Peer victimization on early onset of breast development:mediation effects of morning cortisol and body fat / 中国学校卫生

ABSTRACT

Objective@#To explore the relationship and potential mechanism between peer victimization and early onset of breast development in girls, and to provide new strategies for precocious puberty prevention.@*Methods@#A total of 950 girls aged (9.0±1.2) years participated in this survey in Ma anshan City in China. Revised Bully/Victim Questionnaire (BVQ) was used. Each girl was assessed on breast Tanner stage by one female pediatric endocrinologist. All the girls collected morning awakening saliva sample with Salivette at home. Body fat percentage (%BF) was derived from Bioelectrical Impedance Analyzer (BIA) measurements.The association between peer bullying and early breast development was analyzed by stepwise Logistic regression.The mediation coefficient was estimated using the Logistic regression.@*Results@#Totally 23.2% (220/950) of all the girls reported being victimized at school. More girls reported peer victimization had early breast onset (24.1%,53) compared with girls with no victimization experience ( 13.7 %,100). Logistic regression analyses indicated that peer victimization was associated with early onset of breast development ( OR=1.74, 95%CI =1.16-2.59) after body fat and awakening cortisol adjusted. Mediation analysis showed that high cortisol and high fat both had indirect effects in the association between peer victimization and early onset of breast development.Mediating analysis showed that both high cortisol level and high body fat rate had indirect effects between peer bullying and early breast development, and the mediating effect values were 0.37 and 0.45,respectively.@*Conclusion@#Peer victimization significantly correlated with early onset of breast development among girls, which might be mediated through HPA axis hyperactivity and high adiposity.