Subclinical Hypothyroidism in Children: When a Replacement Hormonal Treatment Might Be Advisable

Abstract

Aim of this mini review was to analyze the main variables which should be taken into account when the decision regarding a possible treatment with L-T4 has to be considered for a child with subclinical hypothyroidism (SH). The indications of periodical monitoring and vigilance have been also discussed. It was inferred that therapy should be recommended for children with underlying Hashimoto's thyroiditis and progressive deterioration of thyroid status over time, particularly in the cases with goiter and hypothyroid symptoms and in those with associated Turner syndrome or Down's syndrome and/or other autoimmune diseases. Treatment might also be recommended for children with proatherogenic metabolic abnormalities. Treatment is not advisable in children with idiopathic and mild SH, no goiter, no hypothyroid symptoms and negative anti-thyroid autoantibodies. In the absence of any therapeutic intervention, clinical status and thyroid function tests should be periodically monitored, in order to individuate the children who might benefit from treatment. It has been suggested that children with a persistent mild elevation of TSH, who are not treated with L-T4, should undergo biochemical monitoring of thyroid function and re-assessment of clinical status every 6 months. After 2 years with stable thyroid function tests, the interval between monitoring can be extended.

The effect of subclinical hypothyroidism on body composition parameters in children

“…Thyroid function was evaluated at 8 am after an overnight fasting by measurement of basal TSH, fT3 and fT4, anti‐Tg and anti‐TPO. MSH was defined as TSH between 4.5 and 10 µU/ml and fT4 was within normal limits for age in at least two different measurements in 1 month 4 . Thyroid function tests and autoantibodies were measured using chemiluminescence (Roche Cobas E601 Immunology Analyzer, Massachusetts, USA) in the biochemistry laboratory (normal values: TSH: 0.5‐4.5 µU/mL, fT4: 0.8‐2.3 ng/dL).…”

“…Prevalence of SH in childhood is lower than 2%. SH has been accepted as a benign and remitting condition, with a low risk to progress to overt hypothyroidism, especially in children with idiopathic and MSH 4 . The clinical presentation of the children with SH may vary from no clinical symptoms to a clear picture of thyroid impairment 5 .…”

“…Some studies indicate that LT4 treatment may be considered in children with MSH in the presence of positive anti‐thyroid autoantibodies, subtle proatherogenic metabolic abnormalities and persistent TSH elevation. LT4 treatment is recommended if child has a TSH level above >10 mU/L, goitre or thyroid nodule 4,5,10 . Nevertheless, there is still controversy about the necessity of treatment in adults and children with SH because the available data do not confirm clear‐cut benefits for early therapy compared with treatment when clinical symptoms develop 9,14‐17 .…”

Levothyroxine supplementation for obesity-associated thyroid dysfunction in children: a prospective, randomized, case control study

“…None of these mechanisms, however, explains the thyroid dysfunction completely and hence the clinical implications remain non-absolute and specific therapy with levothyroxine is controversial [3,4]. Mild SCH, unless associated with Hashimoto's thyroiditis, is frequently considered benign in pediatric population [6,7] and therapy is recommended only if the thyroid stimulating hormone (TSH) remains consistently elevated [8][9][10]. Nevertheless, several recent studies have identified IsHT as an important risk factor for the development and progression of cardiovascular disease and nonalcoholic fatty liver disease (NAFLD) in obese children and adolescents [11][12][13].…”

Subclinical hypothyroidism in childhood, treatment or only follow-up?

“…Treatment with levothyroxine was initiated in all patients who presented TSH ≥10μUI/mL or TSH 5-10μUI/ mL and positive TPOAb/TgAb (G3). The dilemma arises in deciding whether patients with maintained mildly elevated TSH (G2) should be treated or not with levothyroxine and what benefits it can bring against possible consequences of SH, since good-quality studies examining the effect of treatment of SH in children are lacking [9,[24][25][26]. In our case, no patients were treated since none presented associated symptoms or alterations that could be related to it.…”