Endocrine Flashcards
(187 cards)
What’s the most common adrenal incidentaloma?
- mostly non-functioning
- subclinical cushing
> GC secretory
Rotterdam criteria
2/3:
- Hypoandrogenism (clinical or biochemical)
- Menstrual irrgularities
- Polycystic overies on USS (>12 antral follicles in 1 ovary or >10cm3 in vol)
20% of women with PCO have PCOS
20% of patients with PCOS have absent PCO
20% of patients without PCOS have PCO
Insulin stress test
Indications:
To test anterior pituitary growth hormone and ACTH reserve in patients suspected or confirmed as having anterior pituitary failure.
CI:
- epilepsy
- cardiac rhythm disturbances, ischaemic heart disease
- previous cerebrovascular accidents, or any unexplained fits or collapses.
- Adrenal Insufficiency
Protocol:
Estrogen containing medications such as HRT or the pill must be stopped six weeks prior to this test. Patients should be fasting from midnight before the test, and are asked to bring their medications with them for documenting at the start of the test, and to be taken at the end of it.
ECG, 9am cortisol, free thyroxine must all be performed and checked by a doctor before proceeding with this test.
PCOS
Rotterdam criteria
- prevalence of gestational diabetes, impaired glucose tolerance and type 2 diabetesare significantly increased in PCOS, with risk independent of, yet exacerbated by, obesity
- 2-6 x increased risk of endometrial cancer
Complications:
Infertility, miscarriage
Metabolic sx
Sleep apnoea, NAFLD
Depression, Endometrial cancer
Biochemical:
- LH excess
- Hyperinsulinemia
- Reduced SHBG - due to insulin resistance
- Testosterone/FAI/bioavailable T
- Androstenediones or DHEAS are often elevated
DDx that needs to be excluded: thyroid, hyperPRL, cushing sx, non-classical CAH (17-OHP), androgen secreting tumour, ovarian failure (^FSH), hypthalamic amenorrhoea (low GnRH,LH/FSH)
In hereditary haemochromatosis, does venesection help with sexual dysfunction?
No
- you need to give testosterone
When do you treat subclinical hypothyroidism?
- TSH ≥10mIU/l on two separate occasions three months apart.
- <65-70: TSH 7-9.9
- > 65-70:
For women with subclinical hypothyroidism (TSH values above first trimester-specific normal reference range with normal free T4) who are trying to conceive and who have ovulatory dysfunction or infertility, initiating T4 replacement is suggested
Pregnancy and thyroid function
- release of estrogen encourages the production of thyroxine binding globulin
- Total T4 increases, free T4 remains stable
- bHCG stimulates the release of T4, thus** TSH level drops **
Hypokalaemic periodic paralysis
- Autosomal dominant inherited **(non-penetrance is common) **defect in calcium or sodium ion channel on muscle membrane
- Male > female (clinical)
- common precipitate:
> Exercise
>Carbohydrate load
>Stress
Need to rule out TPP and HyperKPP
Prevention:
- Acetazolamide
- K+ sparing diuretics
Associated features Later-onset myopathy
Typical lipid profile in T2DM
- high concentration of TG and small dense LDL low - concentration of HDL cholesterol.
- LDL normal
- Insulin resistance is believed to contribute to this atherogenic dyslipidemia by increasing the hepatic secretion of VLDL and other apolipoprotein (apo)B-containing lipoprotein particles, as a result of increased free fatty acid flux to the liver.
How does thyrotoxicosis result in osteoporosis?
- reduced estrogenisation –> osteoporosis
MODY
Managment of nephrogenic DI
- low salt and low protein
- thiazide diuretic (2nd line)
How do you develop gynacomastia in cirrhosis?
In cirrhosis (as well as alcohol dependency) there is increased activity of peripheral aromatase which converts testosterone to estrogen. This buildup of estrogen causes the development of female secondary sexual characteristics such as breast development
Amiodarone induce thyroid disease
The presentation here, with a very high T4 and suppressed T3, and a background of previous CVD suggests the patient likely has an amiodarone induced thyrotoxicosis. There are two main types of this disease: 1. is due to increased thyroid hormone synthesis due to an increased iodine load. 2 is more like a thyroiditis with thyrocyte toxicity. The distinction between the two types is difficult but is most reliably done by vascular USS - the presence of normal or increased uptake suggests type I, whereas Type II is suggested by decreased uptake
Fenofibrate
- peroxisome proliferator receptor alpha activator used to lower LDL-C, total-C, triglycerides, and Apo B, while increasing HDL-C in hypercholesterolemia, dyslipidemia, and hypertriglyceridemia
- prevent diabetic retinopathy.
Which nerve on the eye is commonly affected in diabetes?
sixth nerve
what’s mechanism of steroids induced osteoporosis?
inhibition of bone formation which is done by an increase in death of osteoblasts.
ventromedial nucleus of the hypothalamus
distinct morphological nucleus involved in terminating hunger, fear, thermoregulation, and sexual activity.” This nuclear region is involved with the recognition of the feeling of fullness.
TPO Ab and pregnancy
- An increased risk of adverse pregnancy outcomes has been reported in euthyroid women with elevated thyroid peroxidase (TPO) antibody concentrations.
- Increased risk of fetal loss, preterm delivery, perinatal mortality, and** large for gestational age** infants has been reported in euthyroid women with high serum TPO antibody concentrations
- high risk for developing subclinical hypothyroidism in the first trimester and thyroiditis in the postpartum period
pseudohypoparathyroidism
PTH resistance due to g-protein deficiency
elevated PTH
hypocalcaemia
N or E phosphate
Graves’ orbitopathy
an autoimmune disease of the retroocular tissues
Risk factors for the development of Graves’ orbitopathy include:
- genetics, female sex, smoking, and prior radioiodine therapy.
TSHR antibody and activated T cells play an important role in pathogenesis of Graves’ orbitopathy by activating retroocular fibroblasts and adipocytes.
The volume of both the extraocular muscles and retroocular connective and adipose tissue is increased, due to i**nflammation and the accumulation of **hydrophilic glycosaminoglycans (GAG), principally hyaluronic acid, in these tissues
GAG secretion by fibroblasts is increased by activated T cell cytokines and by the activation of the receptors for TSH and insulin-like growth factor-1 (IGF-1).
RAI can worsen symptoms
Mod-sev disease - tx with steroids
Non classical CAH
21 alpha hydroxylase
The synacthen test is used to distinguish PCOS from non classical CAH. Synacthen is administered and concurrent **17hydroxy progesterone **levels are measured.
AR
Not present at birth
Fanconi syndrome
- type 2 renal tubular acidosis, accompanied by hypophosphataemia, glycosuria, and aminoaciduria
Presenting features include polyuria, polydipsia, osteomalacia (rickets and growth failure in children) and symptoms secondary to the electrolyte abnormalities associated with the disorder.
Causes:
Rifampicin
cystinosis (most common cause in children)
Sjogren’s syndrome
multiple myeloma
nephrotic syndrome
Wilson’s disease
What are the medical therapy options for hyprecortisolism?
- ketoconazole, mitotane -reduce cortisol synthesis
- pasireotide, or cabergoline: