Female sex, small size at birth and low family income increase the likelihood of insulin resistance in late childhood: the Healthy Growth Study.

Objective: To identify among a wide range of perinatal indices, as well as certain family sociodemographic and parental characteristics, those independently associated with insulin resistance (IR) in late childhood.

Methods: A representative sample of 2195 Greek schoolchildren, aged 9-13 yr, was examined, and based on the biochemical indices collected IR was estimated using the homeostasis model assessment (HOMA-IR < 3.16). Perinatal data were recorded from children's medical records, retrospectively, while family sociodemographics and parental anthropometrics were reported by parents.

Results: The overall prevalence of IR was 28.4%, with a higher prevalence observed for girls compared with boys (p <0.05). Examination of univariate associations, per se, showed that maternal current and pre-pregnancy overweight/obesity, maternal smoking at early pregnancy, children's small birth weight, and rapid growth at infancy as well as female sex and non-Caucasian race increased the likelihood of IR. In contrast, folate supplementation during pregnancy, as well as higher paternal education and annual family income decreased the likelihood of IR in children. Inclusion of all above variables at a multivariable regression model highlighted female sex [odds ratios (OR): 1.67, 95% confidence intervals (CI): 1.30-2.13], small birth weight (OR: 1.41, 95% CI: 1.03-2.01), and higher annual family income (OR: 0.71, 95% CI: 0.53-0.95 for 12 000-30 000 € and OR: 0.68, 95% CI: 0.48-0.96 for >30 000 €) as the only significant correlates of IR after also controlling for children's body mass index (BMI) and Tanner stage.

Conclusions: The current study highlighted small birth weight and female sex as the only perinatal factors independently associated with the occurrence of IR in late childhood, when examined at a multivariable level with a wide range of perinatal indices as well as certain family sociodemographic and parental characteristics.