PTH CIS Flashcards
What are symptoms of hypocalcemia
twitching, muscle cramps, tingling and numbness
what are symptoms of hypercalcemia
constipation, polyuria, polydipsia, lethargy, coma, death
how much calcium is usually bound to albumin
45%
What are PTH dependent hypercalcemic disorders
primary hyperparathyroidism
hypercalemia of malignancy
familial hypocalciuric hypercalemia
What are PTH independent hypercalcemic disorders
thiazide diuretics milk-alkali syndrome immobilization acture renal failure granulomatous disease VIT D or A intoxificiation adrenal insufficiency hyperthyroidism
What causes the hypercalcemia of malignancy
PTH RP
What is the key test in differential Dx of hypercalemia
serum PTH
What causes familial hypocalciuric hypercalcemia
heterozygous inactivation mutation in CaSR
increased PTH and serum Ca
What are the causes of hypocalcemia
Vit D deficiency hypoPTH pseudohypoparathyroidism hypomagnesemia renal failure liver failure acute pancreatitis hypoproteinemia
What causes hypoparathyroidism
usually autoimmune to parathyroid gland
describe pseudohypoparathyroidism
genetic disorder causing resistance to PTH
What is the key test in Dx for hypocalcemia
measurement of 25-OH VIT D
how does hypoproteinemia cause hypocalcemia
losing albumin, so cannot carry Ca
High Ca, low phosphate, extremely high PTH, normal albumin, elevated alkaline phosphatase, elevated urinary Ca excretion and calcium oxalate
hyperparathyroidism, tumor of parathyroid gland
What triggers alkaline phosphatase release
increased bone resorption from PTH levels
how will the levels of ionized Ca be if have alkalemia
decrease
H+ and Ca+ compete with eachother on albumin
On what cell type in bone do PTH R sit on
osteoblasts
what happens with PTH on bone resorption
bind R on osteoblasts
soluble mediators(cytokines)
stimulate osteoclasts
more Ca released from bone
Why do people with primary PTH have increased alkaline phosphatase
increased bone resorption
triggers bone formation
What is alkaline phosphatase a measurement for
bone formation
What is the effect of increased PTH on kidney
increased production of 1,25 OH Vit D
What are the 4 actions of PTH
increased bone turnover, increased intestinal Ca resorption due to increased 1,25 Vit D
decreased serum phosphate
increased renal Ca absorption
What is significant of increased phosphate excretion on serum Ca levels
PTH action
Why does someone with hyperparathyroidism have hypercalciuria
increased Ca resorption, kidney stones
kidney stones presented with dehydration, what is the mechanism
increase in ADH secretion, concentration of urine
pain with pressure applied to tibias is indicative of
Vit D deficiency
What are the levels of Vit D deficiency
0-10 severe
10-20 moderate
20-30 mild
>30 normal
a vit D deficiency leads to what bone disorder
osteomalacia
bone problems associated with renal failure can be charcterized by what levels
a decrease in 1 alpha hydroxylase activity
why do serum calcium levels not increase in bone problems due to renal failure
increase in phosphate leads to biding with Ca and can cause precipitation
bone loss because of renal failure occurs because of what
renal phosphate clearance decreases in renal failure
8 year old with muscle cramping of arms and legs and tingling of lips
Type I DM, addisons, hypothyroidism
low Ca, PTH, normal Vit D and albumin
increased phosphorous
hypoparathyroidism, autoimmune
56 yr old hypercalcemic, asymptomatic except polyuria
increased Ca, low phosphorous, increased PTH, increased alkaline phosphatase and normal albumin
increased urinary cAMP elevated urinary cAMP and hydroxyproline
short QT
T score 2.0
primary hyperparathyroidism
overproduction PTH
T score shows she has osteoporosis
increased bone resorption
When PTH is extremely high and Ca is slightly low what can be suspected
kidney failure
If Ca is extremly high and PTH low/normal what can be suspected
High Ca of malignancy
With very elevated PTH AND Ca what can be suspected
primary hyperparathyroidism
