08: Insulin Resistance

Things to consider if CS of diabetes persist despite treatment

• Right insulin? Dose? Frequency?

• Handling problems

• Insulin resistance

Insulin resistance

Insufficient or inconsistent control despite a normal amount of insulin

Loose, general rule for when we might consider insulin resistance

>1.5 IU/kg BID

Common causes of insulin resistance

• Obesity

• Inflammation

• Endocrinopathies

• Hyperlipidemia

• Misc disease

How does inflammation cause insulin resistance

Inflammatory cytokines antagonize insulin and stimulates glucagon release

Most common inflammatory comorbidity that leads to DKA

Pancreatitis

Hormone excess/deficiency that can cause insulin resistance

Basically all of them

Misc diseases that cause insulin resistance

• CKD

• Liver disease

• Cardiac disease

• Hyperlipidemia

Key components of diagnosing insulin resistance

Good history and thorough physical exam

What concurrent medication could be contributing to insulin resistance

Steroids via any route

Test we might run when hunting for the cause of insulin resistance even if there are no CS

Urine culture & sensitivity

CS of pancreatitis in cats

• Hiding

• Anorexia

• ± Vomiting

• ± Abdominal pain

Endocrinopathy associated with insulin resistance (more in dogs) that causes fragile skin syndrome in cats

Hyperadrenocorticism → high cortisol

T/F: all cats with acromegaly will have the distinctive large face, paws, etc.

False, not all cats have the phenotype changes

Cause of acromegaly

Small, functional pituitary tumor that produces GH

How do we test for acromegaly

Measure IGF-1, which is produced from the liver in response to GH

How long does it take IGF-1 to rise in the face of acromegaly

2 months → you may need to recheck if you happen to catch it in the early stages!

Diagnostic that confirms acromegaly

MRI of the brain

When might it actually be beneficial to run an MRI to confirm acromegaly

If the owner is considering radiation treatment

Secondary treatment option for acromegaly-induced insulin resistance

Cabergoline to improve diabetic control

Tertiary treatment option for acromegaly-induced insulin resistance

Massive dose of insulin

Common causes of secondary hyperlipidemia

• PLN

• Pancreatitis

• Endocrinopathies

• Obesity

Primary hyperlipidemia

Genetic elevation in blood lipids likely due to a deficiency in hormone sensitive lipases

Breed predisposition for hyperlipidemia

Mini schnauzer

Ideal diagnostic for primary hyperlipidemia

Check triglycerides after fasting for 12 hours

T/F: low fat diet works well for management of primary hyperlipidemia

Not really

Best treatment for primary hyperlipidemia

Bezafibrate or fenofibrate

T/F: cancer can cause insulin resistance

You betcha

Considerations for insulin resistance treatment

• Treat underlying disease

• Dietary management for obese patients

• Spay if intact

• Dental care for periodontal disease

What might you consider if your hunt for a cause of insulin resistance reveals nothing

Try changing to a different vial or type of insulin- could be it is a bad vial, could be anti-insulin antibodies