Table 1.

Baseline characteristics of the CKD patient cohort, by serum phosphate levela

% CompleteSerum Phosphate Level (mg/dl [mmol/L])
<2.5 (<0.81; n = 201)2.5–3.499 (0.81–1.13; n = 1782)3.5–4.499 (0.81–1.45; n = 1275)>4.5 (>1.45; n = 232)
Age, mean (SD)100%71.8 (10.1)72.2 (10.1)70.7 (10.5)65.6 (11.5)
Race, % (n)81.5%
    white75.6 (152)72.3 (1289)75.5 (963)77.2 (179)
    black5.5 (11)5.6 (99)5.7 (73)8.6 (20)
    other0.5 (1)1.5 (26)2.3 (29)1.7 (4)
    missing18.4 (37)20.7 (368)16.5 (210)12.5 (29)
Gender, % (n)100%
    male97.5 (196)96.5 (1720)95.3 (1215)95.7 (222)
    female2.5 (5)3.5 (62)4.7 (60)4.3 (10)
Past medical history, % (n)100%
    diabetes32.8 (66)38.2 (680)53.7 (685)62.5 (145)
    ischemic heart disease60.7 (122)58.6 (1044)64.3 (820)59.5 (138)
    congestive heart failure34.3 (69)35.6 (634)45.7 (583)46.6 (108)
    cerebrovascular disease20.4 (41)12.2 (218)13.5 (172)12.1 (28)
    acute renal failure4.5 (9)5.3 (95)8.5 (108)13.4 (31)
Medication use, % (n)100%
    ACE inhibitor42.8 (86)44.9 (800)46.7 (595)47.8 (111)
    angiotensin II receptor blocker9.0 (18)8.5 (151)9.2 (117)13.8 (32)
    statin30.8 (62)37.9 (676)41.6 (530)44.0 (102)
    calcium blocker32.8 (66)34.7 (618)40.2 (512)47.8 (111)
    oral calcium8.0 (16)8.2 (146)12.1 (154)25.4 (59)
Vital signs, mean (SD)
    body mass indexb94.2%29.1 (5.5)29.6 (5.7)29.6 (6.1)29.8 (5.9)
    systolic BP (mmHg)b94.8%143.0 (18.3)142.6 (18.8)143.2 (20.1)147.6 (20.5)
    diastolic BP (mmHg)b94.8%76.3 (10.4)74.2 (10.5)73.2 (11.1)76.5 (11.8)
Laboratory data, mean (SD)
    creatinine (μmol/L)c100%155.9 (28.6)165.7 (43.9)187.8 (73.2)272.2 (154)
    estimated CrCl (ml/min)c94.4%50.4 (18.5)48.6 (17.2)45.9 (19.2)39.5 (18.1)
    albumin (g/L)b97.2%139.3 (14.1)134.7 (15.2)128.2 (15.6)122.6 (16.1)
    hemoglobin (g/L)b93.5%39.0 (4.3)38.9 (4.0)38.3 (4.7)37.5 (5.3)
    bicarbonate (mmol/L)b87.1%26.3 (3.0)26.1 (2.7)25.7 (3.1)24.6 (3.3)
    calcium (mmol/L)b96.0%2.3 (0.1)2.3 (0.1)2.3 (0.1)2.3 (0.2)
  • a CKD, chronic kidney disease; ACE, angiotensin-converting enzyme; CrCl, creatinine clearance.

  • b Time-averaged values during the 18-mo baseline period.

  • c Cockroft-Gault estimated CrCl from serum creatinine value at the study start date.