Serum insulin-like growth factor 1 in the aging horse.

This research article is a study on the levels of insulin-like growth factor 1 (IGF-1) in horses as they age, with evidence showing that aging does not significantly affect IGF-1 levels in horses from early to late adulthood.

Objective and Background

• The primary goal of the study is to determine if and how serum insulin-like growth factor 1 (IGF-1) levels in horses change as they age. The purpose of the study was driven by the fundamental role IGF-1 plays in the anabolic processes in the musculoskeletal system of mammals and its reported decrease with age in humans and horses.

Methodology

• In the cross-sectional study, 72 healthy horses were observed. For the longitudinal study, 37 paired serum samples were evaluated. The ages of the horses ranged from 5 to 27 years.
• The researchers measured the levels of serum IGF-1 protein using an ELISA kit designed specifically for use in equine samples.

Results

• There was no association found between the levels of serum IGF-1 and the age of the horses in the initial cross-sectional study.
• In the longitudinal study and after applying a latent variable model to the data, it was discovered that the serum IGF-1 levels showed an average increase of 5.2% over a five-year period. However, for horses that crossed the change point of approximately 9 years of age between the two samples, there was an 11.0% decrease in serum IGF-1 levels.

Conclusion

• Contrary to previous reports in humans and horses, this study did not find substantial evidence that age affects the levels of IGF-1 in horses from early to late adulthood. The study implied that other factors, apart from aging, may be responsible for changes in IGF-1 levels, though these factors were not identified or investigated in the current study.