An oral sugar test (OST) has been developed as a clinical diagnostic technique to identify horses with insulin dysregulation (ID). Diagnosis is currently based on arbitrary cut-off values. The aim of the study was to establish appropriate cut-off insulin values for ID at different time points during an OST.
Forty-nine horses of different breeds with a wide range of insulin sensitivity were subjected to a modified OST (0.2 mL/kg Dansukker glykossirap) and a euglycemic hyperinsulinemic clamp (EHC) 24 hours apart. Using a glucose disposal rate (M-value) of < 2.5 mg/kg/min as a definition for insulin resistance by the EHC, the insulin cut-off values for the different time points during the OST were calculated by receiver operating characteristic (ROC) curve analysis. Spearman correlations were used to study correlations between the M-value and OST insulin concentrations at 60, 90 and 120 minutes.
Oral sugar test derived 60, 90 and 120 minutes insulin concentrations of > 44.4, 50.9, 38.8 µIU/mL respectively, were indicative of ID. Using EHC as the gold standard, optimal sensitivity and specificity for diagnosing ID were 88 and 96%, respectively, for time point 60 minutes; 84 and 92%, respectively, for time point 90 minutes and 84 and 88%, respectively, for time point 120 minutes. Oral sugar test derived insulin concentrations (60, 90 and 120 minutes) were inversely related (rho ≥ -0.81, p < 0.001) to the M-value.
Results indicate that time-specific OST insulin cut-off concentrations should be used, when diagnosis of ID is based on single blood sampling.
Swedish University of Agricultural Sciences
I started my PhD education in 2012, at the Swedish University of Agricultural Sciences, Uppsala, Sweden. My PhD-research topic is within the field of equine endocrinology, with specific focus on insulin resistance and the Equine metabolic syndrome. In December 2017 I defended my thesis. Currently I do research part time and work as assistant professor part time. I have six peer-reviewed research articles published within the area of equine endocrinology as well as two research articles undergoing review.
Thursday, June 14
2:30 PM – 2:45 PM
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