Levothyroxine Treatment on Cardiac Function in Children With Subclinical Hypothyroidism

The Effect of Levothyroxine Treatment on Cardiac Function in Children With Subclinical Hypothyroidism

This study aims to evaluate the effect of the treatment with levothyroxine on cardiac function in children with subclinical hypothyroidism.

Study Overview

• Status: Recruiting
• Conditions: Children; Subclinical Hypothyroidism; Cardiac Function; Levothyroxine
• Intervention / Treatment: Drug: L-thyroxine

Detailed Description

Subclinical hypothyroidism (SH) is a branch of hypothyroidism which is characterized by increased thyroid stimulating hormone (TSH) and normal thyroxine (T4).

Inadequate serum thyroid hormone levels impair cardiac function and may result in multiple cardiovascular risk factors, such as endothelial dysfunction, increased intima-media thickness, increased vascular resistance, and pericardial effusion.

• Study Type: Interventional
• Enrollment (Estimated): 40
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Zeinab E Elshareef, MBBCH; Phone Number: 00201001700194; Email: zeinabibraheem26@gmail.com

Study Locations

• Egypt
  • El-Gharbia
    • Tanta, El-Gharbia, Egypt, 31527
      • Recruiting
      • Tanta University
      • Contact: Zeinab E Elshareef, MBBCH; Phone Number: 00201001700194; Email: zeinabibraheem26@gmail.com
      • Sub-Investigator: Doaa M EL Amrousy, MD
      • Sub-Investigator: Dina E Abd EL hai, MD
      • Sub-Investigator: Ola A Taha, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age from 4 to 15 years.
• Both sexes.
• Patients with stable elevated thyroid-stimulating hormone (TSH) ≥ 4.5 mIU/L with normal free T4 and ft3 in different measurement 4 - 6 weeks apart.

Exclusion Criteria:

• Overweight and obesity
• Hypertension
• Previous use of levothyroxine, antiepileptic drugs, or cardiac drugs within the last 6 months.
• Arrhythmia.
• Congenital or acquired heart disease
• Liver or kidney disease
• Hyperlipidemia
• Diabetes
• Infectious diseases
• Respiratory diseases
• Malignancies

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Treatment group; Children with subclinical hypothyroidism who will receive L-thyroxine treatment in a dose of 2μg/kg/d (the smallest dose can be given) and the dose will be titrated every 4 weeks until a normal thyroid-stimulating hormone (TSH) level is maintained.	Drug: L-thyroxine; Children with subclinical hypothyroidism who will receive L-thyroxine treatment in a dose of 2μg/kg/d (the smallest dose can be given) and the dose will be titrated every 4 weeks until a normal thyroid-stimulating hormone (TSH) level is maintained.
No Intervention: No treatment group; Children with subclinical hypothyroidism who will receive no treatment.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Assessment of left ventricle systolic function	Left ventricle systolic function will be measured using left ventricle (LV) ejection fraction (LV EF%) where: (LV EF%) = (LVEDD)³ - (LVESD) / (LVEDD)³×100% LVEDD=left ventricular end-diastolic dimension. LVESD=left ventricular end-systolic dimension. LVFS=LV fractional shortening.	3 months post-procedure

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Assessment of left ventricle fractional shortening	Left ventricle fractional shortening (LV FS) will be measured. where: LV FS= LVEDD-LVESD/LVEDD X 100%. LVEDD=left ventricular end-diastolic dimension. LVESD=left ventricular end-systolic dimension.	3 months post-procedure

Collaborators and Investigators

• Sponsor: Tanta University

Study record dates

Study Major Dates

• Study Start (Actual): May 24, 2025
• Primary Completion (Estimated): May 1, 2026
• Study Completion (Estimated): May 1, 2026

Study Registration Dates

• First Submitted: January 31, 2026
• First Submitted That Met QC Criteria: January 31, 2026
• First Posted (Actual): February 6, 2026

Study Record Updates

• Last Update Posted (Actual): February 6, 2026
• Last Update Submitted That Met QC Criteria: January 31, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Hormones; Hormones, Hormone Substitutes, and Hormone Antagonists; Amino Acids, Peptides, and Proteins; Amino Acids; Amino Acids, Aromatic; Amino Acids, Cyclic; Thyroid Hormones; Thyroxine
• Other Study ID Numbers: 36264MS959/5/25

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: The data will be available upon a reasonable request from the corresponding author after the end of study for one year.
• IPD Sharing Time Frame: After the end of study for one year.
• IPD Sharing Access Criteria: The data will be available upon a reasonable request from the corresponding author.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

Drug and device information, study documents

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