Diabetes Mellitus Type II

Question 0

What is the cause of the osmotic symptoms in diabetes?

Answer 0

The body’s need to dilute the high sugar levels in the blood with extra water

Question 1

What are the osmotic symptoms of diabetes?

Answer 1

Increased thirst

Frequent micturition

Question 2

What effect does the increase in osmotic substance in the blood have on the circulation?

Answer 2

It reduces it

Question 3

Why do diabetics often suffer lethargy and reduced concentration?

Answer 3

High or low blood glucose levels - both are to do with an imbalance of blood glucose and amount of / effectiveness of circulating insulin

Question 4

What is the role of insulin?

Answer 4

To transport glucose from the blood and to cells for energy

Question 5

What is the primary difference between type 1 and type 2 diabetes?

Answer 5

Type 1 - inefficient production of insulin
Type 2 - ineffective use of circulating insulin / reduced sensitivity to it (largely due to increased level of glucose, insulin levels not enough)

Question 6

What are the key risk factors for type 2 diabetes?

Answer 6

Sedentary lifestyle
High fat sugary diet
Raised BMI
Smoking 
Drinking alcohol

Question 7

What is considered a normal fasting sugar level?

Answer 7

</= 6mmol/L

Question 8

What fasting glucose level is consistent with prediabetes?

Answer 8

6.1-7 mmol/L

Question 9

What fasting glucose level is consistent with diabetes?

Answer 9

> 7.0 mmol/L

Question 10

Why is testing HbA1C more useful clinically than fasting glucose?

Answer 10

It gives a longer term impression of blood glucose levels (average over past 8-12 weeks)

Question 11

What does HbA1C test?

Answer 11

Glycated haemoglobin

Question 12

What lifestyle changes should a type II diabetic make?

Answer 12

Dietary - reduce fat and sugar intake
Smoking cessation
Exercise more / lose weight

Question 13

List some of the more serious consequences of poorly controlled blood glucose in a diabetic.

Answer 13

Diabetic retinopathy
Cellulitis / ulcers / gangrene / sensory peripheral neuropathy / amputation
Coronary artery disease
MI (mostly due to inadequate blood supply)

Question 14

If diabetic vascular disease is suspected what investigation most likely to be useful?

Answer 14

Angiography

Question 15

If arterial stenosis is recognised what can be done to improve blood flow and reduce further risk of ischaemia?

Answer 15

Percutaneous Coronary Investigation (angioplasty)

Question 16

A Random Plasma Glucose (RPG) of between 7.8 and 11.0 mmol/L is indicative of what?

Answer 16

Impaired glucose tolerance (pre-diabetes)

Question 17

A RPG result of more than what is indicative of diabetes?

Answer 17

11.1

Question 18

What is considered a normal fasting plasma glucose?

Answer 18

< 6.1

Question 19

What fasting glucose result is indicative of diabetes?

Answer 19

> 7 mmol/L

Question 20

Impaired glucose tolerance is indicated by a fasting glucose of?

Answer 20

Between 6.1 and 7.0 mmol/L

Question 21

What does OGTT stand for?

Answer 21

Oral Glucose Tolerance Test, it is a good test for pre-diabetes and insulin resistance (drink high glucose drink and have blood tests at certain intervals after)

Question 22

What does the HbA1c test demonstrate?

Answer 22

It gives a picture if the average levels of glycosylated haemoglobin over a 3-4 month period (the average lifespan of a RBC)

Question 23

What % of the HbA1c result relates to the glycosylated haemoglobin levels for the previous 4 weeks?

Answer 23

50%

Question 24

What factors affect HbA1c?

Answer 24

``` Haemolysis (reduced RBC survival so falsely low result) Renal impairment Iron deficient anaemia Pregnancy Blood transfusion ```

Question 25

Name the 4 main types of diabetes

Answer 25

Type 1 diabetes mellitus Type 2 diabetes mellitus Secondary diabetes (pancreatic damage, hepatic cirrhosis, endocrine) Gestational diabetes

Question 26

What 2 organs are associated with glucose production?

Answer 26

``` The liver (~75%) The kidneys (~20%) ```

Question 27

What are the main 2 anatomical factors which contribute to glucose homeostasis?

Answer 27

Liver production and skeletal muscle use

Question 28

By which process is the majority of glucose produced by the liver created?

Answer 28

Glycogenolysis

Question 29

By what process is glucose produce in the kidneys? (And to a lesser extent than glycogenolysis in the liver)

Answer 29

Gluconeogenesis

Question 30

Define glycogenolysis

Answer 30

The breakdown of glycogen to form glucose

Question 31

Define gluconeogenesis

Answer 31

The production of glucose and glycogen using non-glucose precursors i.e. Fats and proteins

Question 32

What affect does glucagon have in the blood?

Answer 32

It releases glucose into the blood (therefore increasing blood glucose)

Question 33

What is glycogen?

Answer 33

The principle storage form of glucose in human cells | highest concentration in the liver with many in skeletal cells and some in kidneys, few in brain

Question 34

How much of the glucose filtered by the kidneys is reabsorbed by them?

Answer 34

Nearly all of it!

Question 35

What are the main 4 type of hormones involved in glucose homeostasis?

Answer 35

Insulin Glucagon Incretin Glucocorticoids (e.g. GH and cortisol)

Question 36

Where is insulin produced and what is its role in glucose homeostasis?

Answer 36

Beta cells of the pancreas (found in the Islets of Langerhans); released during digestion and removes glucose from the blood (carrying them to cells for utilisation)

Question 37

Where is glucagon produced and what is its role in glucose homeostasis?

Answer 37

Produced in the alpha cells of the pancreas (found in the Islets of Langerhans). It is released in response to low glucose levels and stimulates glycogenolysis and gluconeogenesis as well as breakdown of triglycerides (stored fat)

Question 38

List 5 functions of insulin.

Answer 38

1) enhances peripheral glucose uptake 2) inhibits glycogen breakdown in liver 3) enhances storage of glucose as glycogen 4) increases protein synthesis 5) increase triglyceride storage

Question 39

Name the other 4 counterregulatory hormones to insulin besides glucagon.

Answer 39

Growth Hormone Cortisol Adrenaline Noradrenaline

Question 40

Persistent elevation of counterregulatory hormones will have what affect on a person?

Answer 40

It can reduce their sensitivity to insulin

Question 41

If there was an insufficiency in counterregulatory hormones what would occur once insulin acted?

Answer 41

Hypoglycaemia

Question 42

Briefly describe the process of how glucose stimulates insulin secretion

Answer 42

Glucose binds to GLUT-2 receptor on pancreatic Beta cell > glycolysis occurs in the cell releasing ATP > ATP sensitive K+ channels on the cell close causing depolarisation > Ca++ channels open > Ca++ influx > insulin released via exocytosis NB sulphonylureas act on Beta cells in similar way)

Question 43

Briefly, how does preproinsulin become insulin?

Answer 43

Preproinsulin enters the rough ER > part of this peptide cleaved off in rough ER lumen to become proinsulin > at Golgi App. cleaved again to become insulin. Then released via exocytosis when stimulated by the NS / glucose

Question 44

Which of the 2 insulin release phases is missing of deficient in type 2 diabetes?

Answer 44

1st phase (immediately after eating)

Question 45

What are incretins and what do they do?

Answer 45

They are GI hormones which stimulate a decrease in blood glucose levels by increasing the amount of insulin released from Beta cells of the Islet of Langerhans

Question 46

Name the main 2 incretins

Answer 46

GLP-1 and GIP (GLP-1 more important)

Question 47

What enzyme inactivates GLP-1 and GIP down?

Answer 47

Dipeptidyl peptidase-4 (DPP-4)

Question 48

What results from decreased incretins in type 2 diabetes?

Answer 48

Decreased insulin and increased glucagon > Increased blood glucose which can't be utilised > glycogen breakdown in liver > protein breakdown in skeletal muscles > reducing weight and adipose tissues breakdown into ketones

Question 49

In normal physiology what prevents glucose being excreted in urine?

Answer 49

After glucose is filtered through the glomerulus it is then reabsorbed back into the circulation by SGLT2 in the proximal tubule

Question 50

Ancanthosis is what?

Answer 50

A hardening/thickening of the skin that appears darker than the healthy skin. It can be a sign of diabetes (more specifically insulin resistance) - associated with obesity. Can also be associated with Cushing's or polycystic ovary syndrome