Influence of subclinical hypothyroidism on metabolic parameters in obese children and adolescents

Abstract

Background: Subclinical hypothyroidism (SH) is a common condition in obese children. However, its effect on glucose and lipid metabolism in obese children remains controversial.Purpose: The present study aimed to investigate the association between SH and metabolic parameters.Methods: A total of 215 obese children and adolescents aged 6–18 years were included in this retrospective cross-sectional study. The patients’ anthropometric measurements such as thyrotropin (TSH), free thyroxine (fT4), fasting plasma glucose, and insulin levels, as well as homeostasis model assessment for insulin resistance (HOMA-IR) index, and lipid profiles were evaluated. The patients were allocated to the SH group (fT4 normal, TSH 5–10 mIU/L) (n=77) or the control group (fT4 normal, TSH<5 mIU/L) (n=138). The glucose and lipid metabolisms of the 2 groups were compared.Results: SH was identified in 77 of 215 patients (36%). Mean body mass index was similar in both groups. The mean serum insulin, HOMA-IR, and triglyceride (TG) levels were higher and the mean high-density lipoprotein cholesterol level was lower in the SH group than in the control group (<i>P</i>=0.007, <i>P</i>=0.004, <i>P</i>=0.01, and <i>P</i>=0.02, respectively). A positive correlation was observed between TSH level and insulin level, HOMA-IR, and TG level.Conclusion: SH was identified in some of the obese children and adolescents. A clear association was observed between SH, insulin resistance, and dyslipidemia in obese children.

Función tiroidea en escolares con obesidad

“…En analogía con el estudio de Jin (24), no se encontró correlación de la TSH en suero con resistencia a la insulina, en contraste con otros reportes (27,28). Los escolares con obesidad y T4 libre baja se correlaciona- ron significativamente con hiperinsulinismo y presentaron promedios mayores de HO-MA1-IR.…”

“…Los valores de hormonas tiroideas no presentaron diferencias, en relación con el grado de maduración sexual y sexo, al igual como lo han señalado algunos autores ( 25,27,32) . Todos los escolares con TSH elevada eran prepúberes.…”

Oxidative DNA damage and subclinical hypothyroidism in children with obesity

“…The current study revealed higher incidence of subclinical hypothyroidism in children with obesity (36%) with significant association between TSH level and BMI. Despite of the significant increased frequency of subclinical hypothyroidism in children with obesity, there is variation in the prevalence between studies which ranged from 7 to 36% [12]. This variation could attribute to different ethnic groups and the contributing effect of hyperlipidemia and metabolic syndrome on the development of subclinical hypothyroidism.…”

“…In pediatric as in adults, thyrotropin >10 mIU/L is potentially indicative of overt hypothyroidism. Subclinical hypothyroidism is identified as isolated raised TSH (>4.5 mIU/L but <10 mIU/L) without clinical symptoms, thyroid antibodies, goiter, or associated thyroidal illness [12]. Obese children were classified according to the level of TSH into obese children with and without subclinical hypothyroidism.…”

Levothyroxine in Children

“…Subclinical hypothyroidism is associated with obesity in paediatric subjects [23,24]. A retrospective study identified subclinical hypothyroidism (normal FT4, TSH 5-10 mIU/L) in 36% of a population of 215 obese children and adolescents [25]. Subjects with vs. without subclinical hypothyroidism were more insulin resistant and showed signs of atherogenic dyslipidaemia (low HDL-C, high triglycerides), but BMI was similar.…”