Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands.
Clin J Am Soc Nephrol. 2011 Jul;6(7):1752-9. doi: 10.2215/CJN.10091110. Epub 2011 May 19.
Serum alkaline phosphatase (AP) is associated with vascular calcification and mortality in hemodialysis patients, but AP derives from various tissues of origin. The aim of this study was to assess the effect of bone-specific AP (BAP) on morbidity and mortality in dialysis patients.
DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: From a prospective cohort study of incident dialysis patients in The Netherlands, all patients with measured BAP at 12 months after the start of dialysis (baseline) were included in the analysis (n = 800; mean age, 59 ± 15 years; mean BAP = 18 ± 13 U/L). By Cox regression analyses, we assessed the impact of BAP levels on short-term mortality (6 months) and longer-term mortality (4-year follow-up).
High levels of BAP strongly affected short-term mortality. After adjustment for confounders, patients in the highest BAP tertile had a 5.7-fold increased risk of death within 6 months compared with patients in the lowest tertile. The effect applied to both cardiovascular and noncardiovascular mortality. Furthermore, high levels of BAP were associated with increased cardiovascular mortality in the longer term. In comparison with total AP, the effect sizes related to clinical outcomes were much higher for BAP.
High levels of BAP were strongly associated with short-term mortality in dialysis patients, pointing out the important impact of bone turnover. Longitudinal assessments of BAP may be useful for the treatment monitoring in clinical practice in dialysis patients.
血清碱性磷酸酶（AP）与血液透析患者的血管钙化和死亡率相关，但 AP 源于不同的组织来源。本研究旨在评估骨特异性 AP（BAP）对透析患者发病率和死亡率的影响。
设计、设置、参与者和测量：本研究从荷兰一项透析患者的前瞻性队列研究中选取，所有在透析开始后 12 个月（基线）时测量了 BAP 的患者（n=800；平均年龄 59±15 岁；平均 BAP=18±13U/L）均纳入分析。通过 Cox 回归分析，我们评估了 BAP 水平对短期死亡率（6 个月）和长期死亡率（4 年随访）的影响。
BAP 水平高与短期死亡率密切相关。在校正混杂因素后，BAP 最高三分位组的患者在 6 个月内死亡的风险是最低三分位组的 5.7 倍。这种影响适用于心血管和非心血管死亡率。此外，BAP 水平高与长期心血管死亡率增加相关。与总 AP 相比，BAP 与临床结局相关的效应大小要大得多。
BAP 水平高与透析患者的短期死亡率密切相关，表明骨转换的重要影响。BAP 的纵向评估可能对透析患者的临床实践中的治疗监测有用。
