Characteristics of girls with pituitary hyperplasia and sexual precocity secondary to primary hypothyroidism.

AIM: To investigate the different characteristics of girls with pituitary hyperplasia secondary to primary hypothyroidism (PPH), with and without sexual precocity.
METHODS: Pituitary hyperplasia secondary to primary hypothyroidism girls were divided into two groups: group A, with sexual precocity (n = 8), and group B, without sexual precocity (n = 14). The following values were measured before and after 3 months levothyroxine therapy: free triiodothyronine (FT3 ), free thyroxine (FT4 ), thyrotropin (TSH), follicle-stimulating hormone (FSH), luteinising hormone (LH), prolactin (PRL), estradiol (E2 ), testosterone (T), pituitary height, uterine volume (UV), ovarian volume (OV) and follicular diameter (FD).
RESULTS: Thyrotropin, FSH, PRL, E2 , T, pituitary height, UV, OV and FD were higher in group A than group B (all p < 0.05); FT3 , FT4 and LH levels were not different (all p > 0.05). In all of the PPH girls, pituitary height was correlated with FT3 , FT4 and PRL (r = -0.545, p = 0.009, r = -0.567, p = 0.006 and r = 0.666, p = 0.001, respectively). PRL was positively correlated with UV, FD and FSH (r = 0.581, p = 0.005, r = 0.482, p = 0.031 and r = 0.667, p = 0.001, respectively), and FSH was positively correlated with OV (r = 0.522, p = 0.013). These abnormalities regressed after therapy.
CONCLUSION: Pituitary hyperplasia secondary to primary hypothyroidism girls with sexual precocity have increased plasma TSH, FSH, PRL, E2 and T levels, pituitary height and uterine, ovarian and follicular size. ©2013 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.