Pulse wave velocity is inversely related to vertebral bone density in hemodialysis patients

Abstract

Abnormalities of bone mineral metabolism in patients with stage-5 chronic kidney disease may contribute to the high incidence of cardiovascular disease. Noninvasive imaging methods may help predict the simultaneous presence of vasculopathy and bone disease. Accordingly, we measured pulse wave velocity and bone mineral density (BMD), and T-scores (number of SDs below the BMD of a younger reference group) of the spine by both dual energy x-ray absorptiometry and quantitative computed tomography (QCT) in 110 maintenance hemodialysis patients. Older age, white race, diabetes mellitus, lower diastolic blood pressure, and lower albumin levels were associated with lower QCT-assessed T-scores (each P<0.05). After age and multivariable adjustment, pulse wave velocity (PWV) increased as QCT BMD decreased (the prevalence of PWV >or=9 m/s was 32.4%, 61.8%, and 76.5% for participants in the highest to the lowest tertile of QCT-assessed BMD; P<0.001). In contrast, there was no relationship between spine dual energy x-ray absorptiometry-BMD and PWV. In unadjusted models, thoracic spine QCT-assessed T-scores correlated significantly, albeit weakly, with aorta calcification (r=0.22; P=0.01) but not with coronary calcification. The odds ratio of PWV >or=9 m/s for patients taking vitamin D(3) or its analogs was 0.51 (95% CI: 0.19 to 1.39). In conclusion, low spine BMD is associated with increased PWV in stage-5 chronic kidney disease, supporting the notion of a close interaction of vascular and bone disease in this patient group. QCT and not dual energy x-ray absorptiometry should be used to assess spine BMD in dialysis patients.