Pearson: Clinical Case 2 Flashcards
What is primary osteoporosis?
deterioration of bone mass that is unassociated with other chronic illness
What is secondary osteoporosis?
Chronic conditions that contribute significantly to accelerated bone loss.
These chronic conditions include endogenous and exogenous thyroxine excess, hyperparathyroidism, malignancies, gastrointestinal diseases, medications, renal failure and connective tissue diseases
When is BMD testing recommended?
In women age 65 and older and men age 70 and older, recommend bone mineral density (BMD) testing.
• In postmenopausal women and men age 50-69, recommend BMD testing when you have concern based on their risk factor profile.
When do you initiate treatment for osteoporosis?
those with hip or vertebral (clinical or asymptomatic) fractures
What is the T score in a Dexa scan?
The T-score shows the amount of bone the patient has compared to a young adult (at the age of 35) of the same gender with peak bone mass T-scores are based on the standard deviation, which reflects differences from the average score.
What is a Z score?
Z-scores are calculated in the same way, but the comparisons are made to someone of approximately the same age, sex, race, height, and weight
Who do you want to treat for osteoporosis?
Pts who have had fragility fractures
pts who are osteopenic and are at high risk (FRAX calculator)
What lab do you order to check vitamin D?
Vit D (25- Hydroxyvitamin D)
What causes primary hyperparathyroidism?
enlargement of one or more of the parathyroid glands
What is secondary hyperparathyroidism?
the body produces extra parathyroid hormone because the calcium levels are too low
What drives PTH?
calcium levels
What are common symptoms of PTH?
Stones, bones, groans and moans
What tests are done to evaluate hyperparathyroidism?
increased levels of parathyroid hormone (PTH), calcium, and alkaline phosphatase, and lower levels of phosphorus.
A 24-hour urine collection test helps to determine how much Ca is being removed from the body.
How much Ca is recommended for menopausal women?
1200 mg Ca (replace up to this level)
How much vit D is recommended for women?
600-800 IU
How is Vit D def defined?
Deficiency is defined as a serum 25-hydroxyvitamin D level of less than 20 ng per mL (50 nmol per L)
insufficiency is defined as a serum 25- hydroxyvitamin D level of 20 to 30 ng per mL (50 to 75 nmol per L).
What acts as a reservoir for Ca?
Bone
What organs eliminate or retain/recover Ca?
Kidney and GI
What two hormones are involved in the regulation of Ca?
PTH
Active vitamin D3= calcitriol
What controls Ca deposition?
Osteoblasts
What controls Ca mobilization?
osteoclasts
What does PTH do?
Mobilizes Ca from bone in response to HYPOcalcemia
Enhances renal absorption of Ca
Regulates the activity of 1,25(OH)D-1a-hydroxylase> INCREASES vit D
What type of hormone is PTH?
peptide hormone
What type of receptor is PTHR?
GPCR
What is calcitriol?
active vit D3= 1,25 dihydroxycholecalciferol
What does vit D do?
promotes absorption of Ca from the GUT
What type of hormone is vit D? What is VDR?
steroid hormone
Nuclear receptor superfamily and a heterodimer partner w/ RXR
Describe the steps required to convert inactive vit D3 to active vit D3.
Vit D3> blood> liver> 25 hydroxylase > 25 hydroxyvitamin D3> Blood> Kidney> 1 aplha hydroxylase> 1,25-dihydroxyvitamin D3> bones, intestines, kidneys
