Growth pattern, growth deceleration, and relevant predictors in girls treated with GnRHa: a retrospective longitudinal study

Objectives This study aimed to analyze the height growth pattern and the incidence of significant growth deceleration in girls with CPP and EFP on GnRHa treatment, and thereby identify relevant predictors of growth deceleration.Methods The data of 99 girls diagnosed with CPP and 47 girls with EFP were included in this retrospective analysis. The incidence of growth deceleration was calculated in both the first and second years. Multivariate logistic regression analysis was used to identify predictors indicative of growth deceleration.Results Growth velocity (GV) trajectories showed gradual decreases to the nadir at 18 months of treatment, and then they recovered till the 24th month of treatment, especially in girls with CPP. Nevertheless, the recovery was significantly greater in the CPP group than EFP. In the first year, no significant difference in the incidence of growth deceleration was found between the CPP group and the EFP group [17.35 vs. 25.53 %, p=0.249]; in the second year, the CPP group had a lower incidence than the EFP group [42.86 vs. 76.92 %, p=0.027]. The multivariate logistic regression analysis suggested that bone age (BA) was an independent predictor of growth deceleration (OR=2.264, 95 % CI: 1.268-4.042, p=0.006). The result of ROC curves showed the cut-off value of BA was 11.05 years.Conclusions GV varies at different periods during GnRHa treatment. GnRHa should be used with more caution for EFP treatment than for CPP. BA can be used to predict the occurrence of growth deceleration during GnRHa treatment.