may qualify if you...

  • Ability to provide informed consent
  • Ability to speak and understand Dutch or English
  • Taking a stable dose of levothyroxine without recent changes
  • Diagnosis of one of the following hypothyroidism types: primary hypothyroidism with euthyroid TSH, hypothyroidism after total thyroidectomy with target TSH, hypothyroidism during Graves' disease treatment with euthyroid TSH, or central hypothyroidism with euthyroid fT4
  • Healthy controls must consider themselves healthy and meet consent and language criteria
Not Eligible

You will not qualify if you...

  • Not euthyroid according to physician
  • Pregnancy
  • For Graves' disease patients, suppressed TSH levels
  • Use of medications including liothyronine (Cytomel), iodide, oral contraceptives, or active treatment for malignancy other than thyroid carcinoma
  • Healthy controls using thyroid medication, lithium, amiodarone, propranolol, iodide, glucocorticoids, oral contraceptives, heparin, growth hormone, or active treatment for malignancy

AI-Screening

AI-Powered Screening

Complete this quick 3-step screening to check your eligibility

1
2
3
+1

Your Study Journey

Screening

Duration - 2 to 4 weeks

Participants are screened for eligibility to participate in the trial.

1 visit (in-person) for eligibility assessment and informed consent

Monitoring

Duration - One-time assessment during the study period of approximately 4 years

Participants provide a single blood sample and complete one questionnaire to assess thyroid hormone status and improve laboratory diagnostics in hypothyroid patients using levothyroxine.

1 visit (in-person) with a single blood draw and questionnaire completion

Trial Site Locations

Total: 1 location

1

Amsterdam UMC

Amsterdam, North Holland, Netherlands, 1105 AZ

Actively Recruiting

Loading map...

Research Team

H

Heijboer

J

Jansen

How is the study designed?

Study Type

OBSERVATIONAL

Masking

N/A

Allocation

N/A

Model

N/A

Primary Purpose

N/A

Number of Arms

5

Similar Trials

A Randomized Controlled Trial of Thyroid Hormone Supplementa...

Thyroid; Functional Disturbance

Actively Recruiting

1 location

A Phase 2/3 Multicenter, Double Blinded, Randomized, Dose-co...

Hypothyroidism

Actively Recruiting

139 locations

Comorbidities Resolution After Mini-Gastric Bypass Surgery f...

Morbid Obesity

Actively Recruiting

1 location

Frequently Asked Questions

Have more questions? Get in touch with our team for quick support

Not the Right Trial for You?

Explore thousands of other clinical trials that might be a better match.
Sign up to get personalized trial recommendations delivered to your inbox.

Already have an account? Log in here

Published Research Related To This Trial

Effect of oral intake of thyroxine on results of thyroid function tests in patients receiving thyroid replacement therapy.

D R Deam, D G Campbell, S Ratnaike

https://pubmed.ncbi.nlm.nih.gov/6621483

Intra-individual variation of thyroxin, triiodothyronine, and thyrotropin in treated hypothyroid patients: implications for monitoring replacement therapy.

M C Browning, W M Bennet, A J Kirkaldy...

https://pubmed.ncbi.nlm.nih.gov/3359603

Twenty-four hour variations of thyroid hormones and thyrotrophin concentrations in hypothyroid infants treated with L-thyroxine.

P Czernichow, B Wolf, J Fermanian...

https://pubmed.ncbi.nlm.nih.gov/6509783