Somatotropic axis resistance and ghrelin in critically ill foals.

The research investigates the correlation between somatotropic axis resistance and ghrelin levels in critically ill foals. It indicates that increases in ghrelin and growth hormone, and decreases in insulin-like growth factor-1 (IGF-1), are connected to the severity of the disease and foal mortality, suggesting that somatotropic axis resistance plays a significant role in foal survival during sepsis.

Research Methodology

• The research was conducted as a prospective multicentre cross-sectional study.
• Blood samples were collected from three groups of foals: septic (44 in total), sick nonseptic (SNS – 62 in total) and healthy (19 in total), all less than 7 days old.
• The classification of foals as septic or SNS was based on positive blood cultures or sepsis scores. Those with sepsis scores of 12 or above were considered septic and those with scores between 5-11 were classified as SNS.
• Data was analysed through nonparametric methods and multivariate logistic regression to identify patterns and connections.

Research Findings

• The study found that septic foals displayed higher levels of ghrelin, growth hormone and triglycerides and lower concentrations of IGF-1 and glucose than healthy foals.
• Similarly, SNS foals had increased levels of growth hormone and triglycerides and decreased concentrations of IGF-1 compared to healthy ones.
• The ratio of growth hormone to IGF-1 was found to be higher in both septic and SNS foals than in healthy ones, marking an indication of somatotropic axis resistance.
• Interestingly, while hormone concentrations did not differ between septic foals that survived and those that did not, the growth hormone to IGF-1 ratio was lower in the non-survivors, suggesting this ratio could be tied to survival.

Conclusions

• The prevalence of somatotropic axis resistance, as evidenced by a high growth hormone to IGF-1 ratio, was common in ill foals, and was associated with energy status (hypoglycaemia, hypertriglyceridaemia) and mortality in septic foals.
• The research concludes that the functional somatotropic axis is important for foal survival during sepsis. Somatotropic resistance is likely to contribute to the severity of disease, onset of a catabolic state and the likelihood of recovery.