Metabolic bone disorders (Oktaei) Flashcards
bone disorder caused by excess PTH
osteoitis fibrosa cystica
bone disorder caused by increased turnover
paget
bone disorder caused by formation < resorption
osteoprorsis = dec bone density
nml Ca, PO4, and bone density but the bones are still fragile is due to
matrix protein problem
a skeletal disorder is characterized by …
↑ risk of fracture
↓ bone strength
bone strength is determined by 2 main features
bone density and bone quality
WHat are the 4 important risk factors for fracture
↑age
female
↓ bone mineral density
↓ BMI > ↑BMI
What are lifestyle risk factors for osteoporosis?
alcohol and smoking
↓ physical activity
excessive thinness
high salt intake
are underweight or overweight pts more at risk for fractures
underweight
What nutritional factors are risk factors for osteoporosis
↓ Ca and Vit D
↑ Vit A
What hormone abnormalities increase risk for osteoporosis
excess:
PTH, cortisol, TH
low:
testosterone, androgens, estrogens, cortisol?, catecholamines? (says adrenal insufficiency)
↓ or ↑ PRL increases risk for osteoporosis. WHy
↑ bc it inhibits pulsatile secretion of estrogen → ↓estrogen → osteoporosis
In general, disorders affecting _____ part of the intestine increases the risk for osteoporosis. Why?
proximal bc that is where Ca is abs
What are examples of GI disorders that increase a person’s risk of osteoporosis
Celiac Disease Gastric Bypass Inflammatory Bowel Disease Malabsorption Pancreatic disease Primary biliary cirrhosis GI surgery
What are the 2 main inherited/genetic dzes that increase a person’s risk for osteoporosis. and then name some others
hemahromatosis
Marfan syndrome
Cystic fibrosis Ehler-Danlos Gaucher’s disease Glycogen storage disease Homocystinuria Hypophosphatasis Idiopathic hypercalciuria Menkes Steely Hair syndrome Osteogenesis Impefecta Porphyria Riley-Day syndrome
Heme disorders assc with osteoporosis
multiple myleoma monoclonal gammopathies leukemia lymphomas hemophilia thalassemia Sickle cell dz systemeic mastocytosis
Why are rheum disorders assc with osteoporosis
treatment is glucocorticoid steroids
ankylosing spondylitis, SLE, RA
Why are CNS disorders assc with osteoporosis
decreased physical activity Epilepsy Multiple sclerosis Parkinson disease Spinal cord injury Stroke
Why is end stage renal dz assc with osteoporosis
phosphorus retention → secondary hyperparathyroidism → ↑bone resorption
What meds are assc with development of osteoporosis
Lauren Poops (in a ) CACA BAG (sorry, lauren)
Lithium Proton Pump Inhibitors Chemo antacids Cyclosporine Anti-convulsants Barbituates Anti-coag Glucocorticoids
lab result that is increases suspicion of celiac’s
anti-transaminases Abs
What does a nml serum Ca with a high urine Ca tell you?
low Ca intake , the body compensated → inc PTH → inc release of Ca and PO4 from bone → Sr Ca is normal but bones are getting thinner and thinner
DEXA bone scan Z vs T score
DEXA Z score:
Bone density as compared to age, sex, ethnicity matched reference population
T score:
Bone density as compared to a young adult reference population.
What are the indications for done density testing:
- W > 65 yrs and Men > 70 yrs
- clinical risk factors, younger postmenopausal women and M 50-69 yrs
- any adult with fracture after 50
- adults with a condition or taking meds assc with low bone mass
T or F: Any low trauma even painless vertebral fracture is consistent with a diagnosis of osteoporosis, but a bone density test needs to be performed to make a diagnosis
F: Any low trauma even painless vertebral fracture does not need a bone density scan for diagnosis
Are most vertebral fractures due to low bone density (symptomatic or asymptotic) when they first occur
asymptomatic
What are the biochem markers of bone formation?
reabs?>
formation:
bone specific alk phos
osteocalcin
aminoterminal pro-peptide of type 1 procollagen
reabs:
Sr C telopeptide
Urinary N-telopeptide
calculation of the ten year probability of a hip fracture and then ten years probability of a major osteoporotic fracture
FRAX
Who is the FRAX intended for?
postmemnopausal women and men age 50 and older
FRAX is calculated using (what bone)
femorl neck bone density