1a Diabetes Mellitus Flashcards by Mia Cameron

Describe the normal response to feeding?

Eat a meal
Glucose levels in the blood are elevated
Pancreas releases insulin
Insulin binds to insulin receptor
This causes GLUT4 receptors to move to the plasma membrane of the cells
Therefore glucose is able to pass into the muscle or fat cell

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Where are GLUT 4 receptors found?

muscle or adipose tissue

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How does GLUT 4 respond to insulin?

It is highly insulin dependant

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Where is GLUT 4 found before moving to the ccell membrane?

Found in vesicles -moves from vesicles to membrane in the presence of insulin

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What does insulin act as a signal of?

Insulin is a signal you have been fed

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What happens to gluconeogenesis when insulin levels are high?

Gluconeogenesis is turned off

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What happens to glycogen levels when insulin is released?

Glycogen levels increase as the glucose is stored as glycogen

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Why is triglycerides the most useful energy store?

It is fully reduced therefore is the mot efficient energy store

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What are NEFAs?

Non-esterified fatty acids

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How do triglycerides form?

They form through an esterification reaction of three NEFA’s and a glycerol molecule

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What is the purpose of adipocytes?

To store energy

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What does lipoprotein lipase do?

Breaks down triglycerides into the glycerol and NEFA molecule so that they can leave circulation and enter into the adipocyte for storage

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What affect does insulin have on lipoprotein lipase?

Insulin switches on lipoprotein lipase

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What happens to the glycerol in adipose cells from the breakdown of he triglyceride?

Can be converted into glucose - via gluceoneogenesis by conversion into dihydroxyacetone phosphate and then into GALP

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What are the effects of insulin in the fed state?

INCREASED:
- Glycogen store
- Glucose uptake
- Triglyceride break down
- protein synthesis

DECREASED:
- Ketogenesis
- gluconeogenesis
-

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What is the brains main energy substrate?

Glucose

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Can the brain use ketone bodies or fatty acids as a source of energy?

Can use ketone bodies as a last resort, but not fatty acids

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Why can fatty acids not be used in the brain as a source of fuel?

The fatty acids cannot pass the blood brain barrier

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What happens to insulin levels during starvation?

They fall

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What happens to glucose uptake in cells during starvation?

It falls

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What happens to hepatic glucose output?

it rises

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What happens to lipolysis when insulin levels are low?

Lipolysis is switched on

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What happens in lipolysis?

Non esterified fatty acids are released

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What happens to the NEFA’s that are released during lipolysis?

They are converted into ketones

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What happens to blood pH when ketones are made and why?

Blood pH starts to fall - this is because ketones are slightly acidic

What happens to gluconeogenesis when insulin levels are low?

The liver turns on guconeogenesis

What is hepatic glycogenolysis?

The generation of glucose from stored glycogen in the liver

What effect does low insulin levels have on beta oxidation?

Increases beta oxidation

What is produced in beta oxidation?

acetyl coa which is then used to produce ketone bodies in the starving state

What are the three keone bodies?

Acetone Acetoacetate 3-beta hydroxybutyrate

Starving for a long period of time results in a sweet, strong smell that you can detect. Why?

Starving state = increased gluconeogenesis, meaning the oxaloacetate which would normally be used in the TCA cycle is being used t make glucose, therefore excess of acetyl CoA - converted into ketone bodies via ketogenesis

What happens in myocytes when insulin levels are low?

no glucose is pumped into muscle cells, so the onboard stores of glycogen are used to make glucose, which then undergoes glycolysis and Krebs cycle to make ATP

What happens to proteolysis when insulin levels are low?

It increases - proteins are broken down into amino acids

What happens to hepativ glucose output when inculin levels are low

It increases

What happens to ketogenesis when insulin levels are low?

It increases

What type of disease is Diabetes Mellitus?

An autoimmune condition

What is destroyed in T1DM

The ISLET cells

What word is used to describe the glucose levels of those with T1DM?

Hyperglycemia

Why does ketone production occur in T1DM?

There is a lack of insulin, therefore your body will behave as if it starving, and will increase ketone body production for energy

What is ketoacidosis?

When you have very large amounts of ketone bodies so they become acidic

If you have the presence of ketone, which type of diabetes do you have?

Type 1

What is the pH range for patients with ketoacidosis?

A pH less than 7.3

What are some complications of ketoacidosis?

Patients with ketoacidosis experience low pH in the blood as the ketones are acidic - a low pH is associated with decreased brain function, which can make the patient unconscious, and experience a low mood, and can also lead to death

What are some osmotic symptoms of T1DM?

Polyuria, polydipsia and nocturia

What is polyuria?

A lot of urine

What is polydipsia?

Drinking a lot of water as you are thirsty often

What is nocturia?

Waking up at night because you have to urinate

What level does resting glucose have to be in order to be diagnosed with T1DM?

>11.1mmol/L

What level does fasting glucose have to be in order for a diagnosis of T1DM to be made?

>7.0mmol/L

Above what value is HbA1c considered high?

>48mmol/mol

What are the values for the diagnosis of diabeteic ketoacidosis?

pH < 7.3, high levels of ketones, HCO3 < 15mmol/L, glucose > 11

How many positive tests do you require for the diagnosis of T1DM?

2 Positive tests or 1 positive test and osmotic symptoms

Why is measuring C-peptide a useful diagnostic test?

C peptide is cleaved from pro-insulin along with insulin. Therefore little c peptide indicates little insulin / pancreas

What antibodies can be tested for a T1DM diagnosis?

GAD and IA2

How do you treat T1DM?

Replace insulin through injections at a specific dose relative to the meal you are going to eat

What happens if you inject insulin without eating food?

Insulin results in more glucose being absorbed, so much so that you become hypoglycaemic

What is hypoglycaemia?

When blood sugars are very low

What happens to the brain during hypoglycaemia?

Since insulin is present, ketone production is stopped. But you have no fuel for brain now, so brain cannot function - results in confusion and unconsciousness

What four things increase to counter act hypoglycaemia?

Glucagon, catecholamines, cortisol and growth hormone

What happens to the hepatic glucose output when the body induces the counter regulatory response to hypoglycaemia?

It increases with glycogenolysis and gluconeogenesis

What is impaired awareness of hypoglycaemia?

The reduced ability to recognize symptoms of hypoglycaemia due to loss of counter regulatory response which leads to recurrent hypo.

What might someone who is having a hypo feel?

Confused, aggressive, irrational

Autonomic symptoms of hypoglycaemia?

Sweating, pallor, palpitations and shaking

What is the definition of severe hypoglycaemia?

An episode in which a person requires third party assistance to treat

What are some neuroglycopenic symptoms of hypoglycaemia?

Slurred speech, poor vision, confusion, seizures and loss of consciousness

What can you give a patient suffering with unconsciousness due to a hypo?

1mg glucagon injection

What can be given to patients suffering from an acute hypo episode?

Jelly babies, lucozade, glucogel

What is T2DM?

Where you have insulin resistance in the liver, muscle and adipose issue, however enough insulin to suppress ketogenesis and proteolysis

Will you ever find ketoacidosis in patients with T2DM?

What are some signs and symptoms of T2DM?

High fasting glucose >7 mmol/L High random glucose > 11.1 mmol/L Large waist circumference Hypertension (135/80 mmHg)

Which type of diabetes is associated with weight gain and loss respectively?

Gain = T2 Loss = T1

Why does T1DM result in polyuria?

The excess glucose ends up in the urine, which draws more water into the urine via osmosis, hence the volume of urine increases

What are the risk factors for T2DM?

Age, PCOS, High BMI, family history, ethnicity, inactivity

What are the four ways to manage T1DM?

Education Technology Exogenous insulin Self monitoring of insulin

What is the basal bolus regime for insulin?

Basal (long acting) insulin is given once for long actin Bolus is given throughout day before meals in order to manage the rises in glucose after meals

What four ways can T2DM be managed?

Education Diet Exercise Oral medication - to stimulate the pancreas to increase insulin production

What other microvascular systems can be affected due to diabetes?

Retinopathy Neuropathy Nephropathy

What macro vascular systems can be affected by T2DM?

Cardiopathy eg heart attack

What is dyslipidemia?

Disturbances in fat metabolism cause changes in the lipid concentration in the blood

What is diabetic retinopathy?

High glucose levels in the blood result in damage to the blood vessels which supply the retina