Diabetes Mellitus

Front 1

What is diabetes insipidus?

Back 1

Same increase in urine volume, but is "flavourless" marching through

deficiency of antidiuretic hormone not related to glucose metabolism

Front 2

By what mechanism is glucose lost in the urine in diabetes mellitus?

Back 2

1. Blood glucose level is enhanced (normal values: 5–9 mM)
2. Renal threshold for glucose re-uptake (10 mM) is exceeded
→ glucose is lost with the urine

Front 3

Facilitated transport of sugar in muscle, fat and most other tissues is insulin _______.

Back 3

facilitated transport is insulin-dependent

Front 4

Active transport of glucose in the intestines and kidney tubules AND facilitated transport in the liver, brain, blood cells, lens and cornea of eye is insulin ______.

Back 4

independent

Front 5

______ is lack of insulin secretion as a consequence
of islet β-cell destruction, due to autoimmune reactions
triggered by virus infections. Its onset is ____.

Back 5

Diabetes type I: sudden onset,
typically at young age

Front 6

________ is lack of insulin effect on target cells –
exact mechanism of causation still contentious. Its onset is _______.

Back 6

Diabetes type II: onset is
slow; mostly in the elderly

Front 7

_________ are an example of diabetes caused by other endocrine diseases.

Back 7

cortisone- or epinephrine-producing
tumors of the adrenal glands

Front 8

___________ can be responsible for drug-induced diabetes.

Back 8

Corticosteroids

Front 9

What 2 effects of diabetes contribute to elevated blood sugar levels?

Back 9

1) inhibition of glucose consumption in peripheral tissures

2) increase of glucose formation in the liver

Front 10

When insulin is lacking, what regulates metabolic regulation?

What does this cause?

Back 10

Insulin antagonists glucagon and epinephrine:

increased gluconeogenesis, inhibited glycolysis

inhibited glycogen synthesis, increased glycogen degradation

Front 11

How does derailment of muscle metabolism contribute to rising glucose levels?

Back 11

Muscles can't take up glucose without insulin, so they meet energy needs by degrading protein. Disposal of nitrogen from the amino acids generates glutamine and alanine, which are transported to the liver to supply the urea cycle and gluconeogenesis with substrate.

Front 12

What effect does lack of insulin have on lipid metabolism?

What problem can this cause?

Back 12

1) disinhibition of hormone-sensitive lipase triggers breakdown of TAG

2) increased levels off fatty acids and glucose lead to increased formation of ketone bodies, cholesterol and triacylglycerol - liver doesn't need insulin to take up sugar and gets stuffed with Acetyl-CoA

This can cause atherosclerosis.

Front 13

What laboratory findings should we expect to find in Type I diabetes patients?

Back 13

high BP (greater than 5-9 mM)

acidic pH (ketoacidosis)

increased blood fats

increased levels of urea (from protein breakdown in muscle)

decreased insulin & C-peptide

Front 14

What are some symptoms of diabetes? Explain them.

Back 14

Thirst, increased urine flow; osmotic pressure b/c of [glu]

Acetone smell - acetone forms as a byproduct of ketone bodies

Weight loss - losing calories, breaking down fats & proteins

Unconsciousness - pH and high osmotic activity of blood draining water from cells

Flu-like infection - Coxsackie vires from destruction of beta-cells

Front 15

What are Coxsackie viruses?
How do they contribute to diabetes?

Back 15

Small RNA viruses related to polio and hepatitus A

-only some cause diabetes - especially Coxsackie B4 -

Cause immunological reaction; activated immune cells may mistake beta-cell antigens for viral antigens & thus destroy the cells

Front 16

Why do diabetic patients lose glucose in the urine?

Back 16

Capacity of glucose reuptake limited by the number of glucose transporter molecules in the tubuli of the nephron - these become saturated just slightly above the physiological range of [glu] in the blood and primary urine filtrate

Front 17

Treatment of type I diabetes

Back 17

- short-term - Intravenous therapy:

1) replacement of fluid
2)adjustment of blood pH and electrolytes
3)rapid adjustment of insulin dosage by monitoring [glu]

-Insulin by injection & adjustment of diet

Front 18

Long-term effects of diabetes when blood glucose is chronically elevated:

Back 18

-increased formation of sorbitol from glucose in lens of eye causes cataracts

-increased blood fats - atherosclerosis

- tissue damage to various organs possibly through sorbitol pathway and glucosylation of proteins - usually tissues that don't require insulin to take up glucose

Front 19

Treatment of type II diabetes

Back 19

-diet to reduce weight

-sulfonylurea drugs like tolbutamide increase insulin secretion

-insulin therapy

Front 20

What is a depot insulin?

Back 20

Insulin complexed with a carrier like protamine from which it is slowly released.

Front 21

What is HbA1?

Back 21

One of the chains of hemoglobin - used as a long-term parameter of diabetes adjustment.

It undergoes a spontaneous rxn with glucose, forming a covalent addcuts calles HbA1c.

The percentage of HbA1 converted to HbA1c is proportional ro rhe avg [glucose] over a time span of several weeks.

Front 22

What is the possible importance of the C peptide?

Back 22

C-peptide is not present in pharmaceutical preparations of insulin but may reduce the severity of diabetic complications like degeneration of kidneys and peripheral nerves.