endocrine basic principles

Question 1

what are the major endocrine glands?

Answer 1

• Thyroid
• Pituitary (+hypothalamus)
• Adrenal
• Calcium/parathyroid
• (Pancreas – predominantly diabetes)
• Reproductive endocrinology

Question 2

how are thyroid hormones measured?

Answer 2

Highly sensitive TSH assay employed to evaluate thyroid hormone
Relies on highly regulated feedback control
Normal TSH = normal thyroid
Raised TSH = Hypothyorid
Suppressed TSH = Hyperthyroid

(high=hypo, low=hyper)

Question 3

why is pituitary dysfunction referred to as secondary hypothyroidism?

Answer 3

it is part of a feedback loop with the pituitary so pituitary dysfunction will have high TSH

Question 4

how is pituitary function assessed?

Answer 4

• 9am cortisol
• FT4, FT3, TSH
• Prolactin
• IGF1
• LH, FSH, E2/Testosterone
• U&E, Plasma/urine osmolality
• Dynamic tests
• Imaging (MRI)

Question 5

what happens when you have cortisol deficiency?

Answer 5

adrenal insufficiency
→ Primary adrenal failure (e.g. Addison’s disease)
→ Pituitary disease

Question 6

what happens when you have cortisol excess?

Answer 6

Cushing’s syndrome - can be caused by:
→ Pituitary origin (tumour)
→ Adrenal origin (tumour)
→ Ectopic ACTH (e.g. cancer in another part of the body)
→ exogenous steroids

Question 7

what are the symptoms of cushing’s disease?

Answer 7

Cushingoid facies
Acne
Hirsutism
Abdominal striae & centripetal obesity
Interscapular & supraclavicular fat pads (fat buildup on the back of the neck & shoulders)
Proximal myopathy
Osteoporosis
Hypertension
Impaired glucose tolerance