Hypothalamo‐pituitary‐gonadal Function in Male Central Precocious Puberty

Abstract

Eleven boys aged 1-10 years with central precocious puberty were studied. According to the pubertal development six were classified as P2, one as P3 and four as P5. In all cases plasma testosterone levels were definitely elevated (1.7-5.8 ng/ml) when compared with pre-pubertal controls. Peak values after HCG (3 X 1500 units) in four of the boys were in the high adult range. The binding capacity of serum testosterone oestradiol binding globuline (TeBG) ranged between 0.5 and 7.30 microgram/dl. Basal plasma levels of LH and FSH were respectively 2.06 +/- 0.64 and 1.2 +/- 0.25 miu/ml, and peak levels after LHRH (0.1 mg/m2) 13.9 +/- 3.7 and 2.6 +/- 0.43 miu/ml respectively. The data demonstrated a significant increase of plasma testosterone and post LHRH LH peak levels in boys with central precocious puberty when compared with pre-pubertal controls. The patients at stage P2 exhibited high levels of plasma testosterone contrasting with the degree of pubertal maturation, high values of TeBG and low response to LHRH which were in the pre-pubertal range. These findings suggest that the testicular sensitivity to LH increases early in boys with central precocious puberty, while the testosterone responsiveness, both at peripheral and hypothalamic levels, is delayed.

Central precocious puberty: clinical and laboratory features*

“…CPP is considered to be organic when it is associated with a lesion of the central nervous system (CNS), and as idiopathic when the computed tomography (CT) or magnetic resonance imaging (MRI) show no associated lesion of the central nervous system. The incidence of idiopathic forms and the pattern of development of CPP vary according to gender (Sigurjonsdottir & Hayles, 1968; Chaussain et al ., 1978; Cacciari et al ., 1983; Cutler, 1990; Kaplan & Grumbach, 1990; and Oerter et al ., 1990). Idiopathic CPP is rare in boys (fewer than 30% of CPP cases), while the opposite is true for girls (up to 80% of CPP cases).…”

Premature Pubarche before One Year of Age: Distinguishing between Mini-Puberty Variants and Precocious Puberty

“…CPP before the age of one year is exceedingly rare, even among patients with organic forms related to brain tumors and/or malformations. Chaussain et al [ 25 ] reported that among the 10 boys with CPP (only one idiopathic aged 10.5 yr), the 3 younger than one year included two boys with tumors of the 3 rd ventricle and one with ventricular dilatation; all had pubertal concentrations of testosterone. Rivarola et al [ 26 ] reported that among the 30 patients with CPP and organic central lesions, 3 were younger than one year and had hypothalamic hamartoma, germinoma or suprasellar arachnoid cyst.…”

Hypothalamo-Pituitary Function in Four Cases of True Precocious Puberty

“…FSH and sexual steroid levels as also gonadotropin response to LHRH are of the postpubertal type [4]. The most common pathological processes of the central nervous system which cause a precocious puberty are: hypothalamic hamartomas, astrocytomas of the hypothalamo-chiasmatic area, tumors of the pineal region, ectopic pinealomas, tumors of the anterior part of the third ventricle, teratomas and suprasellar germinomas.…”