title: Elevated insulin sensitivity in low-protein offspring rats is prevented by a high-fat diet and is associated with visceral fat.
abstract: This study tests the hypothesis that a high-fat postnatal diet increases fat mass and reduces improved insulin sensitivity (IS) found in the low-protein model of maternal undernutrition. Offspring from Wistar dams fed either a 20% (control (CON)) or 8% (low protein (LP)) protein diet during gestation and lactation were randomly assigned to a control (con) or cafeteria (caf) diet at weaning (21 days) until 3 months of age at which point IS was measured (hyperinsulinemic-euglycemic clamp). Fat mass, growth, energy intake (EI) and expenditure (EE), fuel utilization, insulin secretion, and leptin and adiponectin levels were measured to identify a possible role in any changes in IS. IS was increased in LP-con in comparison to CON-con animals. Cafeteria feeding prevented this increase in LP animals but had no effect in CON animals (insulin-stimulated glucose infusion rates (GIRs; mg/min/kg); CON-con: 13.9 +/- 1.0, CON caf: 12.1 +/- 2.1, LP-con: 25.4 +/- 2.0, LP-caf: 13.7 +/- 3.7, P < 0.05). CON-caf animals had similar percent epididymal white adipose tissue (%EWAT; CON-con: 1.71 +/- 0.09 vs. CON-caf: 1.66 +/- 0.08) and adiponectin (microg/ml: CON-con: 4.61 +/- 0.34 vs. CON-caf: 3.67 +/- 0.18) except hyperinsulinemia and relative hyperleptinemia in comparison to CON-con. Differently, LP-caf animals had increased %EWAT (LP-con: 1.11 +/- 0.06 vs. LP-caf: 1.44 +/- 0.08, P < 0.05) and adiponectin (microg/ml: LP-con: 5.38 +/- 0.39 vs. LP-caf: 3.75 +/- 0.35, P < 0.05) but did not show cafeteria-induced hyperinsulinemia or relative hyperleptinemia. An increased propensity to store visceral fat in LP animals may prevent the elevated IS in LP offspring.
authors.affiliation: Human Nutrition Unit, The University of Sydney, Sydney, New South Wales, Australia. alison.gosby@usyd.edu.au
authors.forename: Alison K
authors.initials: AK
authors.lastname: Gosby
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Maloney
authors.forename: Ian D
authors.initials: ID
authors.lastname: Caterson
mesh_terms: D052242:Adiponectin / Q000097:blood; D000818:Animals; D000831:Animals, Newborn; D001786:Blood Glucose / Q000378:metabolism*; D018753:Diet, Protein-Restricted; D004041:Dietary Fats / Q000494:pharmacology*; D005260:Female; D006946:Hyperinsulinism / Q000097:blood; D007328:Insulin / Q000097:blood*; D007333:Insulin Resistance; D050152:Intra-Abdominal Fat / Q000378:metabolism*; D020738:Leptin / Q000097:blood; D008297:Male; D056128:Obesity, Abdominal / Q000097:blood; D011247:Pregnancy; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar
chemical_list: D052242:Adiponectin; D001786:Blood Glucose; D004041:Dietary Fats; D007328:Insulin; D020738:Leptin