PPID diagnositc testing Flashcards
What is EMS (equine metabolic syndrome)
Insulin resistance develops due to obesity => hyperglycaemia => laminitis
What are the diagnostic tests for PPID?
Basal ACTH
TRH stim test
What are the diagnostic tests for EMS?
basal insulin/glucose measurement
Oral glucose challenge test
Combined glucose and insulin test
Fill in the table for how to calculate each value
How is basal plasma ACTH conc used to diagnose PPID?
Chilled EDTA blood sample
PPID = high plasma ACTH
How is a TRH stim test used to diagnose PPID?
measures ACTH (not cortisol)
post TRH stim ACTH value >100pg/ml
What are the 3 stages of insulin resistance?
Describe how EMS causes laminitis
Hyperinsulinaemia
Endothelial cell dysfunction
Digital vasoconstriction
Impaired glucose uptake from epidermal laminar cells
Altered epidermal cell function or mitosis
Matrix metalloproteinase activated
Pro-inflammatory state in lamellar tissue
Describe resting insulin and glucose measurement in EMS diagnosis
High resting insulin suggests insulin resistance
Low insulin + high glucose = T2 diabetes
Affected by many factors e.g., stress, season
Little sensitivity and specificity
Describe the oral glucose challenge test in EMS diagnosis
Fasted overnight
Given oral glucose powder
Insulin measured at 2hrs
High insulin indicative of insulin resistance
Describe combined glucose-insulin testing for EMS diagnosis
Glucose and insulin given via IV
Normal =
- insulin <100 IU/ml at 45 mins
- Glucose below baseline within 30-45 mins
