TY - JOUR
T1 - Seasonal Insulin Responses to the Oral Sugar Test in Healthy and Insulin Dysregulated Horses
AU - Macon, Erica Lyn
AU - Harris, Patricia
AU - Barker, Virginia Day
AU - Adams, Amanda A.
N1 - Publisher Copyright:
© 2022
PY - 2022/6
Y1 - 2022/6
N2 - Seasonal effects on the oral sugar test (OST), used to monitor insulin dysregulation (ID) status to help reduce laminitis risk, are poorly understood in the ID horse. Resting, (basal) insulin (T0) and 60-minute (T60) OST (0.15 mL/Kg BW Karo Light Corn Syrup) insulin responses were evaluated, once per each season over 2 years, in ID (n = 11 14.9 ± 4.3 years; mean ± SD) and non-insulin dysregulated (NID: n = 11 16.4 ± 5.3 years; mean ± SD) horses housed on the same farm. Seasonal morphometric measurements were collected: bodyweight (BW), body-condition scores (BCS), and cresty neck scores (CNS). Seasonal forage from paddocks and hay were collected and analyzed. Insulin was measured by RIA. Data were analyzed via Minitab Software 20.2 (mixed effects model). Season had no effect on BW (P = .99); however, BCS and CNS were higher in ID versus NID in the spring, summer and fall (P < .02). Paddock (P < .05) but not hay (P >. 2) analytes varied across season. ID horses consistently had higher T0, T60 insulin concentrations versus NID (P < .02). Season had no effect on NID T0 insulins (P = .31), but T60 values were higher in the spring versus summer (P = .01). ID horses’ T0 & T60 insulins were higher in spring than fall and summer (P < .01 & P < .05) and winter T60 was higher than fall (P = .04). ID horses changed their ID categorization across season, with T0 confirming ID status only 56% of the time whilst T60 confirmed 94% of the time. Therefore, regardless of seasonal changes, if the OST was used, ID diagnosis would be more consistent.
AB - Seasonal effects on the oral sugar test (OST), used to monitor insulin dysregulation (ID) status to help reduce laminitis risk, are poorly understood in the ID horse. Resting, (basal) insulin (T0) and 60-minute (T60) OST (0.15 mL/Kg BW Karo Light Corn Syrup) insulin responses were evaluated, once per each season over 2 years, in ID (n = 11 14.9 ± 4.3 years; mean ± SD) and non-insulin dysregulated (NID: n = 11 16.4 ± 5.3 years; mean ± SD) horses housed on the same farm. Seasonal morphometric measurements were collected: bodyweight (BW), body-condition scores (BCS), and cresty neck scores (CNS). Seasonal forage from paddocks and hay were collected and analyzed. Insulin was measured by RIA. Data were analyzed via Minitab Software 20.2 (mixed effects model). Season had no effect on BW (P = .99); however, BCS and CNS were higher in ID versus NID in the spring, summer and fall (P < .02). Paddock (P < .05) but not hay (P >. 2) analytes varied across season. ID horses consistently had higher T0, T60 insulin concentrations versus NID (P < .02). Season had no effect on NID T0 insulins (P = .31), but T60 values were higher in the spring versus summer (P = .01). ID horses’ T0 & T60 insulins were higher in spring than fall and summer (P < .01 & P < .05) and winter T60 was higher than fall (P = .04). ID horses changed their ID categorization across season, with T0 confirming ID status only 56% of the time whilst T60 confirmed 94% of the time. Therefore, regardless of seasonal changes, if the OST was used, ID diagnosis would be more consistent.
KW - Insulin dysregulation
KW - Metabolic syndrome
KW - NSC
KW - OST
KW - Season
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U2 - 10.1016/j.jevs.2022.103945
DO - 10.1016/j.jevs.2022.103945
M3 - Article
C2 - 35405290
AN - SCOPUS:85129338397
SN - 0737-0806
VL - 113
JO - Journal of Equine Veterinary Science
JF - Journal of Equine Veterinary Science
M1 - 103945
ER -