Screening for central precocious puberty by single basal Luteinizing Hormone levels

Area of Science:

• Pediatric Endocrinology
• Reproductive Endocrinology

Background:

• Central Precocious Puberty (CPP) is diagnosed by confirming Hypothalamic-Pituitary-Gonadal (HPG) axis activation.
• Distinguishing CPP from other conditions like Premature Idiopathic Thelarche (PIT) and Early Puberty (EA) is crucial for appropriate management.

Purpose of the Study:

• To establish cut-off values for basal Luteinizing Hormone (LH) levels.
• To determine indicative pelvic ultrasound parameters for HPG axis activation in diagnosing CPP.

Main Methods:

• 248 girls with suspected precocious puberty underwent GnRH stimulation tests.
• Basal serum LH, FSH, LH/FSH ratio, and pelvic ultrasound parameters were analyzed.
• Receiver Operating Curves (ROCs) were used to evaluate sensitivity and specificity of diagnostic markers.

Main Results:

• A basal LH level ≥0.14 mIU/mL demonstrated high predictability (90.6% sensitivity, 78.2% specificity).
• Basal LH/FSH ratio ≥0.1 showed 85.9% sensitivity and 78.1% specificity.
• Uterine length cut-off of 35 mm had 83.5% sensitivity but low specificity (42.9%). Ovarian volumes showed poor diagnostic utility.

Conclusions:

• A single basal LH measurement below the identified cut-off may suffice to rule out HPG axis activation.
• This simplifies the diagnostic process for potential CPP cases.