Glucose and Lipid Metabolism in Small-for-Gestational-Age Infants at 72 Hours of Age

Context: Reduced birth weight is associated with increased risk for the insulin resistance syndrome. Part of this risk is hypothesized to originate from intrauterine growth retardation. Objective: The aim of this study is to determine whether or not the components of the insulin resistance syndrome are associated with reduced fetal growth. Design: This was a case-control study. Setting: The study was conducted in Beijing, China. Participants: Included in this study were 296 singleton neonates (177 males and 119 females), including 76 (37 preterm and 39 full-term newborns) classified as small for gestational age (SGA) and 220 who were appropriate for gestational age (AGA) (84 preterm and 136 full-term newborns). Main Outcome Measures: The main outcome measures were postabsorptive glucose, insulin, and lipids levels on the third day after birth. Results: Both full-term and preterm SGA neonates had higher insulin concentrations (mean ± sem, 17.11 ± 1.15 vs.6.80 ± 0.62 μIU/ml in full-term, P < 0.01; 11.99 ± 1.18 vs.8.37 ± 0.78 μIU/ml in preterm, P = 0.03), insulin to glucose ratios (4.48 ± 0.37 vs. 1.78 ± 0.20 in full-term, P < 0.01; 3.28 ± 0.38 vs. 2.30 ± 0.26 in preterm, P = 0.03), triglycerides (2.29 ± 0.23 vs.1.57 ± 0.13 mmol/liter in full-term, P < 0.01; 2.27 ± 0.16 vs. 1.34 ± 0.11 mmol/liter in preterm, P < 0.01), total cholesterol (2.35 ± 0.12 vs. 1.82 ± 0.22 mmol/liter in full-term, P = 0.04; 2.57 ± 0.22 vs. 1.95 ± 0.15 mmol/liter in preterm, P = 0.02), and low-density lipoprotein cholesterol (2.11 ± 0.58 vs. 1.24 ± 0.61 mmol/liter in full-term, P = 0.01; 1.87 ± 0.60 vs. 1.38 ± 0.59 mmol/liter in preterm, P < 0.01) concentrations than did AGA neonates; however, they had similar glucose levels. Among AGA infants, insulin concentration, insulin to glucose ratios, and lipids levels did not significantly differ between full-term and preterm babies. Conclusions: In this study, SGA neonates displayed profiles suggestive of lower insulin sensitivity and less favorable lipid metabolism in the early postnatal period.