Osteoporosis

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Revision as of 22:29, 15 October 2007 by imported>Robert Badgett (→‎Diagnosis)
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Diagnosis

Diagnosis is made be bone densitometry, or be the presence of fragility fractures.

Physical examination

A systematic review by the Rational Clinical Examination concluded that the best physical findings are:[1]

  • weight less than 51 kg
  • tooth count less than 20
  • rib-pelvis distance less than 2 finger breadths
  • wall-occiput distance greater than 0 cm
  • self-reported humped back

Densitometry results are generally scored by two measures, the T-score and the Z-score. Scores indicate the amount one's bone mineral density varies from the mean. Negative scores indicate lower bone density, and positive scores indicate higher.

T-score

The T-score is a comparison of a patient's BMD to that of a healthy thirty-year-old. This value is used in post-menopausal women and men over aged 50 because it better predicts risk of future fracture.Template:Fact The criteria of the World Health Organization are[2]:

  • Osteoporosis is defined as -2.5 or lower, meaning a bone density that is two and a half standard deviations below the mean of a thirty year old woman.
  • Osteopenia is defined as less than -1.0 and greater than -2.5
  • Normal is a T-score of -1.0 or higher

Z-score

The Z-score is a comparison of a patient's BMD to the average BMD of their, sex, and race. This value is used in premenopausal women, men under aged 50, and in children.Template:Fact

Other tests

Screening patients for hypercortisolism with a 2-day, low-dose dexamethasone suppression test ( 0.5 mg of dexamethasone by mouth every 6 hours followed by measurement of serum cortisol at 9:00 a.m. 2 days after the first dose), may identify hypercortisolism in 10% of patients who have both T-scores of –2.5 or less and vertebral fractures.[3]

Screening

The U.S. Preventive Services Task Force (USPSTF) recommends that all women 65 years of age or older should be screened with bone densitometry.[4] The Task Force recommends screening women 60 to 64 years of age who are at increased risk. The best risk factor for indicating increased risk is lower body weight (weight < 70 kg).

Clinical prediction rules are available to guide selection of women for screening. The Osteoporosis Risk Assessment Instrument (ORAI) may be the most sensitive strategy[5]

Treatment

Calcium

A meta-analysis of randomized controlled trials concluded "Evidence supports the use of calcium, or calcium in combination with vitamin D supplementation, in the preventive treatment of osteoporosis in people aged 50 years or older. For best therapeutic effect, we recommend minimum doses of 1200 mg of calcium, and 800 IU of vitamin D (for combined calcium plus vitamin D supplementation)."[3]

References

  1. Green AD, Colón-Emeric CS, Bastian L, Drake MT, Lyles KW (2004). "Does this woman have osteoporosis?". JAMA 292 (23): 2890–900. DOI:10.1001/jama.292.23.2890. PMID 15598921. Research Blogging.
  2. WHO Scientific Group on the Prevention and Management of Osteoporosis (2000 : Geneva, Switzerland) (2003). Prevention and management of osteoporosis : report of a WHO scientific group (pdf). Retrieved on 2007-05-31.
  3. 3.0 3.1 Chiodini, Iacopo, Maria Lucia Mascia, Silvana Muscarella, Claudia Battista, Salvatore Minisola, Maura Arosio, et al. 2007. Subclinical Hypercortisolism among Outpatients Referred for Osteoporosis. Ann Intern Med 147, no. 8 (October 16): 541-548. http://www.annals.org/cgi/content/abstract/147/8/541 (accessed October 16, 2007). Cite error: Invalid <ref> tag; name "pmidpending" defined multiple times with different content
  4. (2002) "Screening for osteoporosis in postmenopausal women: recommendations and rationale". Ann. Intern. Med. 137 (6): 526-8. PMID 12230355[e]
  5. Martínez-Aguilà D, Gómez-Vaquero C, Rozadilla A, Romera M, Narváez J, Nolla JM (2007). "Decision rules for selecting women for bone mineral density testing: application in postmenopausal women referred to a bone densitometry unit". J. Rheumatol. 34 (6): 1307-12. PMID 17552058[e]