A Comparison of Patients with Central Precocious Puberty Who Have a Pubertal versus Prepubertal Ultrasensitive LH at Presentation.

BACKGROUND A random ultrasensitive luteinizing hormone (LH) (LH-ICMA) ≥0.3 mIU/L is highly accurate in confirming a diagnosis of central precocious puberty (CPP). However, a prepubertal value does not exclude the diagnosis. The clinical differences between patients with CPP who have a pubertal versus prepubertal LH-ICMA have not been clearly defined. Furthermore, there is minimal information regarding the utility of this test in boys with CPP. The objective of this study was to analyze differences between patients diagnosed with CPP who had a pubertal versus prepubertal LH-ICMA, including a cohort of boys. METHODS A retrospective chart review of children diagnosed with CPP within the last 10 years who had a baseline LH-ICMA obtained was performed. Variables analyzed included sex, age, ethnicity, bone age, BMI, etiology, Tanner stage (TS), testicular volume, and menarchal status. RESULTS Of 27 boys and 126 girls who qualified for the study, the LH-ICMA was pubertal in 87% and prepubertal in 13%. Girls with a pubertal LH-ICMA had higher baseline estradiol concentrations (p < 0.001) and more advanced breast development (p = 0.015) compared to girls with a prepubertal LH-ICMA. Of girls with a prepubertal LH-ICMA, 74% had at least TS 3 breast development and 1 was post-menarchal. The LH-ICMA was pubertal in 96% of the boys with CPP in this study. CONCLUSIONS The LH-ICMA can be prepubertal even in girls with advanced development. To our knowledge, ours is the largest cohort of boys in whom the accuracy of a random LH-ICMA has been reported.