Low and High Dietary Protein:Carbohydrate Ratios during Pregnancy Affect Materno-Fetal Glucose Metabolism in Pigs1–3

• Published in: The Journal of nutrition Vol. 144; no. 2; pp. 155 - 163
• Main Authors: Metges, Cornelia C., Görs, Solvig, Lang, Iris S., Hammon, Harald M., Brüssow, Klaus-Peter, Weitzel, Joachim M., Nürnberg, Gerd, Rehfeldt, Charlotte, Otten, Winfried
• Format: Journal Article
• Language: English
• Published: Bethesda Elsevier Inc 01.02.2014; American Institute of Nutrition
• Subjects: Biology; Carbohydrates; Catheters; Diet; Enzymes; Fetuses; Glucose; Hogs; Hypotheses; Metabolic disorders; Metabolism; Plasma; Pregnancy; Proteins; Ratios; Weight control; AA; FMG; ST; G6PC; HP-LC; RQUICKI; dp; CGR; LP-HC; PC; IUGR; IVGTT; NEFA; ME; PCK1
• ISSN: 0022-3166; 1541-6100
• DOI: 10.3945/jn.113.182691

Inadequate dietary protein during pregnancy causes intrauterine growth retardation. Whether this is related to altered maternal and fetal glucose metabolism was examined in pregnant sows comparing a high-protein:low-carbohydrate diet (HP-LC; 30% protein, 39% carbohydrates) with a moderately low-protein:high-carbohydrate diet (LP-HC; 6.5% protein, 68% carbohydrates) and the isoenergetic standard diet (ST; 12.1% protein, 60% carbohydrates). During late pregnancy, maternal and umbilical glucose metabolism and fetal hepatic mRNA expression of gluconeogenic enzymes were examined. During an i.v. glucose tolerance test (IVGTT), the LP-HC–fed sows had lower insulin concentrations and area under the curve (AUC), and higher glucose:insulin ratios than the ST– and the HP-LC–fed sows (P < 0.05). Insulin sensitivity and glucose clearance were higher in the LP-HC sows compared with ST sows (P < 0.05). Glucagon concentrations during postabsorptive conditions and IVGTT, and glucose AUC during IVGTT, were higher in the HP-LC group compared with the other groups (P < 0.001). 13C glucose oxidation was lower in the HP-LC sows than in the ST and LP-HC sows (P < 0.05). The HP-LC fetuses were lighter and had a higher brain:liver ratio than the ST group (P < 0.05). The umbilical arterial inositol concentration was greater in the HP-LC group (P < 0.05) and overall small fetuses (230–572 g) had higher values than medium and heavy fetuses (≥573 g) (P < 0.05). Placental lactate release was lower in the LP-HC group than in the ST group (P < 0.05). Fetal glucose extraction tended to be lower in the LP-HC group than in the ST group (P = 0.07). In the HP-LC and LP-HC fetuses, hepatic mRNA expression of cytosolic phosphoenolpyruvate carboxykinase (PCK1) and glucose-6-phosphatase (G6PC) was higher than in the ST fetuses (P < 0.05). In conclusion, the HP-LC and LP-HC sows adapted by reducing glucose turnover and oxidation and having higher glucose utilization, respectively. The HP-LC and LP-HC fetuses adapted via prematurely expressed hepatic gluconeogenic enzymes.