Relationship between Birth Weight and Metabolic Status in Obese Adolescents

Objective. To examine the relationships between birth weight and body mass index, percent body fat, blood lipids, glycemia, insulin resistance, adipokines, blood pressure, and endothelial function in a cohort of obese adolescents. Design and Methods. Ninety-five subjects aged 10-16 years (mean age 13.5 years) with a body mass index >95th centile (mean [±SEM] 33.0 ± 0.6) were utilized from two prospective studies for obesity prevention prior to any interventions. The mean term birth weight was 3527 ± 64 g (range 1899-4990 g;). Results. Body mass index z-score correlated positively with birth weight (r (2) = 0.05, P = 0.03), but not percent body fat. Insulin resistance negatively correlated with birth weight (r (2) = 0.05, P < 0.001), as did fasting plasma insulin (r (2) = 0.05, P < 0.001); both being significantly greater for subjects of small versus large birth weight (Δ Homeostasis Model Assessment = 2.5 and Δ insulin = 10 pmol/L for birth weight <2.5 kg versus >4.5 kg). Adiponectin, but not leptin, blood pressure z-scores or peripheral arterial tomography values positively correlated with birth weight (r (2) = 0.07, P = 0.008). Conclusions. Excess body mass index in obese adolescents was positively related to birth weight. Birth weight was not associated with cardiovascular risk factors but represented a significant determinant of insulin resistance.