Subclinical Hypothyroidism in Children and Adolescents: Is It Clinically Relevant?

Abstract

Although subclinical hypothyroidism (SH) is a common clinical problem, its diagnosis tends to be incidental. According to the definition, it should be asymptomatic, only detectable by screening. The presence or coincidence of any symptoms leads to L-thyroxine treatment. The clinical presentation, especially in younger patients with subclinical hypothyroidism, is still under dispute. Accordingly, the aim of this paper was to review the literature from the past seven years. The literature search identified 1,594 potentially relevant articles, of which 24 met the inclusion criteria. Few studies focus on the symptomatology of subclinical hypothyroidism, and most of them analyzed a small number of subjects. A significant correlation was found by some authors between subclinical hypothyroidism and a higher risk of hypertension, dyslipidemia, and migraine. No evidence of the impact of subclinical hypothyroidism on weight, growth velocity, and puberty was revealed. As the quality of most studies is poor and no definite conclusions can be drawn, randomized, large-scale studies in children and adolescents are warranted to determine the best care for patients with SH.

Unfavorable Course of Subclinical Hypothyroidism in Children with Hashimoto’s Thyroiditis Compared to Those with Isolated Non-Autoimmune Hyperthyrotropinemia

“…1). Although thyroid volume can increase during puberty (1920), and thyroid hormone requirements may increase during the pubertal growth spurt (2122), thyroid dysfunction can develop irrespective of pubertal onset. Furthermore, a previous prospective study with iso-NAHT patients reported that normalization of TSH concentrations was less evident in prepubertal patients than pubertal patients (8).…”

Five-year prospective evaluation of thyroid function in girls with subclinical mild hypothyroidism of different etiology

“…In fact, the majority of these patients (61.9%) spontaneously normalized over time their TSH values, and only a small minority (11.9%) became overtly hypothyroid. Nevertheless, it has to be pointed out that almost a quarter of group A girls required L-T 4 treatment during the observation period, which underlines the importance of a biochemical follow-up, even in the children with idiopathic and mild SH (33,36). According to the recent guidelines of the European Thyroid Association, in these children monitoring can be performed every 12 months due to the low risk of progression (33).…”

Mild subclinical hypothyroidism is associated with paediatric dyslipidaemia

“…Subclinical hypothyroidism (SCH) is defined biochemically as an elevated thyroid stimulating hormone (TSH) in the presence of a normal serum free thyroxine (T4). While most experts recommend levothyroxine therapy for subclinical hypothyroidism with TSH greater than 10 mIU/L, there is lack of consensus on whether mild SCH with TSH levels between 5 and 10 mIU/L should be treated . Several studies in adults demonstrate an association between elevated TSH and total and low density lipoprotein(LDL) cholesterol concentrations .…”