Endocrine Workshop

Question 1

What questions would you ask someone with endocrine issues?

What other signs could you see?

Answer 1

• PC and specific symptoms
• PMH – previous autoimmune conditions, recent viral infections
• FH – any family history of graves disease etc.
• Medication history – amiodarone (for arrhythmias + heart problems), levothyroxine, recent contrast media
• Obstetric history (menopause → increase in sweating, pregnancy → inflammation of thyroid gland)

Signs

• Essential tremor
• Thyroid eye disease

Question 2

Explain the role of the thyroid gland

Answer 2

• Endocrine gland in the neck
• Secretes 2 main hormones (a lot is protein-bound e.g. albumin)
  
  1. Thyroxine (T4) - 85%
     
     1. Majority then converted to T3 peripherly
  2. Triiodothyronine (T3)
• C-cells secrete calcitonin which control calcium homeostasis
• Regulates metabolism and impacts heart rate

Iodine converted to iodide by thyroid perioxidase, attaches to tyrosine on thyroglobulin. When TSH stimulates the follicular cells of the thyroid this creates T4 and T3.

Question 3

Explain how the hypothalamic-pituitary axis works

Answer 3

Question 4

What is thyrotoxicosis?

Answer 4

• Clinical syndrome of excess circulating thyroid hormones (Irrespective of source)
• Hyperthyroidism is increased thyroid hormone synthesis and secretion specifically from the thyroid gland

Question 5

What are the effects of thyrotoxicosis?

Answer 5

• Excessive thyroid hormone:
  
  • increased base metabolic rate
  • increased bone turnover
  • increased gut motility
  • increased cardiac output
  • increased activation of the sympathetic nervous system

Question 6

What are the causes of thyrotoxicosis?

Answer 6

• Problem with the thyroid gland
• Problem with the pituitary gland
• Medication/dietary

Question 7

Give examples of thyroid problems

Answer 7

• Graves disease
• Toxic Adenoma/Toxic multi-nodular goitre
• Thyroiditis (Viral infection/Post partum)

Question 8

Explain what Graves disease is…

Answer 8

• Most common cause of thyrotoxicosis
• Autoimmune condition mediated via anti-TSH-Receptor autoantibodies
• More common in females (Can occur at any age)
• Strongly associated with other autoimmune conditions (T1DM, Addison’s)

More info

• Anti-TSH antibodies bind to TSH-receptors on the thyroid gland and stimulate increased production of T3 and T4 from the thyroid gland

Question 9

What are the symptoms of Graves disease?

Answer 9

• Diffuse goitre (diffuse enlargement of the thyroid gland)
• Eye disease (e.g. exopthalamus - protruding eye balls, opthalmoplegia, conjunctival oedema, papilloedema, keratopathy - damage to the cornea due to dryness)
• Dermopathy ( small lesions or spots on the skin - pretibial myxoedema)
• Acropathy (soft tissue swelling of hands & feet)

Question 10

What are some important history questions to ask someone with Graves disease (suspected)?

Answer 10

• Family History
• Past Medical History (Autoimmune disorders)
• Smoking History

Question 11

What is a toxic multi-nodular goitre?

Answer 11

• Multiple nodules on the thyroid gland secreting thyroid hormone
• Nodules non responsive to negative feedback
• More commonly in older patients (>60 years old)

Doesn’t have typical features of Graves Disease - e.g. eye disease, dermopathy

Question 12

What is thyroiditis?

Answer 12

Thyroiditis - Inflammation of the thyroid gland

• Sub-acute de Quervain’s thyroiditis – inflammation of the thyroid gland post viral infection
  
  • Painful neck
  • Hyp_er_thyroid → _Eu_thyroid → Hyp_o_thyroid
• Post-partum thyroiditis
  
  • 2-6 months following birth
  • Hyp_er_thyroid → Hyp_o_thyroid

Question 13

What are differential diagnosis’s of thyroid disease?

Answer 13

• Graves disease
• Toxic nodular goitre
• Thyroiditis

Question 14

What is TSHoma and what can it lead to?

Answer 14

Rare pituitary tumour secreting TSH

• Leading to secondary hyperthyroidism

Question 15

What medication/dietary supplements can lead to thyroid problems?

Answer 15

• Amiodarone
  
  • Medication used to treat arrythmias
  • Increases iodine levels thus, increases thyroid hormone production by follicular cells
• Iodine excess
  
  • Increased thyroid hormone production
  • E.g. from contrast media for investigations OR excess dietary iodine
• Levothyroxine (Over-replacement)
  
  • Can lead to hyperthyroidsm

Question 16

What are some symptoms of hyperthyroidism?

& other symptoms that are specific to Graves disease

Answer 16

Graves specific symptoms

1. Eye signs – exophthalmos, opthalmoplegia
2. Pre-tibial myxedema
3. Thyroid acropachy

Question 17

What investigations would you do on someone who has thyroid problems?

Answer 17

• Thyroid function tests
  
  • TSH, T4, T3 (good measure FT4, FT3 → FT4 more important because more is made & is convertedto T4 peripherally
• Antibodies
  
  • TSH-ab (+ve in 70-100% of Graves & Hashimoto’s) → Graves
  • TPO-ab (+ve in ~70% of Graves & -ve* (or normal) in *Hashimoto’s*) → *Autoimmune
• Imaging
  
  • Thyroid uptake scan (raised uptake in Graves) OR (reduced uptake → thyroiditis,hashimoto’s & excess iodine intake)
  • Thyroid USS

Question 18

What is the management of thyroid conditions?

Answer 18

• Symptom control
  
  • B blockers
• Anti-thyroid drugs (ATD)
  
  • Carbimazole, propylthiouracil
  • ‘Block and replace’ → give anti-thyroid drugs to completely suppress natural thyroid hormone production then replace with levothyroxine.
  • or ‘Dose titration’ → give sufficient amount of ATD to suppress thyroid hormone back to normal levels. Only option in pregnancy
• Surgery
  
  • Used for relapsed Graves
  • Needs to be euthyroid prior to surgery otherwise thyroid storm
  • Complications:
    
    • Hypothyroidism
    • Surgical complications
• Radioiodine therapy
  
  • Taken as drink leads to destruction of gland
  • NOT given in pregnancy, children, breast-feeding women & avoid kids & pregnant women
  • Can lead to hypothyroidism

Question 19

What is a thyroid storm? (symptoms & risk factors & treatment)

Answer 19

• Rare but potentially life threatening complication of thyrotoxicosis
• High mortality
• Features:
  
  • Altered mental status
  • Tachycardia/Arrthymias
  • Fever
  • Nausea & vomiting, diarrhoea
  • Abdo pain
  • Seizures
• Risk Factors:
  
  • Acute infection
  • Postpartum
  • Post surgery or RAI
  • Withdrawal of ATDs
• Treatment:
  
  • B blockers, Steroids and anti-thyroid drugs

Question 20

What is hypothyroidism? (& what are the types?)

Answer 20

• Lack of thyroid hormone
• Reduced metabolic rate, reduced gut motility, reduced sympathetic nerve activity
• Types
  
  • Primary hypothyroidism
    
    • Thyroid problem
  • Secondary hypothyroidism
    
    • Pituitary/hypothalamic problem

Question 21

What is primary hypothyroidism? (& causes)

Answer 21

• Autoimmune hypothyroidism (thyroid problem) →Hashimoto’s thyroiditis
• Iodine deficiency
• Iatrogenic – Surgical treatment, radioiodine therapy, radiotherapy → with cancer in neck
• Drugs → amiodarone, lithium
• Thyroiditis

Question 22

What is Hashimoto’s disease?

Answer 22

• Autoimmune disorder → Destruction of the thyroid gland
• Much more common in females
• Goitre present
• Anti-TPO and Anti-Tg abs present
• Linked to other autoimmune conditions

Question 23

What are the symptoms of HYPOthyroidism?

Answer 23

Often insidious and non-specific

Question 24

What is the management of _hypo_thyroidism?

Answer 24

• Levothyroxine
  
  • Monitor TFTs and titrate dose according to TSH
  • Caution in elderly and heart failure
  • Need to wait weeks after dose changes to repeat blood tests to assess TSH

Question 25

What would **TSH, T3, T4** be in: (blood test) 1. *Primary hypothyroidism* 2. *Secondary hypothyroidism* 3. *Sub-clinical hypothyroidism* 4. *Primary hyperthyroidism* 5. *Secondary hyperthyroidism* 6. *Sub-clinical hyperthyroidism*

Answer 25

Question 26

What is the most common cause of hyperthyroidism? A)Hashimoto’s B)Multi-nodular Goitre C)Graves Disease D) Thyroid cancer

Answer 26

C) Graves disease

Question 27

Which antibodies are most specific for graves disease? A)TSH antibodies B)TTG antibodies C)TPO antibodies D)Anti-CCP antibodies

Answer 27

A)TSH antibodies

Question 28

A 37 year old lady presents to see you with heavy periods, weight gain and low mood. Which blood test is likely to be low? A)TSH B)Testosterone C)T4 D)Cortisol

Answer 28

A)TSH

Question 29

A 50 year old gentleman presents to the GP with weight gain, heat intolerance and insomnia. You suspect he was primary hypothyroidism. Which blood test results correspond to this? A)High TSH, High T3/T4 B)Low TSH, Normal T3/T4 C)Low TSH, Low T3, T4 D)High TSH, Low T3/T4

Answer 29

D)High TSH, Low T3/T4

Question 30

What do the blood tests suggest? TSH - 9 ( 0.4 - 5.0) T4 - 10 ( 9 - 22) T3 - 4 ( 3.5 – 7.8) A)Hyperthyroidism B)Hypothyroidism C)Sub-clinical hypothyroidism D)Sub-clinical hyperthyroidism

Answer 30

C)Sub-clinical hypothyroidism

Question 31

A 42-year-old woman presents to her GP complaining of increased anxiety and palpitations. She has noticed excessive sweating and has lost weight recently. **TSH:** 14 mU/L (0.4-4.0 mU/L) **T4:** 29 mU/L (9-24 pmol/L) Which additional symptom is she likely to complain of? A) Headache relieved by lying down B) Increase in shoe size C) Loss of the outer 3rd of the eyebrows D) Difficulty driving due to reduced peripheral vision

Answer 31

D) Difficulty driving due to reduced peripheral vision

Question 32

What is **acromegaly**?

Answer 32

* *Excessive* **growth hormone** secretion * Usually caused by a *_pituitary adenoma_* * *Insidious* onset and *slow* *progression* * _Delayed_ *diagnosis*

Question 33

Draw a flow diagram of **growth hormone** on the body

Answer 33

Question 34

What are the **symptoms** and **signs** of *acromegaly*?

Answer 34

***_Symptoms_*** * Sweating * Change in shoe, ring size * Change in facial features * Headaches * Lethargy * Joint pains * Galactorrhoea, amenorrhoea ***_Signs_*** * Coarse *facial* features * *Macroglossia* * Deep voice * Spade like hands, enlarged feet, *OA* * *Carpal tunnel syndrome* * *Goitre* and organomegaly *UP to ⅓ patients will have symptoms of **_hyperprolactinaemia_*** due to *adenoma* also secreting ***PROLACTIN***

Question 35

What **investigations** to do with someone with *acromegaly*?

Answer 35

* ***IGF-1*** * Prolonged *oral glucose tolerance test* * *High levels of glucose* should *_suppress_* *GH* release * *_Fails_* to happen in acromegaly * ***MRI pituitary*** *GH release SHOULD be inhibited by glucose*

Question 36

What is the **management** of someone with ***acromegaly***?

Answer 36

* ***_Medical_*** * *Somatostatin analogues* (Octreotide - inhibits GH release) * *Dopamine agonists* (Bromocriptine, cabergoline) → less effective at suppressing GH release * *GH receptor antagonists* (Pegvisomant) * ***_Surgical_*** * Surgical *removal* of *adenoma* is the treatment of choice

Question 37

What are the **complications** of *acromegaly*?

Answer 37

* *Hypertension* * Impaired glucose tolerance and *T2DM* * Obstructive *sleep apnoea* * *IHD* and *heart failure* * Increased incidence of *thyroid* and *colon cancer (common screening provided)*

Question 38

What are some **rarer** causes of *hypertension?*

Answer 38

* ***Conn’s syndrome*** * ***Phaechromocytoma*** * ***Cushing’s syndrome*** * ***Renal artery stenosis***