Environmental Risk Factors And Mismatch Of Physical Development And Cognitive Function In Children With Idiopathic Precocious Puberty

Objective To evaluate the effects of early physical developments and growth environments, ZEA and p,p'-DDE on IPP patients, and the association between physical developments and mental developments in IPP patients.Methods A case-control study was conducted among 78 IPP patients and 100 controlled children with age, sex mated. Growth speed of prenatal and after birth, disease and psychopathological symptoms during pregnancy, early puberty of mother and same-degree relatives, family economic condition, accompany of parents in childhood and diet habits were assessed through questionnaires. Multivariate logistic regression was used to estimated early g physical developments and growth environments on odds of IPP; risk factors of IPP were selected. Serum ZEA and p,p′-DDE were tested with ELISA and gas chromatography respectively and the results were analyzed between two groups. The effects of combination of risk factors of early physical developments and growth environments and EDCs on IPP were also analyzed. Statistical interaction and biological interaction were analyzed respectively. A product variable, early physical developments and growth environments×EDCs, was set in logistic regression model. Statistical interaction was evaluated by odds ratio of product variable. A new viariable setted in logistic regression modle and Excel sheet were used to calculatethe measures of biological interaction. Three measures of biological interaction were presented: RERI, the relative excess risk due to interaction; AP, the attributable proportion due to interaction; and S, the synergy index. Physical developments, including height, weight, waistline, bone age and 1H-MRS, were evaluated. Mental developments were also tested by using Children's Depression Inventory, Conners parent rating scale, WISC-Ⅳand STROOP test. Variations of physical and mental developments between IPP patients and the control were analyzed. Risk factors of early physical developments and growth environments were selected and regarded as control variables. After controlling the relative risk factors, those variations were reanalyzed.Results Relative to the control, the rates of preterm birth, SGA, disease and psychopathological symptoms during pregnancy, better family economic condition, lived in rural, adoption, early maternal menarche (≤12y), early puberty of same-degree relatives, father absence during all childhood were significantly high in IPP patients (P<0.05). In the multivariate logistic regression models, SGA, disease during pregnancy, early maternal menarche, early puberty of same-degree relatives and father absence in 4-6 years old persisted as risk factors of IPP. Concentration of ZEA and positive rates in IPP group were significantly higher than the control. There was no difference of the concentration of p,p′-DDE between two groups, while the positive rate of p,p′-DDE in IPP group was significantly higher than the control (P<0.05). There was no statistical interaction between two risk factors of early physical developments and growth environments and ZEA. P value of product variable was 0.791. There was biological interaction between two risk factors (RERI=34.562,AP =0.745,S =4.193).The bone age of IPP patients were significantly higher than that of the control (P=0.000), there were no difference between two groups in other physical developments, such as height, weight, waistline, BMI and 1H-MRS. In the tests of mental health, psychosomatic disorder and positive rate of total behavior problems in IPP group were significantly higher than the control (P<0.05). Processing Speed intelligence quotient (IQ) in IPP group were significantly lower than the control (P<0.05). After adjusting for bone age, Verbal Comprehension, Perceptual Reasoning, Working Memory, Processing Speed, and total IQ in IPP group were all significantly lower than the control (P<0.05). After adjusting for risk factors of early physical developments and growth environments, the bone age of IPP patients were still higher than the control, and Processing Speed IQ and all IQ items after adjusting for bone age were also lower than the control (P<0.05).Conclusions The effects of early physical developments and growth environments and ZEA on IPP have synergism. Physical developments are advanced, and cognitive functions are lagggard in IPP patients. That is there is mismatch between physical development and cognitive function. Even after adjusting for risk factors of early physical developments and growth environments, this mismatch is still existed.