Effects of Abdominal Aortic Calcification and Facet Joint Arthritis On Lumbar Bone Mineral Density Using Dual-Energy X-Ray Absorptiometry

Background Abdominal aortic calcification (AAC) may overestimate lumbar bone mineral density (BMD) examined by dual-energy X-ray absorptiometry (DXA); however, the degree of effect of AAC on lumbar BMD has not been quantified. In particular, no study has quantitatively compared and analysed segmental BMD and AAC using computed tomography (CT) scan. Thus, this study aimed to quantify the effect of AAC on BMD measurements using DXA via multiple linear regression analysis. Methods This study retrospectively reviewed participants >30 years of age who underwent DXA and spinal CT scans between 2014 and 2016. Variables that significantly affected the BMD of each lumbar segment were identified. Additionally, segmental facet joint arthritis (FJA) and AAC volume were evaluated using CT. Results A total of 620 subjects (153 males and 467 females) were included. The mean age was 71.6 ± 9.1 years (range, 31–89 years). AAC had the highest prevalence in L3 (45.2%), followed by L4 (41.1%). The average volume of AAC was the highest in L4 at 213.67 ± 443.82 mm3, followed by L3 at 161.95 ± 338.09 mm3. Our regression model found that Ln (L4BMD) was significantly correlated with age, BMI, FJA, and AAC volume in female subjects. Additionally, L4 BMD might be overestimated by approximately 0.90% for every 100 mm3 increase in AAC volume. The results for Ln (L3BMD) were almost identical. However, these relationships were not observed in males. Conclusion According to this model, AAC may overestimate lumbar BMD examined by DXA in a dose-dependent manner in females.