Endocrinology Flashcards
Which genetic defect is associated with MODY 3?
Hepatocute nuclear factor-1-alpha
Most common form of MODY
Which forms of MODY are highly sensitive to sulfonylureas?
Which genetic defects are they associated with
MODY 1 and MODY 3
Associated with defect in hepatocyte nuclear factor 4a (MODY 1) and Hepatocyte nuclear factor 1a (MODY 3)
MODY 3 is most common
Which of the following is not a criteria for ordering auto-antibodies in diabetes?
A. Personal or family history of autoimmune disease
B. BMI <30
C. Age <50
D. Acute symptoms
B. BMI <25
Which of the following patients would be most likely to respond to a CRH stimulation test? A. Psuedo cushings B. Cushings disease C. Adrenal adenoma D. Phaeochromocytoma
B. Cushings disease
Corticotroph tumors respond to CRH, ectopic (i.e. non pituitary) ACTH producing tumors do not
Positive result - ACTH rise >40% within 15-30 mins and cortisol rise >20% within 45-60 mins
Which form of MODY is not associated with microvascular complications? Genetic defect?
MODY 2 - mild fasting hyperglycemia, genetic defect in glucokinase gene, not typically associated with microvascular disease
Managed with diet only
Which forms of MODY need insulin?
Mody 5 and 6, defect in hepatocyte nuclear factor 1a (MODY 5) and neurogenic diffferentiation factor-1 (MODY 6)
Which patients should be screened for OP on steroids?
Steroids for 3 months at >7.5mg/day
How does hyperthyroidism occur in pregnancy? What is it associated with?
BHCG stimulates TSH receptor –> TSH supression with associated high fT3 + fT4
Associated with hyperemesis gravidum due to high BHCG
Drugs causing hyperthyroidism?
Iodine
Amiodarone
Interleukin 2
Interferon alpha
Lithium can cause thyroiditis and hyperthyroidism before hypothyroidism
Immunotherapy associated with hypothyroidism
Anti-CTLA4 - ipilimumab, trepilimumab
Anti-PD1 - nivolumab, prembrolizumab
TKI
Bexarotene
Factors that increase TBG?
Drugs that decrease TBG?
Increase:
- estrogen/pregnancy
- hepatitis
- drugs (opioids, fluorouracil, perphenazine)
- acute intermittent porphyria
Decrease:
- high dose androgens
- cortisol/cushings syndrome
- acromegaly
- neprhotic syndrome (loss of TBG)
- danazol
- niacin
Features of MEN 1,
MEN1
Triple Ps - Parathyroid adenomas
Pancreatic tumors
Pituitary adenomas
Features of MEN2a vs MEN2b
MEN2 = PARATHYROID
MEN2a
Medullary thyroid carcinoma
Pheochromocytomas
Parathyroid adenomas
MEN2b (rare skinny men with weird tongues)
Medullary thyroid carcinoma
Pheochromocytomas
Mucosal neuromas
Marfanoid habitus
Which diabetic drugs are contraindicated with a past history of pancreatitis?
DDP4 inhibitors (-gliptins, i.e. linagliptin) + GLP1 agonists (-tides, i.e. exenatide)
Which diabetic drugs are associated with weight loss?
Metformin
SGLT2 inhibitiors
GLP1 agonists
Mechanism of action and effects of GLP1 agonists?
Mimics effects of GLP1 by effects on GLP1 receptor –> increased insulin secretion, decreased glucagon secreation, delayed gastric emptying (inhibits peristalsis of the stomach while increasing tonic contraction of the pyloric region.
Results in reduced appetite, weight loss
Mechanism of action of acarbose?
Alpha-glucosidase inhibitor - a-glucosidase normally converts CHO to monosaccharides, inhibition leads to reduced GI glucose absorption and reduced postprandial BSLs
Most common cause of asymptomatic hyperprolactinemia
Macroprolactin - ask lab to pre-treat samplex with polyethylene glycol
4 causes of increased thyroid uptake on technetium scan
TSHoma
HCG secreting tumor
Graves disease
Toxic multinodular goitre or adenoma
Treatment of hyperthyroidism in trimester 1?
Treatment in trimester 2 and beyond?
Trimester 1 - propylthiouracil
Trimester 2 - carbimazole
1p2c
3 hormones that inhibit food intake
Leptin
CCK
Adiponectin
3 hormones that stimulate food intake
Grehlin
Neuropeptide Y
Agouty-related peptide
Most common genetic cause of obesity
MC4R mutations
Which hormones are deficient in congenital adrenal hyperplasia? Which are in excess?
Deficient - aldosterone, cortisol
Excess - androgens (hirsuitism and amibuous genitalia in women)
Due to alpha-21 dyhydroxylase deficiency
Hormone released from the zona glomerulosa
Aldosterone
Hormone released from the zona fasciulata
cortisol
Hormones released from the zona reticularis
Androgen precursors - DHEAS, androstenedione
Hormones released from the medulla
Adrenaline/norad, dopamine
Romosuzumab mechanisms of action
Inhibits sclerostin –> enhances Wnt signalling –> increased osteoblast matuation
Which steroid is innappropriate for treatment of Addisons?
Dexamethasone, betamethasone - no mineralocorticoird activity (need to prescribe fludrocortisone with it)
PBS criteria for anabolic agents
high fracture risk
BMD -3.0
2 or more minimal trauma fractures
1 symptomatic fracture 12 months after treatment with an antiresorptive
+ no romosuzumab treatment previously
Type 1 amiodarone induced thyrotoxicosis - what is it and treatment
Increased synthesis of T4 and T3
More common in unerlying Graves
Treat with thionamides (methimazole)
Type 2 amiodarone induced thyrotoxicosis - what is it and treatment
Increased release of T4 and T3 due to toxic effect of amiodarone on thyroid epithelial cells
More common in euthyroid people
Treat with preed
Markers of bone formation and resorption
Osteocalcin = formation C-telopeptide = resorption
BSL targets during pregnancy (pre-exisitn diabetes)
HbA1c <6.5 T1, <6.0 T2 - check once per trimester
Pre prandial BSL 4.0 - 5.3
1hr post prandial 5.5 - 7.8
2hr post prandial 5.0 - 6.7
Factors that increase FGF-23
Action of FGF-23
Secreted by osteocytes
Factors that increase it:
- PTH
- Phosphate
- calcium
- calcitriol (activated vitamin D)
Actions:
- increase phosphate excretion by reducing reabsorption
- inhibit vitamin D activation - reduced calcium _ hosphate gut/renal reabsorption
- inhibit PTH
Co-factor of FGF23
Klotho
Sick euthryoid TFTs
Normal TSH
Low T3
Normal T4
Antibodies in type 1 diabetes
Which is specific for beta cells?
Anti-GAD65
ZnT8
IA21
Insulin auto-antibodies (IAA)
Insulin antibodies = specific for beta cells
?maybe islet cell antiboides also
