Effects of bone and mineral metabolism on arterial elasticity in chronic renal failure.

Arterial stiffness (Ast) individually predicts cardiovascular (CV) mortality. Ast increases via vascular calcification and can be characterized by pulse wave velocity (PWV). We assessed the influence of mineral and bone metabolism on Ast in dialyzed (D) and renal transplanted (Tx) children by measuring fetuin-A and bone markers [bone-specific alkaline phosphatase (BALP); beta-CrossLaps (beta)]. Normalized PWV/height (PWV/h) of 11 D and 17 Tx patients was measured by applanation tonometry. Levels of calcium (Ca), phosphate (P), fetuin-A, and bone markers were analyzed. Ca x P/fetuin-A ratio was calculated to characterize the balance of calcification and inhibition. Cumulative dose of calcitriol was also assessed. Fetuin-A was lower in D and Tx compared with healthy controls. Bone markers and Ca x P/ fetuin-A of D were significantly higher than those of Tx and controls. In D PWV/h correlated with Ca x P/fetuin-A and BALP (r=0.8; p=0.005, r=0.6, p=0.05, respectively); BALP correlated with Ca x P/fetuin-A (r=0.7, p=0.01). In Tx, there was a correlation between calcitriol administered before transplantation and PWV/h (r=0.5, p=0.04). Increased bone turnover was coupled with an increased potential of calcium-phosphate precipitation, as shown by the increased Ca x P/fetuin-A. It might explain the connection between disturbed mineral and bone metabolism and Ast. Tx might be beneficial on Ast, though follow-up studies are needed.