Factors Affecting Timing of Hypothyroidism Following Radioactive Iodine Therapy Patients With Graves Disease

The purpose of this retrospective study was to clarify the possible risk factors of early hypothyroidism after RAI therapy in Graves' disease.

Study Overview

• Status: Recruiting
• Conditions: Radioactive Iodine-Induced Hypothyroidism in Graves Disease Patients
• Intervention / Treatment: Radiation: Radioactive Iodine therapy

Detailed Description

Hyperthyroidism is a clinical syndrome caused by increased thyroid hormone in the blood, it can lead to multiple complications, including cardiac, hepatic, and hematologic system complications. More than 80% of hyperthyroidism are caused by Graves' disease (GD). 3% of women and 0.5% of men may suffer GD in their lifetime [1].

Radioactive iodine (RAI) therapy is an important treatment option for Graves' disease (GD), the main side effect of RAI treatment is hypothyroidism, and the factors resulting in hypothyroidism are still controversial [2]. Male gender, smaller thyroid weight, higher thyroid-stimulating hormone, and smaller thyroid volume are Suggested to be the main risk factors for early hypothyroidism [2]-[3].

• Study Type: Observational
• Enrollment (Estimated): 300

Contacts and Locations

• Study Contact: Name: Aya A Alsanory, Master; Phone Number: 00201063490867; Email: ayota17@gmail.com
• Study Contact Backup: Name: Esraa R Hassan, M.D; Phone Number: 00201098589000; Email: Esraaa.roshdy@yahoo.com

Study Locations

• Egypt
  • Assiut, Egypt
    • Recruiting
    • Nuclear medicine unit, department of clinical oncology and nuclear medicine, Assiut university hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 13 years to 70 years (Child, Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

All thyrotoxic patients treated with RAI

Description

Inclusion Criteria:

1. Graves' disease patients after one year of RAI therapy .
2. Suppressed serum thyrotropin (TSH) <0.55 µU/ml , elevated serum free triiodothyronine (FT3) > 6.5 pmol/L , free thyroxin FT4 >22.7 pmol/L .

Exclusion Criteria:

1. Patients with other causes of hyperthyroidism , such as toxic multinodular goiter and single toxic adenoma
2. Thyroid cancer
3. Recurrent GD
4. Previous Thyroid surgery
5. Patients can't complete the follow -up within 6 months.

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Only
• Time Perspectives: Other

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Hypothyroidism; decreased hormone levels (FT3 < 3.5 pmol/L, FT4 < 11.5 pmol/L, TSH > 4.78 μU/mL) and symptoms of hypothyroidism within 6 months' follow-up.	Radiation: Radioactive Iodine therapy; All the patient need to stop ATD and iodine-containing drugs for 5 days prior to RAI treatment, and followed a low-iodine diet for 2 weeks. After fasting and water deprivation for 8 h, all the patients took RAI orally in the morning. After taking RAI, the patients need to continue fasting and water deprivation for extra 2 h to avoid the effects of food on iodine absorption.
Euthyroidism; normal hormone levels (FT3 3.5 to 6.5 pmol/L, FT4 11.5 to 22.7 pmol/L, TSH 0.55 to 4.78 μU/mL), and no symptoms of hyperthyroidism after 6 months' follow-up	Radiation: Radioactive Iodine therapy; All the patient need to stop ATD and iodine-containing drugs for 5 days prior to RAI treatment, and followed a low-iodine diet for 2 weeks. After fasting and water deprivation for 8 h, all the patients took RAI orally in the morning. After taking RAI, the patients need to continue fasting and water deprivation for extra 2 h to avoid the effects of food on iodine absorption.
Hyperthyroidism; increased hormone levels (FT3 > 6.5 pmol/L, FT4 > 22.7 pmol/L, TSH < 0.55 μU/mL) and symptoms of hyperthyroidism after 6 months' follow-up	Radiation: Radioactive Iodine therapy; All the patient need to stop ATD and iodine-containing drugs for 5 days prior to RAI treatment, and followed a low-iodine diet for 2 weeks. After fasting and water deprivation for 8 h, all the patients took RAI orally in the morning. After taking RAI, the patients need to continue fasting and water deprivation for extra 2 h to avoid the effects of food on iodine absorption.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
predictive factors of early hypothyroidism after RAI therapy	Retrospective study from 2013 to 2022 to analyze the correlation between clinical, demographic& and laboratory data and incidence of hypothyroidism by measuring thyroid function tests	1 year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
the incidence of hypothyroidism within 1 year	To detect the frequency of hypothyroidism after RAI and when it is most likely occur after 6 months or one year	10 years

Collaborators and Investigators

• Sponsor: Assiut University
• Investigators: Study Director: Hemat A Mahmoud, M.D, Lecturer; Study Chair: Hanan G Mostafa, M.D, Professor

Publications and helpful links

General Publications

• Hu RT, Liu DS, Li B. Predictive factors for early hypothyroidism following the radioactive iodine therapy in Graves' disease patients. BMC Endocr Disord. 2020 May 29;20(1):76. doi: 10.1186/s12902-020-00557-w.
• Demir BK, Karakilic E, Saygili ES, Araci N, Ozdemir S. Predictors of Hypothyroidism Following Empirical Dose Radioiodine in Toxic Thyroid Nodules: Real-Life Experience. Endocr Pract. 2022 Aug;28(8):749-753. doi: 10.1016/j.eprac.2022.05.001. Epub 2022 May 7.
• Smith TJ, Hegedus L. Graves' Disease. N Engl J Med. 2016 Oct 20;375(16):1552-1565. doi: 10.1056/NEJMra1510030. No abstract available.

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2013
• Primary Completion (Actual): November 1, 2022
• Study Completion (Estimated): December 1, 2023

Study Registration Dates

• First Submitted: November 25, 2022
• First Submitted That Met QC Criteria: December 7, 2022
• First Posted (Actual): December 8, 2022

Study Record Updates

• Last Update Posted (Actual): October 12, 2023
• Last Update Submitted That Met QC Criteria: October 10, 2023
• Last Verified: October 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Immune System Diseases; Autoimmune Diseases; Eye Diseases; Endocrine System Diseases; Thyroid Diseases; Exophthalmos; Orbital Diseases; Goiter; Hyperthyroidism; Hypothyroidism; Graves Disease
• Other Study ID Numbers: Hypothyroidism after RAI

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No