Plasma Activin A concentrations are not a useful biomarker for detecting insulin dysregulation and predicting laminitis risk in ponies.
Authors: McGuire C J, Knowles E J, Harris P A, Menzies-Gow N J
Journal: Journal of equine veterinary science
Summary
# Editorial Summary Insulin dysregulation is a key risk factor for laminitis in ponies, and practitioners currently rely on dynamic testing (such as oral sugar tolerance tests) to identify at-risk individuals; however, researchers at the Royal Veterinary College sought to evaluate whether resting plasma activin A could serve as a simpler, non-dynamic biomarker for ID and laminitis susceptibility. The team measured basal activin A concentrations alongside fasting insulin, post-oral sugar test insulin responses (at 60 and 120 minutes), and HOMA-IR scores in a cohort of ponies, then examined correlations between these variables to assess activin A's predictive utility. Despite previous suggestions of a relationship between activin A and post-prandial insulin response, this study found no significant correlation between resting activin A and any insulin dysregulation parameter—meaning activin A failed as a standalone biomarker for identifying ponies at increased laminitis risk. For practitioners, this finding underscores that there remains no practical shortcut to replace formal dynamic insulin testing when assessing laminitis risk, and relying solely on activin A measurements would miss cases of ID that warrant dietary or pharmacological intervention.
Read the full abstract on PubMed
Practical Takeaways
- •Activin A should not be relied upon as a screening tool for laminitis risk in pony populations—continue using established insulin testing protocols
- •Basal serum activin A testing does not add clinical value to existing metabolic assessments for laminitis prevention
- •Focus on traditional oral sugar tolerance testing and fasting insulin levels as evidence-based methods for identifying at-risk ponies
Key Findings
- •Basal serum activin A concentration was not a useful biomarker for detecting insulin dysregulation in ponies
- •Activin A did not reliably predict laminitis risk despite previous correlations with post-oral sugar test insulin concentrations
- •Circulating insulin concentrations remain the preferred marker for quantifying laminitis risk in non-laminitic ponies