Suboptimal Thyroid Function and Elevated ALT in Children and Adolescents with Severe Obesity: A Single Tertiary Center Experience

Background: Pediatric obesity is a public health issue. Elevated alanine transferase (ALT) may co-exist with suboptimal thyroid function in this population. Objectives: The aim of this cross-sectional study was to investigate and compare the association of thyroid function tests, ALT and metabolic profile in Greek children and adolescents with obesity and severe obesity. Methods: 279 children with body mass index (BMI) ≥95 th percentile, were divided in two groups (obese: 95 th ≤ΒΜΙ<99 th percentile and severely obese: ΒΜΙ≥99 th percentile). Insulin resistance was defined as homeostatic model assessment of insulin resistance (HOMA-IR) ≥ 3. Screening markers of suboptimal thyroid and liver function were expressed as 0.7 ng/dl22mg/dl (females) and >26mg/dl (males) respectively. Results: Elevated ALT levels were found in children with FT4<11 ng/dl in comparison to peers with FT4≥1 (53.3% vs 25%, p: 0.024). Children with severe obesity were younger (p: 0.003) and had higher ALT levels (p: 0.001). In multivariate logistic regression, severe obesity status, FT4<1 and HOMA-IR ≥3 were predictive of higher ALT (ORs: 2.23, 3.37, 3.21 with p: 0.029, 0.04, 0.007, respectively). Conclusions: We suggest that children with severe obesity and insulin resistance are routinely screened for FT4 and ALT as surrogate markers of obesity related thyroid and liver dysfunction.