Intro Diabetes Mellitus

Question 1

At what concentration is glucose found in the urine?(glucose exceeds Tm)

Answer 1

At 200 mg/dl in the urine, bc all glucose transporters are used -> glucose gets excreted

Question 2

What pathophysiological conditions are promoted by glucose exceeding Tm?

Answer 2

Polyuria, Polydipsia (thirstiness), Polyphagia (sensation of hunger -> lots of calories lost through urine -> so hunger builts up)

Question 3

Characteristics of Type 1 - Diabetes

Answer 3

-IDDM (Insulin-dependent DM)
– Juvenile onset
– T-cell mediated autoimmune contribution to etiology
* May have a viral and genetic components

Question 4

Characteristics of Type 2 - Diabetes

Answer 4

-NIDDM (non-insulin-dependent DM)
-Adult onset (more common with
advancing age)
– Obesity-related (55%)
– Significant but diffuse genetic compone

Question 5

What is the main problem in DM type 1?

Answer 5

Absence of Insulin

Question 6

What is the main problem in DM type 2?

Answer 6

Insulin receptor insensitivity is the problem

->Treated with a variety of orally administered and injectable
drugs, including insulin

Question 7

How is high blood glucose regulated?

Answer 7

By insulin, produced by ß-cells of the pancreas and secreted into the blood

Question 8

How does insulin help to take up glucose into the cell?

Answer 8

The hormone Insulin causes glucose to be taken up into the skeletal muscle tissues, the liver, and fat tissues

Question 9

What happens to glucose in skeletal muscles?

Answer 9

Muscles: use as an energy source or convert into glycogen
Liver: converts glucose to glycogen, fats, and proteins

Question 10

What happens if the glucose level goes down?

Answer 10

Glucagon is secreted by alpha cells in the pancreas

Question 11

What is stimulated by Glucagon?

Answer 11

Liver: Gluconeogenesis: converts glycogen to glucose -> glucose secreted into the blood the get blood glucose level back to normal

Question 12

Which organs are not very sensitive to insulin?

Answer 12

Heart, brain, kidneys, spleen

Question 13

How does insulin regulate glucose uptake?

Answer 13

Insulin activates insulin receptors -> the second messenger mobilizes GLUT4 storage vesicles (GSV) on the inner surface -> they fuse on the membrane and form the Glucose transporter for glucose uptake

Question 14

What also stimulates GSV mobilization and glucose uptake in skeletal muscle? -> same effect as Insulin

Answer 14

Exercise and muscle contraction -> so it has the same effect as Insulin

Question 15

How can chronically elevated levels of glucose damage the body?

Answer 15

-Blood vessels blocked -> Increased Heart attacks and strokes
-nephrotic and capillaries in kidney damaged -> renal failure
-Retinal damage -> loss of vision
-Microcirculation bc blood flow is reduced and infections take off -> #1 reason for amputations

Question 16

How can high glucose levels damage the nerves?

Answer 16

Paresthesia – “pins and needles” tingling
Numbness – “I can’t feel the bottom of my feet”

Question 17

How do drugs lower blood glucose?

Answer 17

5 strategies
-secrete more insulin
-make the insulin receptor more sensitive
-reducing glucose synthesis in the liver: reduce GLUCONEOGENESIS
-excrete more glucose in the kidneys -> URINE
-reduce glucose absorption from the gut

Question 18

What are the stages of diabetes?

Answer 18

Normal -> prediabetic -> diabetic

Question 19

How can high blood glucose levels be detected?

Answer 19

One way is the Glycolysated hemaglogin (A1C) test - HbA1C
-> some glucose bind to hemoglobin

Normal: 5.7
Prediabetes: 5.7-6.5
Diabetes: above 6.5

Question 20

What are specific cells responsible for the production of insulin and glucagon?

Answer 20

Islet cells
ß-cells: insulin
alpha-cells: Glucagon