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

AimTo investigate the different characteristics of girls with pituitary hyperplasia secondary to primary hypothyroidism (PPH), with and without sexual precocity. MethodsPituitary 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 3months levothyroxine therapy: free triiodothyronine (FT3), free thyroxine (FT4), thyrotropin (TSH), follicle-stimulating hormone (FSH), luteinising hormone (LH), prolactin (PRL), estradiol (E-2), testosterone (T), pituitary height, uterine volume (UV), ovarian volume (OV) and follicular diameter (FD). ResultsThyrotropin, FSH, PRL, E-2, 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. ConclusionPituitary hyperplasia secondary to primary hypothyroidism girls with sexual precocity have increased plasma TSH, FSH, PRL, E-2 and T levels, pituitary height and uterine, ovarian and follicular size.