Background/objectives: We have reported that maternal overnutrition/obesity (OB) in sheep resulting from feeding 150% of National Research Council (NRC) requirements throughout gestation leads to maternal hyperglycemia and hyperinsulinemia. Further, newborn lambs born to OB vs control-fed (CON, 100% of NRC) ewes exhibited greater adiposity, increased blood cortisol, insulin and glucose and the elimination of the postnatal leptin spike seen in lambs born to CON ewes. This early postnatal leptin peak is necessary for the development of hypothalamic circuits, which program appetite in later life. This study evaluated the multigenerational impact of OB on insulin:glucose dynamics of mature female F1 offspring fed only to requirements throughout gestation and on their lambs (F2 generation).

Design and methods: Adult F1 female offspring born to OB (n=10) or CON (n=7) ewes were utilized. All F1 ewes were subjected to a glucose tolerance test at midgestation and late gestation. Jugular blood was obtained from F2 lambs at birth (day 1) through postnatal day 11, and plasma glucose, insulin, cortisol and leptin concentrations were determined. Dual-energy X-ray absorptiometry was utilized to determine bone mineral density, bone mineral content, lean tissue mass and fat tissue mass.

Results: Fasted blood glucose and insulin concentrations were greater (P<0.05) in OBF1 than CONF1 ewes at midgestation and late gestation. Further, after glucose infusion, both glucose and insulin concentrations remained higher in OBF1 ewes (P<0.05) than CONF1 ewes, demonstrating greater insulin resistance. Blood concentrations of glucose, insulin and cortisol and adiposity were higher (P<0.01) in OBF2 lambs than CONF2 lambs at birth. Importantly, OBF2 lambs failed to exhibit the early postnatal leptin peak exhibited by CONF2 lambs.

Conclusions: These data suggest that these OBF2 lambs are predisposed to exhibit the same metabolic alterations as their mothers, suggesting a multigenerational programming effect.