Osteoporosis
Causes/etiology
Glucocorticoid drugs can cause osteopororis.
Subclinical hypercortisolism may underly about 5% of cases of osteoporosis.[1] These patients can be identified by serum cortisol levels greater than 50.0 nmol/L after a 1-mg overnight dexamethasone test.
Diagnosis
Diagnosis is made be bone densitometry, or by the presence of fragility fractures. However, high-trauma fractures also are associated with osteoporosis.[2]
History and physical examination
A systematic review by the Rational Clinical Examination concluded that the best physical findings in women are:[3]
- 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
For women, a clinical prediction rule (http://hipcalculator.fhcrc.org/) is available to predict risk of a fracture over five years. [4] Of note, the clinical prediction rule did not study the contribution of physical examination findings.
For men, the "MORES" clinical prediction rule uses age, weight, and history of chronic obstructive pulmonary disease to predict risk of a fracture with a number needed to screen of 279 to prevent one fracture:[5]
- sensitivity = 93%
- specificity = 59%
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[6]:
- 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.[7]
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.[8] 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[9]
Treatment
It is no clear which medications are best for treating osteoporosis.[10]
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)."[7]
Vitamin D
Antiresorptives
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.[11]
Selective Estrogen Receptor Modulators (SERMs)
Anabolic therapies
As opposed to antiresorptive drugs, anabolic drugs enhance bone formation.[12]
Parathyroid hormone
Sodium fluoride
Strontium Ranelate
See also
References
- ↑ Chiodini I, Mascia ML, Muscarella S, et al (2007). "Subclinical hypercortisolism among outpatients referred for osteoporosis". Ann. Intern. Med. 147 (8): 541–8. PMID 17938392. [e]
- ↑ Mackey DC, Lui LY, Cawthon PM, et al (2007). "High-trauma fractures and low bone mineral density in older women and men". JAMA 298 (20): 2381–8. DOI:10.1001/jama.298.20.2381. PMID 18042915. Research Blogging.
- ↑ 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.
- ↑ Robbins J, Aragaki AK, Kooperberg C, et al (2007). "Factors associated with 5-year risk of hip fracture in postmenopausal women". JAMA 298 (20): 2389–98. DOI:10.1001/jama.298.20.2389. PMID 18042916. Research Blogging.
- ↑ Shepherd AJ, Cass AR, Carlson CA, Ray L (2007). "Development and internal validation of the male osteoporosis risk estimation score". Ann Fam Med 5 (6): 540–6. DOI:10.1370/afm.753. PMID 18025492. Research Blogging. (Prediction rule in Table 4)
- ↑ 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.
- ↑ 7.0 7.1 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 - ↑ (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]
- ↑ Maclean C, Newberry S, Maglione M, et al (2007). "Systematic Review: Comparative Effectiveness of Treatments to Prevent Fractures in Men and Women with Low Bone Density or Osteoporosis". Ann Intern Med. PMID 18087050. [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.
- ↑ Canalis E, Giustina A, Bilezikian JP (2007). "Mechanisms of anabolic therapies for osteoporosis". N. Engl. J. Med. 357 (9): 905–16. DOI:10.1056/NEJMra067395. PMID 17761594. Research Blogging.