Monitoring gonadotropin-releasing hormone analogue (GnRHa) treatment in girls with central precocious puberty: a comparison of four methods.

AIM: The objective of this study was to validate basal, post-gonadotropin-releasing hormone analogue (post-GnRHa) and first-voided urinary LH (ULH) as alternatives to an LHRH stimulation test in monitoring treatment efficacy in central precocious puberty (CPP).

METHODS

Seventeen girls with CPP were followed over 22.5±9.1 months during GnRHa (triptorelin) treatment. ULH and post-GnRHa LH levels were obtained every 4 months before and 24 h after GnRHa administration, respectively, along with clinical and bone age (BA) evaluation. LHRH stimulation tests were performed annually.

RESULTS

A total of 36 LHRH stimulation tests demonstrated adequate suppression with a peak LH of 0.57±0.33 IU/L. The corresponding basal LH was 0.27±0.16 IU/L. Ninety post-GnRHa LH measurements were similar to LHRH-stimulated LH levels (0.56±0.31 IU/L), whereas 8% of ULH levels were above prepubertal threshold. Fourteen episodes of growth acceleration and ten episodes of BA advancement resolved without treatment modification.

CONCLUSION

Suppressed basal and post-GnRHa LH levels indicate adequate suppression of puberty. Clinical breakthroughs during treatment are transient and resolved spontaneously.