Flashcards in Metabolic Bone Disease Deck (62):
What is the definition of osteoporosis?
Bone deterioration with reduced bone mass, and disruption of the microarchitecture of the bone
What is the T score on a DXA scan that indicates osteoporosis?
Which bone fracture has the highest mortality rate?
What is the #1 cause of nursing home admissions in the US?
What percent of women over 50 years will suffer an osteoporosis related hip fracture?
What are the major issues post hip fracture?
-Increased risk of mortality
-Decreased ability to do ADLs
What is the general amount of treatment (epidemiologically) given post hip fracture?
What is the gold standard in diagnosing osteoporosis?
What is the T and Z score for DXA scans?
T = compared to young adults
Z = compared to age-matched adults
True or false: DXA scan results are race and gender matched
What is the definition of osteopenia as diagnosed by DXA scan?
-1.0 to -2.5
What is considered normal per DXA scan?
-1.0 to +1.0
True or false: anyone with a fragility fracture, by definition, has a diagnosis of osteoporosis, regardless of T or Z score
Who are T scores used for?
Postmenopausal women, and men over 50 yo
Should you ever use a T score in a DXA scan for children?
When is a Z score used compared to a T score, in terms of DXA scans?
In patients who are younger than peak bone mass:
-Men less than 50
What is the diagnostic criteria for osteoporosis in terms of Z scores?
less than -2.0
What is the role of smoking and excessive EtOH consumption in the risk for fracture?
Increases the risk
What is the role of body weight in terms of risk for fracture?
Lower weight = higher risk
What is the recommended dose of Vit D3 for patients over 50 years?
800 -1000 IU / d
What are the five recommendations that should be made to patients over 50 years old to reduce the risk for osteoporosis?
-Counsel risk of OP and fractures
-Check for secondary causes
-Vit D3 intake
-Weight bearing exercises
-Avoid smoking and excess EtOH
What is the recommended amount of Ca for patients over the age of 50?
When should BMD testing begin in men and women?
Men = over 70
Women = over 65
When is BMD testing indicated for men/women over 50?
Concern for OP based on risks
At what T score should therapy begin for osteoporosis, according to the FRAX model? What about in relation to their 10 year hip fracture probability? What about all major osteoporosis related fractures?
T score between -1 to -2.5 at the femoral neck, hip, or spine
10 year hip fracture probability of more than 3%
10 year all fractures more than 20%
Why is it that age is more important than T scores?
Quality of bone lessens with age
How often should BMD testing be performed for patients on pharmacotherapy?
What is the FRAX model?
mathematical model that predicts the risk of hip frature based on risk factors
True or false: the FRAX model is only to be applied to patients who are treatment naive
What is the only DXA scan data (which bone) does the FRAX model take into account?
What is the anabolic therapy for osteoporosis?
What are the three anticatabolic therapies available for osteoporosis?
What are the most efficacious drugs used for osteoporosis?
What is the MOA of bisphosphonates?
Binds to hydroxyapatite, and inhibits osteoclast action by causing apoptosis
What is the MOA of denosumab?
binds to the RANK-L, and inhibits activation via RANK receptor (osteoclast-mediated bone destruction)
What is the MOA of teriparatide? How is it given in terms of dosing?
a recombinant form of parathyroid hormone. It is an effective anabolic agent
Low dose leads to bone growth, whereas high dose = destruction
Chronically elevated alk phos is seen in what disease?
What, generally, is Paget's disease of the bone?
Accelerated bone turnover and abnormal bone remodeling.
What are the histological characteristics of Paget's disease of the bone?
Osteoclasts with multiple nuclei
True or false: the majority of Paget's patients are asymptomatic
What are the s/sx of Paget's disease of the bone, when they occur?
What are the complications of bony deformities of Paget's disease?
Nerve impingement (e.g. sciatica, CN palsies, hearing loss, HA, etc.)
What are the labs that are elevated with Paget's disease of the bone?
True or false: Ca and Phosphate levels in Paget's disease of the bone are typically elevated
What should be done for all patients with a diagnosis of Paget's disease? Why?
baseline bone scan, and radiographs of affected sites
can help you diagnose bone changes later on, and differentiate from Paget's disease
True or false: the areas affected by Paget's disease often change throughout a person's lifetime
False--rarely do they change
What is the goal of PDB treatment?
Ease pain and normalize bone remodeling
When should PDB be treated? (3)
Alk phos is elevated
bone scan reveals increased activity
What is the drug category of choice for PDB?
bisphosphonates--Zoledronic acid in particular
What are the two processes that are defective in Rickets?
-Deficient mineralization at the growth plate
-architectural disruption of bone structure
What usually causes calcipenia rickets?
Dietary deficiency of Vit D and/or Ca
What causes phosphatemic rickets?
Renal phosphate wasting--may be caused by fanconi syndrome
What is Fanconi's syndrome?
disease of the proximal renal tubules in which glucose, amino acids, uric acid, phosphate and bicarbonate are passed into the urine, instead of being reabsorbed.
The loss of bicarbonate results in type 2 or proximal renal tubular acidosis.
What are the skeletal findings of both calcipenic and phosphopenic rickets?
-Delayed closure of the fontanelles
What are the wrist findings of Rickets?
What are the s/sx of osteomalacia?
-bone pain and muscles weakness
-muscle spasms/ cramps
What is the characteristics gait with osteomalacia?
What happens to alk phos, PTH, and vit D levels in osteomalacia?
Vit D is decreased, with compensatory increase in PTH and alk phos
How often is alk phos elevated with osteomalacia?
Looser's lines = ?
Looser zones, also known as cortical infractions, or Milkman's lines, are wide, transverse lucencies traversing part way through a bone, usually at right angles to the involved cortex and are associated most frequently with osteomalacia and rickets.
What level of Vit D is considered satisfactory? What is the goal for those in treating osteoporosis?
20 ng /ml = you're all good
30 ng/ml + for osteoporosis