Can Levothyroxine Treatment Reduce the Development of Cardio-metabolic Disorder in Subclinical Hypothyroidism?
Can Levothyroxine Treatment Reduce the Development of Cardio-metabolic Disorder in Subclinical Hypothyroidism?
2. Aim/ Objectives The aim of this study is to evaluate the clinical, laboratory and
 echocardiographic findings in children with SCH.

 To investigate the effect of replacement therapy with levothyroxine on cardiovascular risk
 factors in children with SCH.
Sub-clinical hypothyroidism (SCH) is a form of thyroid dysfunction in which the
 thyroid-stimulating hormone (TSH) level is high, while serum total/free thyroxine (T4/fT4) is
 within the normal reference range . SCH is mostly detected accidentally as most of the
 patients manifest few or no signs of thyroid dysfunction.

 The most common causative factor for SCH is chronic autoimmune thyroiditis characterized by
 high titers of thyroid peroxidase antibodies, thyroglobulin antibodies and rarely TSH
 receptor blocking antibodies. However, mutations in several proteins involving in TSH action
 including TSH receptor gene and mutations of dual oxidase 2 (DUOX2), phosphodiesterase 8B and
 thyroid peroxidase have also been demonstrated as causes of TSH elevation .

 SCH might be associated with endothelial dysfunction due to early changes in proatherogenic
 profiles as there is elevation in plasma levels of total cholesterol (TC) and low-density
 lipoprotein-cholesterol (LDL-C) in SCH patients , also there is increased risk of
 hypertension in SCH patients than in euthyroid .

 Many studies found that homocysteine concentration appears to be increased in hypothyroidism
 and decreased in hyperthyroidism, and there is relationship between hyperhomocysteinemia and
 cardiovascular disease, including increased platelet aggregation, increased coagulation or
 reduced thrombolysis and endothelial dysfunction .

 The acute-phase reactant hs-CRP is known to be a sensitive and non-specific marker for
 inflammation, tissue damage and infection . Serum hs-CRP measurements are used to determine
 cardiovascular risk. hs-CRP is regarded as a predictive marker for myocardial infarction,
 stroke, peripheral artery disease and sudden cardiac death .

 The treatment of children with SCH is controversial; and there is not enough evidence that
 treatment can prevent the risk of developing cardiovascular and metabolic disorders in SCH.
Inclusion Criteria:

 -  1. Patients aged from 5-15 years diagnosed with SH (patients with elevated TSH and
 normal Ft4 on two different measurements 4-6 weeks apart).

 Exclusion Criteria:

 -  1. Patients with acute or chronic disorders (anemia, infection, diabetes mellitus,
 malignancy, liver and renal disorder).

 2. Patients with a history of medication that affect thyroid function tests as
 glucocorticoids, dopamine or dobutamine, amiodarone, lithium, interferons,
 alemtuzumab.

 3. Patients with BMI>95 percentile.