The Value Of MRI And IGF-1 In The Diagnosis And Differential Diagnosis Of ICPP Girls

Objective:To observe the value of magnetic resonance imaging (MRI) and insulin-like growth factor-1 (IGF-1) in diagnosis and differential diagnosis of idiopathic central precocious puberty (ICPP) girls and ICPP girls complicating growth hormone deficiency (GHD).Methods:We selected 60 ICPP girls with complete data and effective treatment in the pediatric endocrine clinic of Shandong Provincial Hospital from 2007.2 to 2009.12 as objects of study. They were divided into 3 groups:typical ICPP group,36 patients, age (7.22±2.59) years; ICPP complicating GHD group,16 patients, age (7.65±1.14) years; early ICPP group,8 patients, age (5.88±1.36 years).30 healthy children, age (7.28±2.5) years, were selected as control group. All patients had MRI scans of their hypothalamic-pituitary area. Anterior pituitary were divided into five grades according to Elster's grade on MRI. Uterus and ovaries were observed by ultrasound B-mode, bone age (BA) was determined by x-ray of left hand.The serum concentrations of IGF-1, FT3, FT4, TSH, LH, FSH, E2, T and PRL, ACTH and COR, liver and kidney function, biochemistry were measured in basal blood samples, and the peak of LH and LH/FSH were obtained at 30 min and 60 min after GnRH stimulation test. ICPP complicating GHD group underwent additional GH stimulation test. The relationships between the anterior pituitary height and 0 min LH, LH/FSH, E2, peak LH, peak LH/FSH and bone age advance (BA-CA) were observed; The rank correlation of the anterior pituitary Elster's grade and Tanner stages also observed;The differences of above-mentioned indexes in different observed groups were compared with each others.Results:1. Pituitary height and IGF-1 were both significantly higher in both typical ICPP group and early ICPP group than the control group(p<0.01), but there were no significant differences between typical ICPP group and early ICPP group; CA, (BA-CA), peak LH and LH/FSH, E2 in typical ICPP group were significantly higher than those in early ICPP group(p<0.01); Gonadotropin-releasing hormone analogue (GnRHa) had an significant effect on the treatment of early ICPP.2. Compared typical ICPP group with ICPP+GHD group, the advances of bone age(BA-CA), pituitary height, IGF-1, LH peak and the peak LH/FSH were significantly higher in typical ICPP group than in ICPP+GHD group; Compared with the control group, pituitary height and IGF-1 in typical ICPP group were significantly higher than in the control group, and both pituitary height and IGF-1 in the ICPP+ GHD group were significantly lower than in the control group.3. A significantly linear positive correlation were found between the pituitary height and (BA-CA),IGF-1,0 minute LH and LH/FSH, peak LH and LH/FSH,E2,(respectiver=0.45,0.65,0.54,0.45,0.58,0.57; 0.54, p<0.05-0.01).4. Elster's grade of anterior pituitary had a significant positive correlation with Tanner stages(r=0.54,P<0.001), the Elster's grade of ICPP which was equal or greater than 4 accounted for 86.4%.Conclusions:1. MRI and IGF-1 are sensitive indicators of early diagnosis of ICPP.2. MRI and IGF-1 can be used for the differential diagnosis of ICPP and ICPP+GHD. 3. MRI is closely related to the clinical manifestations and the function of pituitary-gonad axis.