Serum Levels Of Ghrelin, Insulin-like Growth Factor-1，insulin Related To Growth And Development In Small For Gestational Age Preterm Infants

Background and ObjectiveWith the development of perinatology and neonated emergency technology inrecent years, the survival rate of the critical neonates is higher and higher, and theincidence of small for gestational age （SGA）infants is much higher，especially inpreterm infants. A survey showed that the incidence of SGA in preterm infants (13.1%)was much higher than that in full-term infants (6.05%) in our country，and themortality and incidence of short and long term complications in SGA are higher. Thestudies on the growth, development and pathogenesis of SGA have been drawinggrowing attention. Ghrelin, insulin-like growth factor-1(IGF-1), insulin are importantendocrine hormones of human body, which are believed to have functions in regulatingenergy metabolism and promoting growth, they may play a significant role in thegrowth of intrauterine and extrauterine in infant. We explored the effect of serumghrelin, IGF-1, insulin levels on the growth and development of SGA preterm infantsshortly after birth by measuring the serum concentrations of ghrelin, IGF-1, insulin inpreterm infants in the24hours and on the tenth after birth.Objects and methods1.Study objects：27SGA preterm infants and28AGA preterm infants in24hours afterbirth who were admitted to department of neonatology, the First Affiliated Hospital of Anhui Medical University from May,2012to October,2012were selected as SGAgroup, AGA group respectly.19SGA and22AGA preterm infants’ hospitalization staywere more than10days. All babies met the diagnostic criteria of SGA and AGA, andexcluded the babies with multiple gestations, NRDS, asphyxia, heredity metabolicdiseases, congenital anomalies, serious infectious diseases and the mother with diabetesin pregnancy-related，etc.2. Study methods(1) Data collection: to record the gender, gestational age, mode of delivery, age,diagnasis pregnancy complications of mother.(2) The birth weight，length，head circumference of27SGA preterm infants and thebirth weight of28AGA preterm infants were measured, and the body mass index (BMI)was calculated too. The weight on tenth day after birth was only measured in the babieswhose hospitalization stay was more than10days.(3)Sample test: All babies’ serum were collected in24hours after birth and the serum ofthe babies whose hospitalization stay was more than10days were collected on the tenthday after birth, the levels of serum ghrelin, IGF-1, insulin were detected by ELISA.(4) Statistical analysis：The data were analyzed by SPSS18.0software.Results1.Compared with the AGA group，the level of serum ghrelin in the SGA group in24hours after birth was significantly higher，the levels of IGF-1，insulin were obviouslylower (P＜0.01). In the SGA group, the serum concentration of ghrelin was negativelyassociated with IGF-1and INS(P＜0.01), and the serum concentration of INS waspositively associated with IGF-1(P＜0.01).2. The serum concentration of ghrelin in SGA preterm infants was negatively associatedwith gestational age, birth weight, length, BMI in24hours after birth (r=-0.680，P＜0.01；r=-0.69，P＜0.01；r=-0.469，P＜0.05；r=-0.527，P＜0.01)., and had no correlation with head circumference. The levels of serum IGF-1in SGA preterm infants waspositively associated with gestation age, birth weight，length, head circumference，andBMI in24hours after birth(r=0.659，P＜0.01；r=0.740，P＜0.01；r=0.485，P＜0.05；r=0.651，P＜0.01； r=0.601，P＜0.01); The levels of serum IGF-1and INS in SGApreterm infants was positively associated with gestation age, birth weight，length, headcircumference，and BMI in24hours after birth(r=0.590，P＜0.01；r=0.594，P＜0.01；r=0.425，P＜0.05；r=0.411，P＜0.05；r=0.426，P＜0.05).3. On the tenth day after birth，the weight growth percentage of SGA preterm infantswas higher than that of AGA preterm infants (P＜0.01), the serum ghrelin level in SGApreterm infants was higher than that in AGA preterm infants（P＜0.05）also, while theserum IGF-1and insulin were no significant difference between the two groups (P＞0.05).Conclusion1.Ghrelin, IGF-1, insulin are involved in the intrauterine growth and the developmentof SGA preterm infants, the inadequate secretion or excess secretion of these hormonesare related to SGA clearly.2.Ghrelin, IGF-1, insulin may play an important role in SGA preterm infants’extrauterine growth and development，and might be as parameters of monitoringextrauterine growth and development in SGA preterm infants.3.Exogenous ghrelin, IGF-1, INS may be helpful to SGA preterm infants’ extrauterinegrowth and development.