Hyposecretion of AP hormones Flashcards
State the 5 Anterior Pituitary hormones?
Growth Hormone, Prolactin, TSH/Thyrotrophin, Gonadotrophins (LH/FSH) and ACTH
State the difference between primary, secondary and tertiary endocrine disease?
P - Affects endocrine gland, and releasing hormone here i.e. thyroid
S - affects the anterior pituitary hormone release
T - hypothalamic
Define Hypopituitarism, adding what a deficiency of ALL AP hormones is called?
Decreased production of all anterior pituitary hormones or specific hormones
What are the causes of Hypopituitarism (broadly)?
Congenital (rare) - mutations in TF’s for normal AP development e.g. PROP1. Must be GH and 1 other hormone deficient.
Acquired (common)
State some causes of acquired hypopituitarism?
- Tumours (hypothalamic - craniopharyngiomas) or (pituitary adenoma/cysts/metastases)
- Radiation (most likely to be GH deficient first, and TSH last)
- Infection e.g. meningitis
- Inflammatory/Autoimmune i.e. hypophysitis
- Infiltrative Diseases e.g. neurosarcoidosis
- Trauma
- Peri-partum infarction (SHEEHAN’s)
- Pituitary Apoplexy, usually haemorrhage but can be infarction
Presentation of panhypopituitarism (SIMMOND’s)?
LH/FSH - secondary amenorrhoea, erectile dysfunction
ACTH and TSH - fatigue
Describe what a PPI (Sheehan’s Syndrome) is, and how it presents?
PPI - specifically describes a post part hypopituitarism, secondary to HYPOTENSION following a postpartum haemorrhage. this causes reduced blood supply to the pituitary gland, causing infarction.
less common in developed countries
Presents w:
- failure to lactate (prolactin) - most obviously noted
- lethargy, weight loss, anorexia (TSH, ACTH)
- failure to resume menses (LH/FSH)
What is a Pituitary Apoplexy? How does it present, and what is a risk factor?
Intrapituitary haemorrhage (>infarction), often dramatic and first presentation of pituitary adenomas. Anticoagulants - RISK Severe onset sudden headache, bi-temporal hemianopia, also if the cavernous sinus is involved then can cause ptosis (droopy eyelid) and diplopia (double vision).
State 2 ways to diagnose hypopituitarism, and why we do not use blood tests?
No basal plasma blood tests as varying levels of hormones i.e. Cortisol follows a day rhythm, w highest levels in morning. GH and LH/FSH is pulsatile, and T4 has a long half life.
1. Biochemical Diagnosis
Stimulated Pituitary function tests - STRESS
insulin induced hypoglycaemia
also can give TRH and GnRH to stimulate release of their respective hormones too.
2. Radiology
Pituitary MRI - apoplexy, adenoma, empty sella etc.
How would you treat Hypopituitarism?
HRT TSH - Thyroxine GH - GH LH/FSH - testosterone/oestrogen and progestogen ACTH - hydrocortisone cannot compensate prolactin!
What does GH deficiency cause in adults, and children?
adults - less clear effect
children - short stature, <2 S.D.s of mean height for age
State some other causes of short stature?
Malabsoption Malnutrition Emotional Stress Genetic - PWS, Turners, Down's Systemic Disease - CF Endocrine - Cushing's Skeletal dysplasia i.e. achondroplasia (FG3 mutation)
State how the following affect the growth axis?
- PWS
- Pituitary Dwarfism
- Laron’s Dwarfism
- Hypothalamus
- Lack of GH from AP
- GH receptor defect
How to diagnose short stature in children?
Growth charts and plotting predicted height (mid-parental height) alongside actual height.
How is GH deficiency caused in adults?
Trauma, Surgery, Radiation and Tumours
