Vascular calcification in patients undergoing kidney and simultaneous pancreas-kidney transplantation

Vascular calcification (VC) is common in patients with chronic kidney disease (CKD) on dialysis, and an inverse relationship of VC to bone mineral density (BMD) has been reported. Because elderly patients are prone to atherosclerosis and BMD artefact, we examined the prevalence and epidemiology of VC in younger patients undergoing transplantation, and its relationship to BMD.

Laboratory testing was performed immediately before kidney or simultaneous pancreas-kidney (SPK) transplantation. Within 4 weeks patients underwent BMD evaluation and lateral abdominal X-ray. Aortic calcification was scored using a validated 24-point scale.

Of 650 consecutive patients X-rays were available for 531 (82%). Their median age was 41 years (16-71), 58% were male, dialysis vintage was 20 months (0-402) and 69% had kidney and 31% SPK transplants. VC scores were ≥1 in 47%, with the median score 6 (1-24) and was associated with age, dialysis vintage and presence of cardiovascular, cerebrovascular or peripheral vascular disease. In a multivariate analysis of patients with and without VC, those with VC were older and of longer dialysis vintage (OR 1.07 and 1.17 per 12 months respectively; P < 0.001 for both). In that analysis, VC was not significantly associated with gender, transplant type, presence of diabetes, current or former smoking or calcium or calcitriol therapy, and was not inversely related to hip, spine or forearm BMD Z-scores.

VC is common in younger patients undergoing transplantation and, similar to older patients, is associated with age, dialysis vintage and cardiovascular pathology. However, in this younger patient group, there was no significant inverse association of VC to BMD.