We studied vertebral morphometry and its relation to bone mineral density (BMD) in normal Brazilian women (n = 605). All women (age 22–97 years) were ambulatory and healthy. A lateral spine scan was done for morphometric X-ray absorptiometry using an imaging densitometer. In 429 of these women, BMD of the spine and proximal femur also were measured using dual-energy X-ray absorptiometry. All women were white with mean (± 1 SD) age of 53.7 (± 9.5) years. About 21% of the women over 50 years had a T score for spine BMD lower than –2.5 SD, and 7% had a femoral neck BMD below this osteoporosis threshold. Vertebral heights (anterior, HA; middle, HM; and posterior, HP) and ratios (HA/HP and HM/HP) were assessed. There was no systematic difference between younger (20–49 years) and older (50+ years) women in heights or ratios. The vertebral heights were normalized for those observed in each individual case for the L2–L4 sequence. This normalization was adequate for all vertebral heights; the Z score averaged about +0.1. The average Z score for HA/HP was +0.01, but that for the HM/HP was −0.72, indicating that the latter ratio might differ from the reference population used (white American and European women). We observed a small positive correlation between vertebral heights and spine or femur BMD, but this was due entirely to the influence of body size on BMD. On a group basis, the HM/HP showed a significant association with axial BMD; the 1 SD difference between the lowest and highest quartile was associated with a difference of 8–15% (0.5–1.0 SD) in axial BMD.
Morphometric Dual-Energy X-Ray Absorptiometry of the Spine: Report of a Large Series and Correlation with Axial Bone Mineral Density.
Antonio C. Bianco, Luiz F. Malvestiti, Cecilia H.A. Gouveia, Salim Wehba, Shlomo Lewin, And Marilia M.S. Marone. Journal of Bone and Mineral Research. September, 1999.