Endocrine II Flashcards
What are the two types of DI?
Cranial - low ADH
Nephrogenic - not responsive to ADH
Which two drugs can cause DI?
Lithium
Demeclocycline
How is DI diagnosed?
Fluid depravation for 8h, then ADH
Step 1 - fluid depravation
- If urine osmolality >600 then stop
- If urine osmolality <600 then continue to stage 2
Step 2 - give desmopressin IM
- Cranial DI: urine osmolality increases to >600 after desmopressin
- Nephrogenic DI: no increase in urine osmolality after desmopressin
Treatment of nephrogenic DI?
NSAIDs
Thiazides
Treatment of hirsutism?
Cyproterone
Definitive test for acromegaly?
Oral glucose tolerance test (suppression test)
Rising levels of glucose inhibit GH secretion
In healthy patient, in OGTT, GH levels should be undetectable
In acromegaly, there is failure to suppress GH secretion
Patient >60 with bone pain, hypercalcaemia, increased ALP = ?
Multiple myeloma
Osteolytic lesions seen on x-ray
Really long arms + legs + gynaecomastia = ?
Klinefelter’s syndrome
List three clinical features of Kartagener’s syndrome
Dextrocardia
Abnormal frontal sinus
Primary ciliary dyskinesia
Decreased anti-malarian hormone + increased FSH = ?
Reduced ovarian reserve
In hypopituitarism, which hormones area affected in which order?
GH FSH + LH PRL TSH ACTH
Describe the treatment for hypopituitarism
- Hydrocortisone - before any other hormone
- Thyroxine if hypothyroid
- Men - testosterone replacement
- Women (premenopausal) - oestrogen patches or contraceptive pill
- Gonadotrophin therapy is needed to induce fertility in both men and women
- GH - refer to endocrinologist for insulin tolerance testing
Treatment of chlamydia?
Azithromycin
What is Sheehan’s syndrome?
Post partum hypopituitarism caused by ischaemic necrosis due to blood loss and hypocolaemic shock during and after childbirth
WHAT DO STEROIDS DO TO BLOOD GLUCOSE LEVELS
STEROIDS INCREASE BLOOD GLUCOSE LEVELS
List the four main functions of cortisol
- Maintain normal plasma glucose levels
- Under stress it allows the body to have a fuel source
- Increased responsiveness of adrenoreceptors to adrenaline - helps with circulation to prevent patient going into shock
- Anti-inflammatory roles at high levels
What effect does cortisol have on metabolism?
Increases the amount of raw material that the body can use as energy in times of stress
- Increases lipolysis
- Decreases glucose uptake into tissues
- Increases gluconeogenesis
- Increases proteolysis
What does uncontrolled secretion of cortisol do to blood glucose?
Dramatically increases blood glucose
If cortisol increases blood glucose, what symptoms will this give the patient?
Polyuria
Polydipsia
What is the classic triad of symptoms of excess adrenaline?
Hypertension
Sweating
Headaches
What is the stimulus for erythropoietin secretion?
Hypoxia - causes stem cells in the bone marrow to produce RBCs to increase the oxygen carrying capacity of the blood
What is calcidiol?
A prehormone produced in the liver, originating in the skin
In the kidneys is is converted to calcitriol
This is stimulated by PTH
What are the two roles of angiotensin II?
Directly vasoconstricts
Indirectly elevates BP by aldosterone
What should you think of cortisol as?
A stress hormone
What are the three main clinical uses of corticosteroids?
- Suppress inflammation e.g. asthma
- Suppress immune system e.g. autoimmune conditions - Crohn’s
- Replace treatment - for people who don’t produce enough
What are the end product deficiencies in each of these enzymatic deficiencies?
- 21aOH
- 11bOH
- 17aOH
21aOH - problem with glucocorticoid and mineralocorticoid -> increased androgen
11bOH - problem with glucocorticoid and mineralocorticoid -> increased androgen
17aOH - problem with glucocorticoid and androgen -> normal aldosterone
What are the clinical features of 11bOH deficiency?
Females virilised
Salt wasting rare
What are the clinical features of 17aOH deficiency?
Males virilised
Females fail to achieve puberty
Salt wasting not observed
What is significant about hypovolaemia in hyponutraemia?
This implies that there is a very big sodium deficit
Must give the patient the sodium which they lack
What does oedema tell you?
Water is in the wrong place
You are likely to have too much sodium, in the wrong place
Which genes are associated with
- Carney complex
- McCune-Albright
- Von Hippel-Lindau disease
- Nerofibromatosis type I
Carney complex - PRKAR1A
McCune-Albright - GNAS1
Von Hippel-Lindau disease - VHL
Nerofibromatosis type I - NF1
What are glucose levels in Addison’s?
Low - CORTISOL INCREASES GLUCOSE LEVELS
List some causes of primary and secondary adrenal insuffifiency
Primary - Addisons - CAH - TB, tumor Secondary - Exogenous steroid use - Pituitary/hypothalamic tumours
Diagnosis of secondary adrenal insufficiency?
When might this be negative?
Long synacthen test
If acute this may be negative - give steroid anyway
What is biochemistry like in Addison’s?
Hyponatraemia
Hyperkalaemia
Hypercalcaemia
Hypoglycaemia
Unexplained abdominal pain + vomiting = ?
Addison’s
Which antibodies are positive in autoimmune addisons?
21-hydroxylase adrenal autoantibodies
Hypertension + hypokalaemia = ?
Primary aldosteronism