Week 6- Endocrine Pancreatic Disorders Flashcards
What is the pathophysiology of Diabetes Mellitus?
in dogs
An absolute deficiency in insulin → require lifelong treatment with exogenous insulin
* Similar to type 1 DM in humans
Histology:
* ↓↓ size + number of pancreatic islets
* ↓↓ number of β-cells within islets
* β-cell vacuolation, enlargement, degeneration
What is the pathophysiology of Diabetes Mellitus?
in cats
Usually a relative insulin deficiency
* Insulin resistance combined with β-cell dysfunction
* Prolonged hyperglycaemia → glucotoxicity to β-cells → can cause permanent β-cell dysfunction
* Similar to type II DM in people
Pancreatic β-cells retain some insulin-secreting capacity until prolonged glucotoxicity + islet amyloid
deposition results in permanent loss
What are the main consequences of Diabetes Mellitus?
Glucose unable to enter cells, so tissues cannot use it
* “Starvation” state
* Accelerated glycogen breakdown and gluconeogenesis in the liver
* Accumulation of glucose in the circulation → hyperglycaemia and glycosuria
* Protein metabolism shifts to proteolysis → free amino acids to use for gluconeogenesis
* Lipid catabolism, mobilised triglycerides → increased free fatty acids → undergo beta
oxidation in liver to make energy → ketones
What does the biochemistry look like in Diabetes Mellitus?
Fasting hyperglycaemia (fluoride tube if external lab) >12-15mmol/L
* Rule out stress hyperglycaemia – home urine dipstick/BG testing
* ↑↑ ALT, ALKP
* ↑↑ cholesterol, triglycerides
What does the urinalysis look like in diabetes mellitus?
glycosuria, UTI, ketones
* Renal threshold: 10-11mmol/L in dogs, 15mmol/L in cats
* Other causes: stress, primary renal glycosuria, Fanconi, spurious
How would you treat diabetes mellitus with insulin?
- initiate treatment + diet
if ketotic/ acidotic -> hospitalise for IV management
What are the benefits of continuous glucose monitoring?
- Easy to place
- Can last for 10-14 days
- Owner can view themselves
What are the risks of continuous glucose monitoring?
- Erroneous readings/ sensor malfunction
- Skin irritation
Effect on the owner - Lag?
What is the definition of diabetic remission?
euglycaemia with no insulin therapy for over 4 weeks
How do I acheive remission?
- Tight glycaemic control
- Reduced carbohydrate load
- Resolution of insulin resistance
What is the function of SGLT-2 Inhibitors?
BG levels down → reduced glucotoxicity to pancreatic
β-cells → recover insulin-secreting function
What are the concerns with using SGLT-2 inhibitors?
Insulin needed to inhibit lipolysis and ketogenesis
o Cats with DM – insulin resistance, but may also
have complete lack of insulin (i.e. β-cells nonfunctional)
o Diagnostic challenge – check ketones regularly
especially in first 14d (7% of cats develop eDKA
in one study, most within first 14d)
How might you diagnose diabetic ketoacidosis?
Blood ketone meter (measures BHB) or urine dipsticks
* Blood gas analysis
* Look for comorbid factors e.g. pancreatitis, UTI
How might you treat diabetic ketoacidosis?
IVFT + KCl supplementation, IV or IM insulin +
IV glucose, analgesia, supportive Tx
How might you monitor diabetic ketoacidosis?
Hourly glucose checks – Freestyle useful
* K+ at least BID until consistently normal
* CARE hypophosphataemia
What is Hypersomatotropism?
chronic, excessive production of growth hormone (GH)
by a functional pituitary tumour
What is acromegaly?
the syndrome (phenotypic changes) resulting from hypersomatotropism
What are the features of acromegaly?
Excessive soft tissue + bone growth = broad facial features, protruding jaw,
snorting/stertor
* Uncontrolled DM + weight gain
* Hypertrophic cardiomyopathy
How might you diagnose acromegaly?
measure IGF-1 (induced by GH; GH assays not available) + advanced imaging
for pituitary mass
How might you treat acromegaly?
Hypophysectomy (58/68 survival to discharge, 41/58 diabetic remission); PO
levothyroxine and hydrocortisone long term
What is an insulinoma?
Neoplasm of pancreatic beta cells
