Establishing Reference Values for Serum Neutrophil Gelatinase-Associated Lipocalin (NGAL) in Turkmen Horses: Effects of Gender, Age, Pregnancy and Physical Activity.

Overview

• This study established reference values for serum Neutrophil Gelatinase-Associated Lipocalin (NGAL) concentrations in healthy Turkmen horses and examined how factors like age, gender, pregnancy, and physical activity influence NGAL levels.

Background

• NGAL is a glycoprotein involved in immune responses and inflammation.
• It has diagnostic importance particularly in acute kidney injury (AKI) and systemic diseases in various species.
• Reference values for NGAL in horses, especially the Turkmen breed, were previously lacking.

Objective

• The study aimed to define baseline serum NGAL concentrations in clinically healthy Turkmen horses.
• It also sought to analyze the impact of physiological factors—age, sex, pregnancy, and physical activity—on serum NGAL levels.
• Correlation with hematological and biochemical parameters was also explored.

Methods

• Sample: 90 clinically healthy Turkmen horses were selected.
• Grouping: Horses were categorized by:
  • Age groups: under 2 years, 2 to 8 years, and over 8 years.
  • Sex: males, females, and castrated males.
  • Pregnancy status in females.
  • Physical activity levels (although exact categories for activity were not specified).
• NGAL Measurement: Serum NGAL concentrations were measured using an enzyme-linked immunosorbent assay (ELISA), a sensitive lab technique for protein quantification.
• Statistical Analysis: Associations between NGAL and physiological factors were assessed; significance was evaluated, presumably with standard statistical tests.

Results

• Reference Values:
  • Median serum NGAL concentration: 0.9 ng/mL.
  • 2.5th percentile: 0.38 ng/mL.
  • 97.5th percentile: 2.55 ng/mL.
• Effect of Age:
  • No statistically significant differences overall between age groups.
  • However, horses younger than 2 years showed the highest median NGAL (1.04 ng/mL), suggesting a trend but not significant.
• Effect of Sex:
  • No significant differences in NGAL levels between males, females, or castrated horses.
• Pregnancy and Physical Activity:
  • Both pregnancy and physical activity were associated with slight increases in NGAL levels.
  • These increases were not statistically significant (p > 0.05), indicating that the differences could be due to chance.
• Correlation:
  • The paper mentions examining biochemical and hematological parameters, but no significant or specific correlations are reported in the abstract.

Conclusions and Implications

• This study is the first to establish serum NGAL reference intervals specifically for healthy Turkmen horses.
• Although physiological factors like pregnancy and activity show some trends in NGAL levels, these were not statistically significant in this sample, suggesting NGAL is relatively stable across these variables in healthy horses.
• NGAL may have diagnostic value in monitoring equine health, particularly in detecting renal injuries or systemic inflammatory conditions.
• Further studies are needed to:
  • Clarify NGAL’s role in equine kidney function and systemic diseases.
  • Test NGAL in combination with other biomarkers for early detection of inflammation and kidney injury in horses.
  • Explore if larger samples or different conditions reveal clearer influences of physiological factors on NGAL.