GLYCEMIC CURVE BEFORE AND AFTER EXERCISE IN A SPORT HORSE WITH ISOLATED POSTPRANDIAL HYPERINSULINEMIA

Abstract

Postprandial hyperinsulinemia (PPHI) is characterized by excessive insulin elevation following food intake, which can occur even with normal fasting insulin levels, and is associated with metabolic disturbances and an increased risk of laminitis in horses. This study evaluated the glycemic curve of a dressage horse diagnosed with PPHI following a post-exercise hypoglycemic episode, monitoring three dietary management phases: T1 (initial diet), T2 (first dietary intervention), and T3 (current management), with pre- and post-exercise measurements in T1 and T2, and fasting, pre-, and post-exercise measurements in T3. Intra-temporal analysis showed a significant reduction in blood glucose after exercise in T1 (mean difference: 57 mg/dL; p = 0.02) and T2 (mean difference: 13.4 mg/dL; p = 0.03), whereas values remained stable in T3 (p = 0.10). Inter-temporal analysis revealed significant differences in post-exercise glycemia between phases (p = 0.001), with progressive increases in mean values: T1 = 46.8 ± 20.4 mg/dL; T2 = 67.6 ± 4.6 mg/dL; T3 = 105.8 ± 18.0 mg/dL. Dietary interventions progressed from a rapidly digestible starch-rich feed (T1) to slow-release energy feeds (T2) and, subsequently, feeds enriched with beet pulp and vegetable oil (T3), promoting greater glycemic stability. In conclusion, personalized nutritional management improved metabolic safety during exercise and helped prevent endocrine-metabolic complications, highlighting its essential role in the care of horses with PPHI.