627 - Peak LH level as a potential predictor of weight gain in children and adolescents receiving GnRHa therapy

Poster Number: 627
Publication Number: 627.2832

Background: Precocious puberty (PP) is the onset of puberty in before the age of 8 years in girls or 9 years in boys. The standard therapeutic approach to central precocious puberty (CPP) is to downregulate the central gonadostat using gonadotropin releasing hormone analog (GnRHa) to decrease peripheral sex hormone levels. Weight gain has been associated with GnRH therapy, but long-term studies with adequate patient population are lacking. We designed this study to determine the impact of the GnRHa therapy on BMI z-scores, and the associated drivers of the changes in BMI.

Objective: To determine the relationship between GnRHa therapy and BMI z-scores in children with central precocious puberty.

Design/Methods: A retrospective longitudinal study of 123 subjects of ages 5-18 years who underwent Lupron stimulation testing for the diagnosis of CPP and received GnRHa from January 1997 to December 2022. We compared the changes in height, weight, and BMI z-scores based on the route of GnRHa administration: injection or implantation. We used multiple linear regression to analyze the changes in the anthropometric parameters at the follow-up time points (12 months or 24 months) as a function of the baseline z-score measurement, pretreatment luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels, and the treatment method.

Results: Out of the 123 subjects in the cohort, BMI z-scores were available for 104 subjects at baseline; 75 subjects at 12 months, and 43 subjects at 24. Paired t-tests showed a significant increase in BMI z-score from baseline to 12-months (p < 0.0001, n=74), with a mean (SD) increase in BMI z-score of 0.48 (0.68). This significant increase in BMI z-score persisted at 24 months of observation. Age, sex, and the method of GnRHa administration did not influence changes in BMI z-score. The increases in BMI z-score remained significant after adjusting for baseline serum LH and FSH levels for the 72 subjects, p< 0.0001. Mean peak LH concentration from pretreatment Lupron stimulation tests was positively associated with BMI z-score at 12 months (p=0.0042), but peak FSH concentration was not (p=0.11). Specifically, the BMI z-score increased by 0.08 for each unit increase in peak LH.

Conclusion(s): Treatment of CPP with GnRHa is associated with increased BMI over a period of 24 months of observation. The increase in BMI is associated with pre-treatment peak LH levels. This is an important finding as peak LH concentration could serve as a marker for weight gain prediction in their children who are receiving GnRHa.