Does Radioiodine Treatment Prevent Atrial Fibrillation and Bone Loss in Endogenous Subclinical Hyperthyroidism?

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00151723
Recruitment Status : Unknown
Verified September 2005 by Radboud University.
Recruitment status was:  Recruiting
First Posted : September 9, 2005
Last Update Posted : July 18, 2007
Information provided by:
Radboud University

Brief Summary:
Subclinical hyperthyroidism is defined as the presence of serum free thyroxine (T4) and triiodothyronine (T3) levels within the reference range and a reduced serum thyrotrophin (TSH) level. Evidence is accumulating that it has important clinical effects. The SUBstudy is a randomised, Dutch multicenter trial to study whether radioiodine treatment prevents the development of atrial fibrillation and prevents decreases in bone mineral density in patients with endogenous subclinical hyperthyroidism.

Condition or disease Intervention/treatment Phase
Hyperthyroidism Procedure: treatment with 131I Not Applicable

Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 200 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Prevention
Official Title: Subclinical Hyperthyroidism ”To Treat or Not to Treat?” A Dutch Multicenter Trial
Study Start Date : April 2004

Resource links provided by the National Library of Medicine

U.S. FDA Resources

Primary Outcome Measures :
  1. To provide evidence that restoration of euthyroidism (normal TSH) improves thyrotoxic symptoms and signs and quality of life and lowers the risk of subsequent atrial fibrillation and bone loss in subjects with endogenous subclinical hyperthyroidism

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Ages Eligible for Study:   40 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Subclinical hyperthyroidism [TSH ≤ 0.1 mU/L, fT4 and T3 within the normal range of the own laboratory (determined 2 times in own laboratory) with an interval of at least 2 months].
  • Endogenous cause of subclinical hyperthyroidism limited to autonomous adenoma or multinodular goiter (diagnosis made by the attending physician, based on palpation and the result of a thyroid scintigram).
  • Informed consent.

Exclusion Criteria:

  • Medication with anti-thyroid drugs in the last 3 months (also not allowed during follow-up); thyroid hormone in the last 3 months (allowed during follow-up, but TSH levels should be kept between 0.1 mU/L and the upper limit of normal in the own laboratory); and oral glucocorticoids in the last 3 months (allowed during follow-up when absolutely necessary, but patients in whom glucocorticoids are started cannot be evaluated with respect to changes in bone mineral density [BMD]).
  • Radioiodine therapy in the past.
  • Iodine-induced subclinical hyperthyroidism.
  • Pituitary or hypothalamic insufficiency.
  • Pregnancy.
  • Age <= 40 years.
  • Severe non-thyroidal illness.
  • Drug abuse.
  • Unstable angina pectoris, (history of) atrial fibrillation, (history of) congestive heart failure.
  • (History of) osteoporotic fracture(s).
  • Patients younger than 70 years of age with a bone mineral density T-score < – 2.5 standard deviations (SD), or older than 70 years of age with a bone mineral density Z-score < 1.0 SD. (These patients can be randomized but in case it is decided to treat them with anti-osteoporotic drugs they cannot be evaluated with respect to changes in BMD.)
  • Use of betablockers in the last three months. (These patients can be randomised but cannot be evaluated with respect to general and cardiac symptoms. The same applies to patients in whom betablockers are started during follow up.)
  • Other symptoms or signs of hyperthyroidism or obstruction of vital structures which, in the opinion of the attending physician, require active treatment.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00151723

Contact: Elizabeth Hoogendoorn, MD ++31243614599
Contact: Ad Hermus, MD, Prof ++31243614599

Academical Medical Centre Amsterdam Recruiting
Amsterdam, Netherlands
Contact: W. Wiersinga, MD, Prof         
Martini Ziekenhuis Groningen Recruiting
Groningen, Netherlands
Contact: K. van Tol, MD, PhD         
Principal Investigator: K. van Tol, MD, PhD         
University Hospital Groningen Recruiting
Groningen, Netherlands
Contact: G. van den Berg, MD, PhD    ++31-5036161616      
Principal Investigator: G. van den Berg, MD, PhD         
Radboud University Medical Centre Nijmegen Recruiting
Nijmegen, Netherlands, 6500HB
Contact: Elizabeth Hoogendoorn, MD    ++31-243614599      
Principal Investigator: Elizabeth Hoogendoorn, MD         
Maxima Medisch Centrum Recruiting
Veldhoven, Netherlands
Contact: H. Haak, MD, PhD         
Principal Investigator: H. Haak, MD, PhD         
Sponsors and Collaborators
Radboud University
Principal Investigator: Ad Hermus, MD, Prof Radboud University

Publications: Identifier: NCT00151723     History of Changes
Other Study ID Numbers: SUBstudie
First Posted: September 9, 2005    Key Record Dates
Last Update Posted: July 18, 2007
Last Verified: September 2005

Keywords provided by Radboud University:
endogenous subclinical hyperthyroidism

Additional relevant MeSH terms:
Thyroid Diseases
Endocrine System Diseases