Abstract: Background: Leptin is an adipokine released from adipose tissue. There are inconsistent reports of associations between increased leptin concentrations with obesity and laminitis status in ponies.
Hypothesis/Objectives: Increased plasma leptin concentrations will be associated with obesity and laminitis in ponies.
Animals: Cross-sectional study of 211 Shetland and Welsh ponies sampled in Australia and the USA in autumn and/or spring.
Methods: Obesity was defined as a modified-Henneke body condition score > 6/9. Laminitis was defined as a modified-Obel score > 1/12. Plasma leptin concentrations were measured in all ponies by radioimmunoassay at Cornell University. Descriptive and interferential statistics were performed, with significance accepted at p < 0.05.
Results: Australian Welsh ponies had lower spring plasma leptin concentrations than American Welsh ponies (p = 0.0006). Compared to spring values, American Welsh ponies had lower autumnal plasma leptin concentrations (p = 0.01) while Australian Shetlands had higher autumnal plasma leptin concentrations (p = 0.004). Australian Welsh ponies had lower plasma leptin concentrations than Australian Shetlands in autumn (p = 0.009). Obese ponies (n = 122) had higher plasma leptin concentrations than non-obese ponies (n = 136, p < 0.0001). No difference in plasma leptin concentrations between laminitic (n = 50) and non-laminitic ponies (n = 120) were detected (p = 0.73).
Conclusions and clinical importance: Plasma leptin concentration is associated with obesity in ponies but varied with country, season, and breed, warranting careful interpretation of results. The clinical utility of measuring plasma leptin concentration in the diagnosis of laminitis remains to be determined.
.jpg "Brianna L. Clark, BVSc MANZCVS photo")
