13 Diabetes Mellitus

Question 1

What does glucagon do to blood glucose

Answer 1

raises blood glucose

Question 2

What is diabetes characterized by

Answer 2

loss of insulin or decreased insulin responsiveness

*major disease in animals and people

Question 3

What are 3 metabolic characteristics of diabetes

Answer 3

Decrease glucose uptake
Increase protein catabolism
Increase lipolysis

Question 4

What are the 2 major forms of diabetes

Answer 4

Insulin dependent (IDDM)
Insulin independent (NIDDM)

Question 5

What are diabetes mellitus clinical signs

Answer 5

hyperglycemia, glycosuria
polydipsia, polyuria hyperphagia

in severe cases:
weight loss
cataracts in dogs
plantigrade posture in cats

vascular changes, microangiopathies

Question 6

What are some predisposing factors to diabetes

Answer 6

genetic factors
dogs: females > males
cats: neutered males slightly more common
pancreatitis
immune -mediated destruction (dogs?)
amyloidosis (cats)
obesity (decreased receptors > down-regulation)

Question 7

Why does PU/PD occur

Answer 7

Excess glucose spills into urine and osmotically drags water with it > polyuria, polydipsia, weight loss

Question 8

What is the more common diabetes in dogs

Answer 8

IDDM

Question 9

What is the more common diabetus in cats

Answer 9

NIDDM and IDDM

1/3 of cats are NIDDM

Question 10

What are the 4 risk factors for diabetes in the cat

Answer 10

Age, obesity, neutering, gender (male more common)

Question 11

What drugs can you give to cats instead of insulin

Answer 11

Drugs that increase insulin receptors or sensitivity of the receptors

Question 12

What does insulin do to blood glucose

Answer 12

Lowers blood glucose

• moves glucose intracellularly
• causes liver to store glycogen
• facilitates fat deposition in adipose tissue

Question 13

What is the result of decreased glucose uptake?

Answer 13

hyperglycemia (increased blood sugar) causes:
decreased glyconeogenesis
increased polyuria, polydipsia, polyphagia

Question 14

What is the result of increased protein catabolism?

Answer 14

increased plasma aa
increased weight loss > decrease in growth
increased negative nitrogen balance

Question 15

What is the result of increased lipolysis?

Answer 15

increased free fatty acids
ketosis
acidocis

Question 16

Insulin-dependent diabetes (IDDM)

Answer 16

Type I (often autoimmune)

• destruction or loss of function of pancreatic beta cells leads to low insulin levels
• animals often have relatively high glucagon and are prone to ketosis
• most severe form of the disease
• etiology is unclear but can involve genetics, pancreatitis, autoimmunity, obesity, and viral causes

Question 17

non-insulin-dependent diabetes (NIDDM)

Answer 17

Type II

• decreased number or responsiveness of insulin RECEPTORS
• less severe than IDDM
• can progress to IDDM
• results from insulin resistance secondary to obesity r other causes

Question 18

Diabetes-species differences

Answer 18

carnivores are relatively susceptible; herbivores less so
diabetes mellitus - most common endocrine malady
incidence varies with age, breed etc
major illness in both dogs and cats

Question 19

renal threshold

Answer 19

dogs: 180-220 mg/dl (more like humans)
cats: 240-300 mg/dl

cat has amazing capacity to absorb glucose from the kidney so just bc no glucose in urine does NOT mean there are no metabolic changes

Question 20

consequences of insulin deprivation on lipid & protein metabolism?

Answer 20

loss of calories > weight loss

compensatory effect > hyperphagia

Question 21

diabetic ketoacidosis

Answer 21

insulin deficiency + dehydration + stress →
mobilization of fat →
ketone body formation →
ketone accumulation in blood →
acidosis, dehydration, hypotension, depression

glucose and ketones spill over into urine →
worsens dehydration

Question 22

diabetes mellitus diagnostics

Answer 22

baseline glucose values
 - street hyperglycemia in cats
 - postprandial (after a meal) hyperglycemia  
urinalysis
 - glucose present in urine (glucosuria)

Question 23

diabetes in the dog

Answer 23

IDDM much more common
disease of older dogs (7-9yrs)
treatment: insulin

Question 24

diabetes in the cat

Answer 24

NIDDM and IDDM
1/3 of cats are NIDDM
treatment: insulin and/or drugs
cat very different than dog

Question 25

transient diabetes

Answer 25

reversible suppression of the pancreatic β-cells
waxing and waning of clinical signs
may progress to permanent diabetes

20% of cats will stop being diabetic all on their own
dogs can show transient diabetes during pregnancy or progesterone treatment

Question 26

Who purified insulin?

Answer 26

1921 xmas day
Banting > nobel prize
Best