Osteoporosis
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
A clinical prediction rule (http://hipcalculator.fhcrc.org/) is available to predict risk of a fracture over five years. [2] Of note, the clinical prediction rule did not study the contribution of physical examination findings.
Bone densitometry
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[3]:
- 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.[2]
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)."[2]
Bisphosphonates
Once yearly, intravenous zoledronic acid reduced second hip fractures in a randomized controlled trial of women after an initial hip fracture. In this trial, 19 patients had to be treated for one hip fracture to be prevented.[6]
References
- ↑ 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.
- ↑ 2.0 2.1 2.2 John Robbins et al., “Factors Associated With 5-Year Risk of Hip Fracture in Postmenopausal Women,” JAMA 298, no. 20 (November 28, 2007), http://jama.ama-assn.org/cgi/content/abstract/298/20/2389 (accessed November 27, 2007). Cite error: Invalid
<ref>tag; name "pmidpending" defined multiple times with different content Cite error: Invalid<ref>tag; name "pmidpending" defined multiple times with different content - ↑ 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.
- ↑ (2002) "Screening for osteoporosis in postmenopausal women: recommendations and rationale". Ann. Intern. Med. 137 (6): 526-8. PMID 12230355. [e]
- ↑ 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]
- ↑ Lyles KW, Colón-Emeric CS, Magaziner JS, et al (2007). "Zoledronic Acid and Clinical Fractures and Mortality after Hip Fracture". N Engl J Med. DOI:10.1056/NEJMoa074941. PMID 17878149. Research Blogging.