Comparative evaluation of therapy with L-thyroxine versus no treatment in children with idiopathic and mild subclinical hypothyroidism

Clinical Outcomes After Discontinuation of Thyroid Hormone Replacement: A Systematic Review and Meta-Analysis

Background: Levothyroxine (LT4) is one of the most commonly prescribed medications. Although considered a life-long replacement therapy, LT4 therapy can be discontinued for some patients. This study aims at: (i) reviewing the evidence on clinical outcomes of patients undergoing thyroid hormone replacement discontinuation, (ii) identifying the predictors of successful discontinuation, and (iii) systematically appraising frameworks used for deprescribing thyroid hormone. Methods: We searched multiple bibliographic databases, including Ovid MEDLINE(R) and Epub Ahead of Print, In-Process & Other Non-Indexed Citations and Daily, Ovid Embase, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus, from inception to February 2020 for studies in which thyroid hormone replacement was discontinued. Clinical outcomes assessed included: proportion of patients that remained euthyroid or needed to restart thyroid hormone replacement after discontinuation and frequency of clinical symptoms of hypothyroidism and adverse effects. We also evaluated predictors for discontinuation and deprescribing frameworks. Reviewers (F.J.K.T., N.B., N.M.S.O., S.M.) evaluated studies for inclusion, extracted data, and assessed methodological quality independently and in duplicate. Results: Seventeen observational studies at moderate to high risk of bias met inclusion criteria, including a total of 1103 patients (86% women) with an age range of 2-81 years. Approximately a third of patients undergoing thyroid hormone discontinuation remained euthyroid at follow-up (37.2%, 95% confidence interval [CI 24.2-50.1%], I² 97.5%). Subgroup analysis showed that patients with a previous diagnosis of overt hypothyroidism (OH) were less likely to remain euthyroid (11.8% [CI 0.4-23.2%], I² 90.3%) than patients with a prior diagnosis of subclinical hypothyroidism (SCH) (35.6% [CI 8.2-62.9%], I² 94.0%). No study followed a framework for systematically deprescribing LT4. Conclusions: Low-quality evidence suggests that up to a third of patients remained euthyroid after thyroid hormone discontinuation, with a higher proportion of patients with an initial diagnosis of SCH remaining euthyroid than patients with an initial diagnosis of OH. A deprescribing framework focusing on adequate selection of patients for deprescribing LT4 and a systematic process is warranted to guide clinicians in re-evaluating the need for LT4 in their patients.

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

Background

Subclinical hypothyroidism (SH) is defined as serum levels of thyroid-stimulating hormone (TSH) above the upper limit with normal concentrations of free T4 (fT4). Its management remains challenging. The aim of the study was to evaluate clinical and laboratory findings as well as the clinical course of children with SH followed in a third level hospital. Sixty-five patients aged between 2 and 18 years old were retrospectively studied.

Methods

The patients were followed for a median period of 9 months (range 6 months to 24 months). Those who normalized TSH levels were discharged (Group 1). If TSH persisted mildly elevated (5-10μUI/mL) with normal fT4 and negative TPOAb/TgAb, they were classified as Group 2 and followed semi-annually without treatment. Those patients whose TSH raised ≥10μUI/mL or who maintained TSH 5-10μUI/mL and positive TPOAb/TgAb were considered suitable for thyroxin therapy (Group 3, G3).

Results

In 89% of our patients, TSH concentrations spontaneously reverted to normality or remained stable without treatment (Groups 1 and 2), whereas less than 11% progressed to clinical hypothyroidism (Group 3). Baseline TSH was significantly lower in group 1 than in group 3. In group 3 the prevalence of female sex (71%) was higher and TPO antibodies were present in 85% of patients. The risk of developing overt hypothyroidism in patients with positive anti-thyroid antibodies respect to those who normalized TSH was 45 (95%CI 6.5–312.5).

Conclusion

Baseline TSH, female sex and the presence of thyroid autoimmunity were the best predictors of the evolution to SH over time.

The effect of subclinical hypothyroidism on body composition parameters in children

BACKGROUND

It's known that overt hypothyroidism increases body fat content and weight. There's limited research about the effect of subclinical hypothyroidism (SH) on body composition in children and the effect of LT4 treatment. We aimed to evaluate body composition parameters in healthy subjects and in children with mild SH (MSH) and determine the effect of LT4 treatment.

METHODS

Sixty-four healthy children and 32 children with MSH were included. Anthropometric measurements and hormonal parameters were evaluated. Body composition was evaluated using bioelectric impedance analysis (BIA). Patients were put on LT4 treatment. BIA was performed again after 12 months of therapy.

RESULTS

There was no significant difference between the anthropometric parameters and basal metabolic rate of the healthy children and the MSH group. The percentage of trunk muscle mass (TMM) in the MSH group was lower than in the control group (P < .05). After 12 months of LT4 treatment, the percentage of total fat-free mass (FFM), TMM and trunk fat-free mass (TFFM) were increased and percentage of total body fat mass and trunk fat mass were decreased (P < .05). The difference between the percentage of TMM in the MSH group and control group was insignificant after LT4 treatment (P > .05).

CONCLUSIONS

The percentage of TMM in children with MSH was found lower than healthy control group. After LT4 treatment, the percentage of the FFM, TMM and TFFM were increased and the difference between percentage of TMM in children with MSH and healthy controls was insignificant. Our data indicated that MSH might be associated with early changes in body composition parameters.

Clinical factors predicting the successful discontinuation of hormone replacement therapy in patients diagnosed with primary hypothyroidism

BACKGROUND

Although reversible in some patients, primary hypothyroidism is considered a permanent condition requiring lifelong hormone therapy. This study aimed to investigate the factors predicting the successful discontinuation of levothyroxine (L-T4) therapy in patients with primary hypothyroidism.

METHODS

A retrospective study was performed in primary hypothyroidism patients who met inclusion criteria: patients who maintained stable L-T4 therapy for more than 1 year, following gradual dose reduction of L-T4 based on the clinical decision (L-T4 tapering); patients receiving either no L-T4 or a fixed minimum dose for more than 1 year after L-T4 tapering. Reduction in L-T4 dosage by 12.5-50 μg within 3 months was considered as L-T4 tapering. Serum free T4, TSH, and clinical symptoms were evaluated before, during and after tapering. Logistic regression and decision tree analyses were performed to predict the successful discontinuation of L-T4.

RESULTS

Among 382 patients, 22.5% and 58.4% showed successful discontinuation (T4-Discontinued) and dose reduction (T4-Reduced) of L-T4 therapy, while other did not obtained any reduction of L-T4 dose (T4-Unchanged). The median number of tapering visit was 1.0 (range, 1.0-4.0). In T4-Discontinued group, the TSH level and the positive rate of anti-thyroperoxidase at the time of L-T4 initiation were lower, the duration of L-T4 therapy was shorter, and the maintenance dose of L-T4 at the time of tapering was lower than those in the T4-Unchanged group. In ultrasonography, normal parenchyma was preserved in the T4-Discontinued group while others showed higher rates of heterogeneous or hypoechoic parenchymal changes. Among those different characteristics, the longer duration of L-T4 therapy and the higher maintenance dose of L-T4 at the time of tapering significantly predicted the failure of discontinuation of L-T4 in multivariate analysis. A decision tree showed that patients with a duration of L-T4 therapy >4.6 years had lower success rate of discontinuation.

CONCLUSION

Shorter duration of L-T4 therapy and lower L-T4 dose at the time of tapering are the predictable factors for successful L-T4 tapering in stably maintained primary hypothyroidism patients.

Long-Term Follow-Up and Outcomes of Autoimmune Thyroiditis in Childhood

Background: Autoimmune thyroiditis (AIT) is the most common cause of acquired hypothyroidism in children. The natural outcome of AIT in childhood has been reported previously however follow-up duration is generally short and results variable. Objectives: To characterize clinical and biochemical findings at presentation of AIT, evaluate long-term outcomes and assess which factors at presentation predict evolution over time. Study cohort: 201 children under 18 years of age at presentation (82% female) were enrolled. Subjects were divided into five subgroups according to thyroid stimulating hormone (TSH) level at referral. Results: Mean follow-up was 8.1 years (range 0-29 years). At presentation, 34% of patients had overt hypothyroidism, 32% subclinical hypothyroidism (SCH), 16% compensated hypothyroidism, 14% were euthyroid, and 3.7% had Hashitoxicosis. Children with overt hypothyroidism were younger (10.6 vs. 13.2 years) and had higher thyroid peroxidase antibody titers. At the time of the study, levothyroxine (LT₄) therapy was required in 26% of children who were euthyroid at presentation, 56% of SCH patients, 83-84% of those with TSH above 10 mIU/L, and 57% of those with Hashitoxicosis. Over the years, 16% of children presenting with overt hypothyroidism stopped therapy. Free T₄ at presentation was the only predictor of outcome over time. Conclusions: Our findings suggest that only 26% children who were euthyroid at presentation developed hypothyroidism, whereas over 50% of those with SCH went on to require treatment. Of those presenting with overt hypothyroidism, 16% recovered with time. The only predictive parameter for LT₄ therapy at the end of the study was free T₄ levels at presentation. Long-term follow-up is required to determine ongoing therapy needs and screen for additional autoimmune diseases.

Evaluation of the relationship of subclinical hypothyroidism with metabolic syndrome and its components in adolescents: a population-based study

PURPOSE

This study investigated the association of subclinical hypothyroidism (SCH) with metabolic syndrome (MetS) and its components in adolescents.

METHODS

The study population included 1006 adolescents (aged 10-18 years) from the Korea National Health and Nutrition Examination Surveys; SCH subjects were compared with euthyroid subjects. MetS was defined using the International Diabetes Federation criteria. The risks of MetS and its components in SCH and euthyroid subjects were calculated using binary logistic regression analyses.

RESULTS

Study subjects had a mean age of 14.2 ± 2.5 years, and 53% were male. The prevalence of MetS was 2.5% in the overall study population (3.2% of males and 1.7% of females). Among the 1006 subjects, 143 (14.2%) had SCH. The risk of MetS was not higher in SCH subjects than in euthyroid subjects (odds ratio [OR], 1.50; 95% confidence interval [CI], 0.54-4.11); however, among the components of MetS, the risk of abdominal obesity was higher in SCH subjects than in euthyroid subjects (OR, 2.08; 95% CI, 1.04-4.15) after adjusting for age, sex, and body mass index (BMI). Although not statistically significant, a trend toward increased risk of elevated blood pressure (BP) was observed in SCH subjects relative to euthyroid subjects after further adjusting for age, sex, and BMI (OR, 2.01; 95% CI, 0.89-4.52). Furthermore, non-obese SCH subjects had higher systolic BP compared with non-obese euthyroid subjects after adjusting for age, sex, and BMI (P = 0.014).

CONCLUSIONS

SCH was not associated with the presence of MetS. However, SCH may be associated with abdominal obesity and possibly elevated BP in adolescents.

Association between mild hyperthyrotropinemia and hypercholesterolemia in children with severe obesity

Background Severe obesity is associated with a number of cardiometabolic risk factors. Thyroid-stimulating hormone (TSH) levels are often slightly increased in children with obesity. The clinical significance of the mild elevation in TSH in children with obesity is unclear. Objective To examine the association between TSH and lipids in children with severe obesity. Methods We performed a retrospective analysis of records of children with severe obesity with simultaneous measurements of TSH and lipids. Children with TSH <0.3 mIU/L and ≥10 mIU/L were excluded. The relationship between TSH and lipids was evaluated using univariate/multiple variable linear and logistic regression. Results The study included 834 children (age 13.8 ± 4.1 years, males 46%, body mass index [BMI]: 36.9 ± 7.6 kg/m2; BMI z-score 2.6 ± 0.4). Seventy-four (8.9%) children had TSH between 5 and <10 mIU/L (high TSH [HTSH]). TSH was positively associated with non-high-density lipoprotein (HDL) cholesterol (β: 1.74; 95% confidence interval [CI] 0.29-3.20, p = 0.02). Total cholesterol and non-HDL cholesterol were higher in males with HTSH compared to those with normal TSH (175.5 vs. 163.5 mg/dL, p = 0.02 and 133.7 vs. 121.4 mg/dL, p = 0.02, respectively). The odds of elevated non-HDL cholesterol (≥145 mg/dL) was higher in males with HTSH relative to those with normal TSH (odds ratio [OR]: 2.78; 95% CI 1.35-5.69, p = 0.005). Conclusions TSH levels were positively associated with non-HDL cholesterol in children with severe obesity. Males with mildly elevated TSH had higher total cholesterol and non-HDL cholesterol compared to males with normal TSH. Further studies are warranted to determine if levothyroxine therapy would result in improvement in total cholesterol or non-HDL cholesterol in children with severe obesity with mildly elevated TSH.

Management of Subclinical and Overt Hypothyroidism Following Hemithyroidectomy in Children and Adolescents: A Pilot Study

Background: To reduce surgical complications and avoid lifelong thyroid hormone replacement, hemithyroidectomy is preferred in children and adolescents with benign nodular thyroid disease. However, hypothyroidism following hemithyroidectomy may occur, and postoperative thyroid hormone replacement for hypothyroidism following hemithyroidectomy is usually administered without a full understanding of the clinical characteristics of hypothyroidism. Methods: To investigate the incidence and risk factors of hypothyroidism after hemithyroidectomy in children and adolescents, and to identify whether postoperative thyroid hormone replacement is necessary, a retrospective review of 43 patients under 18 years of age who underwent hemithyroidectomy from January 2009 to October 2016 was conducted. All hypothyroid patients were retrospectively analyzed to determine the incidence and predisposing factor(s) of postoperative hypothyroidism. All patients were measured regarding age, sex, serum thyrotropin (TSH), anti-thyroid antibody, and histological evidence of lymphocytic infiltration. Hypothyroid patients were measured for symptoms, timing of diagnosis, and thyroid hormone replacement. Results: The mean age at the time of surgery was 13.65 ± 3.04 years. Of the cohort, 34 patients were female (79.07%), and the mean follow-up time was 28 ± 9 months. Hypothyroidism was diagnosed in 11 of the 43 patients. The mean postoperative TSH level was 7.17 ± 2.13 μIU/ml. The mean preoperative TSH level was 3.11 ± 0.59 μIU/ml in hypothyroid patients compared with 1.92 ± 0.72 μIU/ml in euthyroid patients (P < 0.05). A preoperative TSH level >2.2 μIU/l and lymphocytic infiltration graded 3 or 4 were found to be independent risk factors for the development of hypothyroidism. There were no significant differences between groups in terms of patient age or sex. Conclusions: In the pediatric and adolescent population, patients with elevated preoperative TSH levels or the presence of lymphocytic infiltration may increase the risk of risk of hypothyroidism. In our study, postoperative levothyroxine (L-T4) treatment was necessary in 16.28% of cases after hemithyroidectomy. Patients with mild postoperative hypothyroidism should be followed up, without the need for immediate L-T4 replacement, so as to expect patients to recover spontaneously.

Hashimoto Thyroiditis and Dyslipidemia in Childhood: A Review

Hashimoto autoimmune thyroiditis (AIT) is the most common cause of acquired hypothyroidism in the pediatric population. Development of AIT is mediated mainly by cellular immune response directed toward thyroid autoantigens, leading to inflammation and impaired function of thyroid gland. Both thyroid dysfunction and inflammation affect the metabolism of plasma lipoproteins. The alterations in lipid profile worsen with the advancement of hypothyroidism, ranging from discrete changes in euthyroid AIT patients, to atherogenic dyslipidemia in the overt hypothyroidism. In this review, characteristics of dyslipidemia in pediatric AIT patients, and the consequences in respect to the risk for cardiovascular disease (CVD) development are discussed. Additionally, benefit of L-thyroxine treatment on serum lipid profile in pediatric AIT patients is addressed. Finally, potential usefulness of novel lipid biomarkers, such as proprotein convertase subtilisin/kexin type 9 (PCSK9), non-cholesterol sterols, low-density lipoprotein particle size and number, and high-density lipoprotein structure and functionality in AIT patients is also covered. Further longitudinal studies are needed in order to elucidate the long-term cardiovascular outcomes of dyslipidemia in pediatric patients with Hashimoto AIT.

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

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.

Mild subclinical hypothyroidism is associated with paediatric dyslipidaemia

BACKGROUND

There is a lack of consensus on the cardiometabolic consequences of mild subclinical hypothyroidism (SCH) among children. The objective of the current study was to compare lipid profiles in children with mild SCH with those of euthyroid children.

STUDY DESIGN

Retrospective medical record review.

PATIENTS

Children (ages 2-18 years) who had undergone simultaneous measurement of TSH, free thyroxine (T4) and lipids. Lipids in children with mild SCH (TSH 5-<10 mIU/L and normal free T4, n = 228) were compared with those in euthyroid children (n = 1215).

RESULTS

TSH level was positively associated with total cholesterol and nonhigh density lipoprotein (non-HDL) cholesterol [β 0.05(0.03-0.08), P < .0001 and β 0.05(0.03-0.08), P < .0001, respectively]. Total cholesterol was significantly higher in children and adolescents with mild SCH compared with euthyroid children (4.43 ± 1.14 mmol/L vs 4.2 ± 0.85 mmol/L, P = .0005). Similarly, non-HDL cholesterol level was also higher in children with mild SCH relative to euthyroid children (3.08 ± 1.14 mmol/L vs 2.91 ± 0.8 mmol/L, P = .001). The adjusted odds ratio of having elevated total cholesterol and elevated non-HDL cholesterol was greater in children with mild SCH compared with euthyroid children (OR 1.88, 95% CI; 1.28-2.73; P = .001 and 1.72, 95% CI 1.2-2.5; P = .003, respectively). The presence of thyroid autoimmunity was not associated with higher rates of dyslipidaemia.

CONCLUSIONS

Mild SCH in children and adolescents was associated with higher rates of elevated total cholesterol and elevated non-HDL cholesterol. Randomized placebo controlled studies are warranted to determine if treatment of mild SCH in children leads to improvement in lipid profile.

Mild Hypothyroidism in Childhood: Who, When, and How Should Be Treated?

Mild hypothyroidism, also known as subclinical hypothyroidism (SH), is biochemically defined as serum TSH levels above the upper limit of the reference range, in the presence of normal serum concentrations of total T4 and free T4 (FT4). In the neonatal period, mild hypothyroidism can be defined by the presence of a TSH value between 6 and 20 mIU/L and normal FT4 levels. After the neonatal period, SH can be defined mild if TSH ranges between 4.5 and 10 mIU/L. The management of mild hypothyroidism in childhood is challenging. The major concern is to establish whether this condition should always be considered an expression of mild thyroid dysfunction. Indeed, the effects of untreated mild hypothyroidism are still not completely defined. In the neonatal period, concern exists about neurocognitive outcome; in children, although there is no clear evidence of alterations in growth or neurocognitive development, subtle cardiovascular abnormalities have been documented. Therefore, there is still uncertainty about the need of treatment across all ages, and the management should be based on the age of the child, the etiology, and the degree of TSH elevation, as well as on other patient factors. This review updates current evidences on diagnosis and management of mild hypothyroidism in childhood.

Advances in pediatrics in 2017: current practices and challenges in allergy, endocrinology, gastroenterology, genetics, immunology, infectious diseases, neonatology, nephrology, neurology, pulmonology from the perspective of Italian Journal of Pediatrics

This review provides an overview of a remarkable number of significant studies in pediatrics that have been published over the past year in the Italian Journal of Pediatrics. We have selected information from papers presented in the Journal that deal with allergy, endocrinology, gastroenterology, genetics, immunology, infectious diseases, neonatology, nephrology, neurology, pulmonology. The relevant epidemiologic findings, and developments in prevention, diagnosis and treatment of the last year have been discussed and placed in context. We think that advances achieved in 2017 will help readers to make the future of patients better.

Subclinical hypothyroidism in children: is it always subclinical?

Aim of this commentary is to report current knowledges on the main clinical and metabolic abnormalities which might be observed in children with longstanding and untreated subclinical hypothyroidism (SH) and to comment the most recent views about natural evolution of thyroid function in the cases with either idiopathic or Hashimoto’s thyroiditis-related SH. On the basis of these preliminary remarks, the essential guidelines for an appropriate and tailored management of SH children are also proposed.

Thyroid function test evolution in children with Hashimoto's thyroiditis is closely conditioned by the biochemical picture at diagnosis

ᅟ

Aim of this commentary is to summarize the salient literature views on the relationships between presentation and evolution patterns of thyroid function in children with Hashimoto’s thyroiditis (HT).

According to the most recent reports, children with HT and subclinical hypothyroidism (SH) are more prone to the risk of developing severe thyroid dysfunctions over time, if compared to those presenting with euthyroidism.

In contrast, children presenting with HT and either overt or subclinical hyperthyroidism are incline to exhibit a definitive resolution of the hyperthyroid phase within some months, although there is a wide variability between the different individuals.

The natural history of frank hypothyroidism in the children with HT has never been investigated so far, since in these cases an immediate onset of replacement treatment is mandatory.

Conclusions

1) a deterioration of thyroid status over time may be observed especially in the children presenting with SH, but also in those presenting with euthyroidism; 2) a definitive resolution of the hyperthyroid phase is generally observed in those presenting with either overt or subclinical hyperthyroidism.

Atypical phenotypic aspects of autoimmune thyroid disorders in young patients with Turner syndrome

Aim of this commentary is to analyze the current views about the phenotypic features of Hashimoto’s thyroiditis (HT) and Graves’ disease (GD) in Turner syndrome (TS) girls, in terms of epidemiology, clinical and biochemical presentation, long-term course and metamorphic autoimmunity evolution. In TS GD course is not atypical, whereas HT course is characterized by both a mild presenting picture and a severe long-term evolution of thyroid function tests. Furthermore, TS girls seem to have an increased risk of switching over time from HT to GD. On the light of these findings, it may be concluded that TS girls with HT need a careful monitoring of thyroid status over time.

Conclusions: 1) In children the association with TS is able to condition a peculiar phenotypic expression of HT in terms of epidemiology, presentation course and long-term metamorphic autoimmunity; 2) by contrast, children with TS do not exhibit an atypical clinical and biochemical course of GD, but only a significantly higher prevalence of this disease.

The debate on treating subclinical hypothyroidism

Subclinical hypothyroidism (SCH) represents a mild or compensated form of primary hypothyroidism. The diagnosis of SCH is controversial, as its symptoms are non-specific and its biochemical diagnosis is arbitrary. The treatment of SCH was examined among non-pregnant adults, pregnant adults and children. In non-pregnant adults, treatment of SCH may prevent its progression to overt hypothyroidism, reduce the occurrence of coronary heart disease, and improve neuropsychiatric and musculoskeletal symptoms associated with hypothyroidism. These benefits are counteracted by cardiovascular, neuropsychiatric and musculoskeletal side effects. SCH is associated with adverse maternal and fetal outcomes that may improve with treatment. Treating SCH in children is safe and may improve growth. Importantly, the evidence in this field is largely from retrospective and prospective studies with design limitations, which precludes a conclusive recommendation for the treatment of SCH.

Subclinical hypothyroidism in paediatric population treated with levothyroxine: a real-world study on 2001-2014 Italian administrative data

OBJECTIVE

To estimate the prevalence of subclinical hypothyroidism (SH) among children, by using levothyroxine low dosage as disease proxy, and to describe prescription pattern.

DESIGN

An historical cohort study was performed through administrative databases of 12 Italian Local Health Units covering 3,079,141 inhabitants. A cohort of children (aged 0-13 years) was selected in the period 2001-2014. A subgroup of new users (aged 0-9 years) was identified and followed up for 5 years.

METHODS

The prevalence was provided as mean value of the whole period, as annual trend, by patient gender and age. Demographic details, information on levothyroxine dosage, comorbidities and co-medications were provided. Therapy duration and medication persistence were evaluated among new users.

RESULTS

644 children treated with levothyroxine low dosage was selected, with a mean annual prevalence of 0.20 per 1000 children. The temporal trend of prevalence was stable, with a slight reduction in the 2005-2008. Prevalence by age showed an increase after 10 years. Patients were treated with an average annual dose of 4290 µg/year and 66.9% of children were affected by comorbidities. Among 197 new users, 62.9% received therapy only for one year, whereas out of those treated two or more years, 89.0% resulted persistent to the therapy.

CONCLUSIONS

This study provides real-world epidemiology of SH among children, and it depicts the clinical and therapeutic characteristics of these subjects. Its findings showed that the SH treatment of this disorder was widely variable, also due to lack of evidence concerning paediatric population.

Thyroid function in children and adolescents with Hashimoto's thyroiditis after l-thyroxine discontinuation

OBJECTIVE

Thyroid function may recover in patients with Hashimoto's thyroiditis (HT).

DESIGN

To investigate thyroid function and the need to resume l-thyroxine treatment after its discontinuation.

SETTING

Nine Italian pediatric endocrinology centers.

PATIENTS

148 children and adolescents (25 m and 123 f) with HT on treatment with l-thyroxine for at least one year.

INTERVENTION AND MAIN OUTCOME MEASURE

Treatment was discontinued in all patients, and serum TSH and fT4 concentrations were measured at the time of treatment discontinuation and then after 2, 6, 12 and 24 months. Therapy with l-thyroxine was re-instituted when TSH rose >10 U/L and/or fT4 was below the normal range. The patients were followed up when TSH concentrations were between 5 and 10 U/L and fT4 was in the normal range.

RESULTS

At baseline, TSH was in the normal range in 139 patients, and was between 5 and 10 U/L in 9 patients. Treatment was re-instituted after 2 months in 37 (25.5%) patients, after 6 months in 13 patients (6.99%), after 12 months in 12 patients (8.6%), and after 24 months in an additional 3 patients (3.1%). At 24 months, 34 patients (34.3%) still required no treatment. TSH concentration >10 U/L at the time of diagnosis was the only predictive factor for the deterioration of thyroid function after l-thyroxine discontinuation.

CONCLUSIONS

This study confirms that not all children with HT need life-long therapy with l-thyroxine, and the discontinuation of treatment in patients with a TSH level <10 U/L at the time of diagnosis should be considered.

Analysis of the factors affecting the evolution over time of subclinical hypothyroidism in children

Aim of this commentary is to report the most recent views about natural history of subclinical hypothyroidism (SH) according to the different etiologies. In children with idiopathic SH the natural evolution is often favourable, with a high percentage of cases reverting to euthyroidism or remaining SH even after a prolonged follow-up. By contrast, the risk of a significant deterioration of thyroid status is distinctly higher in the SH children with Hashimoto’s thyroiditis (HT). This risk is even higher in the cases with both HT-related SH and chromosomal abnormalities, such as Turner or Down’s syndrome.

Subclinical hypothyroidism in childhood - current knowledge and open issues

Subclinical hypothyroidism is defined as serum levels of TSH above the upper limit of the reference range, in the presence of normal concentrations of total T₄ or free T₄. This biochemical profile might be an indication of mild hypothyroidism, with a potential increased risk of metabolic abnormalities and cardiovascular disease recorded among adults. Whether subclinical hypothyroidism results in adverse health outcomes among children is a matter of debate and so management of this condition remains challenging. Mild forms of untreated subclinical hypothyroidism do not seem to be associated with impairments in growth, bone health or neurocognitive outcome. However, ongoing scientific investigations have highlighted the presence of subtle proatherogenic abnormalities among children with modest elevations in their TSH levels. Although current findings are insufficient to recommend levothyroxine treatment for all children with mild asymptomatic forms of subclinical hypothyroidism, they highlight the potential need for assessment of cardiovascular risk among children with this condition. Increased understanding of the early metabolic risk factors associated with subclinical hypothyroidism in childhood will help to improve the management of affected individuals.

Effects of L-thyroxine treatment on early markers of atherosclerotic disease in children with subclinical hypothyroidism

OBJECTIVE

To investigate the effect of levothyroxine (L-T4) treatment on early markers of atherosclerotic disease in children with mild idiopathic subclinical hypothyroidism (SH).

DESIGN

Two-year, open, case-control prospective study.

METHODS

A total of 39 children, aged 9.18±3.56 years, with SH and 39 healthy controls were enrolled in the study. Waist-to-height ratio (WHtR), blood pressure, triglycerides, total cholesterol (total-C), HDL-C, LDL-C, non-HDL-C, triglycerides/HDL-C, atherogenic index (AI), homocysteine (Hcy), asymmetric dimethylarginine (ADMA), flow-mediated dilation (FMD) and intima-media thickness (IMT) were evaluated at baseline and after 2 years of L-T4 treatment in SH children and after 2 years of follow-up in controls.

RESULTS

At study entry WHtR was higher in SH subjects compared with controls (0.56±0.08 vs 0.49±0.07, P=0.04) and significantly decreased after 2 years of treatment (0.50±0.06, P<0.0001). Mean HDL-C levels (50.47±11.43 vs 61.06±13.83mg/dL, P=0.002) were lower, while triglycerides/HDL-C (1.63±1.07 vs 1.19±0.69, P=0.05), AI (3.32±0.90 vs 2.78±0.68, P=0.005), and Hcy (9.35±2.61 vs 7.71±1.94μmol/L, P=0.01) were higher in SH subjects compared with controls and improved after 2 years of treatment (HDL-C 56.26±13.76mg/dL, P<0.0001; triglycerides/HDL-C 1.23±0.78, P=0.006; AI 2.82±0.68, P<0.0001; and Hcy 8.25±2.09μmol/L, P=0.06). ADMA concentrations at baseline were higher in SH subjects compared with controls (0.77±0.21 vs 0.60±0.16μmol/L, P=0.001) and decreased after therapy (0.58±0.13μmol/L, P<0.0001). FMD, IMT and other metabolic parameters were not different among SH subjects and controls at baseline and after 2 years.

CONCLUSIONS

Children with SH may have subtle pro-atherogenic abnormalities. Although L-T4 treatment exerts some beneficial effects, the long-term impact of therapy on metabolic outcomes in SH children still remains unclear.

Early Discrimination between Transient and Permanent Congenital Hypothyroidism in Children with Eutopic Gland

AIM

To analyze the factors that might allow an early discrimination between permanent (P) and transient (T) congenital hypothyroidism (CH).

METHODS

Clinical, biochemical and imaging data of 64 children with eutopic gland, who were positively screened and treated for CH during the period 1998-2011, were retrospectively analyzed.

RESULTS

During a 3-year treatment period, the mean doses of <smlcap>L</smlcap>-thyroxine (L-T4) per kilogram of body weight at various times were significantly lower in the 46 children with T CH than in the remaining 18 with P CH. No patients with T CH had required any increment of the doses of L-T4 per kilogram of body weight to maintain normal thyroid-stimulating hormone levels over time, whereas 16/18 children with P CH during the same period had needed some dose increments (p < 0.0001).

CONCLUSIONS

(a) L-T4 requirements >4.9 µg/kg/day at 12 months or >4.27 µg/kg/day at 24 months are highly suggestive of P CH, irrespective of gland ultrasonography; (b) L-T4 requirements <1.7 µg/kg/day at 12 months or <1.45 µg/kg/day at 24 months are highly suggestive of T CH, at least in the cases with eutopic gland, and (c) the analysis of L-T4 requirements during the first years of treatment might allow an early discrimination between T and P CH in the cases with eutopic gland.

Subclinical hypothyroidism in children

NEED AND PURPOSE OF REVIEW

Subclinical hypothyroidism is a biochemical diagnosis characterized by raised thyroid stimulating hormone and normal free T4, without clinical features of hypothyroidism. This review analyzes the current evidence to arrive at a consensus and algorithm to manage this condition.

METHODS

We searched Pubmed, Cochrane and Embase for articles published between 1990 to 2014, and identified 13 relevant articles dealing with pediatric subclinical hypothyroidism which were suitable to include in our review.

CONCLUSIONS

Subclinical hypothyroidism is often a benign problem which requires expectant management with periodic monitoring of thyroid function tests and natural progression to overt hypothyroidism occur lot less frequently than expected. There is a paucity of robust randomized intervention studies, especially studies focusing on clinical outcomes. Thyroid replacement therapy is not justified in children with subclinical hypothyroidism when Thyroid stimulating hormone is <10 mIU/L. The main risk factors for progression to overt hypothyroidism are female sex, goiter, family history of thyroid disorder, strongly positive thyroid peroxidase antibodies and symptoms suggesting hypothyroidism. An algorithm for managing this condition is suggested.

Evaluation of Subclinical Hypothyroidism in Children and Adolescents: A Single-Center Study

The main purpose of our retrospective study was to evaluate the medical care of the patients with subclinical hypothyroidism (sHT) and to investigate the rationale for administering L-thyroxine (LT-4) to young sHT patients. Patients and Methods. Based on a retrospective review of the charts of 261 patients referred to the Endocrinology Outpatient Clinic between 2009 and 2014 with suspicion of sHT, 55 patients were enrolled for further analysis. Data collected was baseline age, anthropometric measurements, serum TSH, fT4, fT3, anti-thyroid autoantibodies, positive family history, absence/presence of clinical symptoms, length of follow-up, and data concerning LT-4 therapy (therapy: T1; no therapy: T0). Results. T1 encompassed 33 (60.0%) patients. There were no differences between T1 and T0 (p > 0.05) with regard to age, TSH concentrations, BMI Z-score, and hSDS values, though follow-up was longer in T1 (p < 0.01). Four (11.8%) children in T1 and none in T0 had a positive family history of thyroid disorders. Fifteen (68.2%) patients in group T0 became euthyroid. One (1.8%) girl (T1) developed overt hypothyroidism. Conclusions. A small percentage of patients can proceed to overt hypothyroidism. Only positive family history seemed to influence the decision to initiate LT-4 therapy. Further prospective studies are warranted in order to establish treatment indications, if any, and the mean recommended dosage of LT-4.

Natural history and management of congenital hypothyroidism with in situ thyroid gland

BACKGROUND/OBJECTIVE

Normally sited glands account for increasing congenital hypothyroidism (CH). Mechanisms often remain unknown. To report the incidence of CH with in situ thyroid gland (ISTG) and describe the natural history of the disease without known etiology.

METHOD

Clinical, biochemical and imaging data at diagnosis were retrospectively analyzed in 285 children positively screened for CH in Ile-de-France between 2005 and 2008. If treatment was discontinued, management of hormonal substitution and follow-up of biochemical thyroid function was performed.

RESULTS

93 full-term CH neonates displayed ISTG (40.6%), including 50 with unexplained mechanism. Follow-up data were available in 32 of them. Therapy was withdrawn from 20 children at a median age of 23.5 months (6-66), among whom 18 remained still untreated over a median duration of 15.3 months (4.4-29.6). In 11 children, levothyroxine (L-T4) dosage was increased over time to maintain biochemical euthyroidism. No statistical differences in initial TSH or FT4 levels, iodine status or birth weight were found between children with transient and permanent hypothyroidism.

CONCLUSION

Withdrawal of L-T4 substitution was feasible in 56.2% of full-term children with CH with ISTG but unexplained mechanism, emphasizing the need for systematic therapy withdrawal. However, further studies are warranted to standardize withdrawal protocol.

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

AIM

To follow-up for 5 years thyroid status evolution in 127 girls with mild (TSH 5-10 mU/l) subclinical hypothyroidism (SH) of different etiologies.

PATIENTS

The population was divided into two age-matched groups of 42 and 85 girls with either idiopathic (group A) or Hashimoto's thyroiditis (HT)-related SH (group B). Group B was in turn divided into three subgroups, according to whether SH was either isolated or associated with Turner syndrome (TS) or Down syndrome (DS).

RESULTS

At the end of follow-up the rate of girls who became euthyroid was higher in group A (61.9% vs 10.6%), whereas the rates of patients who remained SH (55.3% vs 26.2%), became overtly hypothyroid (30.6% vs 11.9%) or required levothyroxine (l-T4) therapy (63.5% vs 23.8%) were higher in group B. Among the girls of group B, the risk of remaining SH or developing overt hypothyroidism was higher in the subgroups with TS or DS than in those with isolated HT.

CONCLUSIONS

Long-term prognosis of mild and idiopathic SH is frequently benign, even though a l-T4 treatment may be needed throughout follow-up in almost a quarter of cases; long-term prognosis is different in the girls with either idiopathic or HT-related SH; and the association with either TS or DS impairs the outcome of HT-related SH.

The association with Turner syndrome significantly affects the course of Hashimoto's thyroiditis in children, irrespective of karyotype

Only few studies have investigated to now whether the association with Turner syndrome (TS) may affect the course of Hashimoto's thyroiditis (HT) in children. Aim of this study was to ascertain whether the presentation and long-term course of HT in TS children may be characterized by a peculiar and atypical pattern. The clinical and biochemical findings at HT diagnosis in 90 TS children (group A) were compared with those recorded in 449 girls with HT but without TS (group B); in group A patients, thyroid function tests were re-evaluated after a median time interval of 4.9 years. At HT diagnosis median TSH levels and the rate of cases presenting with a thyroid dysfunction picture were significantly lower in group A, irrespective of karyotype abnormalities. In group A only 34.8 % of the girls who had initially presented with euthyroidism remained euthyroid even at re-evaluation, whilst 67.7 % of those who had presented with subclinical hypothyroidism became overtly hypothyroid over time; also such evolutive pattern was irrespective of karyotype abnormalities. (1) In TS girls, HT presents with a milder hormonal pattern, which often deteriorates over time; (2) these biochemical features are not necessarily linked with a specific karyotype.

Predictors of Malignancy in Children with Thyroid Nodules

OBJECTIVE

To evaluate the diagnostic accuracy of clinical, laboratory, and ultrasound (US) imaging characteristics of thyroid nodules in assessing the likelihood of malignancy.

STUDY DESIGN

Data from 184 children and adolescents with thyroid nodules were evaluated and compared with respective cytologic/histologic outcomes. A regression model was designed to assess the predictors associated with malignancy and to calculate ORs.

RESULTS

Twenty-nine malignant neoplasms (25 papillary, 1 medullary, 3 Hurtle-cell carcinomas), 8 follicular adenomas, and 147 goitrous nodules (92 based on cytology, 55 on follow-up) were diagnosed. Fine-needle aspiration biopsy diagnostic accuracy, sensitivity, and specificity were 91%, 100%, and 88%, respectively. Male sex, compression symptoms, palpable lymphopathy, thyroid stimulating hormone concentration, microcalcifications, indistinct margins, hypoechoic US pattern, pathologic lymph node alterations, and increased intranodular vascularization were associated with malignancy. Regular margins, mixed echoic pattern, and peripheral-only vascularization were associated with benignity. During follow-up, nodule growth was associated with malignant disease, especially with levothyroxine therapy. A multivariate analysis confirmed that microcalcifications, hypoechoic pattern, intranodular vascularization, lymph node alterations, and thyroid stimulating hormone concentration were independent predictors of malignant outcome. For each predictor, we provide sensitivity, specificity, and positive/negative predictive values.

CONCLUSIONS

Clinical, laboratory, and US features of nodules can be used as predictors of malignancy in children. Although none has diagnostic accuracy as high as that of fine-needle aspiration biopsy, these predictors should be considered in deciding the diagnostic approach of children with thyroid nodules.

The Role of Thyrotropin-Releasing Hormone Stimulation Test in Management of Hyperthyrotropinemia in Infants

OBJECTIVE

Hyperthyrotropinemia, which can be either a permanent or a transient state, is an asymptomatic condition and there is a controversy in management and long-term consequences. The aim of this study was to evaluate the results of thyrotropin-releasing hormone (TRH) test in infants with hyperthyrotropinemia.

METHODS

Data of the patients who underwent a TRH test for mildly elevated thyroid-stimulating hormone (TSH) levels between 2004 and 2011 in a single academic pediatric endocrinology unit were retrospectively reviewed from the case files.

RESULTS

Twenty infants (13 female, 7 male) with the median (range) age of 33 days (25-50) were enrolled into the study. The median basal TSH was 7.0 mIU/L (4.9-8.9) and free thyroxine level was 1.4 ng/mL (1.2-1.6) at the time of the TRH test. Thyroid ultrasonography was performed to 10 of the cases, and one of them had thyroid hypoplasia. TRH test revealed normal results in four infants, while sixteen infants had exaggerated response suggestive of primary hypothyroidism. The median follow-up period was 3.5 years (2.3-3.7). Therapy was discontinued in seven cases (2 had normal TRH response, 5 had exaggerated response) with the median age of 3.2 years (2.5-4). Of these seven infants, three had an elevated TSH on follow-up and L-thyroxine was restarted. All of the infants, in whom therapy was restarted, had exaggerated response to TRH.

CONCLUSION

TRH test response could be a useful diagnostic test to evaluate the persistence of the disease during the infantile age period.

[Congenital hypothyroidism]

Congenital hypothyroidism (CH) is a cause of preventable mental retardation; therefore, timely diagnosis and treatment by the primary care physician is very important. CH screening must be performed between the second and fifth days of life with capillary blood done with a heel prick and must be confirmed by measurement of thyroid hormones in venous blood. The most common cause of CH is thyroid dysgenesis, which may be identified by a thyroid scan carried out before initiating treatment. Treatment should be with levothyroxine (10-15μg/kg/day) and should not be delayed or suspended during the first 3 years of life due to the deleterious effect on neurodevelopment in case of low thyroid hormones during this time. Preterm or sick infants or those with Down syndrome require special consideration. This article provides diagnostic and therapeutic algorithms for CH.

Underlying Hashimoto's thyroiditis negatively affects the evolution of subclinical hypothyroidism in children irrespective of other concomitant risk factors

BACKGROUND

The pediatric literature does not contain any studies comparing the evolution of Hashimoto's thyroiditis (HT)-related subclinical hypothyroidism (SH) with idiopathic SH longitudinally.

AIM AND DESIGN

In the present study, the two-year evolution of HT-related SH in 32 children with no concomitant risk factors (group A) was compared to that observed in 90 age-matched children with idiopathic SH (group B). The aim was to ascertain whether the association with HT could, per se, affect the evolution of thyroid status over time in SH children irrespective of other coexisting factors, such as thyromegaly, association with other autoimmune diseases, and/or concomitant therapies.

RESULTS

During the two-year follow-up, the percentage of children whose thyrotropin (TSH) values increased >10 mIU/L was significantly higher in group A (p<0.0005), whereas the percentages of those who either maintained a stable TSH (5-10 mIU/L) or normalized the TSH (<5 mIU/L) were significantly higher in group B (p<0.025). Moreover, the percentage of children who developed a pathological thyroid enlargement during follow-up was significantly higher in group A (p<0.0005).

CONCLUSIONS

The association with HT exerts a negative influence on the evolution over time of mild SH, irrespective of other concomitant risk factors. In children with mild and HT-related SH, the risk of a deterioration in thyroid status over time is high (53.1%), while the probability of spontaneous TSH normalization is relatively low (21.9%). In contrast, in children with mild and idiopathic SH, the risk of a deterioration in thyroid status over time is very low (11.1%), whereas the probability of spontaneous TSH normalization is high (41.1%).

Isolated Subclinical Hyperthyrotropinemia in Obese Children: Does Levothyroxine (LT4) Improve Weight Reduction during Combined Behavioral Therapy?

Objective. The study aim was to analyze whether anthropometrical parameters and TSH values in obese children with isolated subclinical hypothyroidism (IsHT) treated with levothyroxine (LT4) and weight reduction program differ from those managed by dietary and behavior counselling only. Material and Methods. 51 obese children with IsHT, who were treated according to the same weight reduction program, were retrospectively analyzed. They were divided into two groups: Group 1, n = 26, and Group 2, n = 25, without or with LT4 therapy, respectively. Changes in anthropometrical (delta BMI z-score) and hormonal (delta TSH) status were analyzed at the first follow-up visit. Results. In both groups significant decrease of TSH and BMI z-score values were noted. TSH normalized in 80.9% of children from Group 1 versus 90.5% from Group 2, p = NS. Delta BMI z-score was insignificantly higher in Group 1 compared to Group 2. Delta TSH was significantly related to initial TSH level in children treated by lifestyle intervention program only. Conclusions. In obese children with sHT dietary-behavioral management intervention contributed to reduction of body mass index, irrespective of levothyroxine use. This finding suggests that moderately elevated levels of TSH are a consequence rather than cause of overweight and pharmacological treatment should be avoided.

Cardiovascular risk factors in children with long-standing untreated idiopathic subclinical hypothyroidism

CONTEXT

Subclinical hypothyroidism (SH), defined as increased TSH serum levels and normal serum free T4 concentrations, has been associated with an increased risk of coronary heart disease in adults. Data in children and adolescents are scanty.

OBJECTIVE

The objective of the study was to investigate the clinical and biochemical cardiovascular risk factors in children with mild SH (serum TSH concentrations 4.5-10 mU/L).

DESIGN AND SETTING

This is a cross-sectional and controlled study conducted at a tertiary referral center on patients with persistent idiopathic long-standing (3.2 ± 0.4 y) mild SH. At study entry patients and controls underwent a clinical and biochemical assessment for cardiovascular risk.

PARTICIPANTS

Forty-nine children aged 8.5 ± 0.5 years with SH and 49 controls were enrolled in the study.

MAIN OUTCOME MEASURE

Systolic and diastolic blood pressure, body mass index (BMI), waist to height ratio, lipid profile, homocysteine, high-sensitivity serum C-reactive protein, fibrinogen, adiponectin, insulin, and homeostasis model assessment index were measured.

RESULTS

Waist to height ratio (P < .0001), atherogenic index (P = .001), triglycerides to high-density lipoprotein-cholesterol ratio (P = .01), and homocysteine levels (P = .002) were significantly higher and high-density lipoprotein-cholesterol significantly lower (P = .003) in SH subjects compared with controls. No significant differences were found in the other clinical and biochemical cardiovascular risk factors analyzed. Multivariate regression model revealed that BMI and thyroid status were the main independent factors affecting dependent variables. Even after an adjustment for BMI, most of the variables still remained significantly associated with mean TSH levels or SH duration.

CONCLUSIONS

Mild long-lasting untreated idiopathic SH may be associated with subtle proatherogenic abnormalities. Although it is difficult to establish whether these mild abnormalities represent the early steps in the initiation of atherogenesis, these children need to be carefully monitored for metabolic complications.

Effect of long-term GH treatment in a patient with CHARGE association

CHARGE association is characterized by ocular Coloboma, Heart malformations, choanal Atresia, Retardation of growth and development, Genital abnormalities and inner and external Ear abnormalities. Growth failure is a frequent find mainly associated with feeding difficulties or systemic diseases. To date, GH deficiency has been reported in only few patients with CHARGE association however long-term effects of GH treatment, up to final height, have never been reported. We describe a patient with CHARGE association and GH deficiency treated with GH from the age of 3 years and 10 months up to adult height.

Treatment with thyroid hormone

Thyroid hormone deficiency can have important repercussions. Treatment with thyroid hormone in replacement doses is essential in patients with hypothyroidism. In this review, we critically discuss the thyroid hormone formulations that are available and approaches to correct replacement therapy with thyroid hormone in primary and central hypothyroidism in different periods of life such as pregnancy, birth, infancy, childhood, and adolescence as well as in adult patients, the elderly, and in patients with comorbidities. Despite the frequent and long term use of l-T4, several studies have documented frequent under- and overtreatment during replacement therapy in hypothyroid patients. We assess the factors determining l-T4 requirements (sex, age, gender, menstrual status, body weight, and lean body mass), the major causes of failure to achieve optimal serum TSH levels in undertreated patients (poor patient compliance, timing of l-T4 administration, interferences with absorption, gastrointestinal diseases, and drugs), and the adverse consequences of unintentional TSH suppression in overtreated patients. Opinions differ regarding the treatment of mild thyroid hormone deficiency, and we examine the recent evidence favoring treatment of this condition. New data suggesting that combined therapy with T3 and T4 could be indicated in some patients with hypothyroidism are assessed, and the indications for TSH suppression with l-T4 in patients with euthyroid multinodular goiter and in those with differentiated thyroid cancer are reviewed. Lastly, we address the potential use of thyroid hormones or their analogs in obese patients and in severe cardiac diseases, dyslipidemia, and nonthyroidal illnesses.

2014 European thyroid association guidelines for the management of subclinical hypothyroidism in pregnancy and in children

This guideline has been produced as the official statement of the European Thyroid Association guideline committee. Subclinical hypothyroidism (SCH) in pregnancy is defined as a thyroid-stimulating hormone (TSH) level above the pregnancy-related reference range with a normal serum thyroxine concentration. Isolated hypothyroxinaemia (defined as a thyroxine level below the 2.5th centile of the pregnancy-related reference range with a normal TSH level) is also recognized in pregnancy. In the majority of SCH the cause is autoimmune thyroiditis but may also be due to iodine deficiency. The cause of isolated hypothyroxinaemia is usually not apparent, but iodine deficiency may be a factor. SCH and isolated hypothyroxinaemia are both associated with adverse obstetric outcomes. Levothyroxine therapy may ameliorate some of these with SCH but not in isolated hypothyroxinaemia. SCH and isolated hypothyroxinaemia are both associated with neuro-intellectual impairment of the child, but there is no evidence that maternal levothyroxine therapy improves this outcome. Targeted antenatal screening for thyroid function will miss a substantial percentage of women with thyroid dysfunction. In children SCH (serum TSH concentration >5.5-10 mU/l) normalizes in >70% and persists in the majority of the remaining patients over the subsequent 5 years, but rarely worsens. There is a lack of studies examining the impact of SCH on the neuropsychological development of children under the age of 3 years. In older children, the evidence for an association between SCH and impaired neuropsychological development is inconsistent. Good quality studies examining the effect of treatment of SCH in children are lacking.

Intergenerational and intrafamilial phenotypic variability in 22q11.2 deletion syndrome subjects

BACKGROUND

22q11.2 deletion syndrome (22q11.2DS) is a common microdeletion syndrome, which occurs in approximately 1:4000 births. Familial autosomal dominant recurrence of the syndrome is detected in about 8-28% of the cases. Aim of this study is to evaluate the intergenerational and intrafamilial phenotypic variability in a cohort of familial cases carrying a 22q11.2 deletion.

METHODS

Thirty-two 22q11.2DS subjects among 26 families were enrolled.

RESULTS

Second generation subjects showed a significantly higher number of features than their transmitting parents (212 vs 129, P = 0.0015). Congenital heart defect, calcium-phosphorus metabolism abnormalities, developmental and speech delay were more represented in the second generation (P < 0.05). Ocular disorders were more frequent in the parent group. No significant difference was observed for the other clinical variables. Intrafamilial phenotypic heterogeneity was identified in the pedigrees. In 23/32 families, a higher number of features were found in individuals from the second generation and a more severe phenotype was observed in almost all of them, indicating the worsening of the phenotype over generations. Both genetic and epigenetic mechanisms may be involved in the phenotypic variability.

CONCLUSIONS

Second generation subjects showed a more complex phenotype in comparison to those from the first generation. Both ascertainment bias related to patient selection or to the low rate of reproductive fitness of adults with a more severe phenotype, and several not well defined molecular mechanism, could explain intergenerational and intrafamilial phenotypic variability in this syndrome.

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy from the pediatric perspective

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare autosomal recessive disease caused by mutations of the AutoImmune REgulator gene. The clinical spectrum of the disease encompasses several autoimmune endocrine and non-endocrine manifestations, which may lead to acute metabolic alterations and eventually life-threatening events. The clinical diagnosis is defined by the presence of at least two components of the classic triad including chronic mucocoutaneous candidiasis (CMC), chronic hypoparathyroidism (CH), Addison's disease (AD). Other common features of the disease are hypergonadotropic hypogonadism, alopecia, vitiligo, autoimmune hepatitis, Type 1 diabetes, gastrointestinal dysfunction. APECED usually begins in childhood. CMC is the first manifestation to appear, usually before the age of 5 yr, followed by CH and then by AD. The clinical phenotype may evolve over several years and many components of the disease may not appear until the 4th or 5th decade of life. The phenotypical expression of the syndrome shows a wide variability even between siblings with the same genotype. In view of this heterogeneity, an early diagnosis of APECED can be very challenging often leading to a considerable diagnostic delay. Therefore, clinicians should be aware that the presence of even a minor component of APECED in children should prompt a careful investigation for other signs and symptoms of the disease, thus allowing an early diagnosis and prevention of severe and life-threatening events. Aim of this review is to focus on clinical presentation, diagnosis and management of the major components of APECED in children particularly focusing on endocrine features of the disease.

Hashimoto's thyroiditis in childhood: presentation modes and evolution over time

Aim of this survey is to report the most recent views about Hashimoto’s thyroiditis (HT) natural history according to the different presentations. In children presenting with either euthyroidism or subclinical hypothyroidism HT spontaneous course is frequently characterized by a trend towards deterioration of thyroid function, whereas in those presenting with overt hyperthyroidism a definitive resolution of hyperthyroid phase is to be expected. Another possible even though unusual outcome of HT is the conversion to Graves’ disease.

Non-autoimmune subclinical hypothyroidism due to a mutation in TSH receptor: report on two brothers

Subclinical hypothyroidism (SH) is a condition characterized by a mild persistent thyroid failure. The main cause is represented by autoimmune thyroiditis, but mutations in genes encoding proteins involved in TSH pathway are thought to be responsible for SH, particularly in cases arising in familial settings. Patients with the syndrome of TSH unresponsiveness may have compensated or overt hypothyroidism with a wide spectrum of clinical and morphological alterations depending on the degree of impairment of TSH-receptor (TSH-R) function. We describe the case of two brothers with non autoimmune SH carrying the same heterozygous mutation in the extracellular domain of TSH-R and presenting with different clinical, biochemical and morphological features. The first one had only a slight persistent elevation of TSH, a normal thyroid ultrasound and did never require l- thyroxine (L-T4) replacement treatment. The second one had a neonatal persistent moderate TSH levels increase associated with a thyroid gland hypoplasia and was treated with L-T4 since the first months of life.

These two cases support the recent association of TSH-R mutations inheritance as an autosomal dominant pattern with variable expressivity and suggest that the decision to start replacement therapy in patients with persistent SH due to TSH resistance should be individualized.

Endocrine disorders in childhood and adolescence. Natural history of subclinical hypothyroidism in children and adolescents and potential effects of replacement therapy: a review

OBJECTIVE

Subclinical hypothyroidism (SH) is quite common in children and adolescents. The natural history of this condition and the potential effects of replacement therapy need to be known to properly manage SH. The aim of this review is to analyze: i) the spontaneous evolution of SH, in terms of the rate of reversion to euthyroidism, the persistence of SH, or the progression to over hypothyroidism; and ii) the effects of replacement therapy, with respect to auxological data, thyroid volume, and neuropsychological functions.

METHODS

We systematically searched PubMed, Cochrane, and EMBASE (1990-2012) and identified 39 potentially relevant articles of which only 15 articles were suitable to be included.

RESULTS AND CONCLUSIONS

SH in children is a remitting process with a low risk of evolution toward overt hypothyroidism. Most of the subjects reverted to euthyroidism or remained SH, with a rate of evolution toward overt hypothyroidism ranging between 0 and 28.8%, being 50% in only one study (nine articles). The initial presence of goiter and elevated thyroglobulin antibodies, the presence of celiac disease, and a progressive increase in thyroperoxidase antibodies and TSH value predict a progression toward overt hypothyroidism. Replacement therapy is not justified in children with SH but with TSH 5-10 mIU/l, no goiter, and negative antithyroid antibodies. An increased growth velocity was observed in children treated with levothyroxine (l-T(4); two articles). l-T(4) reduced thyroid volume in 25-100% of children with SH and autoimmune thyroiditis (two studies). No effects on neuropsychological functions (one study) and posttreatment evolution of SH (one study) were reported.

Subclinical hypothyroidism in children

The prevalence of SH in the pediatric population is < 2%, the caveat being the limited number of studies addressing SCH in the pediatric population. congenital deveolopental anamolies. Mutations in the several proteins are important causes of this condition. Despite the limited data available, SCH in children and adolescents appears to be a benign and remitting disease with a low risk of evolution to OH. It appears that thyroid hormones appear to be functioning well despite elevated TSH. Predictors of progression include, goiter, celiac disease, and positive anti TPO.

Bone health in children with long-term idiopathic subclinical hypothyroidism

Background

Subclinical hypothyroidism (SH) is a relatively common condition characterized by a mild persistent thyroid failure. The management of children with SH is still a controversial issue and the decision to treat with L-thyroxine represents a clinical dilemma. Thyroid hormone and TSH play an important role in skeletal growth and bone mineral homeostasis.

Aim

To evaluate whether untreated idiopathic SH may affect bone health in childhood and to compare two different diagnostic tools such as dual-energy X-ray densitometry (DXA) and quantitative ultrasound (QUS).

Patients and Methods

Twenty-five children and adolescents (11 males) aged 9.8 ± 3.5 years (range 4.2-18.7) with untreated idiopathic SH were enrolled in the study. SH was diagnosed on the basis of normal FT4 levels with TSH concentrations between 4.2 and 10 mU/l. Children have been followed for 3.3 ± 0.3 years from the time of SH diagnosis. Twenty-five healthy children, age- and sex-matched, were enrolled as controls. Patients and controls underwent DXA to evaluate lumbar spine bone mineral density (BMD) and QUS at proximal phalanges of the non-dominant hand to assess bone quality, measured as amplitude-dependent speed of sound (Ad-SoS) and bone transmission time (BTT).

Results

Mean BMD Z-score was −0.4 ± 1.36 in patients and −0.2 ± 1.2 in controls. Mean Ad-SoS Z-score was 0.01 ± 1.0 in patients and 0.1 ± 1.2 in controls and mean BTT Z-score was −0.03 ± 0.8 and 0.04 ± 1.1 respectively. All values were within the normal range, both in patients and in controls. There were no statistically significant differences between the two groups.

Conclusion

Bone health, evaluated by lumbar spine DXA and phalangeal QUS, is not impaired in our children, despite long-term duration of idiopathic SH. Data about bone status provided by QUS are comparable to those provided by DXA. Therefore, QUS may represent a good, cheaper and safe screening test for bone evaluation in children with SH.

Clinical Heterogeneity in two patients with Noonan-like Syndrome associated with the same SHOC2 mutation

Noonan-like syndrome with loose anagen hair (NS/LAH; OMIM #607721) has been recently related to the invariant c.4A > G missense change in SHOC2. It is characterized by features reminiscent of Noonan syndrome. Ectodermal involvement, short stature associated to growth hormone (GH) deficiency (GHD), and cognitive deficits are common features. We compare in two patients with molecularly confirmed NS/LAH diagnosis, the clinical phenotype and pathogenetic mechanism underlying short stature. In particular, while both the patients exhibited a severe short stature, GH/IGFI axis functional evaluation revealed a different pathogenetic alteration, suggesting in one patient an upstream alteration (typical GHD) and in the other one a peripheral GH insensitivity.

Since only a few cases of NS/LAH associated to SHOC2 mutations have been so far described, the complex phenotype of the syndrome and the exact mechanism impairing GH/IGFI axis still remain to be elucidated and studies on larger cohort of subjects are needed to better delineate this syndrome.

Acute adrenal failure as the presenting feature of primary antiphospholipid syndrome in a child

Introduction

Antiphospholipid syndrome (APS) is characterized by recurrent arterial and venous thrombosis and detection of antiphospholipid antibodies (aPLs). This syndrome may be associated with connective tissue disorders, or with malignancies, but it may also appear in isolated form (primary APS). We report on a pediatric patient presenting with acute adrenal failure as the first manifestation of primary APS.

Case report

A previously healthy 11-year-old boy developed fever, abdominal pain, and vomiting. An abdominal computed tomography scan showed nodular lesions in the adrenal glands. He was referred to our Department and a diagnosis of APS and acute adrenal failure was considered, based on positive aPLs (IgG and IgM), elevated ACTH levels and low cortisol levels. Other features were anemia, thrombocytopenia, elevated inflammatory parameters, hypergammaglobulinemia, prolonged partial thromboplastin time, positive antinuclear, anticardiolipin, anti-platelet antibodies, with negative double-stranded DNA antibodies. Lupus anticoagulant and Coomb’s tests were positive. MRI revealed a bilateral adrenal hemorrhage. A treatment with intravenous metylprednisolone, followed by oral prednisone and anticoagulant, was started, resulting in a progressive improvement. After 2 months he also showed hyponatremia and elevated renine levels, indicating a mineralcocorticoid deficiency, requiring fludrocortisones therapy.

Conclusion

The development of acute adrenal failure from bilateral adrenal haemorrhage in the context of APS is a rare but life-threatening event that should be promptly recognized and treated. Moreover, this case emphasizes the importance of the assessment of aPLs in patients with acute adrenal failure in the context of an autoreaction.