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.
Definition and controversy
Osteopenia was defined in June 1992 by the World Health Organization
. 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. Dr. Steven R. Cummings, of the University of California at San Francisco, said in 2003 that "There is no basis, no biological, social, economic or treatment basis, no basis whatsoever, for using minus one." Cummings also said that "As a consequence, though, more than half of the population is told arbitrarily that they have a condition they need to worry about."
The pharmaceutical company Merck
, 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 energy 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.
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 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.
- Osteopenia, University of Washington Department of Radiology
- Susan Kelleher, "Disease expands through marriage of marketing and machines", Seattle Times, June 26-30, 2005
- Osteopenia - a controversial diagnosis
- "Bone-Strengthing Drugs May Be Overprescribed", HealthDay, Jan 18, 2008
- "Grappling With a Diagnosis of Osteopenia", U.S. News & World Report, Jan 30, 2008