Diabetes: Insulin Resistance and DKA Flashcards
What is insulin resistance generally defined as?
> 1.5 - 2.0 U/kg in dog
or
3 U/cat
disproportionately needs more insulin than it should
Insulin Resistance, some thing else is going on
▫Bacterial infections* (periodontal disease, UTI)
▫Major organ failure (heart, liver, kidney)
▫Pancreatitis
▫Concurrent endocrinopathies* (hyperadrenocorticism, acromegaly,
hyperthyroidism, hypothyroidism)
*more steady state and chronic
Main Suspects for Insulin Resistance
- Result of too much insulin
- Response to either hypoglycemia
(BG < 60 mg/dl) or too rapid a decline in BG - Secretion of counter-regulatory stress hormones
- Can results in an overall increase of BG with
worsening of Pu/Pd and increased fructosamine
Insulin-induced hyperglycemia/
Somogyi Phenomenon
- Pituitary adenoma
- Excessive GH secretion
→Insulin resistance
→IGF-1 →Bony and soft tissue overgrowth
(HCM, kidneys, liver, endocrine glands, DJD, Spondylosis and more…) - Signs develop slowly
Acromegaly (Hypersomatotropism)
abnormal growth of the hands, feet, and face, caused by overproduction of growth hormone by the pituitary gland
acromegaly
- CATS: always diabetics
- DM often appears first
- The “typical” physical manifestations are often NOT present or obvious
- Weight loss is NOT a feature despite uncontrolled DM
Acromegaly
- ↑Insulin-like Growth Factor-1 (IGF-1)
- Good screening test in a cat that is difficult to regulate when other differentials have been ruled out
- Confirm diagnosis with brain imaging
Acromegaly: Diagnosis
Treatment for Acromegaly
- Radiation therapy
- manage with insulin
- Clinical signs overlap
▫Pu/Pd/PP, distended abdomen, abnormal hair coat - CBC/Chem/UA overlap
▫↑liver enzymes, Chol, TG, dilute urine
Diabetes and Cushing’s disease
- In a diagnosed HAC, concurrent DM is easy to confirm (↑BG, glycosuria and ↑fructosamine)
- In diabetics, concurrent HAC is very difficult to confirm: DM causes chronic stress
▫DM (especially uncontrolled) will cause false positive results on screening tests for HAC
▫Adrenal glands are normal in size in DM but they are not always enlarged in HAC - Diabetics can and should be controlled (albeit insulin resistance) prior to testing for HAC
Diabetes and Cushing’s disease
Could look like Cushing’s because?
The diabetes is causing stress
is a serious complication of diabetes mellitus
▫10% mortality in human medicine!
Diabetic ketoacidosis (DKA)
are derived from oxidation of fatty
acids by the liver and are used as an energy source
during periods of glucose deficiency (the good)
Ketone bodies
Fatty acids in the Liver can be:
- Incorporated into triglycerides
- Metabolized into CO2 and water
- Converted to ketone bodies
(the good)
ketone bodies
acetoacetate, β-
hydroxybutyrate, and acetone
Excessive production of _____________, as occurs in uncontrolled diabetes, results in their accumulation in the circulation
ketone bodies
(the bad)
are substrates for
energy metabolism when needed
Ketone Bodies
(the bad)
- Ketones are weak acids (unmeasured anions) and drive an acid base shift
- High anion gap metabolic acidosis causes sickness
Ketosis (ketonemia, ketonuria)
- acid accumulation (ketones), decreased HCO3, and increased Anion Gap
Metabolic Acidosis
is a powerful inhibitor of lipolysis and fatty acid oxidation
Insulin
Relative or absolute deficiency of insulin “allows” ____________ to increase, thus increasing the availability of fatty acids to the liver and in turn promoting ketogenesis
lipolysis
Why did my patient develop DKA?
- untreated diabetic without insulin
- untreated diabetic without insulin and a source of insulin resistance
- treated diabetic without enough insulin due to a source of insulin resistance
- Severe acidosis
- Hyperosmolality
- Increased osmotic diuresis
- Dehydration
- Electrolyte derangements (K, P, Ca, Na)
Consequences of DKA