Plasma leptin, ghrelin and adiponectin concentrations in young fit racehorses versus mature unfit standardbreds.
Authors: Gordon Mary E, McKeever Kenneth H, Betros Cynthia L, Manso Filho Helio C
Journal: Veterinary journal (London, England : 1997)
Summary
# Editorial Summary Metabolic hormones that regulate appetite and energy expenditure show distinct patterns in horses of different fitness levels and body compositions, yet their specific relationships remain poorly characterised in equine populations. Gordon and colleagues compared plasma concentrations of leptin, ghrelin, adiponectin, insulin, cortisol and glucose in 34 fit young racehorses (mean age 4 years, 475 kg) versus 12 unfit mature Standardbreds (mean age 11 years, 521 kg), measuring these alongside body condition score and rump fat thickness. Fit horses displayed substantially lower leptin (1.0 versus 4.4 ng/mL), markedly higher ghrelin (54 versus 33 pg/mL) and greater adiponectin concentrations (1820 versus 1333 ng/mL) compared with unfit animals, with leptin showing a strong positive correlation to body fat percentage (r = +0.72) whilst adiponectin showed negative correlation (r = –0.40); importantly, glucose, insulin and cortisol remained unchanged between groups. For practitioners, these findings suggest that leptin and adiponectin may serve as objective markers of metabolic health and fat deposition in racehorses, potentially useful in monitoring conditioning programmes and identifying metabolic dysfunction independent of visual body condition scoring, though the practical application of these biomarkers in routine practice remains to be established.
Read the full abstract on PubMed
Practical Takeaways
- •Hormonal profiles (particularly leptin, ghrelin, and adiponectin) differ substantially between fit and unfit horses and may help assess metabolic health status independent of traditional measures like BCS alone
- •Leptin concentrations appear to be a reliable biomarker for body fat percentage in horses, potentially useful for monitoring weight loss or fitness conditioning programs
- •Fitness conditioning and body composition changes correlate with significant metabolic shifts that may influence appetite regulation and energy partitioning in performance horses
Key Findings
- •Fit horses had significantly higher plasma ghrelin (54 vs 33 pg/mL) and adiponectin (1820 vs 1333 ng/mL) concentrations compared to unfit horses
- •Fit horses had substantially lower plasma leptin concentrations (1.0 vs 4.4 ng/mL, P<0.001) despite lower body condition scores and percent fat
- •Plasma leptin showed strong positive correlation with percent body fat (+0.72), while adiponectin showed negative correlation (-0.40)
- •No significant differences in cortisol, insulin, or glucose between fit and unfit horses despite differences in body composition and fitness status