Subclinical Hypothyroidism as the Most Common Thyroid Dysfunction Status in Children With Down’s Syndrome

Abstract

IntroductionThyroid dysfunctions are one of the most common abnormalities coexisting in children with Down’s syndrome (DS) and have been reported in up to 54% of cases.Aim of the StudyThe purposes of this retrospective study were to investigate the course of subclinical hypothyroidism in children with DS, to evaluate the thyroid function of these subjects in relation to the risk of developing overt thyroid disease and autoimmunity, and to identify clinical and biochemical characteristics of patients prescribed L-T4 therapy in children and adolescents with DS and SH.Material and MethodsThe records of DS patients referred to the Endocrinology Outpatient Clinic between 2010 and 2015 for screening of thyroid function were observed till the end of 2019 June and analyzed retrospectively. The children diagnosed with congenital hypothyroidism, acute lymphoblastic leukemia, and seizures and treated with drugs that may have interfered with thyroid function like lithium, antiepileptic, or iodinated drugs and glucocorticoids were excluded from the study.ResultsThe data of 77 DS patients were collected, evaluated, and analyzed. The study group consisted of 73 patients (32 girls and 41 boys with the mean age at baseline of 3.0 ± 4.5 years). A total of 63/73 (87%) children were diagnosed with SH. The 16/63 (25.4%) patients were followed-up without the treatment (group SH-T0), and therapy with levothyroxine (L-T4) was introduced in 47/63 (74.6%) SH children with a mean dosage of 1.8 ± 1.0 μg/kg/day (group SH-T1). Thyroxine supplementation did not improve growth expressed as ΔhSDS (0.1 ± 1.3, ranged −2.1 to 3.8 in SH-T0 vs. 0.0 ± 0.7, ranged −1.7 to 1.4 in SH-T1, p = 0.96) and ΔBMI Z-score (0.3 ± 0.9, ranged −0.9 to 2.6 in SH-T0 vs. 0.3 ± 1.1, ranged −2.1 to 2.9 in SH-T1, p = 0.65). Positive anti-TPO and anti-TG antibodies were detected in 7/63 (11.1%) DS cases.ConclusionsSH is the most frequent presentation of thyroid gland dysfunction in DS children. A small percentage of patients develop an overt hypothyroidism, particularly in females with mostly positive titer of antithyroid autoantibodies.

Nutrition as Prevention of Diet-Related Diseases—A Cross-Sectional Study among Children and Young Adults with Down Syndrome

“…The spectrum of thyroid dysfunction includes congenital hypothyroidism, subclinical hypothyroidism, acquired hypothyroidism (autoimmune/non-autoimmune), and hyperthyroidism [12]. Correct functioning of the thyroid gland is very important in the development of any child, especially a child with DS, as it ensures normal physical and mental development [13]. Thyroid diseases also occur in about 20-50% of adults with DS.…”

Endocrine, auxological and metabolic profile in children and adolescents with Down syndrome: from infancy to the first steps into adult life

“…Some studies revealed benefits of replacement therapy and normalization of TSH values in terms of growth velocity, height, and head circumference ( 17 , 47 , 48 ); no improvement of motor and cognitive development was found ( 47 ). Besides, most of these results have been systematically challenged by different authors, who did not confirm such findings ( 31 ).…”

“…Levothyroxine dosage is titrated, until biochemical euthyroidism is achieved. Though an average dosage of 1-2 mcg/kg/day is usually sufficient in the general population, daily doses ranging from 0.3 to 6.6 mcg/kg have been reported in children and adolescents with DS ( 31 ). The first evaluation of efficacy by assessing thyroid function tests is indicated not earlier than 6 to 8 weeks following treatment prescription and then every six months ( 32 ).…”

Emotional and behavioral features associated with subclinical hypothyroidism in children and adolescents with Down syndrome

“…For example, higher rates of hypothyroidism have been documented, with estimated prevalence of 23.5% in pediatric age and 39-61% in adult age (Carroll et al, 2008;Tsou et al, 2020). Another thyroid dysfunction particularly frequent in DS is SH, whose prevalence in this population has been estimated up to 87% (O' Grady and Cody, 2011;Szeliga et al, 2022), remarkably higher than the prevalence reported in general population (5%) (Chiovato et al, 2019). SH diagnosis is possible when serum thyroid-stimulating hormone (TSH) is slightly elevated and the levels of total or free thyroxine and triiodothyronine are normal (O'Grady and Cody, 2011).…”

“…It has been proposed that the increased prevalence of thyroid dysfunctions in youth with DS could be determined by a delayed maturation of the hypothalamic–pituitary-thyroid axis; this would result in a temporary process not necessitating treatment ( Sharav, 1988 , 1991 ). Accordingly, literature suggests that only a limited percentage of individuals with DS and SH develops an overt hypothyroidism, particularly females with mostly positive titer of antithyroid autoantibodies ( Szeliga et al, 2022 ).…”