Estimation of Insulin Resistance in Healthy and
Ketotic Cows during an Intravenous Glucose Tolerance Test
Radojica Djoković1*, Vladimir Dosković1,
Marko Cincović2, Branislava Belić2, Natalija Fratrić3,
Boban Jašović4 and Miroslav Lalović5
1Department
of Animal Science, Faculty of Agronomy, Čačak, University of
Kragujevac, Cara Dusana 34, Čačak,Serbia; 2Department of Veterinary Medicine,
Faculty of Agriculture, University of Novi Sad, Trg Dositeja
Obradovića 8,Novi Sad, Serbia;
3Deprtment of
Phisiology, Faculty of Veterinary Medicine, University of Belgrade,
Bulevar Oslobodjenja 18, Belgrade, Serbia;
4Department of
Animal Science, Faculty of Agriculture, University of Priština,
Lešak, Jelene Anžujske bb., Serbia;
5Department of
Animal Science, Faculty of Agriculture, University of East Sarajevo,
Sarajevo, Vuka Karadžića 1, Sarajevo, Bosnia and Herzegovina;
*Corresponding author: radojicadjokovic@gmail
Abstract
The objective of this study was to determine
insulin resistance in healthy (n=8) and ketotic (n=7) dairy cows based on the
difference between basal and dynamic changes in glucose, insulin, non-esterified
fatty acids (NEFA), β-hydroxybutyrate (BHB) concentrations, and on the
determination of their mutual relationship and relationship with insulin
resistance indices (RQUICKI and RQUICKI-BHB), after intravenous glucose
tolerance test (IVGTT). The RQUICKI index showed a significant linear
correlation (P<0.05) with basal insulin, glucose, NEFA and BHB levels. However,
RQUICKI-BHB index values exhibited a negative correlation (P<0.01) with basal
NEFA and BHB values and their clearance rates, as well as with glucose clearance
rate, and a positive correlation (P<0.05) with basal insulin values as well as
with insulin and glucose responses during IVGTT. The correlation between basal
values of these parameters and the values measured or calculated during IVGTT is
the result of RQUICKI-BHB values, as the exclusion of RQUICKI-BHB leads to loss
of the statistical significance of the correlations between basal and dynamic
values. Insulin resistance in ketotic cows is characterized by decreased insulin
response to glucose and increased insulin resistance of the tissue, their
correlation being the result of the RQUICKI-BHB index value.