Table 1.

Patient demographics, comorbidities, medication use, and laboratory variables by serum potassium categories at enrollment

VariableOverall (n = 820)Hypokalemia (n = 122)Eukalemia (n = 633)Hyperkalemia (n = 65)P
Demographics
    age (years; mean ± SD)60.5 ± 15.460.6 ± 16.160.7 ± 15.458.4 ± 14.00.499
    male (n [%])448 (55)52 (43)346 (55)50 (77)<0.0001
    black (n [%])167 (20)37 (30)117 (19)13 (20)0.012
Vital signs (mean ± SD)
    BMI (kg/m2)29.4 ± 6.929.8 ± 6.929.3 ± 6.929.4 ± 7.70.847
    SBP (mmHg)139.7 ± 21.7142.8 ± 23.9139.4 ± 21.6137.8 ± 18.80.211
    eGFR (ml/min per 1.73 m2)25.4 ± 10.627.0 ± 13.725.3 ± 9.923.2 ± 10.10.059
Cause of CKD (n [%])
    diabetes265 (32)39 (32)199 (32)27 (42)0.262
    hypertension402 (49)60 (49)310 (49)32 (49)0.99
Medication use (yes/no; n [%])
    ACEIs332 (41)34 (28)260 (41)43 (66)<0.0001
    ARBs144 (17)35 (29)144 (23)7 (11)0.021
    aspirin304 (37)41 (34)236 (37)27 (42)0.549
    β blockers392 (47)62 (51)295 (47)35 (54)0.414
    calcium channel blocker353 (43)64 (52)294 (46)23 (35)0.083
    diuretics409 (50)75 (61)317 (50)34 (52)0.069
    erythropoietin199 (24)30 (25)150 (24)19 (29)0.609
    statins352 (42)39 (32)278 (44)34 (52)0.014
Laboratory (mean ± SD)
    serum albumin (g/dl)3.8 ± 0.53.7 ± 0.53.8 ± 0.53.7 ± 0.50.098
    serum CO2 (mEq/L)24.2 ± 3.926.2 ± 3.724.1 ± 3.821.2 ± 3.5<0.0001
    serum potassium (mmol/L)4.6 ± 0.93.7 ± 0.34.7 ± 0.45.8 ± 0.3<0.0001
    serum phosphorus (mg/dl)4.2 ± 1.14.3 ± 1.54.1 ± 1.04.5 ± 1.10.031
Patient outcomes (n [%])
    death86 (10)16 (13)64 (10)6 (9)0.576
    ESRD303 (36)57 (36)213 (35)33 (48)0.145
    coronary artery disease7011 (9)50 (8)9 (14)0.258
    cardiovascular disease508 (7)38 (6)4 (6)0.977
    peripheral arterial disease708 (7)55 (8)7 (11)0.581
    any cardiovascular event19032 (27)139 (22)19 (29)0.249
  • Hypokalemia: SK ≤4.0 mmol/L; eukalemia: SK >4.0 and <5.5 mmol/L; hyperkalemia: SK ≥5.5 mmol/L. ARB, angiotensin II receptor blocker; BMI, body mass index; SBP, systolic BP.