Neuroendocrine and non-neuroendocrine markers of inflammation associated with performance in endurance horses.

This research studied the relationship between inflammation, neuroendocrine response, and performance in endurance horses. The study concluded that pre-competition levels of oxidative stress, cytokines, and anti-inflammatory neuroendocrine hormones could predict the performance of horses in endurance events.

Objective and Hypotheses:

• The main goal of the study was to understand how endurance exercise influences inflammation and neuroendocrine response in horses, and how these factors connect to performance.
• The hypothesis was that evidence of systemic inflammation is associated with poor performance in horses competing in endurance events.

Research Methodology:

• Blood samples were collected from horses both before they started and at the finish or elimination point of the 80km and 160km races during the 2006 American Endurance Ride National Championship competitions.
• Two indicators were measured in the blood samples – the α-MSH (an anti-inflammatory neuroendocrine hormone) and TNF-α (a pro-inflammatory cytokine).
• In addition, the level of total Oxidative Stress (measured by TBARS – a generic marker of cell damage caused by reactive oxygen species) was also assessed.

Results and Analysis:

• In the 80 km group, TBARS significantly increased post endurance exercise but not in the 160 km group.
• Changes in the levels of TNF-α and α-MSH as a result of exercise were not significant in either group.
• Pre-competition TBARS levels were significantly higher in horses that failed to complete the 80 km race.
• Pre-competition α-MSH levels were also found to be significantly lower in nonfinishers in the 160 km group.
• There was a positive correlation between competition speed and precompetition α-MSH in the 80km race and a negative correlation with precompetition TNF-α when distances were combined.

Conclusions:

• From these results, it appears that baseline measures of oxidative stress, circulating cytokines and anti-inflammatory neuroendocrine hormones can provide insight into a horse’s endurance performance.
• This suggests that these biomarkers might be predictive of athletic performance in endurance horses, opening avenues for future research investigating the effects of training on these markers.