Diabetes Mellitus

Question 1

Name the 4 cells that compose the Islets of Langerhans

Answer 1

alpha
beta
delta
F

Question 2

alpha cells produce

Answer 2

glucagon

Question 3

What does glucagon do?

Answer 3

makes a higher serum glucose level

Question 4

what do beta cells produce?

Answer 4

insulin

amylin

Question 5

What does insulin do?

Answer 5

lowers serum glucose level buy letting glucose be absorbed by tissues

Question 6

What do delta cells produce?

Answer 6

somatostatin

Question 7

What does somatastatin do?

Answer 7

results in extension in the period of time nutrietns are available in the GI tract for digestion and assimilation

Question 8

What do F cells produce?

Answer 8

pancreatic polypeptide

Question 9

Define diabetes mellitus

Answer 9

a condition characterized by a relative or absolute insulin deficiency

Question 10

2 general ways diabetes can occur

Answer 10

• beta cell destruction/dysfunction

- decreased response of the target tissue to circulating insulin

Question 11

What can cause beta cell destruction/dysfunction?

Answer 11

• genetic factors
• immune mediated destruction of islet cells (dog)
• pancreatic induced destruction of islet cells (dog)
• amyloid depsostion displacing or effacing islet cells (cat)

Question 12

What can cause decreased response of the target tissue to circulating insulin?

Answer 12

• presence of insulin antagonizing hormones
• poor absorption of insulin
• improper handling or administration of insulin, use of expired insulin, improper dosage/frequency

Question 13

What does insulin to do help maintain glucose homeostsis?

Answer 13

facilitates the entry of glucose into the cells

Question 14

Why is glucose important to the body?

Answer 14

only source of energy for the CNS under normal conditions; CNS must get a constant supply of glucose from systemic circulation

Question 15

Dow does insulin deficiency effect glucose homeostasis?

Answer 15

glucose can’t enter the cells to be metabolized for energy production, meaning glucose stays in the blood creating hyperglycemia

Question 16

List clinical signs of Diabetes

Answer 16

glucosuria
polyuria
polydipsia
decreased weight 
polyphagia

Question 17

How does hyperglycemia result in glucosuria

Answer 17

BG concentration rises enough to exceed the renal threshold, resulting in a spill over of excess glucose into the urine

Question 18

How does hyperglycemia result in polyuria

Answer 18

excess glucose in urine changes the osmotic pressure of urine, stimulating the kidneys to excrete more water

Question 19

How does hyperglycemia result in polydipsia

Answer 19

loss of excess water signals CNS that increased water intake is needed to maintain normal hydration status

Question 20

How does hyperglycemia result in decreased weight

Answer 20

the excessive amount of glucose in circulation and therefore lack of glucose in tissues makes the body believe that there is an energy deficiency; body attempts to utilize any energy stores it has left resulting in muscle wasting and weight loss

Question 21

How does hyperglycemia result in polyphagia

Answer 21

insulin also mediates movement of glucose into cells of hypothalamus in the region of the satiety center; lack of glucose means there is no inhibition of the satiety center so the patient is hungry

Question 22

Describe how diabetes mellitus is classified in vet med

Answer 22

Insulin dependent- insulin can be given to manage the Dz

Non insulin dependent- usually seen in obese cats as result of the inability of the target tissues to recognize and react with insulin resulting in hyperglycemia; other Tx such as weight loss, dietary management, and hypoglycemic meds may be needed instead

Question 23

Other than IDDM and NIDDM, be able to describe 2 other types of diabetes mellitus that may occur in vet med

Answer 23

a. Transient Diabetes Mellitus
i. Primarily in cats that have subclinical diabetes where destruction of beta cells is gradual and some functional beta cells remain; once the event that pushed the pancreas beyond its ability to produce insulin resolve and the CS are treated with insulin, cat may no longer need insulin
ii. May eventually become permanently diabetic in the future
b. Secondary Diabetes Mellitus
i. Usually occurs with increased progesterone levels, administration of megestrol acetate, or presence of increased cortisol levels (hyperadrenocorticism, corticosteroid meds)
ii. Resolves with resolution or removal of whatever is causing the insulin antagonism

Question 24

What might a PE look like on a diabetic patient?

Answer 24

• Minimal to no changes on PE
• Possibly weight loss and muscle wasting
• Unkempt haircoat
• Other abnormalities dependent on presence or absence of any concurrent disease

Question 25

2 lab alterations that are necessary to document the presence of diabetes mellitus

Answer 25

persistent hyperglycemia with concurrent glucosuria

Question 26

List several other alterations that may occur in the serum biochem with diabetes mellitus

Answer 26

- CBS usually normal - Serum biochem panel - Hyperglycemia - Increased hepatic enzymes (result of fat deposition in liver which is common in diabetes or a result of pancreatitis) - Hyperlipidemia - Hypercholesterolemia - UA - Glucosuria

Question 27

The common therapeutic goal for either IDDM or NIDDM

Answer 27

eliminate CS of polyuria, polydipsia, polyphagia

Question 28

Describe the therapeutic approach to IDDM

Answer 28

- Insulin therapy is mandatory | - Dietary management is highly suggested

Question 29

Describe the therapeutic approach to NIDDM

Answer 29

- Dietary management - Weight loss and exercise --> reversing any obesity-induced insulin antagonism - Oral hypoglycemic meds --> directed at increasing insulin secretions from whatever beta cells may still be function or at facilitating glucose entry into the target cells; overall goal of this med is to decrease the serum glucose concentration into normal range

Question 30

How should insulin be stored?

Answer 30

refrigerate | gently rock or roll bottle to redistribute insulin molecules into soln before giving

Question 31

Serial Blood Glucose Curve - what it is - uses - when to do

Answer 31

- serum BG measured immediately prior to admin of insulin and continuing measurements of serum BG every 2hrs for 8 to 24hrs - used to determine changes for... dose, duration of admin, type of insulin - done every 3-4 months or if P demo continuing or worsening CS`

Question 32

Fructosamine - what it tells you - uses

Answer 32

- picture of where serum BG levels have been over past week | - not adequate for determining proper adjustments in insulin dose or type of insulin

Question 33

Fructosamine vs glycosylated hemoglobin

Answer 33

glycosylated hemoglobin gives you past month

Question 34

Urine dipstick monitoring

Answer 34

- beneficial in diagnosis but not a helpful monitoring tool b/c presence of glucosuria may vary throughout day depending on feeding schedule - O may try and change insulin dose

Question 35

Common diseases diabetic animals make be prone to ot develop

Answer 35

``` UTIs cataract formation diabetic polyneuropathy diabetic ketoacidosis insulin-induced hypoglycemia (Somogyi phenomenon) ```

Question 36

Why do UTIs occur in diabetic pets?

Answer 36

-Secondary to persistence of glucosuria -Diabetic immune system is not completely normal. -Add that with an excess of glucose in the urine that provides energy for bacteria, and you get a UTI May no show any CS of UTI

Question 37

Why do cataracts form? Dog or cat?

Answer 37

Dog - Form as result of excessive glucose diffusing to the lens that results in formation of sorbitol and fructose which can't diffuse out of the lens and instead attract water - Results in swelling of fibers of lens and cataract formation

Question 38

What is diabetic polyneuropathy?

Answer 38

- Rare - Cats with dropped hock stance - Cause unknown - Reversible with proper Tx

Question 39

What is diabetic ketoacidosis?

Answer 39

Occurs as result of insufficient insulin availability, persistent hyperglycemia, and subsequent production of ketone bodies that have detrimental effects on many organ systems

Question 40

Describe what happens with insulin induced hypoglycemia

Answer 40

- When excessive insulin is given, a massive entry of glucose into cells results in significant decrease in circulating serum glucose - This puts pet into hypoglycemic state, so glucogenic hormones start increasing the serum glucose concentration which results in a surge in serum glucose concentration - There is no endogenous insulin present, so rising serum glucose concentration cannot be dampened and serum glucose levels can become significantly high