Significant association between bone-specific alkaline phosphatase and vascular calcification of the hand arteries in male hemodialysis patients.

BACKGROUND/AIMS Bone-specific alkaline phosphatase (BAP) hydrolyzes pyrophosphate, which inhibits vascular calcification. We examined association between serum BAP and vascular calcification of male hemodialysis patients. METHODS Hand roentgenography of 167 male maintenance hemodialysis patients was conducted, and visible vascular calcification of the hand arteries was evaluated. Serum levels of 3 bone formation markers (BAP, osteocalcin, and N-terminal propeptide of type I collagen) and 2 bone resorption markers (C-terminal telopeptide of type I collagen, and cross-linked N-telopeptide of type I collagen) were measured, along with serum intact parathyroid hormone (PTH). RESULTS Of 167 patients, visible vascular calcification was seen in 37 patients. Among the bone formation and resorption markers, serum BAP was significantly higher in patients with vascular calcification than in those without (p<0.05); although the other 5 serum bone markers were not significantly different between them. Multivariate logistic regression analyses revealed that log [BAP] was significantly associated with vascular calcification after adjustment for age, hemodialysis duration, presence of diabetes, log [intact PTH] and each of the other 5 bone markers (p<0.0001). CONCLUSIONS Higher serum BAP, but not other bone markers, is significantly associated with the presence of vascular calcification in male hemodialysis patients.