Correlation between cord blood insulin/igf-1 and early post natal growth in small for gestational age babies.

To compare the levels of insulin, glucose and IGF-1 in term born AGA and SGA babies and demonstrate difference in IGF-1 and insulin resistance as measured by the HOMA-IR index. To demonstrate any difference in catch up growth in AGA and SGA babies and its correlation with diet and these hormonal parameters at 3.5 and 6 months. METHODS: Maternal and Neonatal details were collected at birth and recorded. Cord blood samples for measurement of glucose , insulin and IGF-1 were taken from 60 infants(30 AGA and 30 SGA). Using this information, HOMA-IR was calculated. The cohort was followed up at 3.5 and 6 months and a growth assessment was done. The dietary history was also collected. Infants were categorized as adequately, inadequately and rapidly growing based on the catch up growth at 3.5 months in both the AGA and SGA arms. Glucose, insulin and IGF-1 levels were taken at 6 months. The hormonal profiles at birth and at 6 months were correlated to the growth rates. Data analysis was done using the SPSS version 21. The Mann whitney U test was used to compare the two groups. RESULTS: The SGA babies were lighter, shorter and had a smaller head circumference at birth compared to the AGA babies. The cord blood insulin (P=0.0002) and IGF- 1(<0.01) were higher in AGA group. There was a linear correlation between the birth weight and the cord blood insulin (p=0.01) and IGF-1(p<0.01).The growth velocity at 3.5 months was similar between the AGA and SGA groups, however, the SGA babies continued to be shorter and lighter than the AGA ones. Insulin and IGF-1 levels at birth had no correlation with catch up growth.