Term
| beyond having less mass, what is the other problem w/bone affected by osteoporosis? |
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Definition
| micro architecture is also defective |
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Term
| where do fractures from osteoporosis most commonly occur? |
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Definition
| the hip - which is more dangerous than breast CA in terms of survival |
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Term
| when does active bone formation cease? |
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Definition
| 30 y/o, from which there is a downward trend of bone density which accelerates w/menopause |
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Term
| why do female runners/dancers tend to have more stress factors? |
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Definition
| heavy physical activity can lead to amenorrhea and lack of estrogen = bone loss. lack of fat also increases risk of fracture from fall. |
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Term
| what is the reason for age-related bone loss? |
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Definition
| after 30 there is an uncoupling where the bone formation component does not keep up with active bone resorption component (this is opposed to menopause where there is increased bone resorption). |
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Term
| what is the vertebral change w/osteoporosis? |
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Definition
| concave vertebral wedge fracture = dowager's hump |
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Term
| what are the risk factors for osteoporosis? |
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Definition
| white/asian, aging, early menopause, steroids, bed rest, fam hx, smoking, alcohol use, soda (phosphates), previous fractures and propensity to fall. |
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Term
| what is in the ddx for osteoporosis? |
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Definition
| genetically: osteogenesis imperfecta and homocystinuria. endocrine: cushing's, thyrotoxicosis (lower bone mass but don’t fracture because micro architecture not disturbed), acromegaly, primary hyperparathyroidism, hypopituitarism and DM. bone marrow replacement: malignant/non-malignant. malignancy: multiple myeloma, metastasis, hormone-like secretion (OAF - osteoclastic activating factor and PTHrP - parathyroid related protein). nutritional: osteomalacia (vit D deficiency) and protein/Ca2+ deficiency. |
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Term
| what lab studies are done for osteoporosis? |
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Definition
| Ca2+ phosphatase, free T4 (thyrotoxicosis), free cortisol (cushings), ESR (malignancy), PTH/vit D levels, and DEXA scan |
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Term
| what is the single most accurate predictor of increased fracture risk? |
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Definition
|
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Term
| what are the 3 ways to look at bone mass via DEXA scan? |
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Definition
| 1) absolute value of g:cm^2. 2) Z score: compared to pts of same sex/age. 3) T score: compared to peak at 30 (most commonly used). a T score greater than -1 is considered normal, and less than -2.5 is considered osteoporosis (in between = osteopenia). |
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Term
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Definition
| a new assessment of osteoporotic fracture risk based on bone density, age, fracture/osteoporosis hx, steroid use, and smoking |
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Term
| what has to precede osteoblastic bone formation? |
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Definition
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Term
| what is therapy for osteoporosis? |
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Definition
| calcium, vit D, physical activity. possibly hormone replacement. |
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Term
| what is the major cause of osteoporosis fracture? |
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Definition
| family pet. mats in front of sinks are also common. |
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Term
| what is tx for osteoporosis? |
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Definition
| HRT, raloxifene, bisphosphonates (alendronate/risedronate), calcitonin, PTH, denosumab, and injectable bisphosphonates (boniva/reclast) |
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Term
| what is the effect of estrogen on bone mass? |
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Definition
| estrogen prevents hip fracture and provides marked improvement to bone density |
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Term
| what is the risk of breast CA for post-menopausal pts on estrogen/progesterone? other risks? |
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Definition
| increased risk of undetected breast CA becoming more present after 5 years of therapy. there is also an increased risk of PE, breast tenderness, irregular bleeding, and fluid retention. |
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Term
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Definition
| selective estrogen receptor modulators such as raloxifene, which were developed in response to breast CA risk w/estrogen. it has estrogen-like activity in bones (lowers vertebral fracture risk - not at hip) but actually may decrease breast CA risk (antagonizes estrogen receptors at breast and uterus) and lower LDLs. ADRs: increased hot flashes, leg cramps, and DVTs. |
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Term
| what characterizes nasal calcitonin as an anti-osteoporotic fracture drug? |
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Definition
| it only has risk reduction at 200 IU and only protects the spine (not the hip). |
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Term
| what is the MOA and benefits/risks for bisphosphonates? how are the risks addressed? |
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Definition
| *MOA: inhibition of osteoclasts. *benefits: fracture reduction (vertebral and hip), BMD increase, non hormonal. *risks: nausea, upper GI irritation, arthralgia, osteonecrosis of the jaw, spontaneous/atraumatic long bone fractures (resorption is necessary for new bone formation), and esophageal CA. these risks can be minimized by taking 5 years on, 2 years off or on another drug (cycling). |
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Term
| how does PTH ultimately decrease osteoporosis? |
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Definition
| PTH injection increases bone resorption markedly for a few hours then once its levels fall there is a 24 hour period of bone formation. this markedly increases density, but doesn't have any better protective effect than raloxifine. |
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Term
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Definition
| a monoclonal antibody which interferes w/RANKL ligand binding - impairing osteoclastic function/formation/survival. it does provide a decrease in vertebral and hip fractures. it is given by injection every 6 mos. ADRs: hypocalcemia, increased risk of serious bacterial infection, and osteonecrosis. it is not considered an initial therapy, but instead is given to pts intolerant to bisphosphonates. |
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Term
| what are the primary/secondary/tertiary hyperparathyroidisms due to? |
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Definition
| primary: generally parathyroid adenoma (95% of the time), secondary: commonly renal insufficiency/vit D deficiency, tertiary: glands become autonomous and do not respond once secondary cause is addressed. |
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Term
| why was hyperparathyroidism called the disease of “bones, stones, abdominal groans and psychic moans”? |
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Definition
| b/c it can cause osteitis cystica, nephrolithiasis, abdominal hyperacidity (groans), increased pancreatitis, and psychological symptoms (depression/fatigue/neurologic/etc). only some pts are this symptomatic however - many may be asymptomatic. |
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Term
| what are the guidelines for treating pts w/hyperparathyroidism? |
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Definition
| if pts have very high serum calcium (1 pt. above upper normal range), urinary calcium, renal insufficiency, bone disease (low bone density) or are under age 50+ then should go to surgery - otherwise their Ca2+ levels can just be monitored every 6-12 months. |
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Term
| how is hyperparathyroidism diagnosed? |
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Definition
| the presence of elevated PTH w/hypercalcemia (PTH should be unmeasurable w/hypercalcemia). PTHrP levels should be checked in case there is a tumor secreting it and vit D levels can be checked as well. r/o familial hypercalciuric hypercalcemia, medications, granulomatous disorders (increased Ca2+), and endocrinopathies. |
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Term
| what is medical treatment hyperparathyroidism? |
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Definition
| push fluids to prevent Ca2+ crystallization along w/normal Ca2+ and vitamin intake. |
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Term
| what is surgical treatment hyperparathyroidism? |
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Definition
| administer a radiographic compound (sestamibi) which concentrates in the parathyroid glands. then, before surgery, probe for radiation, find it and take out the gland via microscopic sx. after, check to make sure there’s no radiation left. |
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Term
| what is sx becoming recommended for all hyperparathyroid pts? |
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Definition
| new studies show that even asymptomatic hyperparathyroid pts have increased morbidity (fracture, cardiac problems). post sx, pts do not show signs of "feeling better" per se, but they do increase bone mass. |
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Term
| what is hyperparathyroidism more likely to be due to in younger pts? |
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Definition
| hyperplasia - which may not light up the radiographic scan |
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Term
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Definition
| a calcimimetic, which tricks the parathyroid gland into thinking Ca2+ are even higher and thus the rx is able to shut off the PTH secretion via negative feedback. there is little data on whether this is as good as sx. |
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Term
| what is hypoparathyroidism usually due to? |
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Definition
| iatrogenic: postsx or radiation. idiopathic. malignant infiltration or resistance states (pseudohypoparathryoidism = genetic resistiance to PTH). vit D deficiency. |
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Term
| what is osteomalacia due to? |
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Definition
| vit D deficiency from malabsorption, phosphate deficiency or mineralization defects |
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Term
| what is pagets disease of the bone? |
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Definition
| unknown etiology, possibly viral induced neoplastic change in osteoblastic cells. treat w/bisphosphonate. |
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