Diabetes Mellitus Flashcards Preview

Z OLD ESA 1- Metabolism > Diabetes Mellitus > Flashcards

Flashcards in Diabetes Mellitus Deck (79)
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1
Q

What is diabetes?

A

When blood glucose is too high (hyperglycaemia)

2
Q

What are the long term effects of hyperglycaemia?

A

Causes damage to small and large blood vessels

3
Q

What is the result of damage to blood vessels due to hyperglycaemia?

A

Premature death from cardiovascular diseases

4
Q

How is the problem of diabetes developing?

A

Huge and growing problem, cost to society is high and escalating

5
Q

Why may the problem of diabetes be worse than anticipated?

A

High proportions to diabetes cases undiagnosed

6
Q

What type of diabetes constitutes most of those that are undiagnosed?

A

Type 2

7
Q

Why can type 2 diabetes go undiagnosed?

A

Because you can be quite well with diabetes for many years with blood sugars only marginally raised

8
Q

What is the problem with undiagnosed diabetes?

A

Even with only small blood sugar elevations, over time damage is caused to the blood vessels

9
Q

What are the potential causes of blood glucose rising in diabetes?

A
  • Inability to produce insulin due to ß-cell failure and/or

- Insulin resistance preventing insulin working effectively- it doesn’t work at the receptor

10
Q

What are the most important and common types of diabetes mellitus?

A

1 and 2

11
Q

What are all types of diabetes mellitus characterised by?

A

Hyperglycaemia, other many other metabolic abnormalities present as well

12
Q

How does diabetes mellitus present?

A
  • Typical symptoms of hyperglycaemia

- Symptoms of inadequate energy production

13
Q

What are the typical symptoms of hyperglycaemia?

A
  • Polyuria
  • Polydipsia
  • Blurring of vision
  • Urogenital infections
14
Q

Why does hyperglycaemia cause blurring of vision?

A

Glucose comes out into the vitreous humour, altering the refractive index

15
Q

Give an example of a urogenital infection common in hyperglycaemia

A

Thrush

16
Q

What are symptoms of energy utilisation?

A

NAME?

17
Q

What does the severity of symptoms of diabetes depend on?

A

NAME?

18
Q

What must be obtained prior to diagnosing diabetes?

A

Laboratory confirmation

19
Q

What tests can be used to diagnose diabetes?

A
  • Fasting blood glucose
  • Oral glucose tolerance test
  • HbA1 c (in type 2 only)
20
Q

What do you do in an oral glucose tolerance test?

A

Give 75g glucose to drink after fasting, and take sample after 2 hours

21
Q

What does the HbA1 c test measure?

A

The amount of glucose attached to RBCs

22
Q

What do you need to confirm diabetes?

A
  • Symptoms and 1 abnormal test or

- Asymptomatic and 2 abnormal tests

23
Q

Will a diabetic patient always test positive for all 3 tests?

A

No

24
Q

What are the diagnostic criteria for diabetes?

A
  • Fasting venous plasma glucose; ≥7.0 mmol/l
  • Random venous plasma glucose; ≥11.1 mmol/l
  • Elevated HbA1 c; ≥6.5%
  • Oral glucose tolerance test; fasting venous plasma glucose≥7.0 mmol/l and/or 2 hrvenous plasma glucose; ≥11.1 mmol/l
25
Q

When is oral glucose tolerance test used?

A

Rarely, except for in pregnancy

26
Q

What causes type 1 diabetes?

A

An absoloute insulin deficiency due to autoimmune and non-autoimmune destruction of ß cells

27
Q

What causes type 2 diabetes?

A

Insulin deficiency and insulin resistance

28
Q

What types, other than 1 and 2, of diabetes mellitus are there?

A
  • Genetic defects of ß-cells
  • Genetic defects of insulin action
  • Drug-induced diabetes
  • Associated with other hormone disorders
  • Iron overload-haemochromatosis
  • After pancreatectomy
29
Q

What percentage of diabetes cases are type 1?

A

5-10%

30
Q

How fast are ß-cells destroyed in type 1 diabetes?

A

Variable- can be very rapid to years

31
Q

What is present in type 1 diabetes?

A

Antibodies; islet-cell and GAD 65

32
Q

When does type 1 diabetes develop?

A

90% diagnosed under 30 years old, but can occur at any time

33
Q

How has the prevalence of type 1 diabetes changed?

A

It has doubled ever 20 years since 1945

34
Q

What is the aetiology of type 1 diabetes?

A

Not fully understood

35
Q

What proves type 1 diabetes is not all genetic predisposition?

A

Twin studies

36
Q

How does type 1 diabetes present?

A
  • Rapid onset symptoms (usually weeks)
  • Weight loss
  • Polyuria
  • Polydipsia
  • In late presentation, may be vomiting due to ketoacidosis
37
Q

Describe the typical patient presenting with type 1 diabetes

A
  • Usually (not always) young-
38
Q

What is insulins action on glucose metabolism?

A
  • Enhances uptake of glucose by liver, muscle and adipose tissue
  • Inhibits liver glycogen breakdown
39
Q

What is insulins actions on fat metabolism?

A
  • Promotes clearance of free fatty acids

- Prevents lipolysis

40
Q

What is insulins effect on amino acid metabolism?

A
  • Active transport of amino acids into cells
  • Inhibits catabolism of proteins
  • Inhibits gluconeogenesis in liver
41
Q

What does insulin deficiency cause?

A
  • Lipolysis

- Hyperglycaemia

42
Q

What is the result of lipolysis caused by insulin deficiency?

A

Increase in free fatty acids, therefore an increase in ketones, causing acidosis, which leads to cardiovascular collapse

43
Q

What does hyperglycaemia cause?

A

Hyperosmolarity and glucosuria

44
Q

What does glucosuria cause?

A

Electrolyte losses (particularly sodium and potassium) and dehydration

45
Q

What does dehydration cause?

A

Renal failure

46
Q

How is a vicious cycle set up with dehydration causing renal failure?

A

The renal failure causes further dehydration

47
Q

What does the renal failure cause?

A

Shock, which causes cardiovascular collapse

48
Q

What are the clinical signs of type 1 diabetes?

A

NAME?

49
Q

How is the presence of ketones in urine most easily measured?

A

Ketostick

50
Q

What does presence of ketones in urine signify?

A

An absolute lack of insulin

51
Q

How is type 1 diabetes treated?

A

Exogenous insulin

52
Q

How is exogenous insulin given?

A

By subcutaneous injection several times a day

53
Q

Why is diabetes treatment a specialised field?

A

The amounts and type of insulin required is dependant upon many factors

54
Q

What happens if a type 1 diabetes diagnosis is missed?

A

Severe consequences- death, sometimes in hours

55
Q

What should an ideal insulin do?

A

Mimic the characteristics of normal insulin

56
Q

What is the pathology of type 2 diabetes?

A

Dual pathology- insulin resistance and relative insulin lack

57
Q

What is the aetiology for type 2 diabetes?

A

Both causes have separate possible aetiologies- genetic and environmental factors

58
Q

What is the most common single cause of insulin resistance?

A

Obesity

59
Q

What shows that type 2 diabetes has genetic factors?

A

Twin studies

60
Q

What factors have caused the type 2 diabetes epidemic?

A

Environmental, not genetic

61
Q

Why does obesity lead to type 2 diabetes?

A
  • Obesity leads to insulin resistance first
  • This causes an increased secretion of inslin
  • Eventually the pancreas can’t keep up, causing pancreas exhaustion
  • Hyperglycaemia develops
  • As the pancreas is going at full speed, it is unable to accelerate- first phase secretion is lost and then basal insulin secretion
  • Amyloid type deposits in the islet cells, causing ß-cell failure
62
Q

What happens after bariatric surgery or a very low calorie diet?

A
  • Within 7 days, fasting blood glucose normalises in type 2 diabetes before any weight loss
  • Massive fall in liver fat content and return of normal insulin sensitivity
  • Over 8 weeks, first phase insulin release and maximal rates of insulin release return to normal
  • This change is in step with decreasing pancreatic fat content normalising ß cell function
63
Q

What does the effect of bariatric surgery or very low calories on type 2 diabetes mean?

A

It can be considered as a potentially reversible metabolic disorder precipitated by chronic intraorgan fat

64
Q

What causes the improvements in glucose and insulin resistance following bariatric surgery or very low calorie diets?

A
  • Calorific intake falls immediately post measure
  • Sudden reversal of traffic into the fat stores brings about profound change in intracellular concentration of fat metabolites
  • Under hypocalorific conditions, fat is mobilised first from the liver and other ectopic sites rather than from visceral or subcutaneous sites
  • Fasting glucose improved because of an 81% decrease in liver fat content and normalisation of hepatic insulin sensitivity
65
Q

How does type 2 diabetes present?

A

Very variable symptoms

  • May have polyuria, polydipsia, weight loss
  • May be asymptomatic
66
Q

Why are type 2 diabetes symptoms variable?

A

Because slower rise in blood glucose

67
Q

How can type 2 diabetes be discovered when the patient is asymptomatic?

A

On routine screening

68
Q

How old are type 2 diabetes patients

A

Usually, though not universally, older- most over 40, but seen increasingly in younger people and children

69
Q

What % of type 2 diabetes patients are overweight/obese?

A

90%

70
Q

Diagnostically, how can type 2 diabetes be differentiated from type 1?

A

Absence of ketones in urine

71
Q

What does the absence of ketones in urine signify?

A

ß-cells are still producing some insulin, though not enough to control glucose levels

72
Q

What happens if type 2 diabetes if left untreated?

A
  • Gradual worsening of symptoms

- Worsening/onset of complications of diabetes

73
Q

What are the problems with gradual worsening/onset of diabetes complications?

A
  • Significant morbidity
  • Mortality
  • Financial cost
74
Q

Does a patient require diabetic control if they are asymptomatic?

A

Yes

75
Q

How is type 2 diabetes treated

A

NAME?

76
Q

What lifestyle factor can be used to treat type 2 diabetes?

A

Exercise

77
Q

What effect does exercise have on type 2 diabetes?

A

Improves insulin sensitivity

78
Q

Give 8 drug therapies used for the treatment of type 2 diabetes

A
  • Biguandines
  • Sulphonylureas
  • Thiazolidinediones
  • DPP4 inhibitors
  • α-glucosidase inhibitors
  • SGLTs
  • GLP1 analogues
  • Insulin
79
Q

How are patients with diabetes monitored?

A

NAME?