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

Thyroid hormone levels and BMI-SDS changes in adolescents with obesity

Background

Thyroid hormones play an important role in energy metabolism and weight control, explained mostly by inducing thermogenesis and increasing basal metabolic rate. It has recently been shown that FT4 levels are associated with food preferences, which might also play a role in modulating body weight. The aim of this longitudinal follow-up study was to analyze the relationship of thyroid hormones levels (FT4, TSH) at baseline with weight/BMI-SDS changes in children and adolescents with obesity.

Methods

Three hundred seventy-seven children and adolescents have been enrolled to this study and followed up without a systematic intervention program for 5.59 ± 1.85months. Children and adolescents were divided into three subgroups: 1) 144 adolescents with obesity (15-19 years), 2) 213 children with obesity (10-14.9 years), and 3) 20 lean adolescents (15-19 years). Thyroid hormones were measured at the baseline, and anthropometry was performed at the baseline and during the follow-up. For further analyses, participants were divided according to the BMI-SDS change into two groups: 1. with BMI-SDS decrease, and 2. with BMI-SDS increase.

Results

Adolescents with obesity from the BMI-SDS decrease group had significantly lower baseline serum levels of TSH compared to the BMI-SDS increase group (2.4 ± 1.0 vs. 3.2 ± 2.0mIU/l; p=0.005). Similar difference was found for FT4 levels (14.7 ± 2.2 in the BMI-SDS decrease group vs. 15.5 ± 2.7pmol/l in the BMI-SDS increase group, p=0.048). Moreover, the BMI-SDS decrease was present in significantly higher percentage of adolescents with obesity with lower than median TSH level compared to those with higher than median TSH level at baseline (61.1% vs 38.6%, p=0.011). Likewise, the BMI-SDS decrease was present in significantly higher percentage of adolescent females with obesity and lower than median FT4 compared to those with higher than median FT4 level at baseline (70.6% vs. 23.5%, p<0.001). No associations of baseline thyroid hormones with the BMI-SDS change were observed in children with obesity or lean adolescents.

Conclusion

Adolescents with obesity and increased BMI-SDS during the follow-up had significantly higher baseline levels of both TSH and FT4 compared to BMI-SDS decrease group. These results support the previous findings that higher FT4 in individuals with obesity may influence weight gain.

Evidence Base Update on Behavioral Treatments for Overweight and Obesity in Children and Adolescents

OBJECTIVE

This review provides an update to a previous Evidence Base Update addressing behavioral treatments for overweight and obesity in children and adolescents.

METHOD

Articles were identified through a systematic search of the biomedical literature in PubMed/MEDLINE (1946-), Elsevier EMBASE (1947-), SCOPUS (1823-), Clarivate Web of Science Core Collection (WOS, 1900-), PsycINFO (1800-), The Cochrane Library and Clinicaltrials.gov published between June 2014 and August 2022.

RESULTS

Family-based treatment (FBT) remains a well-established treatment for overweight and obesity in children and is now well-established in adolescents and toddlers. Parent-only behavioral treatment remains well-established in children and is now well-established among adolescents and children. Possibly effective treatments continue to include FBT-parent only for adolescents, and behavioral weight loss (BWL) with a family component for adolescents, children, and toddlers. Several variations of FBT and BWL can now be considered possibly effective including FBT+motivational interviewing, FBT+social facilitation maintenance, group-based FBT, low-dose FBT, BWL+stress management, and camp-based BWL. Cognitive behavioral treatment (CBT) for adolescents also met criteria for possibly effective treatments. Current research has also established that behavioral treatments can be effectively delivered in alternative settings (e.g. primary care) and through alternative mediums (e.g. telehealth).

CONCLUSIONS

Research continues to support the use of multicomponent lifestyle interventions in accordance with recent recommendations from the American Academy of Pediatrics, the American Psychological Association, and the United State Preventative Services Task Force. However, more work is needed to ensure appropriate access for children with comorbid medical and psychiatric disorders and children from socially, politically, and economically marginalized groups.

Subclinical hypothyroidism in children and adolescents as mild dysfunction of the thyroid gland: a single-center study

INTRODUCTION

Subclinical hypothyroidism (SH) is a biochemical diagnosis made when a serum thyroid-stimulating hormone (TSH) is ele-vated with circulating thyroid hormone levels within their reference ranges.

AIM OF THE STUDY

Aim of our prospective non-randomized study was to evaluate the course of SH.

MATERIAL AND METHODS

All patients with suspicion of SH referred to the Endocrinology Outpatient Clinic between 2014 and 2018 were recruited to prospective study.

RESULTS

A total of 130 patients with SH were recruited for this study. Thirty-five (26.9%) patients were followed up without levothy-roxine (L-T4) (SH-T0 group) and therapy with L-T4 was randomly introduced in 95/130 (73.1%) SH children (SH-T1 group). We did not find statistical differences in hSDS and BMI Z-score between the SH-T0 and SH-T1 groups (p = 0.761 and p = 0.843, respectively). Introducing L-T4 in patients with short stature did not affect the linear growth at the end of FU ex-pressed as hSDS. OH developed in six children (6.3%) in the SH-T1 group. After conducting a multivariate logistic regres-sion, we found that the baseline TSH concentration and BMI Z-score are possible predictors of OH.

CONSLUSIONS

Our study confirmed a low risk of progression of SH to overt hypothyroidism. The majority of patients remains SH or resolved for nor-mal thyroid function. The L-T4 therapy did not effect on linear growth and body weight. The main predictor of worsening to hypothyroidism were a higher TSH level and Z-score BMI.

Obesity and Thyroid Axis

Development of obesity is primarily the result of imbalance between energy intake and energy expenditure. Thyroid hormones influence energy expenditure by regulating cellular respiration and thermogenesis and by determining resting metabolic rate. Triiodothyronine influences lipid turnover in adipocytes and impacts appetite regulation through the central nervous system, mainly the hypothalamus. Thyroid-stimulating hormone may also influence thermogenesis, suppress appetite and regulate lipid storage through lipolysis and lipogenesis control. Subclinical hypothyroidism may induce changes in basal metabolic rate with subsequent increase in BMI, but obesity can also affect thyroid function via several mechanisms such as lipotoxicity and changes in adipokines and inflammatory cytokine secretion. The present study investigated the complex and mutual relationships between the thyroid axis and adiposity.

A Lifestyle (Dietary) Intervention Reduces Tiredness in Children with Subclinical Hypothyroidism, a Randomized Controlled Trial

Purpose: Subclinical hypothyroidism (SH) in children and adults is a subject for discussion in terms of whether to treat it or not with respect to the short-term clinical implications and consequences of SH and in the long term. If treatment with thyroxine supplementation is not indicated, no other treatment is available. We investigated whether a lifestyle (dietary) intervention improves or normalizes SH or decreases the presence of Thyroid Stimulating Hormone (TSH) and/or tiredness. Methods: We randomized children aged 1–12 years with SH to the control group (standard care = no treatment) or intervention group (dietary intervention). The dietary intervention consisted of green vegetables, beef, whole milk and butter for 6 months. The rest of the diet remained unchanged. We measured TSH, FreeT4, Lipid profile, Body Mass Index (BMI) and Pediatric Quality of Life (PedQL) multidimensional fatigue scale scores. Results: In total, 62 children were included. After 6 months, TSH decreased in both groups without a significant difference between the groups (p = 0.98). PedQL fatigue scores for sleep (p = 0.032) and total fatigue scores (p = 0.039) improved significantly in the intervention group, compared to the control group. No unfavorable effects occurred in the lipid profile or BMI. Conclusion: The lifestyle (dietary) intervention did not normalize SH and TSH levels, but it significantly reduced tiredness. These results suggest that children’s well-being can be improved without medication.

Serum TSH level in obese children and its correlations with atherogenic lipid indicators and carotid intima media thickness

Objective: Moderately elevated level of thyroid-stimulating hormone accompanied by normal serum concentrations of free thyroxine, suggesting subclinical hypothyroidism, is the most common hormonal abnormality in obese children. Controversy remains, whether a thyroid dysfunction related to obesity has an influence on the cardiovascular risk factors. The aim of the study was to assess correlation between thyroid-stimulating hormone and free thyroxine and chosen atherogenic lipid indicators, and carotid intima media thickness in obese children and adolescents. Methods: A study group consisted of 110 obese children (11.5 ± 2.9 years) and 38 healthy children (13.4 ± 2.6 years). Obesity was defined using International Obesity Task Force criteria. In each patient anthropometric measurements, thyroid-stimulating hormone, free thyroxine, a lipid profile were evaluated. Carotid intima-media thickness was measured in 74 obese children and 28 lean children. The resulting data were used to calculate indicators of atherogenesis: total cholesterol to HDL cholesterol ratio; triglycerides to HDL cholesterol ratio and LDL cholesterol to HDL cholesterol ratio. Results: Obese children had higher mean serum thyroid-stimulating hormone levels compared to their lean peers and an adverse atherogenic lipid profile. Serum free thyroxine concentrations were comparable between the groups. Serum thyroid-stimulating hormone values correlated with total cholesterol to HDL cholesterol ratio; triglycerides to HDL cholesterol ratio, LDL cholesterol to HDL cholesterol ratio, and intima-media thickness. In a multivariate regression analysis, thyroid-stimulating hormone weakly correlated only with intima-media thickness after adjustment for age, gender and Body Mass Index (β = 0.249, p = 0.04). This relationship weakened after considering a lipid profile (β = 0.242, p = 0.058). No relationship was found for free thyroxine. Conclusion: Serum level of thyroid-stimulating hormone in obese children did not seem to impact atherogenic lipid indicators and carotid intima-media thickness. Therefore, an adverse lipid profile should still be considered the main risk factor for development of cardiovascular diseases in obese children.

Reference values for TSH may be inadequate to define hypothyroidism in persons with morbid obesity: Di@bet.es study

OBJECTIVE

To analyze the reference range of thyroid-stimulating hormone (TSH) in different BMI categories and its impact on the classification of hypothyroidism.

METHODS

The study included 3,928 individuals free of thyroid disease (without previous thyroid disease, no interfering medications, TSH <10 µUI/mL and thyroid peroxidase antibodies [TPO Abs] <50 IU/mL) who participated in a national, cross-sectional, population-based study and were representative of the adult population of Spain. Data gathered included clinical and demographic characteristics, physical examination, and blood and urine sampling. TSH, free thyroxine, free triiodothyronine, and TPO Ab were analyzed by electrochemiluminescence (E170, Roche Diagnostics, Basel, Switzerland).

RESULTS

The reference range (p2.5-97.5) for TSH was estimated as 0.6 to 4.8 µUI/mL in the underweight category (BMI<20 kg/m² ), 0.6 to 5.5 µUI/mL in the normal-weight category (BMI 20-24.9 kg/m² ), 0.6 to 5.5 µUI/mL in the overweight category (BMI 25-29.9 kg/m² ), 0.5 to 5.9 µUI/mL in the obesity category (BMI 30-39.9 kg/m² ), and 0.7 to 7.5 µUI/mL in the morbid obesity category (BMI ≥40). By using the reference criteria for the normal-weight population, the prevalence of high TSH levels increased threefold in the morbid obesity category (P < 0.01).

CONCLUSIONS

Persons with morbid obesity might be inappropriately classified if the standard ranges of normality of TSH for the normal-weight population are applied to them.

Thyroid Function and Thyroid Autoimmunity in Relation to Weight Status and Cardiovascular Risk Factors in Children and Adolescents: A Population-Based Study

OBJECTIVE

In obese subjects, slight increases have been observed in thyrotropin [thyroid-stimulating hormone (TSH)] levels, but data in children are scarce. The aim of this study was to evaluate whether thyroid function and autoimmunity vary with weight status in a healthy population of children and adolescents and to determine whether hyperthyrotropinemia is associated with any cardiovascular risk factor.

METHODS

This cross-sectional epidemiological study was conducted in Almería (Spain) on a representative sample of 1317 healthy subjects aged 2-16 years. Thyroid function, thyroid autoimmunity and cardiovascular risk factors were measured. Chi-square test, analysis of variance and multiple linear regression were used in the statistical analyses.

RESULTS

The obese children and adolescents had thyrotropin levels (mean ± standard deviation) of 3.12±2.44 mU/L. These levels were higher than those of overweight subjects (2.79±1.51 mU/L) and of normal weight subjects (2.73±1.30 mU/L) (p=0.02). Levels of free thyroxine and urinary iodine did not differ significantly between the groups. The prevalence (95% confidence interval) of thyroid autoimmunity was lower in the individuals with normal weight (2.9%; 2.0-4.2) than in the overweight (6.3%; 3.9-9.9) and obese subjects (5.6%, 2.5-11.3) (p=0.02). TSH levels were associated with obesity (β=0.36; p<0.001) and thyroid autoimmunity (β=1.10; p<0.001). They were not associated with any cardiovascular risk factor.

CONCLUSION

Obese children and adolescents had higher levels of thyrotropin than those who were overweight and of normal weight. The differences among the groups were of very little clinical significance and could possibly be linked to the higher prevalence of thyroid autoimmunity in obese subjects. The hyperthyrotropinemia in these subjects was not associated with any cardiovascular risk factor.

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.