Diabetes Flashcards
Where is insulin produced?
In the beta cells, in the Islets of Langerhans in the pancreas
What is the normal range for blood glucose?
4.4 and 6.1 mmol/l
How does insulin reduce blood sugar?
Causes the cells to absorb more glucose which can be used as energy
Causes muscles and the liver cells to absorb glucose and convert it into glycogen to be stored
What is the role of glucagon?
It works to increase blood glucose by causes glycogenolysis (glycogen to glucose) and gluconeogenesis (production of glucose in the liver from proteins and fats)
Where is glucagon produced?
The alpha cells in the islets of Langerhans in the pancreas
What is type 1 diabetes?
Where the pancreas cannot produce insulin. This causes hyperglycaemia as glucose cannot be moved into cells from the blood.
What is type 2 diabetes?
When a resistance to insulin is built up over time. The beta cells also become damaged so produce less insulin. This causes blood glucose levels to rise and hence hyperglycaemia.
What are some risk factors for type 2 diabetes?
Old age Ethnicity (black, Chinese, south asian) Family history Obesity Sedentary lifestyle Hyperlipidaemia (high lipid diet)
How does type 2 diabetes commonly present?
Fatigue Polydipsia Polyuria Unintentional weight loss Infections (glucosuria)
How is type 2 diabetes diagnosed?
Oral glucose tolerance testing (OGTT) - measure plasma glucose 2 hours after giving a 75g glucose drink >11.1mmol/L
Can also do random glucose levels > 11.1mmol/L
Fasting glucose >7mmol/L
HbA1c > 48mmol/mol
What is the diagnostic criteria for pre diabetes?
HbA1c - 42 - 47mmol/mol
Fasting glucose 6.1 - 6.9mmol/L
OGTT - 7.8 - 11mmol/L
What lifestyle changes can be made to help type 2 diabetes?
Diet modifications - low sugar foods. Eat vegetables and oily fish.
Exercise
Weight loss
Stop smoking
What is regularly monitored for in type 2 diabetics?
Diabetic retinopathy
Kidney disease
Diabetic foot
What are the medication options for type 2 diabetics?
first line - metformin
second line - add sulfonylurea, pioglitazone, DPP4 inhibitors or SGLT2 inhibitors
third line - triple threapy
then may need insulin adding
How does metformin work?
Increases insulin sensitivity and decreases hepatic gluconeogenesis
What are the side effects of metformin?
Diarrhoea
Abdominal pain
Lactic acidosis
Decreased appetite
How does pioglitazone work?
Increases insulin sensitivity and decreases hepatic gluconeogenesis
(takes 6-8 weeks to work due to the way it altters gene transcription)
What are the side effects of pioglitazone?
Weight gain Fluid retention / oedema Anaemia Heart failure Extended use may increase risk of bladder cancer
How does gliclazide (sulfonylurea) work?
Stimulates B cells in the pancreas to produce and secrete insulin
What are the side effects on gliclazide (sulfonylurea)?
Weight gain
Hypoglycaemia
Increased risk of CVD and MI if used as monotherapy
What are incretins?
Hormones produced by the GI tract in response to meals. These act to decrease glucose levels by increasing insulin secretions and inhibiting glucagon production
How does sitagliptin work?
It is a DPP-4 inhibitor therefore increases the release of incretins which work to increase insulin release.
What are the side effects of sitagliptin (DPP-4 inhibitors)?
GI upset
Symptoms of URTI (upper resp tract infections)
Pancreatitis
What does DPP-4 stand for?
Dipeptidyl-peptidase-4
How does exenatide work?
GLP-1 (glucagon like peptide) receptor agonist -increases insulin secretion and supresses glucagon secretion.
How is exenatide administered?
Subcutaneous injection
What are the side effects of exenatide?
GI upset
Weight loss
Dizziness
How does dapagliflozin work?
SGLT-2 inhibitor. This causes more excretion of glucose into the urine from the blood.
What are the side effects of gliflozins?
Glucosuria
UTIs
Weight loss
What are the different types of insulin?
Rapid acting Short acting Intermediate acting Long acting Combined
What is DKA?
Diabetic ketoacidosis - lack of glucose in the cells causes ketone production. These then build up in the blood.
Why does diabetes cause polyuria and polydipsia?
Excess glucose overwhelms the kidneys, meaning glucose enters the urine. Glucose is osmotically active so draws water with it causing polyuria. This leads to dehydration which causes the thirst (polydipsia)
How does DKA present on investigation?
Hyperglycaemia Dehydration Ketosis Metabolic acidosis Potassium imbalance
What are the symptoms of DKA?
Polyuria Polydipsia Nausea and vomiting Acetone smell on breath dehydration leading to hypotension Altered conciousnes
How is a case of DKA managed?
Fluid resuscitation
Insulin infusion
Monitor potassium and ketones and correct if necessary.
What happens if injections are always in the same site?
lipodystrophy - subcutaneous fat hardens meaning insulin isn’t absorbed properly
What are the symptoms of hypoglycaemia?
Tremor Sweating Irritability Dizziness Pallor Decreased conciousness
What are the macrovascular complications of diabetes?
Coronary artery disease = MI
Stroke
Hypertension
Peripheral ischaemia = poor healing = diabetic foot and ulcers
What are the microvascular complications of diabetes?
Peripheral neuropathy
Retinopathy
Kidney disease (glomerulosclerosis)
How is diabetes monitored?
HbA1c - every 3-6 months
Capillary blood glucose
How is type 1 diabetes managed?
Insulin regime involving multiple injections subcutaneously
Monitor dietary intake of carbohydrates
Monitor blood glucose levels
