Effect of feeding glucose, fructose, and inulin on blood glucose and insulin concentrations in normal ponies and those predisposed to laminitis.
Authors: Borer, Bailey, Menzies-Gow, Harris, Elliott
Journal: Journal of animal science
Summary
# Editorial Summary: Carbohydrate Feeding Responses in Laminitis-Prone Ponies Identifying ponies at risk of pasture-associated laminitis remains clinically challenging, yet insulin resistance—increasingly recognised as a key pathophysiological mechanism—offers a potential screening tool through controlled carbohydrate challenge tests. This 2013 study compared blood glucose and insulin responses in seven clinically normal ponies against five with prior laminitis episodes when fed glucose, fructose, or inulin supplements (1 g/kg daily for 3 days), alongside a no-supplement control, across both spring and autumn after dietary adaptation periods. Previously laminitic ponies demonstrated significantly elevated peak insulin concentrations and greater insulin area-under-the-curve (AUC) values after glucose and fructose feeding, with the most pronounced differences appearing 2–4 hours post-feeding and particularly marked when ponies were adapted to autumn pasture; notably, baseline glucose and insulin concentrations alone did not reliably distinguish the groups. The authors propose that measuring peak insulin at 2 hours following a single 1 g/kg glucose dose represents a practical diagnostic approach for identifying laminitis-prone individuals, though the seasonal and dietary-dependent nature of these responses suggests practitioners should consider timing of testing and recent nutritional management when interpreting results.
Read the full abstract on PubMed
Practical Takeaways
- •Measuring peak insulin concentration 2 hours after a standard glucose challenge (1 g/kg) could help identify ponies at risk of laminitis before they show clinical signs—particularly valuable for spring/fall risk assessment
- •Ponies on fall pasture show more variable and elevated insulin responses; additional monitoring and dietary management during this season may be warranted for laminitis-prone individuals
- •Fructose and inulin supplementation cause minimal glycemic and insulinemic responses compared to glucose, making them potentially safer carbohydrate choices for insulin-resistant ponies
Key Findings
- •Previously laminitic ponies (PLP) showed significantly greater peak insulin concentrations 2 hours after glucose feeding (P = 0.016) compared to normal ponies
- •Insulin area under the curve was greater in PLP than normal ponies after glucose and fructose feeding (P = 0.017), but glucose AUC showed no significant differences
- •Peak glucose and insulin concentrations occurred 2-4 hours after water-soluble carbohydrate feeding, with greater variability in fall pasture-adapted ponies
- •A single glucose dose (1 g/kg) with peak insulin measurement at 2 hours may serve as a practical screening method to identify laminitis-prone ponies before clinical disease onset