Endocrine Flashcards
Ant/Post pituitary hormones
Ant: LH, FSH, GH, TSH, Prolactin, ACTH
Post: ADH, Oxytocin
WHO diabetes criteria
- Fasting plasma glucose >7
- Random/post OGTT >11.1
- HbA1c >48
Repeat test if no symptoms
4 commonest T1DM Abs
- Glutamic acide decarboxylase (GAD65)
- Islet cell (ICA),
- Insulin
- IA-2
All fade as disease progresses
C-peptide role
By-product of insulin production
Diabetes non medical management
- Eye screening service
- Annual foot check
- Annual urine A:Cr
- HbA1c 3-6/12ly
- Annual BP
Risks of diabetes in pregnancy
Macrosomia
-> Shoulder dystocia
Miscarriage
Preterm labour
Pre-eclampsia
Worsening diabetes complications (retina/foot etc)
Hyperthyroidism presenting features
Weight loss
Anxiety
Cardiac:
- Palpitations
- AF
- SVT
Neurological:
- Essential tremor
- Proximal muscle weakness
- Eye protrusion (Graves’ only)
GI:
- Increased appetite
- Diarrhoea
Oligomenorrhoea/irregularity/loss of libido
Hyperthyroidism investigations
- TFTs - High fT4/3 (3 more sensitive), likely low TSH (secondary rare)
- TSH receptor antibodies
- Thyroid US/Radioiodine if unclear cause, Abs negative to identify e.g. nodule/adenoma
Graves’ examination findings
Hands/arms:
- Tremor
- AF
- Vasodilation, clammy
- Palmar erythema
- Thyroid acropachy, onycholysis
Arms:
- Proximal myopathy
- Hypertension
Face:
- Exophthalmos
- Lid lag
- Reduced colour vision
Neck:
- Goitre
- With bruit
Legs:
- Pretibial myxoedema
- Brisk reflexes
Associations:
- Myasthenia gravis
- Vitiligo
- Rarely splenomegaly
- Osteoporosis
Hyperthyroidism causes
- Graves’ most common
- Toxic nodular goitre
- Thyroid adenoma
- Postnatal thyroiditis
- Initial phase of subacute/de Quervain thyroiditis
Graves’ management
Lifestyle:
- Stop smoking!!
Medical:
- Symptomatic - propranolol
- Carbimazole (propylthiouracil if storm) - block/replace or titration according to TFTs. Trial 18/12 then withdraw - 50% relapse
- Radioiodine - usually first line (using anti thyroid drugs before and after Rx). Avoid if: pregnancy, orbitopathy (consider + steroid). Often leads to lifelong hypoT
Surgical:
- Thyroidectomy - make euT first with carbimazole etc. Total preferred as lower risk recurrent hyperT. LevoT afterwards
Antithyroid drug SEs
Carbimazole:
- Agranulocytosis - report fever/sore throat, rash
- Rash
Propylthiouracil
- ANCA+ small vessel vasculitis
Radioiodine advice
- Frequent handwashing
- Double flush toilet
- Avoid close contact, esp women & children
Thyroid storm precipitants
- Post thyroidectomy
- Radioiodine
- Infection
- MI
- Trauma
Thyroid storm management
Fever, agitation, hyperthermia, tachy
- A-E & resus
- Propranolol or shorter acting BBs. Consider non-DHP CCBs
- Carbimazole & later iodine
- Steroids to prevent peripheral T4-3 conversion
- Endocrine advice, consider thyroidectomy (if not done and failing to improve)
Hypothyroidism signs
Hands:
- Bradycardia
- Dry, thin skin
- Cool
- Possible ataxia
- Phalen’s/Tinel’s
Face:
- Anaemia and carotenaemia
- Loss of eyebrows
- Xanthelasma
- Peri-orbital oedema
Neck
- Goitre (hashimotos) or thyroidectomy scar
- JVP in CCF
Legs:
- Slow-relaxing reflexes
- Proximal myopathy
Causes primary hypothyroidism
- Hashimoto’s thyroiditis most common in UK
- Iodine def most common globally
- Hyper T treatment - post thyroidectomy/radio I, carbimazole etc
- Drug SEs: Amiodarone, Lithium
- Infiltrative (sarcoid/haemochromatosis)
- Subacute (de Quervain’s)
Hashimoto’s associations
Other autoimmune:
- T1DM
- Addison’s
- Pernicious anaemia
- Vitiligo
- Sjogren’s
Other:
- Turner’s, Down’s
- CF
- PBC
- Hypercholesterolaemia
- POEMS (polyneuropathy, organomegaly, endocrinopathy, m-protein band (plasma cytoma), skin pigmentation)
Hypothyroidism investigations
- TFTs
- Anti TPO, thyroglobulin (hashimotos)
- FBC - mild normocytic anaemia
- Glucose
- Cholesterol (raised)
Hypothyroidism management
Levothyroxine
- Monitor 6/52ly after starting/changing (Half life 1/52)
- Then annually
Risks of angina with rx
Risks of CAD without, even if subclinical
Can unmask Addison’s -> crisis
Parathyroid axis
PTH secreted in response to low Ca
Leads to increase osteoclast activity, increase vit D activation, increase Ca reabsorption/PO4 secretion in kidney
Primary hyperparathyroidism causes
- Mostly solitary adenoma
- 20% gland hyperplasia
- Parathyroid cancer very rare
Parathyroidectomy complications
- Hypoparathyroidism
- Recurrent laryngeal nerve damage (-> hoarse)
Causes secondary hyperparathyroidism
- Low vit D (diet, low sunlight, malabsorption)
- CKD (low vit D activation)
Secondary hyperparathyroidism bone profile results
Low Ca
High PTH (appropriately)
Secondary hyperparathyroidism presentation
Hypocalcaemia
- Cramps
- Bone pain & fractures
- Perioral tingling
- Chvostek’s
- Trousseau’s
Management 2ry hyperparathyroidism in CKD
- Phosphate restriction +/- binders
- Vit D/calcium supplementation
- +/- parathyroidectomy
MEN genes
MEN 1 - MEN1
MEN 2 - RET proto-oncogene
MEN 1
The Ps
- Parathyroid adenoma/hyperplasia in 90%
- Pancreas endocrine tumours (gastrinoma, insulinoma, somatostatinoma)
- Pituitary (prolactinoma/GH-secreting tumour)
MEN2a
MAP
- Medullary thyroid carcinoma in almost all
- Adrenal - phaeochromocytoma, often bilateral
- Parathyroid hyperplasia
MEN2b
- Medullary thyroid carcinoma
- Adrenal - phaeo
- Marfanoid appearance
- Mucosal neuromas (lips, eyelids, cheeks, tongue)
Pituitary adenoma visual field defect
Bitemporal hemianopia
Initially bitemporal superior quadrantanopia (pituitary in sella turcica with optic chiasm above)
Acromegaly features
Morphological facial changes:
- frontal bossing
- enlarged nose,
- prognathism
- separation of teeth
- macroglossia
Soft-tissue and skin changes:
- increased sweating,
- oily skin,
- increased skin thickness
- bilateral carpal tunnel syndrome
- proximal myopathy
Respiratory complications: - snoring
- sleep apnoea (central and obstructive)
Osteoarticular features:
- pseudogout
- osteoarthritis
Cardiovascular features:
- hypertension,
- hypertrophic cardiomyopathy,
Metabolic complications:
- impaired glucose tolerance, diabetes mellitus
Organomegaly: for example, thyroid, prostate
Other: hypercalciuria
Acromegaly common co-secretion
GH necessary for diagnosis
Commonly prolactin
Normally other hormones normal - can have pituitary suppression if massive pituitary adenoma
Features hyperprolactinaemia
- Decreased libido
- Infertility
- Amenorrhoea, oligomenorrhoea
- Galactorrhoea
- Erectile dysfunction
Acromegaly investigations
Diagnostic:
- IGF-1
- Then OGTT with GH measurement (failure to suppress diagnostic)
- MRI head for pituitary adenoma
(- CTCAP +/- radiolabelled somatostatin analogue if ectopic source)
Complications to consider
- OSA: sleep study, morning ABG
- Diabetes: HbA1c
- Cardiomyopathy: BP, ECG +/- Echo, triglycerides
- Formal visual field testing
- Pituitary function: TSH,T4; ACTH, prolactin, testosterone
Acromegaly management
Trans-sphenoidal resection
+/- radiotherapy
+/- somatostatin analogues (octreotide)
Alternatives include dopamine agonists (cabergoline), GH antagonists
Complications pituitary resection
Panhypopituitarism
Meningitis
Diabetes insipidus
