Abstract: Objective To analyze the changes in insulin sensitivity of small for gestational age (SGA) and the effect of different feeding for SGA on insulin sensitivity. Methods SGA borns in Peking University Third Hospital obstetrics in June 2011 to June 2014 were collected,for SGA group.Appropriate for gestational age (AGA) borns in the same period and in the same hospital were named as normal control (NC) group.All the subjects were enrolled into the Child Health Care Center to follow-up,examining physical measurements,measuring fasting blood glucose and insulin levels.Then on the basis of the formula,insulin resistance index (IRI) was calculated.According to different feeding within four months after birth,they were divided into breastfeeding group,artificial feeding group and the mixed feeding group.Then according to whether IRI of SGA group was higher than the median of the NC group,SGA was divided into two groups,non insulin sensitive group and insulin sensitive group. Results The growth rate of SGA was faster than that of normal weight infant,but had been unable to catch up with AGA in infant period.By the end of infancy,IRI value of SGA was significantly higher than that of NC group (t=3.715,P<0.05).Insulin sensitivity of SGA with breastfeeding was higher than that of the artificial feeding and mixed feeding(χ²=7.02,P<0.05). Conclusions The growth rate of SGA is faster than that of normal weight infant,but is unable to catch up with normal weight infant.SGA shows differences in insulin sensitivity at the end of infant period.The different feeding at early postnatal period may have some impact on insulin sensitivity of SGA.

Key words: small for gestational age, early feeding, insulin sensitivity