Osteopenia
Encyclopedia
Osteopenia is a condition where bone mineral density is lower than normal. It is considered by many doctors to be a precursor to osteoporosis
. However, not every person diagnosed with osteopenia will develop osteoporosis. More specifically, osteopenia is defined as a bone mineral density T-score between -1.0 and -2.5.
. A group of experts decided that condition would mean a bone density that was one standard deviation below that of an average 30-year-old white woman. The group also defined osteoporosis as bone density 2.5 standard deviations or more below that 30-year-old; previously it had been used only in cases where elderly patients had fractured or broken a bone. An osteoporosis epidemiologist at the Mayo Clinic
who participated in setting the criteria in 1992 said "It was just meant to indicate the emergence of a problem," and noted that "It didn't have any particular diagnostic or therapeutic significance. It was just meant to show a huge group who looked like they might be at risk."
The definition has been controversial. Steven R. Cummings, of the University of California, San Francisco
, said in 2003 that "There is no basis, no biological, social, economic or treatment basis, no basis whatsoever" for using one standard deviation. Cummings added that "As a consequence, though, more than half of the population is told arbitrarily that they have a condition they need to worry about."
, which sells the anti-bone-loss drug Fosamax, estimated in 2003, from its own market research, that about 8 million women had been found to have osteopenia and about a third of them were taking an osteoporosis drug.
Scans of bones anywhere in the body can be done with X-rays, known as DEXA (dual X-ray absorptiometry
). Scans can also be done with portable scanners using ultrasound, and portable X-ray machines can measure density in the heel. A study paid for by Merck found that the extent to which osteopenia was diagnosed varied from 28 to 45 percent, depending on the type of machine. Merck was active in promoting deployment of cheaper scanners to be used on extremities, so that they could be used more widely. However, the clinical utility of these scans compared to scans of core portions of the body is disputed.
The condition can occur in young women who are athletes. It is associated with female athlete triad
syndrome as one of the three components, the other two being amenorrhea and disordered eating
. Female athletes tend to have lower body weight, lower fat percentage, and higher incidence of asthma than their less active peers. The low estrogen levels (stored in body fat) and/or use of corticosteroids to treat asthma can significantly weaken bone over long periods of time. Distance runners in particular are also discouraged from consuming milk products when training, which would result in lower calcium absorption than other groups.
It is also a sign of normal aging, in contrast to osteoporosis
which is present in pathologic aging.
(WHO) Fracture Risk Assessment Tool (FRAX). According to these recommendations, consideration of therapy should be made for postmenopausal women and men older than 50 years of age, if any one of the following is present:
(Notably, the first two conditions identify individuals with osteoporosis. The third condition corresponds to individuals with osteopenia, namely those with T-scores between -1.0 and -2.5.)
When medical therapy is pursued, treatment includes medications with a range of actions. Commonly used drugs are bisphosphonate
s including alendronate
, risedronate
, and ibandronate; selective estrogen receptor modulator
s (SERMs) such as raloxifene
; estrogen
; calcitonin
; and teriparatide
.
Studies have shown that the actual benefits of these drugs may be marginal. Approximately 270 women with osteopenia might need to be treated with drugs for three years so that one of them could avoid a single vertebral fracture.
Strontium ranelate
has been approved in 26 European countries and the UK, having been found to build bone both by slowing the work of osteoclast
s and stimulating osteoblast
s. Phase 3 clinical trials are nearing completion in the US. Other (natural) forms of available strontium include strontium lactate, strontium gluconate, strontium carbonate
, and strontium citrate.http://content.nejm.org/cgi/content/short/350/5/459
http://www.twin-research.com/Publicatons/2008/Seeman-%20Strontium%20ranelat.pdf Food sources include spices (especially basil), seafood, whole grains, root and leafy vegetables, and legumes. Strontium should not be taken with calcium supplements, to improve absorption.
Osteoporosis
Osteoporosis is a disease of bones that leads to an increased risk of fracture. In osteoporosis the bone mineral density is reduced, bone microarchitecture is deteriorating, and the amount and variety of proteins in bone is altered...
. However, not every person diagnosed with osteopenia will develop osteoporosis. More specifically, osteopenia is defined as a bone mineral density T-score between -1.0 and -2.5.
Definition and controversy
Osteopenia was defined in June 1992 by the World Health OrganizationWorld Health Organization
The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...
. A group of experts decided that condition would mean a bone density that was one standard deviation below that of an average 30-year-old white woman. The group also defined osteoporosis as bone density 2.5 standard deviations or more below that 30-year-old; previously it had been used only in cases where elderly patients had fractured or broken a bone. An osteoporosis epidemiologist at the Mayo Clinic
Mayo Clinic
Mayo Clinic is a not-for-profit medical practice and medical research group specializing in treating difficult patients . Patients are referred to Mayo Clinic from across the U.S. and the world, and it is known for innovative and effective treatments. Mayo Clinic is known for being at the top of...
who participated in setting the criteria in 1992 said "It was just meant to indicate the emergence of a problem," and noted that "It didn't have any particular diagnostic or therapeutic significance. It was just meant to show a huge group who looked like they might be at risk."
The definition has been controversial. Steven R. Cummings, of the University of California, San Francisco
University of California, San Francisco
The University of California, San Francisco is one of the world's leading centers of health sciences research, patient care, and education. UCSF's medical, pharmacy, dentistry, nursing, and graduate schools are among the top health science professional schools in the world...
, said in 2003 that "There is no basis, no biological, social, economic or treatment basis, no basis whatsoever" for using one standard deviation. Cummings added that "As a consequence, though, more than half of the population is told arbitrarily that they have a condition they need to worry about."
Diagnosis
The pharmaceutical company MerckMerck & Co.
Merck & Co., Inc. , also known as Merck Sharp & Dohme or MSD outside the United States and Canada, is one of the largest pharmaceutical companies in the world. The Merck headquarters is located in Whitehouse Station, New Jersey, an unincorporated area in Readington Township...
, which sells the anti-bone-loss drug Fosamax, estimated in 2003, from its own market research, that about 8 million women had been found to have osteopenia and about a third of them were taking an osteoporosis drug.
Scans of bones anywhere in the body can be done with X-rays, known as DEXA (dual X-ray absorptiometry
Dual energy X-ray absorptiometry
Dual-emission X-ray absorptiometry is a means of measuring bone mineral density . Two X-ray beams with differing energy levels are aimed at the patient's bones. When soft tissue absorption is subtracted out, the BMD can be determined from the absorption of each beam by bone...
). Scans can also be done with portable scanners using ultrasound, and portable X-ray machines can measure density in the heel. A study paid for by Merck found that the extent to which osteopenia was diagnosed varied from 28 to 45 percent, depending on the type of machine. Merck was active in promoting deployment of cheaper scanners to be used on extremities, so that they could be used more widely. However, the clinical utility of these scans compared to scans of core portions of the body is disputed.
Causes
Like osteoporosis, osteopenia occurs more frequently in post-menopausal women as a result of the loss of estrogen. It can also be exacerbated by lifestyle factors such as lack of exercise, excess consumption of alcohol, smoking or prolonged use of glucocorticoid medications such as those prescribed for asthma.The condition can occur in young women who are athletes. It is associated with female athlete triad
Female athlete triad
Female Athlete Triad is a syndrome in which eating disorders , amenorrhoea/oligomenorrhoea and decreased bone mineral density are present. Also know simply as the Triad, this condition is seen in females participating in sports that emphasize leanness or low body weight...
syndrome as one of the three components, the other two being amenorrhea and disordered eating
Disordered eating
Disordered eating is a classification to describe a wide range of irregular eating behaviors that do not warrant a diagnosis of a specific eating disorder such as anorexia nervosa or bulimia nervosa. Affected people may be diagnosed with an eating disorder not otherwise specified...
. Female athletes tend to have lower body weight, lower fat percentage, and higher incidence of asthma than their less active peers. The low estrogen levels (stored in body fat) and/or use of corticosteroids to treat asthma can significantly weaken bone over long periods of time. Distance runners in particular are also discouraged from consuming milk products when training, which would result in lower calcium absorption than other groups.
It is also a sign of normal aging, in contrast to osteoporosis
Osteoporosis
Osteoporosis is a disease of bones that leads to an increased risk of fracture. In osteoporosis the bone mineral density is reduced, bone microarchitecture is deteriorating, and the amount and variety of proteins in bone is altered...
which is present in pathologic aging.
Treatment and controversy
The treatment of osteopenia is controversial. Currently, candidates for therapy include those at the highest risk of osteoporotic bone fracture based on bone mineral density and clinical risk factors. As of 2008, recommendations from the National Osteoporosis Foundation (NOF) are based on risk assessments from the World Health OrganizationWorld Health Organization
The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...
(WHO) Fracture Risk Assessment Tool (FRAX). According to these recommendations, consideration of therapy should be made for postmenopausal women and men older than 50 years of age, if any one of the following is present:
- Prior hip or vertebral fracture
- T-score of -2.5 at the femoral neck or spine, excluding secondary causes
- T-score between -1.0 and -2.5 at the femoral neck or spine and a 10-year probability of hip fracture ≥3% or a 10-year probability of major osteoporotic fracture ≥10%
- Clinicians' judgment in combination with patient preferences indicate treatment for people with 10-year fracture probabilities above or below these levels.
(Notably, the first two conditions identify individuals with osteoporosis. The third condition corresponds to individuals with osteopenia, namely those with T-scores between -1.0 and -2.5.)
When medical therapy is pursued, treatment includes medications with a range of actions. Commonly used drugs are bisphosphonate
Bisphosphonate
Bisphosphonates are a class of drugs that prevent the loss of bone mass, used to treat osteoporosis and similar diseases...
s including alendronate
Alendronate
Alendronic acid or alendronate sodium — sold as Fosamax by Merck — is a bisphosphonate drug used for osteoporosis and several other bone diseases. It is marketed alone as well as in combination with vitamin D . Merck's U.S...
, risedronate
Risedronate
Risedronic acid or risedronate sodium is a bisphosphonate used to strengthen bone, treat or prevent osteoporosis, and treat Paget's disease of bone. It is produced and marketed by Warner Chilcott, Sanofi-Aventis, and in Japan by Takeda under the trade names Actonel, Atelvia, and Benet...
, and ibandronate; selective estrogen receptor modulator
Selective estrogen receptor modulator
Selective Estrogen Receptor Modulators are a class of compounds that act on the estrogen receptor. A characteristic that distinguishes these substances from pure receptor agonists and antagonists is that their action is different in various tissues, thereby granting the possibility to selectively...
s (SERMs) such as raloxifene
Raloxifene
Raloxifene is an oral selective estrogen receptor modulator that has estrogenic actions on bone and anti-estrogenic actions on the uterus and breast...
; estrogen
Estrogen
Estrogens , oestrogens , or œstrogens, are a group of compounds named for their importance in the estrous cycle of humans and other animals. They are the primary female sex hormones. Natural estrogens are steroid hormones, while some synthetic ones are non-steroidal...
; calcitonin
Calcitonin
Calcitonin is a 32-amino acid linear polypeptide hormone that is producedin humans primarily by the parafollicular cells of the thyroid, and in many other animals in the ultimobranchial body. It acts to reduce blood calcium , opposing the effects of parathyroid hormone . Calcitonin has been found...
; and teriparatide
Teriparatide
Teriparatide is a recombinant form of parathyroid hormone, used in the treatment of some forms of osteoporosis. It is manufactured and marketed by Eli Lilly and Company.-Administration:...
.
Studies have shown that the actual benefits of these drugs may be marginal. Approximately 270 women with osteopenia might need to be treated with drugs for three years so that one of them could avoid a single vertebral fracture.
Strontium ranelate
Strontium ranelate
Strontium ranelate, a strontium salt of ranelic acid, is a medication for osteoporosis marketed as Protelos or Protos by Servier. It is unusual in the sense that it both increases deposition of new bone osteoblasts and reduces the resorption of bone by osteoclasts...
has been approved in 26 European countries and the UK, having been found to build bone both by slowing the work of osteoclast
Osteoclast
An osteoclast is a type of bone cell that removes bone tissue by removing its mineralized matrix and breaking up the organic bone . This process is known as bone resorption. Osteoclasts were discovered by Kolliker in 1873...
s and stimulating osteoblast
Osteoblast
Osteoblasts are mononucleate cells that are responsible for bone formation; in essence, osteoblasts are specialized fibroblasts that in addition to fibroblastic products, express bone sialoprotein and osteocalcin.Osteoblasts produce a matrix of osteoid, which is composed mainly of Type I collagen...
s. Phase 3 clinical trials are nearing completion in the US. Other (natural) forms of available strontium include strontium lactate, strontium gluconate, strontium carbonate
Strontium carbonate
Strontium carbonate is the carbonate salt of strontium that has the appearance of a white or grey powder. It occurs in nature as the mineral strontianite.- Chemical properties :...
, and strontium citrate.http://content.nejm.org/cgi/content/short/350/5/459
http://www.twin-research.com/Publicatons/2008/Seeman-%20Strontium%20ranelat.pdf Food sources include spices (especially basil), seafood, whole grains, root and leafy vegetables, and legumes. Strontium should not be taken with calcium supplements, to improve absorption.
External links
- Osteopenia, University of Washington Department of Radiology
- Susan Kelleher, "Disease expands through marriage of marketing and machines", Seattle Times, June 26–30, 2005
- "Grappling With a Diagnosis of Osteopenia", U.S. News & World ReportU.S. News & World ReportU.S. News & World Report is an American news magazine published from Washington, D.C. Along with Time and Newsweek it was for many years a leading news weekly, focusing more than its counterparts on political, economic, health and education stories...
, Jan 30, 2008 - Kate Murphy, "Splits Form Over How to Address Bone Loss", New York Times, September 7, 2009
- WHO - Fracture Risk Assessment Tool
- Alix Speigel, "How A Bone Disease Grew To Fit The Prescription", NPRNPRNPR, formerly National Public Radio, is a privately and publicly funded non-profit membership media organization that serves as a national syndicator to a network of 900 public radio stations in the United States. NPR was created in 1970, following congressional passage of the Public Broadcasting...
, December 22, 2009