In the context of central precocious puberty, what hormone level would increase with a GnRH stimulation test?

In the context of central precocious puberty, the correct response is the increase in luteinizing hormone (LH) following a GnRH stimulation test. Central precocious puberty is defined as the premature activation of the hypothalamic-pituitary-gonadal (HPG) axis, leading to early sexual development.

The GnRH stimulation test assesses the responsiveness of the pituitary gland to gonadotropin-releasing hormone (GnRH). In a normal physiological response, the administration of GnRH stimulates the anterior pituitary to release luteinizing hormone (LH) and follicle-stimulating hormone (FSH). However, in cases of central precocious puberty, the pathway is already activated, and LH levels specifically are elevated due to increased sensitivity of the pituitary gonadotropes as well as early activation of the HPG axis.

An increase in LH is indicative of the intact functioning of the hypothalamic-pituitary axis and suggests that the precocious activation primarily involves early gonadotropin release, which may further stimulate the gonads to produce sex steroids like testosterone and estrogen. Thus, the significant rise in LH levels following GnRH administration is a hallmark of this condition.