Insulin-like growth factor-1 (IGF-1) serum concentration among 7-year-old extremely low birth weight children – an indicator of growth problems

Abstract

The study aim was to compare somatic development, body composition, insulin growth factor-1 (IGF-1) serum concentration and serum lipid profile between small-for-gestational-age (SGA) and appropriate-for-gestational-age (AGA) 7-year-old extremely low birth weight (ELBW) children and full-term (FT) controls. Fifty-seven AGA ELBW children [mean birth weight (BW) 850 g and mean gestational age (GA) 26.4 weeks] and 24 SGA ELBW children (mean BW 833 g, mean GA 29.5 weeks) were evaluated. The control group included 37 age- and sex-matched FT children from one outpatient center. Nine AGA and four SGA were found to have short stature defined as height < 3rd percentile for chronological age (p = 0.9). In the AGA cohort, the results of weight, head circumference, triceps skin fold and body mass index (BMI) measurements were significantly reduced in the short-stature subgroup. IGF-1 serum concentrations differed significantly between short-stature and normal-stature subgroups (121 vs. 193 ng/mL; p = 0.02). In the SGA cohort, weight and serum concentrations of total cholesterol (5.03 vs. 4.26 mmol/L; p = 0.04), LDL cholesterol (3.24 vs. 2.38 mmol/L; p = 0.01) and IGF-1 (113 vs. 211 ng/mL; p = 0.01) differed significantly between the short-stature and normal-stature subgroups. Short stature at the age of 7 years was diagnosed in a similar percentage of AGA and SGA former ELBW infants. In both cohorts short-stature children have significantly lower weight and serum IGF-1 levels. IGF-1 seems to be involved in prolonged growth restriction among ELBW infants, regardless of whether they were AGA or SGA.