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 microIU/ml in full-term, P < 0.01; 11.99 +/- 1.18 vs.8.37 +/- 0.78 microIU/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.