Endocrinology Exam 1 Cards Flashcards
P3 Zones of the Adrenal Cortex and what they secrete
Glomerulosa - Salt
Fasciculata - Sugar
Reticularis - Sex
3 effects of aldosterone on the body
Water and sodium retention
Potassium Excretion
Increased BP
Renin-Angiotensin-Aldosterone-System
Kidney detects low perfusion pressure
JG cells release Renin
Renin cleaves Angiotensinogen to Angiotensin I
ACE in lungs cleaves AT I to AT II
AT II stimulates release of Aldosterone
Trigger for release of Cortisol
Stress
3 functions of cortisol
Gluconeogenesis
Immune system suppression
Decreased inflammation
When is cortisol the highest? and why?
In the morning because it needs to wake you up
Main sex hormone secreted by the Zona reticularis
DHEA
Role of DHEA
Stimulates, controls and maintains the development of sex characteristics
2 secretions of the adrenal medulla
Epinephrine and Norepinephrine
What inhibits CRH release
Cortisol
Desmolase
CYP11A1
17 alpha hydroxylase
CYP21A2
21 hydroxylase
CYP21A2
Aromatase
CYP19
Aldosterone Synthase
CYP11B2
11 beta hydroxylase
CYP11B1
4 possible cholesterol products from the adrenal cortex
DHEA
5-Dihydrotestosterone
Cortisone
Aldosterone
Role of desmolase
Kicks off the process, without it no products are made
Role of 3 beta HSD
Moves steroids away from becoming DHEA, without it only DHEA can be produced
Role of 17 alpha hydroxylase
Moves steroids towards becoming DHEA, without it only aldosterone can be produced
Role of 11 betahydroxylase
Required to synthesize cortisol only
Role of CYP11B2
Aldosterone synthase, not needed for cortisol synthesis
Role of aromatase
Converts androgens to estrogens
(women smell good)
Primary gland
Last gland in the line (ie. the adrenal glands)
Addison’s disease
Usually autoimmune destruction of the adrenal cortex - results in a loss of glucocorticoids AND mineral corticoids
Most commonly affected enzyme in Addison’s disease
21-hydroxylase
Adrenoleukodystrophy
Accumulation of long chain fatty acids in the adrenal cortex which blunt the effect of ACTH
Drug that diminishes cortisol synthesis
Mitotane
3 drugs that accelerate the metabolism of cortisol
Phenytoin, Barbituates, Rifampin
(Notice 2 of them are CYP inducers)
Drug that inhibits cortisol biosynthesis
Ketoconazole
2 causes of acute addisons disease
Adrenal hemmorhage
Adrenal Crisis
Adrenal Crisis
When a patient with addison’s disease is stimulated by a stressor that requires additional adrenal hormones beyond what they are regularaly receiving
Cause of hyperpigmentation in addison’s disease
ACTH attaches to the melanotic receptors
Cause of vitiligo in Addison’s disease
Antibodies that destroy adrenal cortex, also destroy melanocytes
4 hallmarks of an adrenal crisis
Severe fever - Not in adrenal hemmorhage
Severe abdominal pain
Confusion
Hypotensive shock
(Looks a lot like sepsis)
Adrenoleukodystrophy
Accumulation of long chain fatty acids in the adrenal cortex which blunt the effect of ACTH
2 CBC findings for Addison’s disease
Eosinophilia and Lymphocytosis
Why would you want a blood sputum or urine culture in a suspected adrenal crisis
Because you may be able to find a precipitating cause
Diagnostic and rule out levels of cortisol for Addision’s disease
Under 3 with high ACTH, Over 25 mcg/dL
Plasma ACTH indicative of Addison’s disease
Over 200 pg/mL
Cause of hidden hyperkalemia in Addison’s disease
Vomiting leading to potassium loss
Plasma Renin Activity
Can help diagnose the need for mineralcorticoid replacement but is also very finicky
ACTH stimulation test indication for addisons
administer ACTH and check cortisol in increase
Increase less than 20mc/dL is indicative of Addison’s (not a great test)
When might you use an ACTH stimulation test?
When serum cortisol or serum ACTH are non-diagnostic
How might imaging help in an adrenal crisis and what would you order?
Identification of an underlying etiology
Order a CXR or Abdominal CT
Standard Treatment for Addison’s disease
Hydrocortison PO 15-30mg daily with 2/3rds in the morning and 1/3rd at night
Can also use 3-6 mg prednisone the same way
Cortisone dose adjustment for Addison’s patients with chronic disease
Increase up to 50%
Return to baseline upon stressor resolution
Mineralcorticoid therapy for Addison’s disease
Covered by a “stress” dose of cortisone
If not on a stress dose - use fludracortison .05-3mg daily
Monitor PRA
4 Steps in managing an adrenal crisis
Order serum cortisol and ACTH (don’t wait for results) if undiagnosed
Give an IV hydrocortisone loading dose
Give IV cortisone for 24 hours and then taper
Switch to oral once the patient can tolerate it (isn’t vomiting)
Non-cortisol management of an adrenal crisis
Give broad spectrum antibiotics and adjust with cultures
Treat electrolyte and volume abnormalities
3 things to monitor for in an Addison’s patient
Development of Cushing syndrome
CBC/CMP normality
DEXA scan for osteoporosis (from steroid use)
2 things you might give an Addison’s patient to help them manage emergencies
Emergency injection kit and Zophran for nausea
Cushing Syndrome
Excessive administration of corticosteroids
(ACTH independent)
Cushing disease
Excessive secretion of cortisol due to excess ACTH
(ACTH dependant)
3 less obvious presentations of cushing’s disease
Easy bruising
Proximal muscle weakness
Immune system suppression
3 s/s assocaited with high ACTH
Hyperpigmentation
High BP
Hirsutism/Hair loss
3 H’s
What do NEW stretch marks look like?
Purple not Gray/Brown
2 CBC findings for cushings
Decreased leukocytes and eosinophils
3 CMP findings for Cushing’s
Elevated glucose, hypernatremia and hypokalemia (if Aldosterone is effected
MCC of Cushing’s
Pituitary tumor
3 steps in a cushings diagnostic workup
Establish endogenous or exogenous source
Establish presence of hypercortisolism
Determine cause of hypercortisolism
3 first line tests for hypercortisolism
Dexamethasone, 24 Hour Urine free cortisol, Late night salivary cortisol
Number of positive tests needed for hypercortisolism diagnosis
2
Low-dose dexamethasone suppression test
Give 1 mg PO at 11PM test serum cortisol at 8 AM
Result for dexamethasone suppression test that likely excludes cushing disease
Less than 5mcg/dL
24 Hour urine free cortisol test
Begin collection AFTER first morning void and continue through first void of the next day
Positive 24 hour urine free cortisol result
3x upper limit on two occasions points to Cushing disease
6 interfering factors for a late night salivary cortisol test
Bleeding, brushed teeth, oral intake, steroid use, pregnancy, erratic schedule
When to take a late night salivary cortisol test
11 PM
Positive salivary cortisol test
Elevated cortisol found on TWO separate occasions
Assay to determine cause of hypercortisolism
Serum ACTH
Values for serum ACTH and next step for each
Under 20 = low = Adrenal CT
Over 20 = high = Pituitary MRI
3 red flags for a malignant adrenal adenoma
Over 4 cm
Growing nodule
Density over 10 Housfield Units (HU)
HU
Hounsfield unit - measurement of radiographic density (water is 0)
Findings for pituitary MRI and interpretation thereof
Under 5mm - Inferior petrosal sinus sampling
Over 5mm - Begin treatment
Search for ectopic source of cushings
Chest/Abdomen CT first
Full body PET scan second
Management for exogenous Cushing’s
Slowly reduce exogenous glucocorticoid ACTH therapy
Short acting glucocorticoid that can help with recovery of HPA axis
Hydrocortisone
First line treatment tumor precipitated cushings
Surgical removal or radiation - can result in a need for glucocorticoid replacement
Medications that can manage an adrenal adenoma (3)
11b hydroxylase inhibitors such as:
Metyrapone
Osilodrostat
Ketoconazole
Medication that can manage ACTH tumor
Pasireotide - somatostatin analog
Two first line and one second line medication to manage mineralocorticoid HTN
K sparing diuretics
Spironolactone or Eplerenone
Second line - ACEI
1 drug for hyperandrogenism in women
Flutamide
Role of the StAR protein
Regulates steroid biosynthesis by allowing cholesterol into the mitochondria
Congenital Adrenal Hyperplasia w/ inheritance pattern
Autosomal recessive deficiency in steroid producing enzymes
MC deficiency in CAH
21 alpha hydroxylase
2 classic presentations for CAH
Salt wasting due to aldosterone deficiency
Virializing due to androgen excess
5 signs of salt wasting
vomiting, dehydration, hyponatremia, hyperkalemia, hypotensive shock
3 protein deficiencies that can lead to ambiguous genitalia
StAR protein
3 beta hydroxysteroid deficiency
17 alpha hydroxylase deficiency
2 things that are increased in a 21 hydroxylase deficiency
17-hydroxyprogesterone
Serum DHEA
workup for CAH suspicion
Get electrolytes
Use imaging if needed to rule out other disorders (abdomen CT and Pelvic US)
Goal of CAH treatment
Give just enough Aldosterone and Cortisol to keep things normal
Hydrocortisone administration for CAH
Initially 1-2 mg/kg/day (suprephysiologic
Maintainance .3-.5 mg/kg/day
TID - even doses as a baby, 2/3 1/3 as an adult
Fludrocortisone administration for CAH
Aldosterone substitute
.05-.15 mg daily while monitoring BP and plasma renin activity
What to watch for in CAH hydrocortisone administration in order to ensure that is is working
17-hydroxyprogesterone level normalization
Primary hyperaldosteroneism
Hypersecretion of aldosterone that cannot be suppressed by giving sodium
Clinical presentation of Primary Hyperaldosteroneism
Refractory hypertension
Headaches
Hypokalemia (weakness, paresthesia, fatigue)
2 BMP findings that could indicate hyperaldosteroneism
Hypernatremia, Increased CO2 (represents Bicarb)
PAC/PRA
Plasma renin activity/Plasma aldosterone concentration
Timing for PAC/PRA
Do in the AM while seated
Normal aldosterone/renin ratio
Under 10
4 BP meds that do not effect PAC/PRA ratio
Slow release verapamil, Hydralazine, terazosin, doxazosin
Oral and IV methods for sodium loading
Oral - 3 days of unrestricted salt (over 5g/day)
IV - 2L NS over 4 Hours
Determination of adequate oral sodium loading and next steps
Urine sodium over 250 and normal urine creatinine - begin 24 hour urine collection
Confirmatory result for oral sodium loading
24 hour urine aldosterone concentration of over 12
Confirmatory result for IV sodium loading
Plasma aldosterone concentration of over 10ng/dL
Conn syndrome
Adrenal mass smaller than 4cm
Likely adrenal carcinoma
Adrenal mass larger than 4 cm
Adrenal vein sampling
LAST resort if considering an adenectomy and HTN is severely uncontrolled
2 potassium sparing diuretics for primary hyperaldosteroneism
Spironolactone or eplerenone (more expensive with fewer SEs)
2 Additional BP meds for primary hyperaldosteronism
ACEI, HCTZ
incidentaloma
A tumor that we were not looking for but found
Rule of 10s for pheochromocytoma
10% bilateral
10% extra-adrenal
10% malignant
Classic pheochromocytoma triad
Episodic palpitations, diaphoresis, sweating - combined with HTN
3 things that can precipitate a pheochromocytoma
Stress, Position change, Urination
How long do pheochromocytoma episodes last?
Usually under an hour
Workup for Pheochromocytoma
Plasma free metanephrines
Sitting, then laying down, then urine - 24 hour preferred
Metanephrine threshold diagnostic for pheochromocytoma
3x the upper limit
Imaging for Pheochromocytoma
CT/MRI - chest, abdomen, pelvis
PET scan for malignancy rule-out
Management of pheochromocytoma
Refer to surgery, assess ACTH level post-op
Pre-surgery management of Pheochromocytoma
Alpha adrenergic blockers with high salt and water diet started 3 days later
3 Alpha blockers for pheochromocytoma management
Doxazosin, Prasosin, Terzosin
Functional v Nonfunctional adrenal adenoma demographic
Functional - Younger pts
Non-functional - Older pts
4 History findings pointing to an adrenal carcinoma
Fever, weight loss, abdominal fullness, back pain
Physical exam findings for adrenal carcinoma
Palpable, firm, adherent mass of the abdomen
When should fine needle aspiration be done for an adrenal carcinoma
ONLY when there is known metastasis already and pt does not have pheochromocytoma
Management of adrenal carcinoma
Stage and refer to surgery
Only glucocorticoid offered as a syrup
Prednisolone
Indication for glucocorticoid titration
Therapy longer than 7-10 days
3 things to monitor in patients on glucocorticoids
Glucose, Na retention, K+ loss
5 side effects of glucocorticoids
Gastric irritation/Peptic ulcer
Hypertension
CHF
Osteoporosis
Glaucoma
How can thyroid gland growth cause horseness
It can impinge the recurrent laryngeal nerve
Thyroglobulin
Large protein from which thyroid hormones are cleaved
Difference between T3 and T4
T3 is active, T4 is stable
Reverse T3
Non-functional form of T3 which is made in the tissues in stressful circumstances and cannot be used
Taking directions for thyroid hormone
MUST be taken on an empty stomach
Primary thyroid hormone binding protein
Thyroxine binding globulin
Which thyroid hormone is converted in the tissues
T4 to T3
Action of thyroid hormone
Increases functional activity in the tissues
Thyroid hormone effect on heart strength
Helps with a small increase but pathologic with a large increase
4 things usually on a thyroid panel
TSH, Total T3, Total T4, Free T4
Peak and trough for TSH levels
Peak at 10pm, Trough at 10am
What does an abnormal Total T3 or T4 level indicate
An increase or decrease in Thyroid Binding Globulin
Why might a patient only have T3 and no T4
They are on a T3 only medication
Binding protein for thyroid hormone
TBG - Thyroid Binding Globulin
2 things that can increase TBG levels
Estrogen, Infectious hepatitis
Result of maternal hypothyroidism
Significant decrease in fetal IQ
MCC of hypothyroidism in developed and underdeveloped countries
Developed - Hashimotos
Worldwide - Iodine deficiency
4 facial signs of hypothyroidism
Dry coarse hair, thinning of lateral eyebrows, Periorbital edema, puffy dull face (myxedema)
2 antibodies to screen for in hashimoto’s thyroiditis with chances of a positive result
Anti-Thyroid peroxidase (90-95%)
Antithyroglobulin (70%)
When might thyroid imaging be useful
Detection of thyromegaly or thyroid nodule
What will an ultrasound of a hashimoto’s thyroid look like compared to a normal one
Lack of smoothness - the thyroid should have a very uniform texture
Myxedema crisis
Triggered most often in elderly women who have a stroke or stop taking meds:
Hypo - thermia, tension, ventilation, glycemia, natremia
Medication for myxedema crisis
IV Levothyroxine (L4)
Liothyronine
T3 medication - remember T4 levels will be zero
Subclinical hypothyroidism
Normal FT4 with High TSH
Observe for s/s
Goal of thyroid hormone therapy
Normalize TSH levels
4 things that increase need for thyroid hormone therapy
Medications that interact
Increased estrogen
GI disorders
Weight gain over 10%
3 things that decrease the need for thyroid hormone therapy
Decreased estrogen
Increased androgen
Weight loss over 10%
Desiccated thyroid
Ground animal thyroid - not recommended and from beef or pork products
1 grain of dessicated thyroid
100mcg
3 Contraindications for thyroid replacement therapy
Acute MI, Thyrotoxicosis, uncorrected adrenal insufficiency
Black box warning of all thyroid replacement drugs
Not for treatment of obesity
2 groups at higher risk for thyrotoxicosis
Women and smokers
Mechanism of grave disease
Autoantibodies bind to the thyroid and cause stimulation and excessive function
Detection of graves disease
Look for TSH receptor antibodies, may treat for graves even if they are not found
3 things that can cause thyrotoxicosis
Excessive consumption of seaweed products, Amiodarone (contains iodine), Thyroiditis
Thyrotoxicosis factitia
Thyrotoxicosis caused by ingestion of thyroid hormone
3 manifestations of Graves disease
Bulging eyes, Digital clubbing, Erythematous rough plaques in the lower legs
Cardiopulmonary manifestations of thyrotoxicosis
Forceful heartbeat, Exertional dyspnea,Atrial fibrilation, Can lead to cardiomyopathy
Thyrotoxicosis in pregnancy - 3 things it can lead to
Can lead to eclampsia, preterm delivery and neonatal thyrotoxicosis
4 non-thyroid lab abnormalities seen in thyrotoxicosis
Hypercalcemia, Increased alkaline phosphatase, Anemia, Decreased granulocytes
3 markers for graves disease
Thyroid stimulating Immunoglobulin
Anti-Thyroid Peroxidase
Anti-Thyroglobulin
2 markers for thyroiditis
No antithyroid antibodies
Increased erythrocyte sedimentation rate
1 marker for thyrotoxicosis factitia
Low serum thyroglobulin levels
What might increased uptake of radioactive iodine point to (3)
Graves disease, Toxic nodules, Type I amiodarone thyrotoxicosis
What might decreased uptake of radioactive iodine point to
Thyroiditis, Iodine induced thyrotoxicosis, Type II amiodarone thyrotoxicosis
Cold nodule
Less active than the rest of the thyroid but more likely to be cancer
Hot nodule
More active than the rest of the thyroid which usually shuts down to compensate for its overproduction
How can doppler US help us detect thyroid cancer
By detecting increased/abnormal blood flow to the thyroid gland
Treatment for thyrotoxicosis opthalmopathy
Steroids for trapped intraocular muscles, radiation or surgery if severe
Thyroid storm
Severe, life threatening thyrotoxicosis triggered by radioactive iodine, surgery, or illness
6 treatment parts for a thyroid storm
Thiourea drug to prevent hormone formation
Iodinated contrast agent to prevent T4 to T3 conversion
Beta blocker
Hydrocortisone
Avoid ASA
SUrgery/RAI = Definitive
Subclinical hyperthyroidism
Low TSH with normal FT4 and T3
Is a cystic or solid mass more likely to be cancerous
SOLID
2 opthalmic signs of thyrotoxicosis/hyperthyroidism
Bulging eyes and Double vision from extraoccular muscle impingement
2 beta blockers for graves disease
Propranolol and Atenolol
2 iodonated contrast agents used for thyrotoxicosis and what they do
Iopanoic acid and Ipodate sodium
Block conversion of T3 to T4
Action of thiourea drugs
Inhibit production of thyroid hormone
2 thiourea drugs for graves disease
Methimazole - Preferred in most patients
Propylthiouracil - For first trimester or breast feeding
3 side effects of methimazole
Pruritis, abnormal taste, agranulocytosis
Black box warning for propylthiouracil
Hepatotoxicity
Definitive treatment for graves disease
Use radioactive iodine or surgery for pregnant patients
How long before radiation treatment should methimazole be stopped
4 days
Thyroiditis
Thyroid is not producing hormone, however it is leaking out of the gland causing hyperthyroidism
Treatment for thyroiditis
Thioureas NOT effective
Use beta blockers and contrast agents if severe
NSAID effect on thyroid hormones
They knock T3 and T4 off of Thyroid binding globulins
Hashimoto thyroiditis
Autoimmune thyroiditis common in women
Anti TPO and anti Tg antibodies
May have a tight feeling in neck and complain of hypothyroid symptoms
Painless postapartum thyroiditis
Sets in 1-6 months after delivery
High recurrence and followed by hypothyroidism
Anti TPO antibodies
Painless sporadic thyroiditis
Hyper and then hypothyroidism
Not associated with pregnancy
Thyroid “bipolar” disorder
Subacute thyroiditis
Often associated with pain/dysphagia and low grade fever, often accompanies an upper respiratory tract infection
Suppurative thyroiditis
Nonviral thyroid gland infection usually in the immune compromised
Severe pain and tenderness with fever
Riedel thyroiditis
Asymmetric, stony adherent thyroid gland
Due to fibrosis
May have associated dysphagia, dyspnea, pain and hoarseness
Diagnostic labs for hashimotothyroiditis
Anti TPO/Tg antibodies
Diagnostic labs for subacute thyroiditis
Elevated ESR with low antibody titers with signs of hypo/hyper thyroidism
Suppurative thyroiditis labs
Elevated ESR and leukocytes with other labs normal
2 differentials for high Anti-TPO antibodies
Hashimoto’s or Grave’s disease
Difference between graves and thyroiditis on a US
Graves has increased vascularity, thyroiditis does not
RAI uptake for graves vs. thyroiditis
Graves has increased uptake
Thyroiditis has decreased uptake
Ultrasound finding for hashimoto’s thyroiditis
Non smooth texture
Complication of hashimoto’s thyroiditis
Can cause 1st trimester miscarriage
Management of hashimoto’s thyroiditis
Levothyroxine for replacement for suppressive therapy
Treatment for subacute thyroiditis
High dose aspirin or NSAID - may need contrast agents if severe
Treatment for reidel thyroiditis (3)
Tamoxifen, Steroids, and decompression surgery if needed
Complaint for thyroid vs, Complaint for pharyngeal infection
Sore neck = thyroid
Sore throat = Pharyngeal
Sick euthyroid syndrome
State of abnormal thyroid function in the presence of a non-thyroidal illness
Cytokine thought to be especially involved in sick euthyroid syndrome
IL-6
Management of sick euthyroid syndrome
Observe and treat underlying cause
Percent of thyroid nodules that care cancerous
10%
3 associated s/s that can be found with a large multinodular goiter
Swelling, hoarseness, dysphagia
Diagnostic testing for nodules and goiters of the thyroid
TSH +/- FT4
Thyroid ultrasound - larger, more solid, nodules with unclear borders are red flags for cancer
Evaluation of thyroid nodule for cancer
US guided biopsy - low danger of seeding
Cold nodule
Nodule with little RAI uptake - high cancer risk
Hot nodule
Nodule with high RAI uptake - Low cancer risk
Warm nodule
Nodule with the same metabolic activity as the surrounding tissue
4 characteristics of thyroid nodules that warrant a biopsy
Over 1 cm with suspicious appearance
Any nodule over 2cm
Associated lymphadenopathy
Nodule growth
Management for thyroid nodule
Follow up Q6 months, LT4 suppression may be necessary, ethanol injection for shrinkage, RAI therapy, Surgery
MC thyroid cancer
Papillary thyroid carcinoma - slow growing and autosomal dominant with some iodine uptake
Follicular thyroid cancer
Higher iodine uptake and more likelihood of distant metastasis
Medullary thyroid cancer
Secretes calcitonin and prostaglandins, poor iodine uptake and local metastasis
Anaplastic thyroid cancer
Most aggressive, poor iodine uptake with rapid growth
Common sites for thyroid cancer metastasis
Lymph nodes, Lungs, Bone
2 s/s commonly associated with medullary thyroid cancer
Flushing and diarrhea
Which thyroid cancers might present with hyperthyroidism?
Follicular thyroid cancer
Which cancers might present with high thyroglobulin
Metastatic papillary and follicular cancer -invalid if anti-Tg also present
Thyroid cancers in which calcitonin may be elevated
medullary thyroid cancer - have to rule out other conditions such as pregnancy or thyroiditis
Thyroid cancer in which carcinoembryonic antigen may be elevated
Medullary thyroid cancer - must r/o other cancers
Surgical decision making for known thyroid cancer
Excise whole thyroid if over 1 cm
Single lobe if not
Surgical decision making for indeterminate thyroid lesion (may be cancer)
Excise whole thyroid if over 4cm
Single lobe if not
2 potential management options for differentiated thyroid cancers
Thyroxine suppression (monitor thyroid labs and bone density)
RAI therapy (CI in pregnancy)
Screening for thyroid cancers
At least yearly US screening recommended
Effect of parathyroid hormone on Bone, Kidneys
Bone - Osteoclast activity stimulated to release calcium
Kidney - Resorbs calcium and excreted phosphorus
Vitamin required for phosphorus absorption
Vitamin D
3 hormones that regulate calcium/phosphate balance
Parathyroid hormone
Vitamin D - 1,25
Calcitonin
Normal function of kidney with regards to calcium and phosphate
Keep calcium in, let phosphate out
Effect of the kidney on vitamin D
Changes D25 (inactive) to D1,25 (active)
Effect of vitamin D on GI tract
promotes absorption of Calcium and phosphorus
Calcitonin
Released by special cells in the thyroid and works in opposition to PTH
Total serum calcium
Both bound and free calcium
Ionized calcium
Unbound/Free calcium
Correction equation for serum calcium and when we use it (don’t actually need to memorize the equation)
Serum Ca + [.8 x (4.0-Albumin)]
Use when ionized calcium level is not available, when calcium and protein are off
Current standard diagnosis for hyperparathyroidism
Serum PTH
D3 vitamin D
Cholecalciferol - synthesized in the epidermis
D2 vitamin D
Ergocalciferol derived from plant sources
1 drug that can lead to decreased active vitamin D
HIV protease inhibitors
Parathyroid Hormone Related Protein (PTHrP)
Protein released by cancer cells that acts like PTH at PTH receptors
Clinical presentation of hypercalcemia
Bones, Stones, Groans, Moans
2 medications for hypercalcemia and what they do
Furosemide - Calcium removing diuretic
Corticosteroids - Decrease vitamin D activation in the kidneys
2 signs for hypocalcemia
Chvosteks and Trousseaus signs
Chvostek’s sign
Facial twitching when touching the ipsilateral facial nerve just anterior to the ear
Trousseu’s sign
Carpal spasm induced by inflating a BP cuff on the arm to 20mmHg above obliteration point
Primary hyperparathyroidism
Excessive PTH secretion leading to hypercalcemia and hypophosphatemia
Clinical presentation of hyperparathyroidism
Often asymptomatic but may present with hypercalcemia
Physical exam findings for primary hyperparathyroidism
May have a neck mass if it is cancerous - not definitive
Magnesium and PTH secretion
Low or high levels stimulate secretion
VERY low levels decrease secretion
Caution when diuresing patients with hyperparathyroidism
Too much could increase PTH secretion
Loop diuretics are safer if you don’t want to interfere with calcium
24 hour urine calcium interpretation
Over 200-300 is likely PHPT and excludes FHH
Under 200 is likely FHH or PHPT with vitamin D deficiency
What needs to be done prior to urine calcium testing?
Stop thiazide and loop diuretics
Serum phosphate interpretation
Low - likely primary hyperparathyroidism
High - Likely secondary hyperparathyroidism due to CKD
Serum vitmin D-25 in hyperparathyroidism
Reduced because so much is being converted
Imaging for hyperparathyroid syndrome
Used only when surgery is going to be done
CT for ectopic sources
Nuclear tracker Technetium-99m-sestamibi also available
Procedure for Technetium parathyroid scan
Wait for normal thyroid function to fade so that delayed fade of abnormal parathyroid can be visualized
Management for asymptomatic primary hyperparathyroidism
1 thing to do
3 things to avoid
Weight bearing exercise avoiding thiazide diuretics, Large doses of vitamin a, calcium containing antiacids/supplements
Routine monitoring for asymptomatic primary hyperparathyroidism
Serum calcium and albumin 2x/year
Yearly renal function and urine calcium
DEXA scan every 2 years for osteoporosis
Management for symptomatic hyperparathyroidism patients
Surgical removal often recommended
Cinacalcet also increases parathyroid gland affinity for calcium thus reducing secretion
Temporary measures for primary hyperparathyroidism
Oral or IV bisphosphonates can improve bone density and can temporarily treat the condition, Patient must remain upright for 30 minutes after bisphosphonate ingestion
Management of primary hyperparathyroidism for postmenopausal women
Estrogen replacement or Raloxifene (estrogen agonist/antagonist)
3 common causes of secondary hyperparathyroidism
CKD, VItamin D deficiency, and Hypocalcemia
Effect of hypermagnesemia of PTH release
Suppresses it through unknown mechanism
Clinical findings for hypoparathyroidism
Tetany, Chvostek and trousseu signs, Prolonged QT interval
Acute management for hypoparathyroidism
Airway, IV calcium gluconate, Oral calcium later on. Treatm hypomagnesemia as well if present
Magnesium supplementation for hypomagnesemia
Magnesium sulfate IV and then magnesium oxide PO (can cause gastric acid secretion)
Goal for calcium mainainance therapy
Keep calcium levels just below normal range to avoid renal stones
Recombinant PTH medication and indication
Teriparatide - for those with refractory conditions
Vitamin D deficiency drug and dose
D2, 1500-2000 units PO with calcium
Hypoparathyroidism drug and dose
D2, 50,000-100,000 units PO with calcium
Calcitriol
Active Vitamin D - for patients with renal failure
Hypocalcemia drug and dose
Calcium carbonate PO 1-2g/day
Calcium gluconate dosing
Give more 100-300 mg booster if there is tetany/seizure
give .5-2 mg/kg/hr after
Side effects of magnesium supplemetation
Diarrhea and GI irritation
Somat-
Root for growth
Troph
Root for a specific cell type
Sign of congenital hypopituaitarism
Decreased muscle tone, more feminine physique, short stature
Inhibitor of prolactin
Dopamine
Peak time for serum prolactin levels
4-6 AM
PRL during pregnancy
Increase 10x during pregnancy and rapidly decline IF breastfeeding is not initiated
How does suckling cause prolactin release
By inhibiting dopamine release
2 other things that increase prolactin levels
TRH secretion and Kidney failure
2 things that PRL inhibits
Sex drive and reproductive function
Causes of Hyperprolactinemia
PROLACTINS
Pregnancy
Renal failure
Oral contraceptives
Liver failure
Adenoma
Chest wall disease
Thyroid disease (Hyper)
Infiltrative pituitary disease
Nursing/nipple stimulation
Stalk effect
3 clinical presentations of hyperprolactinemia in women
Amenorrhea, galactorrhea, and infertility
4 clinical presentations of hyperprolactinemia in men
Decreased libido, Infertility, Erectile dysfunction, gyencomastia
5 things to ask about when prolactin is high
Pregnancy
Medications
Renal failure
Thyroid disease
Headache or vision changes
What vision change do you expect with a pituitary tumor
Bitemporal hemianopia - loose peripheries
Serum prolactin evaluation
Get basal fasting morning PRL level repeat if slightly high
3 things to rule out in hyperprolactinemia
Liver/Kidney disease (CMP), Thyroid problems (TSH), Hypogonadism (Testosterone, FSH, LH)
Imaging for hyperprolacintemia
Brain MRI
Treatment for hyperprolactinemia
Treat microadenomas (under 1cm) with sex hormone therapy, dopamine antagonists can also help with any cause
Long and short acting dopamine agonists for hyperprolactinemia
Cabergoline - long acting
Bromocriptine - short acting
Side effects of dopamine agonists
Constipation, nasal congestion, dry mouth, nightmares, insomnia, vertigo
Dopamine agonists and pregnancy
May stop for microadenoma, but should stop and closely monitor with macroadenoma
Hypoprolactinemia
Leads to inability to lactate after pregnancy - often a result of Sheehan syndrome (hypotension after hemorrhage during birth that causes pituitary necrosis)
3 direct effects of growth hormone
Lipolysis in adipose tissue
Gluconeogenesis in the liver
Insulin resistance in the tissues
2 indirect effects of growth hormone via IGF
Stimulates Amino Acid uptake to the muscles
Role of IGF-1 - (2)
Made by the liver in response to GH, stimulates muscle and skeletal growth, also stimulates release of Growth Hormone inhibiting hormone
5 signs of GH deficiency in children
Short stature, Micropenis, increased fat, high pitched voice, can be x-linked
Signs of growth hormone insensitivity
Normal or high GH levels with low growth hormone binding protein and IGF-1
When are growth hormone levels the highest?
At night during stages 3 and 4 of sleep
Best way to evaluate height
Plot points on a chart to look at overall pattern
Children that need a growth evaluation
More than 2.5 SDs below the mean
Height velocity below 25th percentile
Less severe short stature combined with growth failure, other evidence suggesting hypothalamic-pituitary dysfunction
Diagnostic evaluation for growth failure
Evaluate for systemic disease, hypothyroidism, and turner syndrome
Then investigate for Growth hormone deficiency
TL/DR - Rule out other things before working up for Growth hormone issues
GH stimulation test
Needs to be done twice to be diagnostic, use pharmacological or physiological stimuli
2 potential treatments for growth hormone deficiency
Recombinant GH and Somatotropin
Use IGF for GH insensitivity
Common cause of adult GH deficiency
Hypothalamic or pituitary somatotroph damage
Sequence of hormone loss in hypothalamic or pituitary somatotroph damage
GH then FSH/LH then TSH then ACTH
Clinical presentation of adult growth hormone dysfunction
Increased fat mass
Hyperlipidemia
Cardiovascular disease
Increased fractures
Depression and fatigue
3 contraindications for recombinant growth hormone therapy in adults
Active neoplasm
Intercranial hypertension
Uncontrolled diabetes
5 things to watch for in patients on Growth hormone therapy
Fluid retention
Joint pain
Paresthesias
Diabetes
Carpal tunnel (CTS)
Somatomedin
Another name for IGF-1
4 Associated risk factors of acromegaly
Cardiomyopathy
Sleep apnea
Diabetes
Colon polyps
Diagnostic confirmation of acromegaly
GH suppression to under 0.4mcg/L within 1-2 hours of a 75 g oral glucose load
Surgery of choice for tumor related acromegaly
Transsphenoidal surgical resection for both micro and macroadenomas
Treatment for acromegaly in non-surgical candidates
Treat with a somatostatin analog
Dopamine agonists also work (bromocriptine and cabergoline)
somatostatin analogs (4)
End in TIDE
End in STATIN
Signifor
Somatuline Depot
Somatostatin analog that suppresses the gall bladder
Octreotide
Presentation of hypogonadism in women
Oligomennorhea, infertility, decreased libido, osteoporosis
Clinical presentation of hypogonadism in men
Decreased libido, impotency, Decreased muscle mass, decreased beard and body hair growth
Hypogonadism lab workup for males
Check testosterone levels (free and serum) verify with LH and PRL levels
Hypogonadism workup for females
Check hCG to rule out pregnancy, check serum PRL, FSH, LH and TSH
4 treatments for men with hypogonadism
Testosterone replacement to help with normal sex characteristics
hCG given for men with oligospermia
Leuprolidine (GnRH equivalent) if pituitary is intact
Clomiphene can also stimulate pituitary if intact
Treatment for female hypogonadism
Estrogen and progesterone replacement or GnRH is secondary
Peak cortisol secretion time
6 AM
Synthetic oxytocin
Ptosin
2 things that stimulate oxytocin release
Cervix dilation, suckling
2 actions of ADH
Permeability of the collecting duct
Clotting factors from the endothelium
3 things that rigger ADH secretion and 1 thing that inhibits it
Nausea, Hyperosmolarity and Decreased Volume
Inhibited by Cortisol
Water is reabsorbed when the collecting duct is ______________ to water
Permeable
Electrolyte imbalance caused by SIADH
Euvolemic hyponatremia - because the RAAS is suppressed
2 most common causes of SIADH
Ectopic production of ADH or inappropriate secretion
How pulmonary disorders stimulate ADH
Increased CO2 stimulates increased ADH
Clinical presentation of SIADH
Euvolemic and Normotensive with severe hyponatremia leading to cerebral edema
3 signs of mild to moderate hyponatremia
Headache, Muscle Cramps, Depressed reflexes
3 signs of advanced hyponatremia
Vomiting, Somnolence, Acute psychosis
3 signs of grave hyponatremia
Seizures, Coma, Respiratory insufficiency
Diagnostic criteria for SIADH
Hyponatremia with continued excretion of Sodium at an abnormally high concentration, normal BP, skin turgor, absence of adrenal insufficiency
What should correct symptoms in SIADH
Fluid restriction
Acute SIADH
Less than 48 hours
Chronic SIADH
More than 48 hours
Disease resulting in overly rapid correction of hyponatremia and what to monitor
Central Pontine Myelinolysis - monitor daily plasma sodium rise
Treatment of emergent hyponatremia
Raise serum sodium by no more than 10-12 mEq in the first 24 hours and aim for a max of 125-130 mEq/L
Can also use furosemide
Treatment of acute hyponatremia
3% hypertonic saline
Loop diuretics (furosemide)
Vesopressin-2 receptor antagonists (conivaptan)
Water restriction to 500-1500 mL/d
2 vasopressin receptor antagonists
Conivaptan
Tolvaptan
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Risks of vasopressin receptor antagonists
Can correct sodium levels too quickly, avoid in hypovolemic hyponatremia - should be given by a provider with experience
Treatment for chronic hyponatremia
Fluid restriction and V2 receptor antagonists
Diabetes insipidus
Large quantities of urine with low specific gravity
Primary central diabetes insipidus
No identifiable lesion of the pituitary or hypothalamus - may be autoimmune or genetic
Secondary central diabetes insipidus
Damage to hypothalamus or pituitary stock that could be from tumor, infarction, or trauma
Nephrogenic diabetes insipidus
Kidneys unresponsive to ADH, can be an X-linked trait
Vasopressaine-induced diabetes insipidus
Last trimester of pregnancy, vasopressin is destroyed by a circulating enzyme but synthetic desmopressin is unaffected
Clinical presentation of diabetes insipidus
Intense thirst with large urine volume - aggravated by corticosteroid administration
1 diagnostic test to run for diabetes insipidus
24 hour urine collection for volume and creatinine
6 serum levels to check for suspected diabetes insipidus
Serum glucose, urea nitrogen, calcium, potassium, sodium, uric acid levels
Vasopressin challenge test
Give desmopressin acetate IN, SQ, or IV and measure urine volume for 12 hours
Vasopressin in nephrogenic DI
High
Central DI
Neurogenic DI
Pituitary microadenoma
Under 10mm in diameter
Pituitary macroadenoma
Over 10mm in diameter
Mammosomatotrope
Pituitary cell that secretes PRL and GH
4 familial pituitary tumor causes
Multiple Endocrine Neoplasia 1 & 4
Carney complex
Familial Pituitary adenomas (GH secreting)
Most common pituitary tumor secretion
Prolactin
Visual signs of pituitary tumor
Bitemporal hemianopia (loose peripheries)
How could a pituitary tumor cause a headache
Stretching of the dura
Rare symptom of a pituitary tumor
Hydrocephalus
3 diagnostics for a pituitary tumor
MRI of brain
Ophthalmologic exam
Lab studies focused on: Acromegaly, Hyperprolactinemia, Cushings
3 goals of pituitary tumor treatment
Normalize secretions, Relieve systemic symptoms, Shrink tumor to alleviate compression of structures
Surgical approach for pituitary tumors
Transsphenoidal
4 complications of transphenoidal resection surgery and their frequencies
Death - 1%
Transient hypopituitarism - 20%
Permanent diabetes insipidus - 10%
CSF leak - 4%
Radiation for pituitary adenomas
Usually used as a post surgical adjunt - can help ablate nonfunctioning left over tumor tissue
Prolactinoma pharm treatment
Dopamine agonists
Acromegaly pharm treatment
Somatostatin analogs
TSH secereting tumor treatment
Somatostatin analogs, maybe dopamine agonists
ACTH secreting tumor treatment
Surgery or radiation - generally NOT responsive to treatment
Non-functioning pituitary tumor treatment
Surgery or radiation - generally NOT responsive to treatment