The primary objective of my basic research has been to elucidate the roles of placental and fetal hormones in the regulation of maternal metabolism and fetal growth. My work has focused on the lactogenic hormones produced by the pituitary gland and placenta. In recent studies we have used targeted knockout mice to explore the molecular mechanisms by which prolactin and placental lactogen regulate pancreatic beta cell mass and insulin production during pregnancy and postnatal life.
I also have a clinical research interest in the pathogenesis and treatment of obesity and hyperlipidemia and the prevention of type 2 diabetes. In previous studies we showed that the drug metformin reduces fat stores and blood glucose and insulin levels in obese adolescents and may reduce the risk of progression to diabetes in selected patients. We have also examined the unique metabolic characteristics of Prader Willi syndrome, a genetic obesity disorder. Finally, we have recently completed a detailed study of metabolism in malnourished children in Uganda and characterized the effects of concurrent HIV infection on nutritional recovery.