calcium & parathyroid d/o

Question 1

familial hypocalciuric hypercalcemia

Answer 1

loss of function mutation in CaSR making it less sensitive to calcium
benign most times

Question 2

labs with familial hypocalciuric hypercalcemia

Answer 2

mildly high Ca
high-nl/mildly high PTH
low urinary Ca levels
will also have fam hx

Question 3

why is it important to recognize familial hypocalciuric hypercalcemia?

Answer 3

so you don’t subject them to surgery from thinking that it is primary hyperparathyroidism

Question 4

labs when there is hypercalcemia with normal parathyroid gland

Answer 4

high Ca with low PTH
parathyroid gland is fine bc its responding to Ca levels

Question 5

3 ways that hypercalcemia of malignancy works

Answer 5

tumor destroys bone
tumor makes PTHrP
tumor makes 1,25-D

Question 6

other causes of hypercalcemia w/ normal parathyroid

Answer 6

vit D intoxication
sarcoidosis/granulomatous dz– unregulated 1 alpha-hydroxy
hyperthyroidism
milk-alkali syndrome– renal failure, metabolic alkalosis
prolonged immobilization
thiazide diuretics

Question 7

symptoms of hypocalcemia

Answer 7

perioral or digital paresthesias
muscle cramping to point of tetany
seizures

Question 8

primary hyperparathyroidism pathophys

Answer 8

abnormal regulation of PTH by calcium leading to excess PTH secretion causing increased Ca retention in kidneys, absorption in GI and reabsorption from bone

Question 9

expected Ca and PTH levels with primary hyperparathyroidism

Answer 9

elevated Ca and high/inappropriately normal PTH levels

Question 10

most common cause of primary hyperparathyroidism

Answer 10

single parathyroid adenoma (benign)
multiple adenoma, diffuse hyperplasia can occur
parathyroid carcinoma is rare

Question 11

mnemonic for primary hyperparathyroidism symptoms

Answer 11

Bones, Stones, Tummy Groans and Psychic Moans

Question 12

primary hyperparathyroidism effect on bones

Answer 12

increased osteo activity
brown tumors
fractures
subperiosteal bone resorption

Question 13

primary hyperparathyroidism effect on kidney

Answer 13

kidney stones
nephrolithiasis and nephrocalcinosis d/t hypercalciuria

Question 14

primary hyperparathyroidism effect on GI

Answer 14

increased Ca absorption d/t activating Vit D
nausea, vomiting, constipation

Question 15

primary hyperparathyroidism effect on psych

Answer 15

concussion
memory issues
difficulty concentrating

Question 16

how is primary hyperparathyroidism usually diagnosed?

Answer 16

it is usually incidental bc people are usually asymptomatic

Question 17

if patients are usually asymptomatic, what is the concern with primary hyperparathyroidism?

Answer 17

its effect on bone density and the risk of kidney stones

Question 18

how is hypercalcemia diagnosed generally? what is the lab work up?

Answer 18

ionized serum Ca (more accurate than total)
PTH to r/o primary hyperparathyroidism
PTHrP if normal or low PTH to r/o malignancy
Vit D (which one?)

Question 19

List causes of hypocalcemia

Answer 19

primary hypoparathyroidism (parathyroid dysfx)
secondary hypERparathyroidism (external force)
electrolyte abnormalities
diuretics & antiresorptives

Question 20

what is the most common cause of hypocalcemia?

Answer 20

primary hypoparathyroidism

Question 21

expected Ca and PTH levels with primary hypoparathyroidism

Answer 21

low or inappropriately normal PTH + low Ca

Question 22

cause of primary hypoparathyroidism

Answer 22

damaged parathyroid glands via congenital, surgery or autoimmune destruction
impaired PTH secretion from intact glands d/t hypomagnesemia

Question 23

how is hypocalcemia treated?

Answer 23

calcium and active vit D (calcitriol)

Question 24

why would you want to give active vit D (calcitriol) specifically when treating primary hypoparathyroidism?

Answer 24

if you give any inactive form, you’d need PTH to activate it
bypass this by giving an already active form!

Question 25

what is secondary hypERparathyroidism? expected Ca and PTH levels?

Answer 25

hypocalcemia causing increased PTH levels
normal Ca + high PTH

Question 26

what seems odd about the labs with secondary hypERparathyroidism? explain why it actually makes sense.

Answer 26

the increased PTH is due to low Ca so you would expect to see low Ca levels in lab. instead Ca levels are normal
this makes sense because the parathyroid is actually working fine in this condition so the compensatory rise in PTH is able to correct the low Ca levels

Question 27

what causes secondary hypERparathyroidism

Answer 27

any trigger for PTH production
vitamin D deficiency (osteomalecia, rickets) & CKD

Question 28

how does Vit D deficiency cause secondary hypERparathyroidism

Answer 28

no vit D= poor Ca absorption in GI, decreased Ca availability for bone mineralization = low Ca

Question 29

how does CKD cause secondary hypERparathyroidism

Answer 29

poor renal phosphate clearance–> hyperphosphatemia
impaired renal 1 alpha-hydroxylase–> poor Ca absorption

Question 30

what is Chvostek sign

Answer 30

ipsilateral facial spasm, twitching and contraction on tapping of facial nerve in-front of the tragus
seen in hypocalcemia

Question 31

what is Trousseau’s sign

Answer 31

inflation of BP cuff above systolic BP for 3 mins causes painful carpal spasms (wrist & MCP joint flexion w/ adducted fingers)
seen in hypocalcemia

Question 32

primary hyperparathyroidism vs hypoparathyroidism traids

Answer 32

primary hyper– high Ca + high/inappropriately normal PTH + decreased phosphate
primary hypo– low Ca + low/inappropriately normal PTH + increased phosphate

Question 33

DTR in hypercalcemia vs hypocalcemia

Answer 33

decreased DTR in hyper
increased DTR in hypo