Osteoporosis or thinning of the bone often affects
postmenopausal women and predisposes them to fractures. The condition
progresses from a milder condition called osteopenia to osteoporosis.
Osteopenia could be further categorized as mild, moderate or advanced.
A Bone Mineral Density or DEXA scan is used to
diagnose osteopenia or osteoporosis. The test results are given as a T score. A
T score of above -1 is normal. A T score between -1 and -2.5 indicates
osteopenia, and a T score of less than -2.5 indicates osteoporosis.
Preventative Task Force currently advises all women above the age of 65 years
to undergo testing for osteoporosis
. But it is currently unclear how often the test
should be repeated.
A recent study conducted in the United States and
published in the New England Journal of Medicine attempted to clear this
aspect. In the study, 4957 women, 67 years of age or older were studied for a
period of 15 years. These women had either normal bone mineral density or
osteopenia at the start of the study. None of them suffered any fractures or
underwent treatment for osteoporosis at the beginning of the study.
The bone mineral density testing interval in the
study was defined as the estimated time during which 10% of the participants
developed osteoporosis before they had a hip or clinical vertebral fracture or
received treatment for osteoporosis.
found that women with normal bone mineral density or mild osteopenia (T score,
−1.01 to −1.49) will take at least 15 years to suffer from osteoporosis
, thus the test need not be
repeated for at least 15 years in these cases. Women with moderate or advanced
osteopenia, on the other hand, require more frequent testing. In case of moderate osteopenia (T score,
−1.50 to −1.99), the testing should be done every 5 years and in case of severe
or advanced osteopenia (T score, −2.00 to −2.49), it should be done annually.
The required time intervals between testing vary
according to the age of the patient. Thus, the researchers suggest taking the
age of the women into consideration while evaluating the intervals for
screening for osteoporosis. The researchers also suggest considering other
variables like decrease in activity or weight loss, which were not included in
recommendations of the study will definitely reduce health costs and avoid
unnecessary frequent repeating of the test in postmenopausal women with normal
bone mineral density.
1. Bone-Density Testing Interval and Transition to Osteoporosis in Older
Women; Margaret Gourlay et al; N Engl J Med 2012; 366:225-233