Diabetes Tutorial Flashcards
What will T1DM look like histologically?
Insults typical of insulin diabetes causing beta cell destruction
Loss of beta cell secreting insulin
What will T2DM look like histologically?
Amyloid disposition within islet cells
What is monogenic diabetes?
Diabetes due to a mutation in a gene regulating insulin secretion or action e.g. MODY, neonatal diabetes and mitochondrial diabetes
What can cause secondary diabetes?
Cushing's Acromegaly Haemachromatosis Chronic and acute pancreatitis CF HIV drugs Post organ transplantation
What is the WHO criteria for diabetes?
Fasting plasma glucose =>7.0 mmol/L
Plasma glucose after a 75g oral glucose load or a random glucose >= 11.1 mmol/L
What is significant in a history taking of someone who might have diabetes?
Symptoms of hyperglycemia, rapidity of onset, weight loss
Diet - lots of sugar
Medication - corticosteroids
PMH - pancreatitis, heavy alcohol consumption
FMx of diabetes/ autoimmune conditions/ of insulin resistance: CVS, Stroke, Hypertension, high lipids
How can diabetes be investigated?
Confirm hyperglycemia
Ketonuria
Check for GAD antibodies
Insulin conc
What can be done in a clinical exam of diabetes?
General incuding fluid status - tachycardia, postural hypotension
Signs of infection that may be precipitated infection
Microvascular disease? Fundoscopy, foot exam
Features of secondary diabetes? Cushingoid, bronze pigementation, acanthosis
What causes DKA?
Absolute or relative lack of insulin
Increased glucose production but reduced glucose uptake
Increased tissue fatty acid metabolism producing ketone bodies
What are the symptoms of DKA?
Increased weakness and muscle cramps
Nausea and vomiting
Kussmaul’s breathing
Tired, drowsy, confused Coma
What are the symptoms of dehydration?
Polyuria and thirst
How can an MI cause DKA?
Increased counterregulatory hormones such as catecholamines, glucagon, GH and cortisol causing increased glucose production and reduced glucose uptake
What can cause diabetic nonketotic hyperosmolar coma in type 2 patients?
Relative lack of insulin
Increased glucose production and lack of glucose utilisation
Increased blood glucose
Osmotic diuresis causing dehydration leading to polyuria, thirst and an increased sodium and urea in blood
This leads to drowsiness, confusion and a coma
How is plasma osmolality calculated?
Plasma osmolality = 2 x (plasma sodium + plasma potassium + plasma urea + plasma glucose)
What are the normal values for plasma osmolality?
285 - 295
What leve of plasma osmolality can cause impaired consciousness?
340
How is DKA diagnosed?
Confirm diabetes - high lab glucose
Confirm ketosis - blood or urine ketones high
Confirm acidosis - low venous bicarb or acidosis on blood gas
How is DKA managed?
ABC
Hx and exam to look for cause; infection, surgical abdomen, silent MI
Cardiac monitor and other non invasive monitoring
IV fluids - N/Saline 1 litre quickly
IV insulin - 6 units hourly but NO bolus insulin
Watch potassium and replace aggressively to prevent hypokalemia and cardiac arrest. Insulin drives K+ into cells and therefore can drop quickly
What is the first line drug in the treatment of T2DM?
Metformin with a target HbA1c to 53 mmol/mol
What is the second line drug in T2DM if metformin doesn’t create adequate glycaemic control?
Sulphonylurea
What is the side effect of sulfonylurea?
Hypoglycemia
Weight gain