Bone mineral density key determinant of screening interval in postmenopausal women
MONDAY, Oct. 18 (HealthDay News) -- Baseline bone mineral density (BMD) appears to be the most important determinant of the osteoporosis screening interval among postmenopausal women, according a study presented at the annual meeting of the American Society for Bone and Mineral Research, held from Oct. 15 to 19 in Toronto.
As part of the Study of Osteoporotic Fractures, Margaret L. Gourlay, M.D., of the University of North Carolina in Chapel Hill, and colleagues evaluated data on 5,035 women, aged 67 years and older, enrolled in the study between 1986 and 1988, to determine an optimal BMD testing interval according to baseline T-score category over a total of 15 years of prospective follow-up. Women with osteoporosis were excluded from the analysis and the rest of the women were categorized into high-, moderate-, and low-risk groups according to their baseline BMD T-scores at the hip.
The investigators defined the optimal dual energy X-ray absorptiometry (DXA) testing interval as the estimated time during which 10 percent of women with normal BMD or osteopenia became osteoporotic. Adjusting for covariates, the investigators found that the estimated time was 1.26 years for the high-risk group, 5.06 years for the moderate-risk group, and 16.1 years for the low-risk group.
"These results suggest that baseline BMD is the most important determinant of a screening interval, and that an interval of one year should be considered for older postmenopausal women with a T-score ≤−2. An interval of up to five years may be reasonable for osteopenia with T-score above −2," the authors write. "For women with normal BMD, repeat DXA before 10 years is unlikely to be informative."