18 Adrenal Disorders

Question 1

What are the signs and symptoms of excess cortisol secretion? (Cushing’s syndrome)

Answer 1

1. Increased proteolysis
   
   1. Wasting of proximal muscles
      
      1. Weak arms and legs
2. Hepatic gluconeogenesis- Steroid diabetes
   
   1. ​Hyperglycaemia
      
      1. Polydypsia
      2. Polyuria
3. Increased lipogenesis
   
   1. Abdomen fat deposition
   2. Neck and face- moon shaped face
4. Purple striae on lower abdomen, upper arms, thighs
   
   1. Due to catabolic effects on protein structures
5. Easy bruising
   
   1. Due to catabolic effects on protein structures
6. Immunosuppressive, anti-inflammatory, anti-allergic reactions of cortisol
   
   1. Increased susceptibility to bacterial infections
   2. Acne
7. Osteoporosis (calcium metabolism disturbances)
   
   1. Back pain
   2. Collapse of ribs
8. Mineralocorticoid effects
   
   1. Hypertension- sodium and fluid retention

Question 2

What are the clinical tests for adrenocortical function?

Answer 2

1. Plasma cortisol
2. Plasma ACTH
3. 24hr Urinary excretion of cortisol (&its breakdown products)

Question 3

Give an example of a dynamic function test which can be used to differential diagnose adrenocortical disease.

Answer 3

ACTH stimulation test

Question 4

How can dexamethasone be used to differetially diagnose adrenocortical disease?

Answer 4

• =potent synthetic steroid
• Given orally
• Suppresses ACTH (therefore cortisol) secretion
  
  • (through feedback loop)
• If >50% supression of cortisol= CUSHING’S DISEASE
• (because of diseased pituitary)

Question 5

What disease would a normal response to Synacthen (synthetic analogue of ACTH) administration intramuscularly exclude?

Answer 5

Addison’s

Normal result= increase plasma cortisol by >200nmol/L

Question 6

What is the most common form of a deficiency affecting one or more enzymes required for the synthesis of corticosteroid hormones from cholesterol?

Answer 6

21-hydroxylase enzyme deficiency

–> causes LESS GLUCOCORTICOID and LESS MINERALOCORTICOID production

–> Precursor for this hormone=diverted to more androgen synthesis

Question 7

What can a 21-hydroxylase enzyme deficiency cause?

Answer 7

Genital ambiguity in female infants

Salt-wasting crisis (high rate of sodium loss in urine)

Question 8

What is Conn’s syndrome?

Answer 8

Primary hyperaldosteronism

Question 9

What can cause Conn’s syndrome?

Answer 9

Hyperactivity of adrenal glands

• Unilateral
  
  • ​Adenoma
• Bilateral
  
  • ​Rare genetic syndromes
    
    • Familial hyperaldosteronism type 1
    • Familial hyperaldosteronism type 2

Question 10

What are the signs and symptoms of Conn’s syndrome?

Answer 10

• High BP (Increased sodium reabsorption and potassium secretion- increased blood volume)
• Occasional muscular weakness and spasms
• Tingling sensations
• Excessive urination

Decreased renin does not cause decreased aldosterone

Question 11

Thyroid and vitamin D receptors are part of what receptor family?

Answer 11

Nuclear DNA-binding proteins:

Steroid receptors

Question 12

Steroid receptors all have 3 main regions, what are they?

Answer 12

1. Hydrophobic hormone binding region
2. DNA binding region
3. Variable region

Question 13

What do androgens do in males?

Answer 13

Stimulate growth and development of:

• male genital tract
• male secondary characteristics
• anabolic effects on muscle protein

Question 14

What effect does over secretion of adrenal androgens have on females?

Answer 14

Excessive body hair growth

Menstrual problems

Deepened voice

Increased muscle bulk

Question 15

What hormone stimulates the growth of the female genital tract and female secondary characteristics?

Answer 15

Oestrogen