Table 1

Patient characterisation in two equal strata according to the median of total AP value

Patients within lower AP stratum±SD
N=203
Patients within higher AP stratum±SD
N=204
All patients±SD
N=407
p Value
Age (years)65.3±15.366.9±14.166.1±14.70.286
Vintage (dialysis time before laboratory test; years)2.99±3.532.83±3.412.91±3.460.721
 Median1.641.381.50.63
Proportion of males (%)59.155.957.50.548
Proportion of patients with diabetes (%)42.957.450.10.042
Proportion of patients on PD (%)3.54.94.20.639
Weekly Kt/V (in patients with PD)3.16±1.032.13±1.302.48±1.280.121
Single pool Kt/V (in patients with HD)1.55±0.5271.52±0.4731.54±0.5010.512
Proportion of patients on Ca-free PO4 binders (%)12.813.812.30.947
Proportion of patients on cinacalcet (%)16.715.716.20.627
Mean total AP (U/L)62.1±10.5121±65.191.9±55.3<0.001
 Individual number of AP tests (n)6.98±3.025.76±3.236.37±3.18<0.001
 Individual range of AP levels (U/L)25.9±24.161±76.443.4±59.3<0.001
 Individual lowest AP level (U/L)53.3±10.7±97.6±55.355.6±45.7<0.001
Mean skeletal AP (µg/L)10.3±2.6819.2±10.614.8±8.94<0.001
 Median skeletal AP (µg/L)9.916.714.8<0.001
 Individual number of sAP tests (n)7.53±3.536.09±3.596.81±3.63<0.001
 Individual range of sAP levels (U/L)6.08±5.0912.7±14.79.4±11.5<0.001
 Individual lowest sAP level (U/L)7.89±2.1714.0±9.210.9±7.34<0.001
Mean PTH (ng/L)175±147201±178188±1640.103
 Median1431711880.103
 Mean Ca (mmol/L)2.21±0.1552.19±0.1812.21±0.1690.295
 Mean PO4 (mmol/L)1.61±0.3821.60±0.4031.61±0.3920.724
  • PD, peritoneal dialysis; PTH, parathyroid hormone; sAP, skeletal alkaline phosphatase; SD, standard deviation.