title: Short-term effects of energy changes on plasma leptin concentrations and glucose tolerance in healthy ponies.
abstract: To determine whether plasma leptin concentrations and glucose tolerance are affected by changes in energy balance, nine healthy Shetland ponies were fed at 140% followed by 75% of their maintenance requirements for 13 days in each of the two periods. Bodyweight was recorded every three days. Blood samples were taken every two days and analysed for leptin and cortisol. An oral glucose tolerance test was performed on day 7 of each period. Serial blood samples were analysed for glucose and insulin. Although bodyweight was not affected, plasma leptin concentrations increased (P<0.001) initially during overfeeding, but returned to previous values after 7 days. During underfeeding, plasma leptin concentrations decreased (P<0.001). Underfeeding was associated with a higher AUC for plasma glucose (P=0.02) and plasma insulin (P=0.05) resulting in a decreased glucose tolerance (AUC glucose/AUC insulin; P=0.008), probably due to a plasma cortisol increase caused by the reduced feed intake. It is concluded that changes in energy balance, without altering bodyweight, can influence plasma leptin concentrations in ponies.
authors.affiliation: Laboratory of Animal Nutrition, Ghent University, Heidestraat 19, 9820 Merelbeke, Belgium. Stephaie.VanWeyenberg@Ugent.be
authors.forename: Stephanie Van
authors.initials: SV
authors.lastname: Weyenberg
authors.forename: Myriam
authors.initials: M
authors.lastname: Hesta
authors.forename: Johan
authors.initials: J
authors.lastname: Buyse
authors.forename: Georgios A
authors.initials: GA
authors.lastname: Papadopoulos
authors.forename: Geert P J
authors.initials: GP
authors.lastname: Janssens
mesh_terms: D000818:Animals; D002149:Energy Intake; D005947:Glucose / Q000378:metabolism*; D005951:Glucose Tolerance Test / Q000662:veterinary; D006736:Horses / Q000378:metabolism*; D020738:Leptin / Q000097:blood*
chemical_list: D020738:Leptin; D005947:Glucose