Reference Data for Bone Mineral Density in Swedish Women Using Digital X-Ray Radiometry

During the last decade, digital X-ray radiometry (DXR) has been used to measure bone mineral density (BMD) in the metacarpal bones. The aim of this study was to establish Swedish reference material for bone mass in women, measured in the metacarpal bones with DXR, and compare these data with the data from the manufacturer. A sample of 1440 women aged 20-79 yr living in Örebro County was randomly assigned from the population register. Microdose mammography was used (Sectra MDM L30; Sectra Imtec AB, Linköping, Sweden) to measure BMD. Cole's LMS method was used to calculate DXR. Six hundred sixty-nine (48.3%) women participated. Peak bone mass occurred at the age of 43.4 yr with a BMD of 0.597 g/cm2 (standard deviation: 0.050). Our Swedish data correlated well with the manufacturer's material. Only among women aged 50-59 yr did BMD differ, where the Swedish sample had lower values. The LMS method can be used to describe the DXR data and provide a more detailed picture of bone density distribution. DXR-BMD in Swedish women aged 20-79 yr is equivalent to findings from other studies, showing the same distribution of BMD in most age groups except for ages 50-59 yr.