Relationship between vascular calcification, arterial stiffness and bone mineral density in a cross-sectional study of prevalent Australian haemodialysis patients.

BACKGROUND: Cardiovascular disease in dialysis patients is associated with increased vascular calcification (VC) and arterial stiffness, both inversely correlated with bone mineral density (BMD). Few studies have correlated VC in the dialysis population with measurements of BMD and arterial compliance.
METHODS: We report cross-sectional data on 45 haemodialysis (HD) patients assessing the prevalence of VC and its associations. Patients had computed tomography scans through abdominal aorta and superficial femoral arteries (SFA) to determine VC, pulse wave velocity (PWV) using SphygmoCor device measuring arterial stiffness, and dual-energy X-ray absorptiometry (DXA) to determine BMD.
RESULTS: Patients, 64% male, 38% diabetic, had median age 58 years. Mean PWV was 8.7 +/- 3.5 m/s and median aortic VC score 488.1 +/- 298 Hounsfield units, with 91% having aortic VC present. In univariate linear regression analysis, aortic VC correlated positively with length of HD (P = 0.03) and diabetes (P = 0.06). Increasing PWV was positively associated with age (P = 0.001), diabetes (P = 0.05) and VC (aortic P = 0.08, SFA P = 0.01). In multivariate regression analysis, length of HD and diabetes were significantly associated with aortic VC, whereas age and diabetes were associated with SFA VC and PWV. Mean lumbar spine and femoral neck T-scores on DXA were 0.14 and -1.66 respectively.
CONCLUSION: Increased VC and reduced arterial compliance, both closely related, are common in Australian HD patients. Both are associated with diabetes and increasing age, and greater aortic VC is seen with longer duration of dialysis.