Vascular calcification of the abdominal aorta has minimal impact on lumbar spine bone density in patients with chronic kidney disease

Background: Dual-energy X-ray absorptiometry (DXA) measurements are sensitive to artifacts from surrounding tissues. This study investigates the impact of abdominal aortic calcification (AAC) on bone mineral density (BMD) in patients with chronic kidney disease (CKD). Methods: In 88 patients with CKD stage G5D, lumbar spine BMD was measured in both anterior-posterior (AP) and lateral DXA projections. AAC was determined from lateral lumbar radiographs. Results: Median age was 51 +/- 14 years, and 61 % were men. AAC was present in 59 %. There was no difference in lumbar spine BMD between patients with and without AAC (AP: 0.823 vs. 0.806 g/cm(2), p = 0.66). The Delta BMD between AP and lateral projections was similar in patients with and without AAC (13.4 +/- 6.7 % vs. 11.5 +/- 6.3 %; difference 1.9 %, 95 % CI-0.9 to 4.7 %, p = 0.18). When comparing single vertebrae at levels with high vs. low degree of AAC within the same individual, there was no difference in BMD (AP: 0.827 +/- 0.202 vs. 0.818 +/- 0.291 g/cm(2), p = 0.78), nor in the Delta BMD between AP and lateral projections (12.9 +/- 8.1 % vs. 14.3 +/- 8.3 %, p = 0.12). Conclusion: We could not detect an impact of AAC on lumbar spine BMD. These findings challenge the dogma that lumbar spine BMD by DXA is unreliable due to widespread AAC in patients with CKD.

Automated summary

This study investigated the impact of abdominal aortic calcification on bone mineral density in patients with chronic kidney disease. The findings challenge the traditional belief that measurement of lumbar spine bone mineral density using DXA is unreliable in patients with CKD.