Neonatal body composition, salivary feeding gene expression, and feeding outcomes in infants of diabetic mothers.

Introduction: Infants of diabetic mothers (IDMs) may exhibit decreased oral intake, requiring nasogastric feedings and prolonged hospitalization. The objective of this study was to explore whether saliva serves as an informative biofluid for detecting expression of hunger signaling and energy homeostasis modulator genes and to perform exploratory analyses examining expression profiles, body composition, and feeding outcomes in late preterm and term IDMs and infants born to mothers with normoglycemia during pregnancy.

Methods: In this prospective cohort pilot study, infants born at ≥ 35 weeks' gestation to mothers with gestational or type II diabetes (IDM cohort) and normoglycemic mothers (control cohort) were recruited. The presence of known hunger signaling genes: 5'AMP-activated protein kinase () and neuropeptide Y2 receptor (); adipokines: leptin ) and adiponectin ; and energy homeostasis regulators: ghrelin and proopiomelanocortin in neonatal saliva was determined with RT-qPCR and compared between cohorts. Body composition was assessed via skinfold measurements and compared between cohorts. Feeding outcomes were recorded. Exploratory analyses were performed examining associations between infant body composition, energy homeostasis and hunger signaling gene expression.

Results: Twenty-three infants in the IDM cohort and 22 infants in the control cohort were recruited. and were not reliably detected in neonatal saliva in either cohort. and were less likely to be detected in the IDM cohort, whereas was more likely to be detected in the IDM cohort. Infants in the IDM cohort had greater adiposity compared to infants in the normoglycemia cohort. Only 3 IDMs had documented poor feeding; no infant in the control group struggled to feed. In exploring associations between hunger signaling gene expression with energy homeostasis gene expression and body composition, the odds of detecting salivary expression decreased as fat mass increased, and the odds of detecting expression increased in the presence of expression.

Discussion: Non-invasive assessment of hunger signaling and energy homeostasis gene expression is possible through neonatal salivary analysis. This pilot study lays the foundation for a larger scale study to further investigate the link between exposure to diabetes with body composition and regulation of appetite.