Endocrinology/metabolic Flashcards
What biochemical abnormality does vitamin D deficiency lead to?
Low calcium
Low phosphate
Secondary hyperparathyroidism
Raised ALP
Give an example of a long acting insulin
Glargine (Lantus)
What is the treatment for acute symptomatic hyponatraemia?
Hypertonic saline
What are the causes of a low TSH and normal T4?
Sublcinical hyperthyroidism
Thyroxine ingestion
What is the normal anion gap range?
12-17 mmol/l
What is pseudohypoparathyroidism caused by?
Resistance to PTH
Results in low calcium, high PTH and high phosphate
Skeletal abnormalities including short stature, rounded face, shortened fourth metacarapals
Describe the thyroid morphology in Hashimoto’s thyroiditis
Large, firm and lobulated due to lymphocytic infiltration and fibrosis
Describe the thyroid morphology in Riedel’s thyroiditis
Replacement of the normal thyroid parenchyma by dense fibrosis extending beyond the capsule
Most patients are euthyroid but 1/3rd become hypothyroid
What is the most common type of thyroid cancer?
Papillary - affecting 20-55 year olds
How does ACTH work?
Activates the 20,22 desmolase enzyme which catalyses the rate limiting step in adrenal steroidogenesis
How do you diagnose diabetes mellitus?
HbA1c > 48mmol/mol
Fasting glucose >7 mmol/l
Random glucose >11.1 mmol/l
What is POEMs syndrome?
Polyneuropathy, organomegaly, endocrinopathy and m-protein band from a plasmacytoma & skin pigmentation/tethering
What is milk-alkali syndrome?
Triad of hypercalcaemia, renal failure and metabolic alkalosis secondary to ingestion of large amounts of calcium and absorbable alkali
What is the most common cause of subclinical hypothyroidism?
Chronic autoimmune thyroiditis
How should you further investigate subclinical hypothyroidism?
Repeat measurement after 3 months
In which groups should HbA1C not be used to diagnose DM?
<18y
Pregnant women or women who are <2m postpartum
Symptoms of diabetes <2m
Acutely ill
Medication that may cause hyperglycaemia
Acute pancreatic damage
HIV infection
ESRD
How do you calculate plasma osmolarity?
2xNa + Ur + glucose
What is the normal range for plasma osmolarity?
285-295 mmol/l
Name some clinical features of Grave’s disease
Exophthalmos
Ophthalmoplegia
Thyroid acropatchy
Pretibial myxoedema
What is the genetic defect in MEN1?
Mutations in the tumour suppressor gene MEN1
What is the genetic defect in MEN2?
Mutations in the RET proto-oncogene
Name some causes of hypoglycaemia
Exogenous
Pituitary insufficiency
Liver failure
Addison’s disease
Islet cell tumours
Non-pancreatic neoplasms
How do you biochemically diagnose acromegaly?
IGF-1 is better than GH due to more consistent serum levels
What is a ‘medical’ III nerve palsy?
III palsy with pupillary sparing as fibres for sphincter pupillae run on the outside
What is the HbA1C target if taking a drug associated with hypoglycaemia?
52mmol/mol
Name some secondary causes of DM
Drugs: steroids, thiazides
Pancreatic disease: pancreatitis, Ca, haemoschromatosis, CF
Endocrine: Cushing’s, thyrotoxicosis, phaeo, acromegaly
Others: glycogen storage diseases, insulin receptor antibodies
What are the clinical features of toxic multinodular goitre?
Also known as Plummer’s disease
Most patients are over 50
Consists of a thyroid gland with autonomously functioning thyroid nodules
Which genetic mutations are implicated in hereditary haemochromatosis?
C282Y & H63D HFE mutations commonly tested
In which conditions may you find lanugo?
Premature newborns
Anorexia nervosa
How does Danazol work?
It inhibits pituitary gonadotrophins
Name some clinical features of medullary thyroid carcinoma
Diarrhoea and facial flushing due to excessive calcitonin
Malignancy of parafollicular C-cells
Name some clinical features of papillary thyroid carcinoma
Occurs more frequently in women
Presents in 30-40yr age group