Utility of a 40-minute LH level after depot leuprolide for diagnosis and treatment monitoring in girls with CPP.

In 30 seconds

This randomized controlled trial evaluated the utility of luteinizing hormone (LH) levels measured 40 minutes after depot leuprolide acetate (dLA) injection in 132 girls with idiopathic central precocious puberty (CPP). The study found that peak LH levels after dLA did not significantly differ from those obtained via the GnRH stimulation test, with a sensitivity of 86% and specificity of 90% for diagnosing gonadotropic activation.

Key findings

• Peak LH levels after GnRH test were 11.0 (6.8-17.1) IU/L compared to 9.4 (5.8-16.6) IU/L post-dLA (p=0.06).
• The optimal cut-off for post-dLA LH was ≥5.4 IU/L, with sensitivity of 86% and specificity of 90%.
• At 6 months, peak LH levels were similarly suppressed across treatment groups (2.1 ± 1.6, 2.5 ± 1.8, 2.2 ± 0.9; p=0.2011).
• A post-dLA LH cut-off of <3.07 IU/L had an AUC of 0.83, sensitivity of 80.8%, and specificity of 75.5%.

Why it matters

This study suggests that measuring LH levels 40 minutes after dLA injection can serve as a practical alternative for assessing gonadotropic activation in girls with CPP, especially in settings where GnRH testing is unavailable.