Insulin and Diabetes

What is the difference between T1D and T2D?

• type 1 = loss of insulin production

• type 2 = receptors are resistant to insulin or insufficient secretion of insulin

Where is insulin produced?

Where is glucagon produced?

• insulin = pancreatic beta cells

• glucagon = pancreatic alpha cells

What are causes of hyperglycaemia?

• loss insulin-stimulated glucose uptake (so build-up of glucose in blood)

• loss of insulin repression of gluconeogenesis

• loss of insulin repression of glycogen breakdown

How does insulin repress gluconeogenesis and glycogen breakdown?

• acts as a off switch for these processes

What percentage of diabetes are type 1?

• 5-10%

Why do T1D produces no/little insulin?

• due to pancreatic beta cells being destroyed by immune system = autoimmune disorder

How do T2D cells respond to insulin?

• cells are in an insulin-resistant state

How do beta cells try to compensate for insulin resistance in T2D?

What are drawbacks?

• produce more insulin

• once beta cells can no longer produce enough insulin to combat the resistance = T2D

What are factors that increase likelihood of developing T2D?

• obesity

• lack of exercise

• diet

• genetic factors (increase likelihood of parent, sibling or child has T2D)

When are T1D symptoms made apparent?

• rapid onset of symptoms

• typically severe e.g. ketoacidosis which requires hospitalisation for treatment

What percentage of women develop gestational diabetes?

When does it typically develop?

When does it disappear?

• 25% women

• during 2nd trimester

• after birth of child (so temporary condition)

What are tests used to diagnose diabetes?

• fasting glucose test

  • no food or drink (except water) for 8-10 hrs then test blood glucose

• random glucose test

• glucose tolerance test

• HBA1c test

How is a glucose tolerance test conducted?

• patient fasts for at least 8 hrs

• blood glucose measured immediately before and after drinking 75g of glucose dissolved in water

What are the values for fasting/ random glucose test?

• normal = 3.9-5.9mmol/L

• prediabetes = 5.5 - 6.9 mmol/L

• diabetic = >7mmol/L

What are the values for the glucose tolerance test?

• 11.1 mmol/L indicates diabetes

• 7.9-11.1 indicates impaired glucose tolerance

What is HBA1c?

What does this help to measure?

What does it help to diagnose?

• glycated blood that is the binding of haemoglobin A and glucose

• measures the average blood glucose levels over the last 3 months (average RBC life span)

• T2D, T1D develops quickly (normally quicker than 3 months so might not catch in a HBA1c test)

What are values for HBA1c test?

• >48mmol/mol indicates diabetes

• 42-48mmol/mol indicates risk of developing diabetes

What is BP goal for diabetics?

What is HBA1c goal for diabetics?

What is total cholesterol level goal for diabetics?

• <130/80mmHg

• 448mmo

• no greater than 5

What are symptoms of diabetes (more acute)?

• dehydration

• frequent urination

• fatigue

• nausea and vomiting

• polyphagia (increased hunger)

• weight loss (T1D)

• UTI and thrush (glucose in urine)

• poor wound healing

• blurry vision

How does Diabetic ketoacidosis (DKA) occur?

• due to glucose being unavailable body uses fat as an energy source

• free fatty acids are converted to ketones by the liver → energy source

• ketones cause blood to become more acidic

• life threatening

When should T1D ketone levels be checked?

• at time of diagnosis

• during an illness (when patient is ill)

• during a growth spurt

• when insulin is taken incorrectly

What are symptoms of DKA?

• extreme thirst

• frequent urination

• nausea

• vomiting

• confusion

• irritability

• loss of consciousness → coma → death

What indicates DKA?

• ketones present in urine

• high blood glucose levels

• fruity smelling breath

What is treatment for DKA?

• fluid replacement, insulin and mineral replacement

What are chronic complications of Diabetes?

• vascular damage

• high BP

• neuropathy

• nephropathy

• retinopathy

• increased risk of CV risk

What are regular checks diabetics should do?

• regular eye, kidney, BP, foot checks

When should a diabetic be put on a primary prevention statin?

• if >40 y/old or been diagnosed for 10+ years

How does diabetic foot occur?

• due to either nerve damage leading to sensation loss in peripherals or due to poor blood flow to feet

• patient cant feel cuts so go unnoticed - infection

• no blood flowing - area cant heal

If a mother has poorly controlled diabetes, what are risks in pregnancy?

• increased risk of miscarriage, stillbirth and birth defects