Table 1.

Baseline characteristics of 98,577 hemodialysis patients stratified by change in pulse pressure

VariablesAll∆PP (mmHg)P Value
<–25≥–25 to <–15≥–15 to <–5≥–5 to <55 to <1515 to <25≥25
n (%)98,577 (100)9038 (9)12,958 (13)24,424 (25)27,200 (28)15,406 (16)6177 (6)3374 (3)
Age (y)62±1563±1462±1462±1561±1662±1663±1563±150.04
Women4550474442444649<0.001
Race/ethnicity
 White42444241414346450.001
 Black33313233343331340.02
 Hispanic15151515151414140.01
 Asian33433332<0.001
 Others77787765<0.001
HD duration
 3 to <6 mo5756545557606365<0.001
 6 to <24 mo1819191918171615<0.001
 2 to <5 y1617181716151413<0.001
 ≥5 y98999877<0.001
Comorbidities
 DM5968645855586062<0.001
 IHD2222212121222424<0.001
 Cancer4.64.14.14.44.654.95.3<0.001
 CHF28292827272831300.002
 COPD666666760.01
 CVD788778880.43
 Hypertension80838280798081830.001
 Other cardiac diseases65556666<0.001
 PVD11131211111213130.20
 Nonambulatory state2.82.72.62.72.83.333.4<0.001
 Current smoking555555550.15
Insurance
 Medicare68696968686969690.23
 Medicaid65566666<0.001
 Private9491212741<0.001
 Others17221714141821240.01
Vascular access
 AVF3029313130282525<0.001
 AVG3130333332292724<0.001
 Catheter3941363638434851<0.001
Pre-HD BP (mmHg)
 Systolic BP151±24172±22162±21153±22146±23143±24140±24137±23<0.001
 Diastolic BP78±1580±1680±1578±1477±1477±1577±1677±17<0.001
 PP73±1792±1582±1575±1569±1566±1664±1660±16<0.001
 Mean arterial BP102±17110±17107±16103±15100±1699±1798±1797±18<0.001
Post-HD BP (mmHg)
 Systolic BP141±23129±19134±20136±21141±22149±24157±24164±24<0.001
 Diastolic BP73±1472±1472±1372±1373±1374±1574±1673±17<0.001
 Pulse pressure68±1757±1562±1564±1568±1575±1683±1691±16<0.001
 Mean arterial BP95±1691±1492±1493±1496±1599±17102±17103±18<0.001
 ∆PP (mmHg)−5±16−35±7−20±3−10±3−1±39±319±331±5<0.001
Time on dialysis (min)214±28214±28214±28215±28214±28214±27214±28213±280.35
Ultrafiltration (kg/session)2.6±1.22.9±1.32.8±1.22.7±1.22.6±1.22.5±1.22.4±1.32.3±1.3<0.001
Ultrafiltration (%)a3.4±1.53.6±1.53.6±1.43.5±1.43.4±1.53.2±1.63.1±1.63.0±1.6<0.001
BMI (kg/m2)b26.9±6.127.9±6.527.5±6.327.0±6.126.6±6.026.2±5.826.3±6.126.5±6.2<0.001
Laboratory measures (baseline)
 Kt/V (single pool)1.55±0.301.56±0.301.56±0.301.55±0.301.54±0.311.53±0.311.54±0.311.53±0.31<0.001
 Albumin (g/dl)3.7±0.53.7±0.43.7±0.43.7±0.43.7±0.53.6±0.53.6±0.53.6±0.5<0.001
 Creatinine (mg/dl)8.0±3.27.7±2.98.1±3.18.3±3.28.1±3.37.6±3.17.1±3.07.0±2.8<0.001
 TIBC (mg/dl)208±45212±43210±43208±44207±45206±46208±48207±47<0.001
 Ferritin (ng/ml)c390 (190–683)373 (184–663)414 (198–702)410 (200–698)391 (189–687)377 (183–674)349 (173–640)341 (174–619)<0.001
 Bicarbonate (mg/dl)22.1±3.222.2±3.222.0±3.121.9±3.122.1±3.122.4±3.222.6±3.122.7±3.2<0.001
 Calcium (mg/dl)9.5±0.79.5±0.79.6±0.79.6±0.79.5±0.79.5±0.79.5±0.79.5±0.6<0.001
 Phosphorus (mg/dl)5.6±1.55.7±1.45.7±1.45.7±1.55.6±1.55.5±1.55.4±1.55.4±1.5<0.001
 Hemoglobin (g/dl)12.1±1.312.3±1.312.3±1.212.2±1.312.1±1.312.0±1.412.0±1.412.1±1.4<0.001
 WBC (×103/µl)7.38±2.437.51±2.367.42±2.297.35±2.427.31±2.467.36±2.417.52±2.607.64±2.620.04
 Lymphocyte (%)20.6±7.820.7±7.421.1±7.621.0±7.820.6±8.020.1±7.819.8±7.619.6±7.7<0.001
  • Data are presented as percentages, means±SDs, or as otherwise indicated. The P value for trend shows the differences in each variable across ∆PP categories. HD, hemodialysis; DM, diabetes mellitus; IHD, ischemic heart disease; CHF, congestive heart failure; COPD, chronic obstructive pulmonary disease; CVD, cerebrovascular disease; PVD, peripheral vascular disease; AVF, arteriovenous fistula; AVG, arteriovenous graft; PP, pulse pressure; ∆PP, postdialysis pulse pressure minus predialysis pulse pressure; BMI, body mass index; TIBC, total iron-binding capacity; WBC, white blood cells.

  • a Calculated as [(predialysis weight−postdialysis weight)/predialysis weight]×100.

  • b Calculated using postdialysis weight and height.

  • c Median (interquartile range) is used.