FRI490 Association Between TSH Levels And Early Development Of Secondary Sexual Characteristics Among Children With Congenital Hypothyroidism

Abstract

Abstract Disclosure: M.M. Nunez Stosic: None. T. Seeherunvong: None. Although hypothyroidism typically delays puberty, early pubertal development in patients with hypothyroidism and markedly elevated TSH levels has been reported. Recent studies investigated the association between thyroid function and timing of puberty among normal children. Jung et al. reported an association between serum TSH and LH levels in girls with central precocious puberty. By contrast Wilken et al. found an association between serum T4 level and onset of pubarche but not thelarche among female subjects. We investigated the association between serum TSH levels and onset of secondary sexual characteristics among patients with congenital hypothyroidism. A retrospective study was conducted including girls and boys aged ≥6 years and ≤ 18 years with confirmed primary congenital hypothyroidism who were seen in our pediatric endocrinology clinic at University of Miami, between May 2012 and May 2022. Age of onset of secondary sexual characteristics (SSC) such as body odor, acne, axillary hair, pubic hair, breast/testicular development was recorded. Early onset of SSC was defined by its presence in girls younger than 8 years and in boys younger than 9 years. Onset of SSC was considered early normal if it occurred between 8-9.5 years in girls and between 9-10.5 years in boys. A third group of patients were those with onset of SSC after 9.5 years in girls and after 10.5 years in boys. We recorded the serum TSH levels from age 6-8 years in girls and from 7-9 years in boys. We determined the average TSH levels and the proportion of the serum TSH level above normal range. IBM SPSS Statistics software version 28.0.0.0(190) was used for data analysis. Fifty-seven subjects with a history of congenital hypothyroidism, 36 girls (63.2%) and 21 boys (36.8%) were included in the study. Seventeen patients (29.8%) had early or early normal onset of SSC. The prevalence was more frequent among girls than boys, 14% and 3% respectively (p value= 0.046). Among all 57 subjects, only 9 had normal serum TSH. The mean proportion of TSH levels above normal limit was 62.4% in patients with early or normal early onset of SSC. By contrast, the mean proportion of serum TSH level above normal limit was 53.7% in those patients who had neither early nor early normal onset of SSC (p value=0.044). In summary, early and early normal onset of SSC was associated with higher TSH levels in children with congenital hypothyroidism. Further studies with a larger number of subjects will be needed to define further the specific SSC most associated with an abnormally elevated TSH. Presentation: Friday, June 16, 2023