The Relationship Of Leptin And Bone Mineral Density, PICP, DPD/Cr In Preterm Infants

Objective The aim of this study was to research the relationship of leptin and bone density,bone density,PICP,DPD/Cr in preterm infant,in order to find the effects of leptin on bone metabolism.Materials and methods1.A total of 72 neonates were enrolled in the study.Samples were collected from 29 preterm infants and 43 term infants.The subjects were collected in the neonatal intensive care unit (NICU) at The Second Xiang Ya Hospital from March 1 to September 31,2009.Subjects with small or large for gestational age,with central nervous system diseases,with neuro-muscular disorders,with congenital malformations or received hormone therapy were excluded.And neonate whose mother have severe pregnancy complications were excluded.All subjects were divided into two groups: 31 weeks≤gestational age<37weeks,37weeks≤gestational age<42weeks. Altogether,samples were taken from these neonates on days 0-7 of life.2.Serum was collected to assay leptin,PICP which were detected by ELISA.Urine was collected to assay DPD and Cr.Urine samples were kept at-70℃, deoxypyridinoline(DPD) was detected by ELISA. Deox-ypyridinoline values were corrected by Urine Cr.3.We measured body length,head circumference,leg length,skin-fold thickness of biceps brachii,triceps brachii,spinal iliace and angulus inferior scapulae.4.An Omnisense ultrasound bone sonometer,produced by Sunlight company Israel was used to measure the sound of speed of the tibia.5.Statistical analysis:All data was processed by spss13.0.Results1.The level of tibia SOS in preterm infants was significantly lower than that of term infants.2.The level of serum leptin in premature infants was significantly lower than that of term infants.3.The level of PICP and DPD/Cr in premature infants was sig-nificantly higher than that of term infants. 4.The level of birth weight, gestational age,body length, head cir-cumference,leg length, PI,F%.in premature infants was significantly lower than that of term infants.5.The level of serum leptin in preterm and term infants was positively related to bone SOS,but it disappeared when controlling for birthweight, gestational age,body length, head circumference,leg length, PI,F%;According to the result of multivariate linear stepwise regression analysis,birth weight and gestation age were independent predictors of tibia SOS of preterm and term infants.6.The level of serum leptin in preterm and term infants was nega-tively related to PICP and DPD/Cr,but it disappeared when controlling for birth weight, gestational age,body length, head circumference, leg length, PI,F%.Conclusion1.Preterm infants' s bone development lags behind that of term infants.2.We observed a positive correlation between leptin and bone SOS in preterm infanta,and a negative correlation between leptin and PICP,DPD/Cr,but leptin is not the independent factor.3.The bone turnover of preterm is higher than that of term infants,so we should interfere preterm's bone metabolism earlier.