[Fetal growth restriction and insulin resistance. New findings and review of the literature].

There is a strong association between low birth weight and insulin resistance. The thrifty phenotype hypothesis, which postulates fetal programming for adaptation to an adverse intrauterine environment, resulting in a lower insulin sensitivity in utero, is one of the hypothesis to explain this association. Later in life, syndrome X may develop, featuring hypertension, dyslipidemia, central obesity and type 2 diabetes, associated to an excessive food intake. Our investigation during the first three years of life in a prospective cohort of small (SGA) or appropriate for gestational age newborns, demonstrated that a significant increase of insulin levels is detected in SGA, as early as during the first year of life, but only when catch up growth (CUG) occurs. Orexigenic peptides such as Ghrelin appear to participate in this CUG phenomenon. We also sought to determine whether these associations were observed in individuals born with very low birth weight. We found that in utero as well as postnatal growth rates were independent determinants of insulin sensitivity and secretion. Education about feeding practices and physical activity in SGA children, is a future challenge to prevent the onset of syndrome X in this predisposed population.