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

Abstract

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). 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. 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 ΔBMD 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 ΔBMD between AP and lateral projections (12.9 ± 8.1 % vs. 14.3 ± 8.3 %, p = 0.12). 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. • Low BMD is a risk factor for fractures in chronic kidney disease. • Lumbar spine BMD bias by aortic calcification is often cited as a concern. • Anterior-posterior and lateral lumbar spine BMD were compared in this study. • No impact of aortic calcification on lumbar spine BMD was detected. • Any effect of aortic calcification on BMD is likely of limited clinical relevance.