Endocrinology I & II: Diabetes Mellitus and Acromegaly Flashcards
What is glucagon?
-Peptide from alpha cells in Islets of Langerhans
-Secreted in response to lowered glucose levels
-Action is to oppose insulin
What are catecholamines?
Secreted by adrenal medulla in response to stress which raises blood glucose levels
What is glucocorticoid?
Cortisol which promotes gluconeogenesis, gyconeolysis and protein catabolism
What are hypoglycaemic and hyperglycaemic hormones?
Hypoglycaemic: Hormone that drops glucose levels e.g insulin
Hyperglycaemic: Hormone that encourages increase in glucose levels e.g Glucagon, cortisol, catecholamines and growth hormone
What is diabetes Mellitus?
Group of conditions characterised by chronic hyperglycaemia resulting from reactive insulin deficiency, peripheral tissue resistance or both.
Is usually primary and classified as insulin dependent (type 1)
Compare type I vs type II diabetes
slides
What values suggest someone has diabetes mellitus (glucose tolerance test)?
> 6.7 mmol/l fasting
10 mmol/l two hours after glucose
What is the treatment for diabetes?
Type I - insulin such as actrapid, monotard, mixtard
Diet - fat reduced to 30% of total energy intake
Drugs - sulphonylureas, gibenclamide, tolbutamide, biguanides (metformin)
How do you measure the control of blood glucose levels?
-Fingerprick glucose
-Urine dipstick
-Lab serum glucose
-Glycosylated Hb
What is acute hypoglycaemia?
Blood glucose is less than 2.2 mmol/l (dental emergency)
What are the signs and symptoms of acute hypoglycaemia?
Increased sympathetic tone causes hunger, sweating, pallor and tachycardia
Later changes include aggression and peripheral tingling and altered sensations
Fits, hemiparesis and ultimately coma
What is the treatment of acute hypoglycaemia?
If patient is conscious, rapid ingestion of sugar (IV glucose, 50ml 50% dextrose or glucagon, 1mg IM)
If unconscious or depressed, gag reflex then
What is diabetic ketoacidosis (DKA)?
A condition where raised metabolism is required to fight illness which needs more insulin.
Reduced doses kill by causing relative hypoglycaemia
What is the pathophysiology of DKA?
Insulin deficiency leads to uncontrolled catabolism (cells cannot access glucose)
High blood sugar levels produce glycosuria (a condition characterized by an excess of sugar in the urine, typically associated with diabetes or kidney disease), osmotic diuresis (Osmotic diuresis is increased urination due to the presence of certain substances in the fluid filtered by the kidneys) and dehydration
Tissues that can’t get sugar from the blood start to break down into acidic ketones.
What are the clinical features of DKA?
Profound dehydration due to renal water and electrolyte losses
Low BP and air hunger (breathlessness) to compensate for metabolic acidosis
What are the complications of diabetes?
-Heart disease
-Peripheral vascular disease
-Atheroma
-Stroke
-Increased risk of UTI and skin infections
-Macrovascular: accelerated atheroma leading to stroke, ischaemic heart disease or ischaemic limbs
-Microvascular: diabetic retinopathy can lead to blindness, diabetic nephropathy can lead to renal failure, diabetic neuropathy can lead to loss of sensation
What are the two parts of the adrenal gland and what are their functions?
Medulla - catecholamine production
Cortex - steroid hormone production
What is Addison’s disease?
Hypoadrenalism-underfunction of adrenal gland
(Disease is rare but syndrome is more common)