Endocrine Flashcards
What is diabetes mellitus caused by?
lack or reduced effectiveness of endogenous insulin - hyperglycaemia
Describe the aetiology of diabetes
Reduced insulin secretion and insulin resistance due to:
drugs - steroids, anti-osychotics, thizaides
pancreatic - surgery, trauma, ca,
hormonal - Cushing’s, acromegaly, PCC, hyperthyroidism
congenital lipodystrophy and glycogen storage disease
What are the symptoms of hyperglycaemia?
polyuria polydipsia unexplained weight loss visual blurring genital thrush lethargy
Describe the pathophysiology of diabetes?
Increased carb intake
increased hepatic glucose production
decreased insulin secretion and decreased peripheral glucose uptake
all lead to increased blood glucose
What are the risk factors of diabetes?
obesity
lack of exercise
calorie and alcohol excess
genetics
What investigations are done for diabetes?
venous glucose - fasting >7mmol/l or random >11mmol/L
HBA1c >48 mmol/L –> 6.5%
What is the first line treatment for type 2 diabetes?
Metformin
What is the second line treatment for diabetes?
Sulphonylurea
What is the third line treatment for diabetes?
basal insulin or pre mix insulin
What is the fourth line treatment
Basal and meal time insulin
What is the classic cause of the diffuse goitre?
Grave’s disease
Describe the epidemiology of Grave’s disease?
Female: Male - 9:1
typical age - 40-60 years old
What is the cause of Grave’s disease?
circulating igG autoantibodies (thyroid stimulating immunoglobulins TSI) bind to and activate G-protein coupled TSH receptors which cause smooth thyroid enlargement and increased hormone production
What are the triggers for Graves’ disease?
Stress
infection
childbirth
What are the signs of Graves disease?
eye disease (exophthalmos, ophthalmoplegia, pretibial myxoedema, thyroid acropachy (clubbing, painful finger and toe swelling periosteal reaction, goitre
What is a toxic adenoma?
a solitary nodule producing T3 and T4
On isotope scan, the nodule is hot and the rest of the gland is suppressed
Who gets a toxic multi-nodular goitre?
Elderly
iodine deficient areas
nodules that secrete thyroid hormones
What other forms of hyperthyroidism are there?
thyroiditis - thyrotoxicosis without hyperthyroid
excess exogenous thyroid hormone
drug induced (amiodarone, lithium)
TSH-secreting pituitary tumour
What are the causes of hypothyroidism?
Primary atrophic hypothyroidism
Post-thyroidectomy
Post radioactive iodine
Hashimoto’s thyroiditis
What is Hashimoto’s hypothyroidism?
Primary autoimmune hypothyroidism
autoantibody titres are very high (against TOP) - enzyme that oxidises iodine to be incorporated into thyroid hormones
What are the signs and symptoms of hyperthyroidism
Diarrhoea weight loss increased appetite sweats heat intolerance palpitations tremor irritability labile emotions oligomenorrhoea +/- infertility
pulse fast warm, moist skin palmar erythema thin hair lid lag exophthalmos
What are the symptoms and signs of hypothyroidism?
tired and lethargic decreased mood cold intolerant weight gain constipation menorrhagia hoarse voice memory or cognition decreased dementia myalgia cramps weakness
What are the examination findings of hypothyroidism?
bradycardia reflexes relax slowly ataxia dry, thin hair/skin yawning/drowsy cold hands/decreased temperature ascites +/- non-pitting oedema round puffy face/double chin/obese defeated demeanor immobile CCF
What investigations can be done for hyperthyroidism?
TFT: <0.01mIU/L TSH in hyperthyroid
if TSH normal, diagnosis excluded
Free T3/T4 is elevated
If TSH low but free T3/T4 normal = subclinical hyperthyroidism
