CLINICAL STUDY Serum adiponectin concentrations in relation to maternal and perinatal characteristics in newborns Christos Mantzoros 1 , Eleni Petridou 2,3 , Delia-Marina Alexe 2 , Alkistis Skalkidou 2 , Nick Dessypris 2 , Eugenia Papathoma 4 , Heraklis Salvanos 5 , Greeshma Shetty 1 , Alina Gavrila 1 , Simos Kedikoglou 2 , George Chrousos 6,7 and Dimitrios Trichopoulos 2,3 1 Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA, 2 Department of Hygiene and Epidemiology, Athens University Medical School, Athens, Greece, 3 Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts, USA, 4 Department of Neonatology, ‘Alexandra’ Maternity Hospital, Athens, Greece, 5 Department of Neonatology, ‘Elena Venizelou’ Maternity Hospital, Athens, Greece, 6 Paediatric and Reproductive Endocrinology Branch, National Institute of Child Health and Human Development, NIH, Bethesda, Maryland, USA and 7 First Department of Paediatrics, Ag. Sophia Children’s Hospital, Athens University Medical School, Athens, Greece (Correspondence should be addressed to E Petridou, Department of Hygiene and Epidemiology, Athens University Medical School, 75 Mikras Asias Str, Goudi, Athens 115 27, Greece; Email: epetrid@med.uoa.gr) Abstract Objective: To assess serum adiponectin levels of neonates in relation to ponderal index and birth length with and without adjustment for potential confounding factors including maternal factors and peri- natal characteristics. Design: A cross-sectional study. Methods: Three hundred and three newborns (Caucasian, singleton, full term, with a birth weight of $ 2500g, and apparently healthy) were included in the study. Blood samples were collected from the newborns no later than the fifth day of life for measurements of adiponectin and major IGF system components (IGF-I, IGF-II, IGF binding protein-3 (IGFBP-3)). The data were analyzed using simple and multiple regression analyses. Results: Adiponectin is substantially higher in neonates than in adults, with no evidence of the gender dimorphism observed among adults. We found an inverse association between neonatal adiponectin levels and newborn ponderal index and a positive association with newborn length by univariate ana- lysis. We also found a statistically significant inverse association of adiponectin with jaundice/bilirubin, and a marginally significant positive association of this hormone with IGFBP-3 but no significant associ- ation with any maternal factors. In multivariate analysis, the inverse association between serum adipo- nectin and ponderal index does not remain significant after adjustment for potential confounding factors. In contrast, neonatal adiponectin levels correlate inversely significantly and independently with liver maturity and IGF-II and tend to remain positively associated with IGFBP-3 and increased birth length. Conclusions: An inverse association of adiponectin with ponderal index by univariate analysis is not inde- pendent from confounding factors. In contrast, the positive association between serum adiponectin and birth length may reflect either a direct effect of adiponectin or an adiponectin-mediated increase in the sensitivity of tissues to insulin and components of the IGF system, and needs to be explored further. European Journal of Endocrinology 151 741–746 Introduction Energy homeostasis during fetal development and the perinatal period is of considerable interest because of its implications for fetal growth and development. Peri- natal development is influenced by multiple factors, including fetal, maternal and environmental con- ditions, which may interact with genotype to affect a range of physiological and pathological manifestations later in life such as the metabolic syndrome, cardiovas- cular disease and cancer (1–4). In adults, adiponectin, a 30 kDa protein composed of 244 amino acids (3, 5), is exclusively secreted from adipose tissue and has been found to decrease with obes- ity (6), type 2 diabetes and insulin resistance (7), and to increase with weight reduction or administration of thia- zolidinediones (8). Furthermore, recent observations indicate that adiponectin is inversely associated with markers of inflammation and endothelial dysfunction (9, 10) and is a significant inverse predictor of cardiovas- cular disease and cancer (11 – 14). Thus, regulation of this adipokine in the perinatal period, when many meta- bolic, immune and hormonal pathways are being devel- oped, is of great interest. The purpose of this study was to assess serum adipo- nectin levels in relation to birth length and ponderal European Journal of Endocrinology (2004) 151 741–746 ISSN 0804-4643 q 2004 Society of the European Journal of Endocrinology Online version via http://www.eje.org