The Aetiology and Treatment of Type 2 Diabetes Mellitus Flashcards

1
Q

What tests are performed to diagnose diabetes and what are the defining values?

A

Fasting Blood Glucose:
 Normal < 6
 Impaired Fasting Glucose = 6-7
 Diabetes > 7

Glucose Tolerance Test (2 hr measurement)
 Normal < 7.8
 Impaired Glucose Tolerance = 7.8-11.1
 Diabetes > 11.1

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2
Q

State three factors that influence the pathophysiology of T2DM.

A

Genetics

Intrauterine environment

Adult environment

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3
Q

How is the intrauterine environment important in the pathogenesis of T2DM?

A

There will be epigenetic changes that take place in utero, which affect blood glucose control in the future

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4
Q

What is MODY?

A

Mature onset diabetes of the young (8 types)
It is autosomal dominant

Ineffective pancreatic beta cell insulin production
Caused by mutations of transcription factor genes (glucokinase gene)

Positive family history with NO obesity

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5
Q

What can modulate insulin resistance through adult life before someone develops diabetes?

A

Adipocytokines

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6
Q

What type of babies are more likely to develop T2DM in later life?

A

Small babies (low birth weight)

This is due to intrauterine growth restriction

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7
Q

How does insulin resistance lead to hypertension?

A

Insulin resistance leads to a compensatory hyperinsulinaemia

Though the insulin doesn’t affect the glycaemic control pathway, it stimulates the mitogenic pathway causing smooth muscle hypertrophy –> high blood pressure

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8
Q

What eventually happens to the beta cells in T2DM?

A

Insulin resistance damages the beta cells and eventually results in beta cell failure

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9
Q

Describe how beta cell reserve and insulin resistance change with age.

A

Beta cell reserve decreases with age and insulin resistance increases

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10
Q

Describe the presentation of a typical patient with T2DM.

A

Obese (80%)

Insulin resistance and insulin secretion deficit

Hyperglycaemia and dyslipidaemia

Acute and chronic complications

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11
Q

What dietary changes can someone with T2DM make to reduce the effect of the missing first phase insulin release?

A

Complex carbohydrates – release glucose more slowly

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12
Q

Describe glucose clearance and hepatic glucose output in T2DM.

A

Glucose clearance is decreased

Hepatic glucose output is increased

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13
Q

What normally happens to insulin secretion as insulin resistance increases?

A

Insulin secretion increases to compensate for the increased insulin resistance

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14
Q

Which adipocytes are particularly marked for breakdown of triglycerides?

A

Omental adipocytes (this is why omental fat correlates with risk of heart disease)

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15
Q

What happens to fatty acids when they go into the liver?

A

They cannot be used to make glucose so they are converted to very low-density lipoproteins (VLDLs), which are highly atherogenic

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16
Q

Describe how gut microbiota is implicated in T2DM.

A

They may be important in host signalling – they ferment various lipopolysaccharides to produce short chain fatty acids, which enter the circulation and modulate bile acids (so they can also affect host metabolism)

They are also important in inflammation and adipocytokine pathways

17
Q

What is a very common side effect of diabetes treatment?

A

Weight gain

18
Q

Which diabetes treatment does not cause this problem?

A

Metformin

19
Q

What are the potential complications of T2DM?

A

Stroke

Myocardial Infarction

Neuropathy

Retinopathy

Nephropathy

Hypoglycaemia

20
Q

What dietary measures are recommended for someone with T2DM?

A

Decreased fat (particularly saturated fats)

Decreased refined carbohydrates

Increased complex carbohydrates

Increased soluble fibre

Control total calories/increase exercise

21
Q

What is orlistat and why is it sometimes used in T2DM?

A

Pancreatic Lipase Inhibitor

It reduces the break down of fats in the intestines thus reducing the absorption of fats

22
Q

State 5 classes of drugs that are used to treat T2DM and state how they work.

A

Metformin – insulin sensitiser (biguanides)

Sulphonylureas – makes the existing pancreas produce more insulin

Alpha-glucosidase inhibitors – prolongs the absorption of glucose from the intestine

Thiazolidinediones – addresses peripheral insulin resistance (muscle and fat)

GLP-1 agonists and DPIV inhibitors – increase insulin secretion

23
Q

When should you NOT use metformin?

A

Severe liver failure

Severe cardiac failure

Mild renal failure

24
Q

Name one sulphonylurea.

A

Glibenclamide

Given to lean patients with T2DM

25
Q

Explain how sulphonylureas work.

A

They bind to receptors and block the ATP-sensitive K+ channel

This leads to Ca2+ influx, which causes insulin release

26
Q

Name one alpha-glucosidase inhibitor. Explain how it works and state some side effects.

A

Acarbose

It prolongs the absorption of oligosaccharides and allows the body to cope with the loss of first phase insulin

Side effect: it means that some sugars get to the colon and are fermented –> flatus

27
Q

Name one thiazolidinedione. What are its effects?

A

Pioglitazone

These are peroxisome proliferator-activated receptor (PPAR-) agonists

These are insulin sensitises mainly in peripheral tissues (leads to peripheral weight gain)

28
Q

What does GLP-1 do?

A

Responsible for the incretin effect

Stimulates insulin and suppresses glucagon

29
Q

What breaks down GLP-1?

A

Dipeptidyl peptidase-4 (DP-IV)

30
Q

What class of drugs prolong the duration of GLP-1?

A

Gliptins

They inhibit DP-IV

31
Q

What effect do long-acting GLP-1 agonists and gliptins have on weight gain?

A

GLP-1 agonists = weight loss

Gliptins = neutral

32
Q

What other pharmaceutical interventions must be considered with T2DM patients?

A

Many T2DM patients also have dyslipidaemia and hypertension, which need to be dealt with as well

33
Q

What can occur during pregnancy to identify women who are at high risk of getting diabetes in the future?

A

Gestational diabetes