Endocrine Medicine 2 Flashcards
What zone of the cortex is aldosterone found?
zona glomerulosa
What zone of the cortex is cortisol found?
zona fasicularis
What zone of the cortex are the androgens found?
zona reticularis
What is the precursor for all adrenal hormones?
cholesterol
What are the actions of aldosterone?
what drugs
Salt and water regulation
Enhances sodium reabsorption and potassium loss, indirectly affecting blood pressure (RAAS).
Can be inhibited by drugs like ACE inhibitors and angiotensin II receptor blockers (ARBs).
What are the side effects of ACE inhibitors?
- Cough
- angio-oedema
- Oral lichenoid drug reactions
When is cortisol released?
Circadian release – nocturnal peak
What are the actions of cortisol?
- Inhibits insulin
- Gluocneogenesis
- Lowers the immune reactivity (reduces inflammation)
- Raises blood pressure
- Catabolic effect on bone, fat and protein
- Permissive effect (enhances) actions of adrenaline
What are some therapeutic steroids and what is the potency compared to cortisol?
- Hydrocortisone (cortisol equivalent = 1)
- Prednisolone (4x)
- Dexamethasone (25x)
- Betamethasone (30x)
What is betamethasone used for in oral health?
used for oral mucosal inflammation
What are the adverse effects of therapeutic steroids similar to?
symptoms of cushings disease
What are the adverse effects of therapeutic steroids?
- Hypertension
- Type 2 diabetes
- Osteoporosis
- Increased infection risk
- Peptic ulceration
- Thinning of the skin
- Easy bruising
- Cataracts & Glaucoma
- Hyperlipidaemia (atherosclerosis)
- Increased cancer risk
- Psychiatric disturbance
What does hyperfunction of glucocorticoids cause?
cushings syndrome
How is cushings syndrome/disease caused?
- adrenal tumour - primary (syndrome)
- pituitary tumour - secondary (disease)
What does hyperfunction of aldosterone (mineralocorticoid) cause?
conn’s syndrome
How is conn’s syndrome caused?
adrenal tumour (excess reabsorption of water and Na causing hypertension)
What are the hypofunction diseases?
- Addison’s disease - primary
- Pituitary failure - secondary
How can cushing’s disease be caused outwith adrenal gland/PG?
ecotopic ACTH production in some lung tumours
What are the symptoms of cushing’s syndrome?
- ‘diabetes mellitus’ features
- reduced immunity
- osteoporotic changes
- back pain & bone fractures
- psychiatric disorders (depression, psychosis)
- hirsuitism
- Skin and mucosal pigmentation
- reduced periods & infertility
Why are there diabetes features in cushings syndrome?
steroid hormones are antagonistic to insulin
What are the signs of cushings syndrome?
- moon face
- buffalo hump
- hypertension
- thin skin & purpura
- muscle weakness
- Osteoporotic changes & fractures
What is the precursor ACTH and MSH both originate from?
Pro-OpioMelanocortin
Why does pigmentation increase in some types of cushings condition?
excess ACTH triggers MSh which causes melanocytes to become active
similarities in sequence means that HIGH ACTH levels will stimulate pigment cells
How can adrenal hypofunction happen?
gland failure
pituitary failure
How can hypofunction be caused due to gland failure?
- autoimmune gland destruction (addison’s)
- infection
- Infarction
How can hypofunction be caused due to pituitary failure?
- compression from other adenoma
- Sheehan’s syndrome
How can addison’s disease be caused?
- TB a major cause worldwide
- Autoimmune adrenalitis (90%) (organ-specific autoimmune disease)
What are signs of addison’s disease?
- postural hypotension
- salt and water depletion
absence of ALDOSTERONE and aldosterone effects of GLUCOCORTICOIDS - weight loss & lethargy
- hyperpigmentation (not in secondary hypofunction)
- scars, mouth, skin creases pigmentation effect of increased ACTH secretion
- vitiligo
What are the symptoms of addison’s disease?
- weakness
- anorexia
- loss of body hair (females)
How can cushing’s syndrome be investigated?
- high 24hr urinary cortisol excretion
- abnormal dexamethasone suppression tests - feedback suppression of cortisol via ACTH in normal
- CRH tests
- cushings disease show rise in ACTH with CRH
How can addison’s disease investigated?
- high ACTH level
- negative synACTHen tests
- No plasma cortisol rise in response to ACTH injection
What is synacthen and what is it used to test?
synthetic form of adrenocorticotropic hormone
used to test if cortisol levels rise - if they don’t the problem is gland destruction/adenoma
What are the biomarkers of hyperfunction (cushings) caused by pituitary adenoma/ectopic ACTH production?
*High ACTH
*High Cortisol
What are the biomarkers of hyperfunction (cushings) caused by gland adenoma?
*Low ACTH
*High Cortisol
What are the biomarkers of hypofunction (addisons) caused by pituitary failure?
*Low ACTH
*Low Cortisol
* SYNACTHEN Positive
What are the biomarkers of hypofunction (addisons) caused by gland destruction?
*High ACTH
*Low Cortisol
* SYNACTHEN Negative
How can adrenal hyperfunction be treated?
- Detect cause (adenoma) (pituitary, adrenal, ectopic (lung))
- Surgery - pituitary, adrenal - partial/complete adrenalectomy
What happens during crisis in addisons disease?
- hypotension
- vomiting
- eventual coma
Why does crisis happen?
The crisis state arises from the inability to regulate salt and water balance due to the lack of aldosterone and cortisol. (hypovolemic shock
What is treatment for addisons disease?
Hormone Replacement
* cortisol
* fludrocortisone (aldosterone)
What is steriod prophylaxis?
increase the steroid dose when increased physiological requirement anticipated:
* Infection
* Surgery
* Physiological stress
What are the dental aspects of steriod diseases?
- STEROID precautions may be needed
- liase with physician for infections/illness
- candidiasis in Cushings
- oral pigmentation in Addison’s/Cushings
