[W5] Clinical Biochemistry of Endocrine Disease Flashcards
(23 cards)
What are the four types of hormone action?
Endocrine, paracrine, autocrine, and intracrine.
Name four types of hormones.
Peptides, glycoproteins, steroids, catecholamines.
What is the primary regulatory mechanism in endocrine axes?
Negative feedback.
What is the hormonal sequence in the thyroid axis?
TRH → TSH → T4/T3.
What is the biochemical pattern in hypothyroidism?
↑TSH, ↓T4.
What is the biochemical pattern in hyperthyroidism?
↓TSH, ↑T4.
What hormones are involved in the adrenal axis?
CRH → ACTH → Cortisol.
What is Cushing’s syndrome?
Excess cortisol; symptoms include moon face, hyperglycaemia.
What is Addison’s disease?
Cortisol deficiency; symptoms include hypotension, low sodium, high potassium.
When is cortisol highest during the day?
8–10am.
What test is used for suspected Addison’s?
Short synacthen test.
What test is used for suspected Cushing’s?
Overnight dexamethasone suppression test.
How is GH deficiency tested?
Glucagon stimulation test.
How is GH excess (acromegaly) diagnosed?
Glucose suppression test or IGF-1.
What can cause prolactin excess?
Prolactinoma, stress, pregnancy, medications.
What causes Type 1 DM?
Autoimmune destruction of β-cells.
What causes Type 2 DM?
Insulin resistance followed by β-cell failure.
How is gestational diabetes diagnosed?
OGTT at 24–28 weeks (fasting ≥ 5.6 mmol/L, 2h ≥ 7.8 mmol/L).
What is HbA1c?
Glycated haemoglobin – reflects 3-month average glucose.
What is diagnostic for diabetes (HbA1c)?
HbA1c ≥ 48 mmol/mol.
What method offers more specific hormone measurement?
LC-MS/MS.
Why are free hormone levels important?
Only free hormones are biologically active.
What factors affect hormone levels in lab tests?
Time of day, age, sex, illness, stress, drugs, binding proteins.
