Diabetes Mellitus Flashcards

1
Q

How is diabetes defined when a patient has symptoms?

A
  1. symptoms and random plasma glucose > 11 mmol/l

2. symptoms and fasting plasma glucose > 7 mmol/l

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2
Q

How is diabetes defined when a patient does not have symptoms?

A

A glucose tolerance test is used (give 75 g glucose)

fasting glucose > 7 mmol/l

after 2 hours glucose > 11 mmol/l

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3
Q

What more modern test is now used in diabetes diagnosis?

A

HbA1c

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4
Q

Why is HbA1c used in diagnosis?

A

High sugar levels cause glycation of proteins

Hb1c is part of the haemoglobin that becomes glycated

Raised glucose levels lead to glycation of Hb and raised HbA1c levels

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5
Q

What is the weakness of using HbA1c in diagnosing diabetes?

A

If glucose levels have been high for only a few days, HbA1c levels will be normal

A diagnosis may be missed

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6
Q

What are the 5 presenting features of diabetes?

A
  1. polyuria and polydipsia
  2. weight loss and fatigue
  3. pruritis vulvae and balanitis
  4. hunger
  5. blurred vision
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7
Q

What is meant by polyuria and polydipsia?

A

Polyuria is passing a lot of water, particularly at night

Polydipsia is feeling thirsty all the time

This is due to osmotic diuresis

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8
Q

Why is weight loss a sign of type 1 diabetes?

A

This occurs due to impaired glucose utilisation

Without insulin, cells cannot use glucose

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9
Q

What is an example of pruritis vulvae and balanitis?

A

Vaginal candidiasis

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10
Q

What causes hunger in diabetes?

A

Lack of insulin preventing hypothalamic glucose uptake

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11
Q

What causes blurred vision in diabetes?

A

The lens in the eye cannot adapt to the high sugar levels

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12
Q

What is the aetiology of type 1 and type 2 diabetes?

A

Type 1 is autoimmune and due to beta-cell destruction, meaning no insulin is produced

Type 2 causes insulin resistance and B-cell dysfunction

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13
Q

What is the peak age for type 1 and type 2 diabetes?

A

Type 1: 12 years but can occur at any time

Type 2: 60 years

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14
Q

What is the prevalence of type 1 and type 2 diabetes?

A

Type 1 : 0.3%

Type 2: 6% (can be > 10% above 60 years and in some ethnicities)

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15
Q

What is the presentation of type 1 diabetes?

A

Osmotic symptoms

Weight loss/patient is usually slim

Diabetic ketoacidosis

Symptoms appear acutely - from days to weeks

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16
Q

What is the presentation of type 2 diabetes?

A

Osmotic symptoms

Patients are usually obese

Diabetic complications appear over months to years

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17
Q

What is the treatment for type 1 and type 2 diabetes?

A

Type 1 - insulin (to match size of meals)

Type 2 - Diet and exercise for weight loss

Then oral hypoglycemics, and eventually insulin

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18
Q

What are the events that act as precursors to type 2 diabetes?

A
  1. fat tissue is resistant to insulin
  2. the pancreas produces more insulin to overcome this resistance
  3. the pancreas cannot keep up with the demand for insulin
  4. this increases plasma glucose concentration and leads to diabetes
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19
Q

Why does diabetic ketoacidosis occur in type 1 diabetes?

A
  1. insulin is required in order for the body to utilise glucose to produce energy
  2. fatty acids and proteins are used in energy production opposed to glucose
  3. ketone bodies are formed from fatty acids
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20
Q

What is LADA?

How does it differ from type 1 diabetes?

A

Latent autoimmune diabetes in adults

Beta cell destruction is very gradual

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21
Q

What is treatment like for LADA?

What is it often misdiagnosed as?

A

Patients progress from tablets to insulin within one year

It is often misdiagnosed for type 2 diabetes

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22
Q

What is MODY?

A

Maturity onset diabetes of the young

It is similar to type 2 diabetes

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23
Q

What is involved in MODY?

What should be looked for on diagnosis?

A

Younger people present with diabetes due to a mutation in a transcription factor

It is an autosomal dominant condition so look for a family history of diabetes at a young age

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24
Q

What is gestational diabetes?

What are the future risks involved?

A

Pregnancy is associated with insulin resistance

It goes away after pregnancy, but mother is more at risk from type 2 diabetes in the future

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25
What are examples of secondary diabetes?
1. pancreatic destruction (pancreatitis, cystic fibrosis) 2. acromegaly 3. cushing's sydrome
26
What are the clinical features used for diagnosing type 1 diabetes?
1. weight loss 2. short history of osmotic symptoms (days to weeks) 3. moderate or large urinary ketones Any 2 of these features lead to diagnosis
27
What are the 3 aims of treatment for type 1 diabetes?
1. relief of symptoms 2. prevention of ketoacidosis 3. prevention of microvascular and macrovascular complications
28
What is the difference between microvascular and macrovascular complications?
Microvascular is small vessel disease Macrovascular is large vessel disease
29
What are the 3 types of microvascular complications in diabetes?
1. retinopathy 2. neuropathy 3. nephropathy
30
How is retinopathy tested for?
Regular eye tests are performed in diabetic patients | once a year
31
What causes retinopathy?
small vessels in the back of the eye are damaged the eye may become white
32
How is neuropathy tested for? Why is this test performed?
A regular foot examination This prevents ulceration when people cannot detect pain in their feet Ulceration may lead to amputation
33
What is neuropathy and what causes it?
Small blood vessels surrounding nerve fibres are damaged This leads to death of nerve endings and loss of sensation, particularly in the hands and feet
34
What is the test for nephropathy?
1. urine test for microalbumin | 2. blood test for kidney function (U&E)
35
What is the prognosis associated with diabetic nephropathy?
It has a very poor prognosis There is a large increase in cardiovascular mortality (risk of MI and stroke) It leads to end-stage renal failure, which requires transplant or dialysis
36
What is significant about the development of diabetic nephropathy?
Patients with nephropathy tend to develop proliferative retinopathy and severe neuropathy
37
What is the purpose of treatment for type 1 diabetes and what is the main treatment?
Insulin treatment is used This restores the physiology of the beta cell
38
What are the 2 types of insulin treatment which may be used?
1. twice daily mixture of short/medium acting insulin | 2. basal bolus insulin
39
What is basal bolus insulin?
Once or twice daily medium acting insulin injection plus short acting insulin before meals Insulin is injecting according to meal size and carbohydrate intake
40
What is the aim and risk of insulin treatment?
The aim is to keep blood glucose close to normal This prevents diabetic complications There is a risk of becoming hypoglycaemic
41
How does exercise affect the amount of insulin that needs to be injected?
Exercise lowers blood glucose levels Insulin must be changed according to exercise (less needed)
42
What are the roles of short- and long-acting insulin?
Short acting insulin is injected before meals Long acting insulin is injected to recover the basal insulin
43
What is basal insulin? How does insulin change during meal times?
Basal insulin is the small amount of insulin that is constantly produced by the pancreas There is a large peak in insulin during meals
44
What causes hypoglycaemia in type 1 diabetes? What is the hypoglycaemic range?
Inappropriately high insulin levels Blood glucose is < 3.5 mmol/l
45
What happens to the brain when blood glucose falls to 3mmol/l and 2 mmol/l?
3 mmol/L - prolonged reaction time 2 mmol/L - abnormal EEG and confusion
46
What happens to the brain when blood glucose falls to 1 mmol/L and below?
1 mmol/L - coma and seizures below 1 mmol/L - irreversible cerebral damage if prolonged
47
What is involved in physiological protection against hypoglycaemia?
Counterregulatory hormones These are adrenaline and glucagon They increase hepatic glucose output to increase blood sugar levels
48
What are the autonomic symptoms and signs of hypoglycaemia?
1. nausea 2. tremor 3. sweating 4. tachycardia 5. pallor 6. anxiety (adrenergic)
49
What are the neuroglycopenic symptoms and signs of hypoglycaemia?
1. confusion 2. drowsiness 3. lethargy 4. lack of concentration 5. slurred speech 6. aggression 7. coma
50
How is average glucose control measured? What is the aim?
Average glucose control is measured through HbA1c (this is how glycated the Hb is) This should be 6 - 7 %
51
What is the dilemma in treating type 1 diabetes patients?
1. setting higher glucose targets reduces risk of hypoglycaemia but increases risk of diabetic complications 2. setting lower glucose targets reduces risk of complications but increases risk of hypoglycaemia
52
Why do most patients choose not to monitor their blood glucose or adjust their insulin?
1. risk of hypoglycaemia 2. the process of obtaining readings is too difficult 3. risk of weight gain 4. interference with lifestyle 5. lack of adequate knowledge/training
53
What method is used by diabetics to monitor their blood sugar?
Capillary glucose is used by pricking the finger with a needle Patients should adjust their insulin accordingly
54
Why does injecting insulin carry a risk of weight gain?
If a patient has a lot of hypos, they have to have more sugar This increases weight gain risk Insulin allows sugar to enter the cells
55
What is the prevalence of type 2 diabetes in the UK and developing countries?
Around 6% in the UK 15-20% in many developing countries and some ethnic groups
56
In what 2 ways does type 2 diabetes work?
It is due to B-cell dysfunction or insulin resistance
57
How does insulin resistance affect the liver and muscle/adipose tissue?
It increases hepatic glucose production It reduces insulin-dependent glucose uptake by adipose and muscle tissue This leads to hyperglycaemia
58
What is the consequence of hyperglycaemia due to insulin resistance?
The pancreas secretes more insulin to lower the blood glucose level The insulin response becomes progressively impaired due to pancreatic exhaustion
59
How does type 2 diabetes affect the eyes and kidneys?
1. it is the leading cause of end-stage renal failure | 2. it is one of the leading causes of blindness
60
How does type 2 diabetes affect the heart and brain?
It increases risk of CV mortality and stroke by 2-4 times 8/10 diabetic patients die from CV events
61
How does type 2 diabetes affect other parts of the body?
it is the leading cause of non-traumatic lower extremity amputations
62
How does diagnosis of type 2 diabetes affect life expectancy? What types of complications are usually present at diagnosis?
Life expectancy is shortened by about 10 years Microvascular complications affect 20-25% of patients at diagnosis
63
What is the initial treatment for type 2 diabetes?
Weight loss through change in diet and exercise This can cure diabetes in 1/3 of people
64
What is the treatment for diabetes if diet and exercise is not enough?
Medication to control blood pressure, blood glucose and lipids
65
When treating type 2 diabetes, what other risk factors are treated?
1. nephropathy 2. hypertension 3. overweight 4. thrombosis potential 5. hyperglycaemia 6. hyperlipidaemia
66
What is the role of a-glucosidase inhibitors in treating diabetes?
They reduce the absorption of glucose in the stomach and gut The glucose is lost in the faeces instead
67
What is an example of an a-glucosidase inhibitor? What is the main concern when using these?
acarbose They cause large amounts of wind in the patient, which can be uncomfortable
68
What is the role of sulphonylureas?
They increase insulin production and release by the pancreas
69
What are examples of sulphonylureas? What is the negative about using these?
glicalzide, glimepiride they can cause hypoglycaemia
70
What is the role of pioglitazone?
It helps fat and muscle cells to take up more glucose
71
What are GLP-1 analogues used for in treating diabetes?
They are incretins, which make people feel full This means that people start eating less and lose weight They increase insulin secretion from the pancreas and inhibit glucagon release
72
What is the role of DPP-4 inhibitors in treating diabetes?
They inhibit DPP-4 (dipeptidyl peptidase 4), which breaks down GLP-1
73
What is the role of biguanides in treating diabetes?
They suppress hepatic glucose output They also enhance insulin sensitivity
74
What is the main biguanide used in treating diabetes?
Metformin
75
What are the clinical consequences of hypoglycaemia relating to vascular events?
1. it increases inflammation 2. it causes endothelial cell dysfunction 3. it increases thrombosis All of these factors lead to vascular events and death
76
What are the clinical consequences of hypoglycaemia relating to brain damage?
It can cause cardiac arrhythmias and neurological complications These can lead to brain damage and death
77
How does high and low HbA1c affect mortality?
High HbA1c increases mortality Low HbA1c also increases mortality (due to hypoglycaemia)
78
What is "The Triangle" that is used to give an improved clinical outcome for diabetes patients?
1. improve glucose levels 2. avoid hypoglycaemia 3. limit glucose variability (maintain in a narrow range)
79
How do hypoglycaemic agents affect the cardiovascular system?
They differ in their effects on the cardiovascular system