HPAA clinical aspects Flashcards
Presentation of Cushing’s syndrome
Central obesity
Puffy, moon face
Buffalo hump- fat deposit in the back of the neck.
Hypertension, tachycardia, arrhythmia.
Hirsutism
Diabetes
Osteoporosis
Depression
Thin skin
Pathogenesis of Cushings
Excess cortisol production.
Causes
- Pituitary adenoma secreting excess ACTH
- Adrenal adenoma
- Adrenal carcinoma
- Paraneoplastic ectopic ACTH
- Iatrogenic treatment with steroids
- CRH-secreting tumour
Diagnostic tests for too much cortisol
24 hr free cortisol in urine levels
Midnight saliva/ blood cortisol
9 AM ACTH levels compared with cortisol
- Determines if it is pituitary, adrenal or ectopic.
Dexamethasone suppression
- Inhibits ACTH production
- Should see a drop in cortisol if normal.
Imaging after biochemical tests
- CXR
- MRI pituitary
- CT adrenal
Diagnostic tests for too little cortisol
Hypoglycaemic stress
- Insulin resistance test
- Injection of insulin will not see rise in cortisol levels.
SynACTHen test
- ACTH injection will not see rise in cortisol
- am cortisol
- Lower than normal
Urine and electrolytes
- Hyponatraemia
- Hypokalcaemia
- Low aldosterone and renin
Blood glucose test
- Hypoglycaemic
Cushing’s syndrome
- Treatment
Surgical
- Transphenoidal adenectomy
- Adrenalectomy
Pituitary radiotherapy
If iatrogenic: slowly ween off steroid therapy then stop.
Addison’s disease
- Treatment
Steroid replacement therapy
- Hydrocortisone
- Dose increased to cover stress [esp after surgeries or if nil my mouth]
If primary adrenal insufficiency
- Mineralocorticoid and glucocorticoid replacement therapy
Secondary adrenal insufficiency
- Mineralocorticoid not needed
- Other hormone replacement therapy
11-beta-hydroxysteroid dehydrogenase enzyme
Enzyme that is able to convert cortisol into the inactive cortisone
- and vice versa
Does so in specific tissue, depending on the demand for mineralocorticoid or glucocorticoid.
- If in kidneys, colon, salivary glands–> Mineralocorticoid is preferred= inactivation of cortisol into cortisone.
- In the liver—> Cortisol is activated.
Enzyme allows tissue specificity
- Gating of GC access to receptors via pre-receptors
Circulating adrenal androgens
Androstenedione
DHEAS [dehydroepiandrosterone]
Addison’s disease
- Presentation
Malaise
Weakness
Anorexia
Weight loss
Increased skin pigmentation
Hypotension
Hypoglycaemia
Primary adrenal insufficiency
- Causes/ pathogenesis
Includes Addison’s disease
- Mainly caused by autoimmune destruction of adrenal glands.
Other causes:
- Metastasis
- TB
Secondary adrenal insufficiency
- Causes
Hypoadrenalism caused by impairment of the hypothalamus or pituitary gland.
Causes:
- Pituitary adenoma
- Iatrogenic [ sudden halt of long term steroidal treatment ]
Autoimmune polyendocrine syndromes Type 1
Genetic condition that gives rise to many endocrine and autoimmune conditions.
Caused by mutation in AIRE gene
- Autosomal recessive inheritance
Presentation
- Rare
- Onset infancy
Common phenotype
- Addison’s disease
- Hypoparathyroidism
- Candidiasis
Autoimmune polyendocrine syndromes Type 2
Condition caused by polygenetic factors
- Can give rise to many autoimmune/ endocrine diseases
- More common than Type 1
Onset occurs between infancy and adulthood.
Phenotypes
- Addison’s disease
- T1 diabetes
- Autoimmune thyroid disease
Examples of autoimmune polyendocrine syndromes that can occur together.
T1 DM [endocrine]
Autoimmune thyroid disease [endocrine]
Coeliac disease [gut]
Addison’s disease [endocrine]
Pernicious anaemia [blood]
Alopecia [skin]
Vitiligo [skin]
Hepatitis [liver]
Premature ovarian failure [GYN]
Myasthenia gravis [Neuro]
Patient with: - T1 DM - Fatigue - Weight loss - Hypoendocrine disorders Is highly suspicious of having...
Addison’s disease
