Background: Abdominal aortic calcification (AAC), a marker of advanced atherosclerotic disease, is associated with two-dimensional areal bone density. However, limited studies have assessed its association with three-dimensional pQCT-derived bone outcomes. This is important to further understand the relationship between vascular and bone health, considering the importance of such outcomes to whole-bone strength and fracture resistance. This study examined associations of abdominal aortic calcification (AAC) with total, cortical and trabecular volumetric bone density (vBMD), bone structure and strength among community-dwelling older women.
Methods: A sub-sample of women (n=648; mean±SD age 79.7±2.5 years) from the Perth Longitudinal Study of Aging in Women (PLSAW) were included with AAC assessed on lateral DXA images at 1998/1999 and 2003. We assessed associations between cross-sectional (in 2003) and longitudinal (progression from 1998/1999-2003) AAC with cross-sectional (in 2003) and longitudinal (change from 2003-2005) pQCT measures. Bone density, structure and strength outcomes were derived from pQCT scans at the 4% radius and tibia (predominantly trabecular), and 15% radius (predominantly cortical).
Results: Partial (adjusted for age, BMI, calcium treatment) Spearman correlations revealed no cross-sectional associations between AAC and any pQCT bone measures in 2003. AAC progression was inversely associated with 4% radius total bone area (rs= −0.088, p=0.044) in 2003, with trends for similar associations with 4% tibia and 15% radius total bone area (both p<0.06). Neither AAC in 2003 nor AAC progression were associated with subsequent 2-year pQCT bone changes. ANCOVA showed no consistent differences in bone outcomes between women with and without AAC, with and without AAC progression, nor across categories of AAC extent.
Conclusion: In older women, AAC was not consistently associated with vBMD, bone structure or estimated bone strength at the tibia or radius, nor with longitudinal changes in these outcomes. Further research is required to better understand the nexus between the vasculature and bone.