Increased insulin resistance and oxidative stress in obese and non-obese prepubertal children born large and small for gestational age

Abstract OBJECTIVE: Our aim was to evaluate the effect of BW and obesity on oxidative stress and IR in prepubertal SGA and LGA children compared with appropriate-for-gestational-age (AGA) children. METHODS: We performed a cross-sectional study comparing oxidative stress and IR in 103 children categorized into 6 groups according to BW (26 SGA, 15 AGA, and 16 LGA normal-weight children) and obesity (15 SGA, 15 AGA, and 16 LGA obese children). Indexes of IR (HOMA-IR, G/I) and the marker of oxidative stress (urinary isoprostanes) were evaluated. RESULTS: Homeostasis Model Assessment was higher in both normal-weight SGA and LGA children than in normal-weight AGA children (all P <or= .02). Furthermore, a difference was detected between obese SGA and obese LGA subjects compared with normal-weight SGA (all P <or= .0007) and LGA (all P <or= .01) children, respectively. The G/I ratio was lower in the 3 obese groups than normal-weight AGA (all P <or= .009) and normal-weight SGA children (all P <or= .02). Furthermore, a difference was detected between obese SGA and obese LGA children compared with normal-weight LGA children (all P <or= .0002). Isoprostane levels were higher in both normal-weight SGA and LGA children than in normal-weight AGA children (all P <or= .002). Moreover, both obese SGA and LGA children showed higher levels than obese AGA children (all P <or= .01) and in comparison to the 3 normal-weight groups (all P <or= .04). CONCLUSION: Increased IR and oxidative stress are already present in prepubertal normal-weight SGA and LGA children with a continuous alteration in relation to obesity, suggesting that BW and adiposity represent 2 independent risk factors for degenerative diseases