Veterinary Archives, Vol. 87 No. 4, 2017.
Original scientific paper
https://doi.org/10.24099/vet.arhiv.160204
Inorganic phosphorus decrease after intravenous glucose tolerance test is associated with insulin resistance in dairy cows
Marko R. Cincović
orcid.org/0000-0002-5683-8983
; Department of Veterinary Medicine, Faculty of Agriculture, University of Novi Sad, Novi Sad, Serbia
Radojica Djoković
; Department of Animal Science, Faculty of Agronomy, University of Kragujevac, Čačak, Serbia
Branislavav Belić
; Department of Veterinary Medicine, Faculty of Agriculture, University of Novi Sad, Novi Sad, Serbia
Aleksandar Potkonjak
; Department of Veterinary Medicine, Faculty of Agriculture, University of Novi Sad, Novi Sad, Serbia
Bojan Toholj
; Department of Veterinary Medicine, Faculty of Agriculture, University of Novi Sad, Novi Sad, Serbia
Nenad Stojanac
; Department of Veterinary Medicine, Faculty of Agriculture, University of Novi Sad, Novi Sad, Serbia
Ognjen Stevančević
; Department of Veterinary Medicine, Faculty of Agriculture, University of Novi Sad, Novi Sad, Serbia
Jože Starič
; Section for diseases and health care of ruminants, Veterinary Faculty, University of Ljubljana, Slovenia
Abstract
Inorganic phosphorus (Pi) concentration in blood decreases during an intravenous glucose tolerance test (IVGTT) due to the increase in the level of insulin and glucose. The objective of the present study was to determine the relationship between the intensity of Pi decrease with a dynamic change of insulin and glucose during IVGTT (AUC - total area under curve, AUC increment - area under curve from start of IVGTT to time of maximal response and glucose CR-clearance rate), as well as RQUICKI (Revised Quantitative Insulin Sensitivity Check Index) and RQUICKI-BHB (RQUICKI with beta hydroxybutyrate in formula) indexes of insulin resistance. The experiment included healthy and ketotic cows. Metabolic changes in ketotic cattle are similar to healthy cows in early lactation; ketosis represents impaired metabolic adaptation with higher insulin resistance. In both groups we found increases in insulin and glucose concentrations and Pi AUC during IVGTT, but these changes were less pronounced in the ketotic group. Ketotic cows showed a lower RQUICKI and RQUICKI-BHB index which indicates a higher level of insulin resistance. Pi AUC was in positive correlation with glucose response (glucose AUC), and this correlation is controlled with insulin response to glucose (insulin AUC). Pi AUC also showed a positive correlation with maximal glucose and insulin concentration during IVGTT, AUC and AUC increment for glucose and insulin, and glucose CR. These correlations were controlled by RQUICKI and RQUICKI-BHB indexes. The Pi decrease after the intravenous glucose tolerance test in dairy cows is associated with all aspects of insulin resistance, that include the insulin response to glucose (insulin AUC) and tissue response to insulin (RQUICKI and RQUICKI-BHB).
Keywords
phosphorus; insulin resistance; cow; ketosis; RQUICKI
Hrčak ID:
185571
URI
Publication date:
3.7.2017.
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