Adrenal Gland Disorders I

Question 1

Regulation of adrenal corticosteroid production (2)

Answer 1

Cortisol and androgen production are regulated by hormones produced by hypothalamus and anterior pituitary gland

Aldosterone regulated by renin-angiotensin system and plasma potassium

Question 2

Regulation of aldosterone: Renin-angiotensin system (3)

Answer 2

Major regulator of aldosterone production

Activated in response to decreased blood pressure

Leads to production of Ang II which causes direct (vasoconstriction) and indirect (aldosterone) methods of BP elevation

Question 3

Mechanism of action of corticosteroids (2)

Answer 3

Bind intracellular receptors

Receptor/ligand complex binds DNA to affect transcription

Question 4

6 classes of steroid receptors

Answer 4

-Glucocorticoid
-Mineralocorticoid
-Progestin
-Oestrogen
-Androgen
-Vitamin D

Question 5

Major glucocorticoid actions= CNS (3)

Answer 5

Mood lability

Euphoria/psychosis

Decreased libido

Question 6

Major glucocorticoid actions= Bone/ connective tissue (4)

Answer 6

Accelerates osteoporosis
- Decreased Serum calcium
- Decreased collagen formation
- Decreased wound healing

Question 7

Major glucocorticoid actions= CIRCULATORY/RENAL (3)

Answer 7

-Increased Cardiac output
-Increased Blood pressure
-Increased renal blood flow and GFR

Question 8

Major glucocorticoid actions=IMMUNOLOGICAL (4)

Answer 8

• Decreased capillary dilatate/permeability
• Decreased leucocyte migration
• Decreased macrophage activity
• Decreased inflammatory cytokine production

Question 9

Major glucocorticoid actions= METABOLIC
(3)

Answer 9

Carbohydrate: Increased blood sugar

Lipid: Increased lipolysis, central redistribution

Protein: Increased proteolysis

Question 10

Clinical applications of corticosteroids-principles of use (3)

Answer 10

Suppress inflammation

Suppress immune system

Replacement treatment

Question 11

Clinical applications of corticosteroids- Role in treatment (3)

Answer 11

Allergic disease: asthma/anaphylaxis

Inflammatory disease: rheumatoid arthritis, ulcerative colitis, Crohns disease

Malignant disease

Question 12

Mineralocorticoid Receptor (MR) (4)

Answer 12

-Kidneys
-Salivary glands
-Gut
-Sweat glands

Question 13

Effects of aldosterone via Mineralocorticoid Receptor (MR) (5)

Answer 13

1. Sodium/Potassium Balance
   -K+/H+ excretion
   -Na+ reabsorption
2. Blood pressure regulation
3. Regulation of extracellular volume

Question 14

Primary Adrenal insufficiency (3)

Answer 14

Addison’s disease

Congenital Adrenal Hyperplasia (CAH)

Adrenal TB/malignancy

Question 15

Secondary (and tertiary) Adrenal insufficiency (3)

Answer 15

Due to lack of ACTH stimulation

Iatrogenic (excess exogenous steroid)

Pituitary/hypothalamic disorders

Question 16

Primary Adrenal insufficeny- Causes (6)

Answer 16

Autoimmune/addisons

APS 1 + 2

Infections

Drug induced

Genetic

Bilateral adrenal=
-haemorrhage
-metastases
-infiltration
-adrenalectomy

Question 17

Secondary Adrenal insufficeny- Causes

Answer 17

Pituitary =
-tumours
-surgery
-irradiation
-apoplexy

Trauma

Infections/infiltrations

Sheehans syndrome

Question 18

Tertiary Adrenal insufficeny- Causes

Answer 18

Hypothalamic=
-tumours
-surgery
-irradiation

Trauma

Infections/infiltrations

Cushings disease

Drug induced

Question 19

Diagnosis of adrenal insufficiency (8)

Answer 19

biochemistry
-decreased Na, increased K
-hypoglycaemia

SHORT SYNACTHEN TEST
-Measure plasma cortisol before and 30 minutes after iv/im ACTH injection
-Normal: baseline >250nmol/L, post ACTH >550nmol/L

ACTH levels
-Should be very high(causes skin pigmentation)

Renin/aldosterone levels
very high renin, decreased aldosterone

Adrenal autoantibodies

Other (e.g. imaging)

Question 20

Management of adrenal insufficiency (11)

Answer 20

Do not delay treatment to confirm diagnosis

Hydrocortisone as cortisol replacement
-unwell, give intravenously first
-15-30mg daily in divided doses
-try to mimic diurnal rhythm

Fludrocortisone as aldosterone replacement
-careful monitoring of BP and K

Need education
-‘Sick day rules’
-Cannot stop suddenly
-Need to wear identification

Question 21

Adrenal Crisis – A life threatening emergency (4)

Answer 21

0.9% NaCl (normal saline)

100mg iv hydrocortisone

Underlying cause/precipitant

If in doubt - TREAT

Question 22

Addison’s Disease (8)

Answer 22

Commonest cause of primary adrenal insufficiency

-40-60 cases/million per year
-Autoimmune destruction of adrenal cortex
-90% destroyed before symptomatic
-Autoantibodies positive in 70%

Associated with other autoimmune diseases=
-Type 1 DM
-autoimmune thyroid disease
-pernicious anaemia

Question 23

Clinical Features of Addison’s Disease (5)

Answer 23

Anorexia, weight loss

Fatigue/lethargy

Dizziness and low BP

Abdominal pain, vomiting, diarrhoea

Skin pigmentation