Effects Of GnRHa Treatment On BMI In Girls With Idiopathic Central Precocious Puberty

BACKGROUND:Since gonadotropin releasing hormone analogues（GnRHa）was used in the treatment of girls with idiopathic central precocious puberty（ICPP）,previous studies that evaluated the effect of GnRHa therapy on auxological parameters in ICPP patients mainly focused on the improvement of final height,and less attention has been paid to its impact on body composition.In fact,limited,even somewhat controversial data are available regarding the effects of GnRHa treatment on body mass index（BMI）.A recent report suggested that baseline weight status might influence BMI parameters after treatment.We therefore evaluated auxological parameters during GnRHa therapy in patients with ICPP,specifically focusing on changes in BMI.We also evaluated whether the change of BMI affects treatment outcomes.METHODS:We analyzed data of 131 girls with ICPP retrospectively.These girls were treated with leuprorelin acetate in Xi’an Children’s Hospital during April,2014 to September,2018.All the patients were divided into three groups according to pre-treatment weight status:normal weight（NW）62 cases,overweight（OW）36 cases and obesity（OB）33 cases.BMI was evaluated at 6th,12th,18th,24th and 30th month respectively.In addition,131 patients were divided into two groups according to the changes in BMISDS_CAA at the end of treatment and at the beginning of treatment.And the differences in relevant clinical parameters between the two groups were compared.RESULTS:The average BMI of all the patients was 17.6±2.1kg/m².There was statistic difference compared with normal BMI（15.4±0.3kg/m²）（p<0.05）.The incidence of overweight and obesity was 27.5%and 25.2%in 131 girls with ICPP before treatment.There was no statistic differencefor BMISDS_CAA of all the patients at the end of treatment compared with the beginning of treatment.However,when they stratified according to baseline BMI status,the normal-weight group showed increases in BMISDS_CAA at the end of treatment,and there was statistic difference.Whereas,there was no statistic difference between at the end of treatment and at the beginning of treatment in the overweight and obesity groups.Baseline BMISDS_CAA was an independent predictor of changes in BMI during the GnRHa treatment period.The changes of weight-SDS in three groups were similar,but changes of height-SDS were significantly greater in the overweight group than in the normal-weight group,which explains the reason of the difference in BMI-SDS.There was no statistic difference in LH concentration（simple stimulating test was performed at the end of treatment）,PAH and BA-CA between the two groups based on BMISDS_CAA changes.CONCLUSION:1.The BMI was increased at the end of GnRHa treatment in normal weight group,and there was statistic difference.But it did not happened in overweight and obesity groups.The different pattern of BMI changes suggested that different BMI at the beginning treatment was the main reason.So the individualized lifestyle is of importance for girls with ICPP.2.Changes in BMI during treatment did not affect the improvement of predicted adult height or the inhibition of the hypothalamic-pituitary-gonadal axis in girls with ICPP.In other words,it did not affect the efficacy of GnRHa treatment.