Abdominal Aortic Calcification, Bone Mineral Density, and Fractures: A Systematic Review and Meta-analysis of Observational Studies

BACKGROUND: Abdominal aortic calcification (AAC) has been inconsistently associated with skeletal health. We aimed to investigate the association of AAC with bone mineral density (BMD) and fracture risk by pooling the findings of observational studies. METHODS: MEDLINE, EMBASE, Web of Science, and Google Scholar were searched (August 2021). All clinical studies that assessed the association between AAC and BMD or fracture were included. AAC was categorized into any/advanced (all higher reported groups) versus no/less advanced (lowest reported group). Pooled standardized mean differences (SMDs) and risk ratios (RRs) with 95% confidence intervals (CI) were determined for BMD and fracture, respectively, using random-effects models. RESULTS: Of 2 192 articles screened, 86 (61 553 participants) were included in the review, while 42 provided data for meta-analysis. AAC was associated with lower BMD at the total hip (SMD = -1.05 [95%CI: -1.47 to -0.63]; 16 studies), femoral neck (-0.25 [-0.46 to-0.04]; 10), and lumbar spine (-0.67 [-1.21 to -0.12]; 20). AAC was associated with a greater risk of any fracture (RR = 1.73 [95%CI: 1.48-2.02]; 27). AAC was also associated with vertebral, non-vertebral, and hip fractures. In dose-response analysis, the highest AAC group had greater risks of any, vertebral and non-vertebral fractures. CONCLUSIONS: AAC is associated with lower BMD and increased fracture risk at multiple sites, underscoring the potential importance of vascular disease on skeletal health. Detection of AAC at the time of BMD testing may provide clinicians with prognostic information about bone health to enhance osteoporosis screening programs and fracture risk prediction.