Adiposity rebound and body mass index in Japanese patients with congenital hypothyroidism

Area of Science:

• Pediatrics
• Endocrinology
• Human Growth and Development

Background:

• Congenital hypothyroidism (CH) diagnosis and treatment have improved long-term prognosis.
• However, the association between CH and obesity risk, particularly early adiposity rebound (AR), remains incompletely understood.

Purpose of the Study:

• To investigate the age of adiposity rebound (AR) and adolescent body mass index (BMI) in Japanese patients with CH.
• To evaluate the influence of thyroid function, distal femoral epiphysis (DFE) ossification, and CH disease type on AR and adolescent BMI.

Main Methods:

• Longitudinal anthropometric data from 288 CH patients (aged 1-10 years) were collected.
• Body mass index (BMI) curves were plotted to determine the age of AR.
• Statistical analyses assessed the impact of thyroid hormone levels, DFE ossification, and CH type on AR age and adolescent BMI.

Main Results:

• Mean AR ages were 5.5 ± 1.4 years for boys and 5.9 ± 1.5 years for girls.
• No significant differences in AR age or adolescent BMI were found based on pre-treatment thyroid hormone levels or CH disease type.
• Boys lacking DFE ossification showed higher BMI standard deviation scores at the last visit compared to those with DFE ossification.

Conclusions:

• Early treatment of CH does not entirely mitigate potential long-term influences on body composition.
• Severe fetal hypothyroidism may have lasting effects on adiposity, even after initiation of treatment.
• Distal femoral epiphysis (DFE) ossification status may serve as a potential indicator for later obesity risk in male CH patients.