Reduction in Aortic Pulse Wave Velocity Is Associated with a Short-Term Reduction in Dual-Energy X-Ray Absorptiometry Lumbar Spine Bone Mineral Density T Score

Introduction: Increased vascular stiffness is a risk factor for mortality. We wished to determine whether changes in vascular stiffness are associated with changes in bone mineral density (BMD) in peritoneal dialysis patients. Methods: We measured vascular stiffness by aortic pulse wave velocity (aPWV) and BMD by dual electron absorptiometry (DXA) scanning and compared T scores to compensate for differences in patient ages and gender. Results: Twenty-four patients had repeat aPWV measurements and DXA scans, median 12.4 months apart. aPWV decreased in 15 and increased in 9. As there were more women in the group with an increase in aPWV, we used gender-adjusted DXA T scores Total body T scores fell in both groups, but median T scores remained positive for those with an increase in aPWV, whereas negative T scores on both scans for those with a decrease in or stable aPWV. Lumbar spine T scores fell in those with a reduction in aPWV (-1.6 [-2.4 to 0.6] to -2.1 [-2.4 to 0.3], p < 0.05), whereas there was no significant decrease in those with an increase in aPWV (-0.5 [-1.1 to 0.15] to -0.7 [-1.7 to 0.6]). There were no changes in femoral neck T scores. Conclusions: Our study reinforces the hypothesis of a link between bone disease and vascular disease in dialysis patients. Lumbar spine DXA includes imaging of the aorta and will include aortic calcification, and as such a reduction in lumbar spine T score without a change in femoral neck T score suggests a reduction in aortic calcification. Although our study requires additional confirmation, our data would suggest that changes in aPWV could be used as a surrogate for changes in vascular calcification in the investigation of interventions designed to reduce vascular calcification.