ESPE Abstracts

Context: Thyroid growth and insulin like growth factor-1 (IGF-1) change depending on pubertal status and body mass index (BMI). The previous studies have reported some inconsistent results on association between thyroid volume (TV) and IGF-1 in terms of puberty and obesity.

Objective: The aim of present study is to investigate pubertal effect of on TV and IGF-1 in morbid obese children.

Design: The study population consisted of 250 children with aged 6-18 years. Children were classified into prepubertal and pubertal groups Children with BMI 97th percentile or greater were classified as the morbid obese group (n=145) and those with BMI less than 85th percentile served as the control group (n=105) by age and sex. The following parameters were assessed in children: BMI, pubertal status, TV and serum IGF-1, IGFBP-3 and IGF-1:IGFBP-3 molar ratio.

Results: Mean TV was larger in pubertal morbid obese than in those prepubertal group compared to their control groups (P=0.07, P=0.603). There was positive correlation of IGF-1 with TV in prepubertal and pubertal children (r=0.369, P=0,001; r=0.316, P=0.004). Correlation between IGF-1 and BMI was no found in prepubertal and pubertal groups (r=0.99, P=0.092; r=0.094, P=0.088). Serum mean IGF-1, IGFBP-3 and IGF-1:IGFBP-3 ratio increased significantly in pubertal group (P=0.023, P=0.042, P=0.031).

Conclusion: This study demonstrated in morbid obese children that thyroid size and IGF-1 increased in puberty and there was significant association of thyroid volume with IGF-1 independently from puberty. These results indicate that puberty significantly affects increase in thyroid growth and IGF-1 promotes enlargement of thyroid gland in morbid obese children. Keywords: childhood morbid obesity, insulin like-growth factor-1, thyroid volume, puberty