Gender specificity of body adiposity and circulating adiponectin, visfatin, insulin, and insulin growth factor-I at term birth: relation to prenatal growth.

Abstract

Fetal development is thought to be gender specific for adiposity and circulating insulin and IGF-I but not adipokinemia, as judged by serum visfatin and adiponectin at term birth. We studied the potential relationship between these gender specificities and fetal growth. The study was conducted at a university hospital. Subjects included 96 strictly matched neonates born appropriate for gestational age (AGA; 24 girls, 24 boys) or small for gestational age (SGA; 24 girls, 24 boys). Outcomes included serum insulin, IGF-I, visfatin, total and high-molecular-weight (HMW) adiponectin, osteocalcin at term birth, and neonatal body composition by absorptiometry. Cord insulin and IGF-I levels were higher in girls than boys (P < or = 0.01), in both the AGA and SGA subpopulation. In AGA newborns, fat and lean mass were each gender specific (P < 0.0001), whereas visfatin and total and HMW adiponectin were not. Conversely, in SGA newborns, visfatin and HMW adiponectin were gender specific (higher levels in girls), whereas body adiposity was not. In SGA fetuses, the distribution of adiponectin isoforms was in both genders shifted toward HMW (P < 0.005 vs. AGA). Cord osteocalcin did not differ by either gender or birth weight. At term birth, the gender specificity of adiposity and circulating visfatin and HMW adiponectin appeared to depend on prenatal growth, whereas the gender specificity of insulin and IGF-I levels did not. The fetal shift in adiponectin isoforms may contribute to explain why SGA newborns tend to be hypersensitive to insulin.