Carbohydrates Chem path

Question 1

What are the effects of Insulin?

Answer 1

• Insulin promotes the removal of glucose from the blood through stimulating and relocation of the insulin-sensitive GLUT-4 glucose transporter in muscle and adipose tissue.
• Insulin also stimulates glucose uptake in the liver.
• Insulin stimulates glycogen synthesis.
• Insulin stimulates glycolysis and inhibits gluconeogenesis.
• Insulin is also important in the control of fat metabolism, stimulating lipogenesis and inhibiting lipolysis.
• It stimulates amino acid uptake into cells and protein synthesis, and intracellular potassium uptake.

Question 2

What are secondary causes to diabetes mellitus?

Answer 2

• Chronic pancreatitis
• Total pancreatectomy
• Cushing’s syndrome
• Acromegaly etc.

Question 3

What are some characteristics of Diabetes?

Answer 3

• Hyperglycemia
• Glycosuria
• Polydypsia
• Polyuria
• Polyphagia
• Ketosis, acidosis, coma
• Eventually death if left untreated

Question 4

What is the renal threshold for glucose?

Answer 4

10 mmol/L.

Question 5

What is Polyphagia?

Answer 5

This is the depletion of cellular stores of carbohydrates, fats, and proteins results in cellular starvation and a corresponding increase in hunger.

Question 6

Fill in the blanks. “ Acidosis and Ketosis is due to the overproduction of _________.”

Answer 6

Ketone bodies

Question 7

Fill in the blanks. “ In Diabetes, the low pH (metabolic acidosis) stimulates the respiratory center and produces the rapid, deep, regular _________.”

Answer 7

Kussmaul breathing

Question 8

What are the possible mechanism for beta cell destruction ?

Answer 8

a) by islet cell antibodies of the IgG class

b) by non-immune mechanism (idiopathic up to now)

Question 9

True or False? Type 1 diabetes is normally seen in children while Type II diabetes is normally seen in middle-age adults.

Answer 9

TRUE!!

Question 10

What is the Pathogenesis of Type 1 DM?

Answer 10

This form of diabetes results from a severe lack of insulin caused by autoimmune mediated destruction of islet β-cells.

Question 11

What are the mechanisms of islet Beta- cell destruction ?

Answer 11

1. T-cells react against β-cell antigens resulting in cell damage.
   - T-helpers activate macrophages directed at β-cells
   - Cytotoxic T-cells directly kill β-cells
2. Locally produced cytokines (macrophages & Cytotoxic Ts) damage β-cells.
3. Auto antibodies against β-cells and insulin are detected in 70-80% of patients. The antibodies react with a number of different β-cell antigens. The presence of β-cell antibodies precede frank diabetes and predict development of the disease.

Question 12

Which type of Diabetes mellitus has a greater role of genetic susceptibility?

Answer 12

Type II DM

Question 13

What are the genetic defects associated with Type II diabetes?

Answer 13

• β-cell dysfunction
• Insulin resistance.

Question 14

What is Insulin resistance?

Answer 14

This is a decreased ability of peripheral tissues to respond to insulin, this is associated with quantitative and qualitative abnormalities in the steps of the insulin signaling pathway

Question 15

What is an environmental factor that can play a role in developing Type 2 Diabetes Mellitus?

Answer 15

Obesity

Question 16

Beta cell disfunction can be both qualitative and quantitative. Describe this.

Answer 16

Qualitative - Decreased normal pulsatile insulin secretion in response to hyperglycemia and temporal variation is secretion

Quantitative - Defects associated with decreased β-cell mass.

Question 17

In which type of Diabetes, If present in a twin ( one twin has it) the likelihood of the other twin developing it has a 30-70% chance?

Answer 17

Type I diabetes

Question 18

In which type of Diabetes, If present in a twin ( one twin has it) the likelihood of the other twin developing it has a 50-90% chance?

Answer 18

Type II diabetes
- All monozygotic twins will have the disease in both of. them eventually

Question 19

What are the clinical features of Diabetic Ketoacidosis?

Answer 19

1. D- Delirium/psychosis
2. K- Kussmaul respirations (rapid, deep breathing)
3. A- Abdominal pain/nausea/vomiting
4. Deadly - Dehydration
5. Fr - Fruity breath odour ( due to expired acetone)

“DKA is Deadly Fr”

Question 20

The oral glucose test can be used to diagnose what conditions?

Answer 20

Diabetes
Acromegaly
Glycosuria

Question 21

Which test can be used to monitor blood sugar control over a period of about 2 months?

Answer 21

Haemoglobin A1C

Question 22

Describe the mechanism for the HbA1C test?

Answer 22

When plasma glucose is episodically elevated over time, small amounts of hemoglobin A are non-enzymatically glycosylated to form HbA1C. The amount of hemoglobin A1C in blood reflects how often and how high the blood sugar has been over the past 2 months.

Question 23

How long does HbA1c stay in the blood?

Answer 23

60 days

Question 24

Fill in the blanks. “ The hemoglobin A1C percentage rises as ______.”

Answer 24

As the average plasma glucose level rises.

Question 25

Where are free fatty acids oxidised to form Ketone bodies?

Answer 25

In the liver

Question 26

What are the Acute complications of Diabetes Mellitus?

Answer 26

• Hypoglycemia
• Ketoacidosis
• Hyperosmolar hyperglycemic nonketotic coma

Question 27

What are the chronic complications of Diabetes mellitus?

Answer 27

• Diabetic micro- and macrovascular changes
  * Diabetic neuropathy
  * Diabetic retinopathy
  * Diabetic nephropathy
  * Other complications

Question 28

What are the histological features of Chronic Type II diabetes?

Answer 28

Islets fibrosis and amyloid deposition

Question 29

With regards to chronic complication of diabetes , what underlies the development of retinopathy, nephropathy and neuropathy?

Answer 29

Diabetic microvascular disease

Question 30

What is the most affected organ in Diabetes?

Answer 30

The kidneys