Treating versus Not Treating Subclinical Hypothyroidism (SCH) in Children: A Comprehensive Review

Nada Alaaraj; Fawzia Alyafei; Noor Hamed; Shayma Ahmed; Amal Sabt

Introduction: Subclinical hypothyroidism (SCH) in children, characterized by elevated thyroid-stimulating hormone (TSH) levels with normal free thyroxine (T4) levels, presents a clinical dilemma. The decision to treat SCH with L-thyroxine versus adopting a watchful waiting approach hinges on the potential benefits and drawbacks.

Aim: This review synthesizes evidence from 20 studies to assess the impact of treatment versus non-treatment on cardiovascular risk factors, thyroid function tests, symptoms of tiredness, growth, bone and cognitive function, and attention span in children with SCH.

Results: Our review analyzed 20 studies that highlighted the benefits and drawbacks of treating SCH in children. It covered various aspects such as cardiovascular risk factors, endothelial function, bone health, growth, attention span, tiredness, and thyroid volume. Key findings include:

Table: Treating versus not treating (SCH) in children:
Aspect	Treating SCH with L-thyroxine or Lifestyle Interventions	Not Treating SCH
Cardiovascular Risk Factors	Improvement in cardiovascular risk factors and endothelial function may prevent atherosclerotic disease later in life (Razvi et al., 2007). Can improve left ventricular systolic function (Biondi, et al 1999)	-
Thyroid Function Tests	Normalization of TSH levels reduces the risk of progression to overt hypothyroidism and potentially improves growth and cognitive outcomes (Wasniewska et al., 2012).	Spontaneous normalization of TSH levels in a significant proportion, suggesting benign natural course for many cases (Wasniewska et al., 2009).
Tiredness	Significant reduction in tiredness from lifestyle (dietary) interventions, indicating a positive impact on symptoms associated with SCH (van der Gaag et al., 2020).	-
Growth, bone, and Cognitive Function		Lack of significant impact on neurocognitive function or growth, bone maturation, BMI, and cognitive function suggesting mild untreated SH may not impair these outcomes (Capalbo et al., 2020), (Cerbone et al 2011)
Attention span	SCH have been shown to perform poorly in tests measuring attention, suggesting that SCH may be a risk factor for neuropsychological disorders in childhood (Ergür et al, 2012), Kumar et al, 2018)
Growth Velocity and Thyroid Volume	Replacement may increase growth velocity and reduce thyroid volume. (Monzani et al 2012)
After treatment withdrawal		Treatment does not prevent further TSH increases after treatment withdrawal (Wasniewska et al 2012)

Conclusion: The decision to treat SCH in children should be highly individualized, considering the potential benefits of treatment against the natural tendency for spontaneous resolution. This review emphasizes the importance of close monitoring of thyroid function tests and clinical symptoms to guide decision-making. Given the mixed outcomes associated with treatment and non-treatment, further longitudinal studies are required to better understand the long-term implications of SCH in children.

ESPE Abstracts

P3-249