Abstract:

Objective To explore the relationship between Ghrelin and growth hormone（GH）-insulin-like growth factor（IGF）axis and the effect on the growth and development in 2-7 years old children with small for gestational age（SGA）at birth. Methods Thirty 2-7 years old children with SGA at birth were used as SGA group,and according catching up growth（CUG）or not they were divided into SGA-CUG group and  SGA-no-CUG group.Twenty short stature children with appropriate for gestational age（AGA）at birth were used as AGA short stature group,and nineteen normal height children with AGA at birth were used as control group.Height and
 weight were measured and the standard deviation score（SDS）were calculated.The levels of Ghrelin,IGF-1,insulin-like growth factor binding protein-3（IGFBP-3）and blood sugar were  measured and compared and the correlation was analyzed in all the subjects.Results The levels of plasma Ghrelin（mg·L^-1）in SGA-CUG group and SGA-no-CUG group (0.371±0.093 and 0.446±0.076）were much higher than those in AGA short stature group and control group(0.263±0.174 and 0.245±0.080) （P<0.05）and highest in SGA-no-CUG group.There were no significant differences between SGA-CUG group and SGA-no-CUG group as well as AGA short stature group and control group（P>0.05）.The levels of serum IGF-1（mg·L^-1）and IGFBP-3（mg·L^-1）in SGA-no-CUG group（123.882±46.275 and 33.310±8.836） and AGA short stature group（171.83±65.77 and 42.150±13.515） were significantly lower than those in SGA-CUG group（380.037±137.548 and 147.389±46.430）and control group（354.121±95.023 and 145.058±30.706）（P<0.05）. The correlation analysis in SGA-CUG group and control group showed negative correlation between Ghrelin and calory,weight SDS,IGF-1,IGFBP-3(SGA-CUG group:r=－0.628，P<0.01；r=－0.658，P<0.05；r=－0.854，P<0.000 1；r=－0.685，P<0.001； control group:r=－0.808，P<0.000 1；r=－0.664，P<0.001；r=－0.771，P<0.000 1；r=－0.502，P<0.05).There were no correlation between Ghrelin and year old,height SDS and blood sugar（SGA-CUG group:r=0.255，－0.218，－0.135，all P>0.05； control group:r=0.203，－0.328，－0.228， all P＞0.05）.Conclusion  There is interaction between Ghrelin and GH-IGF axis，and they regulate the growth and development together. There is resistance to Ghrelin and aggression to GH-IGF axis and it will interfere the growth and development untill prepubescence.

Key words: small for gestational age;Ghrelin;insulin-like growth factor-1;insulin-like growth factor binding protein-3