Diagnostic utility and validity of 1,2-o-dilauryl-rac-glycero-3-glutaric acid-(6′-methylresorufin) ester (DGGR) lipase activity in horses with colic.

This research examines the usefulness and validity of the DGGR lipase assay, a test often used for detecting pancreatitis, in diagnosing gastrointestinal diseases in horses showing signs of colic. It found that higher activity of DGGR lipase was associated with more serious conditions and outcomes, including surgical treatment and non-survival, although its effectiveness as a diagnostic tool was limited due to its poor sensitivity and negative likelihood ratio.

Objectives of the study

• The study aimed to analyse the prevalence of increased DGGR-lipase activity in horses showing symptoms of colic, a common digestive issue in horses manifesting in severe abdominal discomfort.
• It also sought to understand any associations between DGGR-lipase activity and the underlying gastrointestinal diseases, the type of treatment required (whether surgical or non-surgical), and the outcome for the horse (whether they survived).

Methodology of the Study

• The study took place at a teaching hospital, where clinical data from 192 horses presented for colic was retrospectively analysed.
• DGGR-lipase activity was measured by collecting frozen plasma within 24 hours of the horses’ presentation.
• Difference and associations between the DGGR-lipase activity and the variables and outcomes were evaluated using non-parametric tests, Chi-squared and Fisher’s exact test which are statistical methods used to test the independence of two categorical variables.
• Measures of the validity of DGGR-lipase as a diagnostic test were also calculated in the study.

Results and Findings

• Increased DGGR-lipase activity above the reference limits was found in 30.2% of the horses with symptoms of colic, and was greater than twice the upper reference limit in 15.6% of the cases.
• The activity of DGGR-lipase was significantly higher in horses with large bowel displacement or torsion compared to those with large bowel impaction, and for gastric impaction, dilation or ulceration.
• DGGR-lipase activity over 2x the upper reference limit was linked significantly with surgical treatment, strangulating disease, and non-survival.
• However, the DGGR-lipase assay’s effectiveness as a diagnostic or screening tool for these outcomes was considered poor to fair, due to its poor sensitivity, poor negative likelihood ratio, and an area under the receiver operating characteristic curve.

Conclusions

• The study concludes that the DGGR lipase assay, while showing some correlation with the severity of conditions in horses showing symptoms of colic, is not a very effective diagnostic tool for these conditions due to its low reliability and sensitivity.
• The findings suggest that other diagnostic tools or methods may be more effective and reliable for diagnosing gastrointestinal diseases in horses with colic symptoms.