Definition of a population-specific dual energy X-ray absorptiometry reference standard in Isfahani women

Abstract

Objective: There are some clues that correct interpretation of bone mineral density (BMD) when measured by dual-energy X-ray absorptiometry (DXA) which requires a population specific reference range. We determined reference values of BMD and the prevalence of osteopenia and osteoporosis in postmenopausal Isfahani women. Methods: In this cross-sectional study, 1118 healthy women from Isfahan, aged between 20 and 80 years were recruited door-to-door for research. BMD was measured at the anteroposterior lumbar spine (L2-L4) (AP) and femoral neck (FN) with the Lunar DPX-IQ densitometer. Peak bone mass (PBM), reference curves of BMD, prevalence of osteoporosis and osteopenia were determined according to World Health Organization (WHO) criteria. Results: In Isfahani women osteoporosis and osteopenia of the AP lumbar spine exists at BMD < 0.898 g/cm2 and between 1.078 g/cm2 and 0.898 g/cm2, respectively. At the FN a BMD < 0.676 g/cm2 defines osteoporosis whereas osteopenia is defined as a BMD between 0.841 g/cm2 and 0.676 g/cm2. The prevalence of osteoporosis and osteopenia at the AP lumbar spine in the age groups 51-55, 56-60, 61-65, 66-70, > 70 years were, 7.9%, 19.6%, 26%, 32.1%, 31.8%, and 28.9%, 36.5%, 38.4%, 41.1%, 45.5%, respectively. The prevalence of osteoporosis and osteopenia at the FN in the same age groups, were, 2.6%, 2%, 12.3%, 14.3%, 22.7% and 28.3%, 39.9%, 43.8%, 50%, 68.2%, respectively. Conclusions: Our data would use a population-specific reference range for DXA measurements and to estimate the prevalence of osteopenia and osteoporosis. © 2008 Asia Pacific League of Associations for Rheumatology.