Context: Low birth weight is associated with an increased risk of metabolic and cardiovascular diseases in adulthood. The development of insulin resistance (IR) seems to play a pivotal role, no data on the oxidant/antioxidant status are available in this risk group.

Objective: Assessment of oxidant/antioxidant status in prepubertal children born small for gestational age in comparison to healthy controls and the relationship to IR.

Design: cross sectional study comparing indexes of IR and oxidant/antioxidant status in three different groups (SGA+, SGA-, controls). Analysis by post-hoc and Pearson correlation.

Setting: Academic Department of Pediatrics.

Participants: 19 SGA+ and 16 SGA- children were compared with 13 controls.

Intervention: None.

Main outcome measures: Indexes of IR (G/I, HOMA-IR) were evaluated and markers of oxidative stress (lag phase, MDA, vitamin E) measured.

Results: HOMA-IR was significantly higher in SGA+ than SGA- children (1.32±0.9 vs. 0.69±0.47; P=0.03) and controls (0.71±0.37; P=0.04). G/I was significantly lower in SGA+ than SGA- children (12.41±5.01 vs. 26.54±17.18; P=0.02) and controls (26.96±20.70; P=0.04). Lag phase was significantly shorter in SGA+ than SGA- children (24.3±4.38 vs. 35.59±11.29 min; P=0.003) and controls (45.28±7.69 min; P=0.0001) and in SGA- than controls (P=0.01). MDA was significantly higher in SGA+ than SGA- children (0.79±0.3 vs. 0.6±0.1 nmol/mg; P=0.03) and controls (0.36±0.04 nmol/mg; P=0.0001) and in SGA- children than controls (P=0.02). Vitamin E was significantly reduced in SGA+ children than controls (27.54±7.9 vs. 43.23±11.32 µmol/liter; P=0.002).

Conclusion: Oxidative stress is present in both SGA+ and SGA- children, with a continuous alteration in relation to IR. Catch-up growth might therefore exert the greatest influence in the development of future diseases.