Osteopenia (cont.)

Anyone who has been diagnosed with osteopenia should implement lifestyle changes and discuss with their physician whether they should take calcium and vitamin D supplements and possibly receive prescription medication for their condition.

Osteopenia is diagnosed using measures of bone mineral density (BMD). The test recommended by the National Osteoporosis Foundation to measure BMD is the dual energy X-ray absorptiometry scan or DXA scan (formerly known as DEXA scan). A DXA scan measures BMD in the hip, spine, and sometimes the wrist. These locations are chosen because these are frequent sites of bone fracture. The DXA is a very accurate predictor of future fracture risk.

The DXA scan gives two results: a "T score" and a "Z score." The Z score compares the patient's BMD to the average of a person of the same age and sex. The T score compares the BMD to a healthy 30-year-old of the same sex. These scores are measured in standard deviations above or below normal. For example, if a T score is -1.0, this indicates a BMD which is 1.0 standard deviations below a healthy 30-year-old of the same sex. In other words, the lower the bone mineral density, the lower the T score or Z score and the higher the risk of fracture. The risk for fracture doubles with every standard deviation below normal. So, someone with a T score of -2.0 has an approximately twofold increased risk of fracture as compared to someone with a T score of -1.0.

T scores are used to diagnose osteopenia and osteoporosis; those between -1.0 and -2.5 indicate osteopenia, and T scores lower than -2.5 indicate osteoporosis. But it is important to realize that T scores are not the only indication of osteoporosis: if someone has a bone fracture without trauma, then they have osteoporosis by definition, regardless of T score. These patients should be treated as though they have osteoporosis, even if their T score is normal or in the osteopenic range.

Other tests used to measure bone density include the peripheral dual-energy X-ray absorptiometry (pDXA), quantitative computed tomography (QCT), peripheral QCT (pQCT), and quantitative ultrasound densitometry (QUS). Sometimes a routine X-ray reveals diffuse osteopenia (osteopenia in all bones visualized by the X-ray) or osteopenia of a particular location, such as spinal osteopenia. Periarticular osteopenia is an indication of inflammation around a certain joint. This can be seen in conditions such as rheumatoid arthritis and does not necessarily indicate a decreased BMD throughout the bony skeleton. While routine X-rays may suggest decreased bone mineral density, the DXA scan is much more precise in diagnosing osteopenia and osteoporosis.

Source: MedicineNet.com
http://www.medicinenet.com/osteopenia/article.htm