Table 1.
Characteristics of Hyperkalemic Patients and Normokalemic Controls Before and After Propensity Score Matchinga,b
| Before Matching |
After Matching |
|||||
|---|---|---|---|---|---|---|
| Hyperkalemia (n = 16,133) | Normokalemia (n = 11,898) | Standardized Difference (%)c | Hyperkalemia (n = 5859) | Normokalemia (n = 5859) | Standardized Difference (%)c | |
| Age (y), mean ± SD | 73.4±12.6 | 66.6±14.3 | 50.2 | 71.2±12.5 | 71.4±11.9 | 1.9 |
| Age group (y), no. (%) | ||||||
| 18-64 | 3576 (22.2) | 4565 (38.4) | 45.7 | 1567 (26.8) | 1504 (25.7) | 2.9 |
| 65-79 | 6850 (42.5) | 5179 (43.5) | 2710 (46.3) | 2786 (47.6) | ||
| ≥80 | 5707 (35.4) | 2154 (18.1) | 1582 (27.0) | 1569 (26.8) | ||
| Male sex, no. (%) | 9109 (56.5) | 6791 (57.1) | 1.2 | 3423 (58.4) | 3398 (58.0) | 0.9 |
| Length of follow-up (mo), mean ± SD | 37.5±24.3 | 45.7±22.6 | 35.2 | 43.0±24.4 | 43.6±22.0 | 2.3 |
| S-K level at index date (mmol/L), mean ± SD | 5.4±0.5 | 4.3±0.3 | 300.0 | 5.3±0.3 | 4.3±0.3 | 346.2 |
| S-K level group (mmol/L), no. (%) | ||||||
| ≥5.1-<5.5 | 11,221 (69.6) | 4619 (78.8) | ||||
| ≥5.5-<6.0 | 3460 (21.4) | 1021 (17.4) | ||||
| ≥6.0-<6.5 | 898 (5.6) | 170 (2.9) | ||||
| ≥6.5-<7.0 | 314 (2.0) | 30 (0.5) | ||||
| ≥7.0 mmol/L | 240 (1.5) | 19 (0.3) | ||||
| CKD stage, no. (%) | 16,133 (100) | 11,898 (100) | 0 | 5859 (100) | 5859 (100) | 0 |
| 1 | 200 (1.2) | 1086 (9.1) | 149.7 | 195 (3.3) | 194 (3.3) | 3.2 |
| 2 | 1140 (7.1) | 3821 (32.1) | 1091 (18.6) | 1070 (18.3) | ||
| 3 | 2655 (16.5) | 4652 (39.1) | 2264 (38.6) | 2301 (39.3) | ||
| 3b | 4128 (25.6) | 1815 (15.3) | 1745 (29.8) | 1770 (30.2) | ||
| 4 | 4745 (29.4) | 379 (3.2) | 394 (6.7) | 379 (6.5) | ||
| 5 | 3265 (20.2) | 145 (1.2) | 170 (2.9) | 145 (2.5) | ||
| eGFR (mL/min/1.73 m2), mean ± SD | 32.3±20.4 | 59.8±21.3 | 131.7 | 49.1±20.5 | 50.4±18.4 | 6.5 |
| HF, no. (%) | 6394 (39.6) | 2090 (17.6) | 50.4 | 1548 (26.4) | 1575 (26.9) | 1.0 |
| Prescribed medical treatment for HF, no. (%) | 4856 (76.0) | 1485 (71.1) | 11.1 | 1144 (73.9) | 1178 (74.8) | 2.0 |
| ACEi or ARB | 3627 (74.7) | 1105 (74.4) | 0.6 | 846 (74.0) | 878 (74.5) | 1.3 |
| β-Blocker | 2658 (54.7) | 835 (56.2) | 3.0 | 654 (57.2) | 674 (57.2) | 0.1 |
| Digoxin | 539 (11.1) | 151 (10.2) | 3.0 | 127 (11.1) | 134 (11.4) | 0.9 |
| Inotrope | 1115 (23.0) | 194 (13.1) | 26.0 | 227 (19.8) | 154 (13.1) | 18.3 |
| MRA | 2048 (42.2) | 335 (22.6) | 42.9 | 447 (39.1) | 279 (23.7) | 33.6 |
| Diabetes, no. (%) | 7717 (47.8) | 5521 (46.4) | 2.9 | 2887 (49.3) | 2876 (49.1) | 0.4 |
| Prescription of antidiabetics, no. (%) | 5821 (36.1) | 3552 (29.9) | 13.3 | 2018 (34.4) | 2043 (34.9) | 0.9 |
| Hypertension, no. (%) | 12,196 (75.6) | 7675 (64.5) | 24.4 | 4158 (71.0) | 4206 (71.8) | 1.8 |
| Dyslipidemia, no. (%) | 5057 (31.3) | 3979 (33.4) | 4.5 | 1970 (33.6) | 2011 (34.3) | 1.5 |
| Total cholesterol (mg/dL), mean ± SD | 176.4±46.8 | 188.7±37.1 | 29.0 | 181.3±45.2 | 184.9±37.8 | 8.6 |
| HDL cholesterol (mg/dL), mean ± SD | 51.1±16.4 | 55.0±15.4 | 24.5 | 53.7±16.7 | 53.8±15.1 | 0.7 |
| LDL cholesterol (mg/dL) Mean ± SD | 102.1±36.0 | 108.8±29.6 | 20.2 | 105.4±35.3 | 106.4±29.3 | 3.4 |
| Other comorbid conditions, no. (%) | ||||||
| Myocardial infarction | 668 (4.1) | 285 (2.4) | 9.8 | 210 (3.6) | 202 (3.4) | 0.7 |
| Peripheral vascular disease | 2705 (16.8) | 1463 (12.3) | 12.7 | 848 (14.5) | 966 (16.5) | 5.6 |
| Cerebrovascular disease | 3904 (24.2) | 2147 (18.0) | 15.1 | 1301 (22.2) | 1354 (23.1) | 2.2 |
| Chronic pulmonary disease | 2569 (15.9) | 1434 (12.1) | 11.2 | 875 (14.9) | 845 (14.4) | 1.5 |
| Atrial fibrillation or flutter | 2399 (14.9) | 996 (8.4) | 20.4 | 651 (11.1) | 687 (11.7) | 1.9 |
| Valvular heart disease | 1776 (11.0) | 697 (5.9) | 18.6 | 471 (8.0) | 480 (8.2) | 0.6 |
| Acute kidney injury | 676 (4.2) | 53 (0.4) | 25.1 | 55 (0.9) | 50 (0.9) | 0.9 |
| Sepsis | 1608 (10.0) | 869 (7.3) | 9.5 | 509 (8.7) | 529 (9.0) | 1.2 |
| Peripheral edema | 478 (3.0) | 126 (1.1) | 13.6 | 86 (1.5) | 88 (1.5) | 0.3 |
| Charlson Comorbidity Index score, mean ± SD | 1.1±1.2 | 0.9±1.0 | 20.8 | 1.0±1.1 | 1.1±1.1 | 1.9 |
| RAASi treatment, no. (%) | 8314 (51.5) | 4635 (39.0) | 25.5 | 2718 (46.4) | 2754 (47.0) | 1.2 |
| ACEi | 1649 (10.2) | 644 (5.4) | 18.0 | 501 (8.6) | 404 (6.9) | 6.2 |
| ARB | 6391 (39.6) | 4013 (33.7) | 12.2 | 2145 (36.6) | 2341 (40.0) | 6.8 |
| MRA | 2401 (14.9) | 376 (3.2) | 41.8 | 586 (10.0) | 297 (5.1) | 18.8 |
| Other drugs associated with hyperkalemia,d no. (%) | 10,325 (64.0) | 5087 (42.8) | 43.6 | 3196 (54.5) | 3248 (55.4) | 1.8 |
| Hyperkalemia treatment at index date, no. (%) | ||||||
| Thiazide diuretics | 481 (3.0) | 227 (1.9) | 7.0 | 98 (1.7) | 188 (3.2) | 10.0 |
| Loop diuretics | 3693 (22.9) | 522 (4.4) | 56.0 | 563 (9.6) | 475 (8.1) | 5.3 |
| Glucose injection + insulin | 342 (2.1) | 4 (0.0) | 20.3 | 23 (0.4) | 4 (0.1) | 6.8 |
| Calcium gluconate | 306 (1.9) | 40 (0.3) | 14.9 | 44 (0.8) | 21 (0.4) | 5.3 |
| Sodium bicarbonate | 1339 (8.3) | 310 (2.6) | 25.3 | 341 (5.8) | 179 (3.1) | 13.5 |
| Potassium binder | 1444 (9.0) | 20 (0.2) | 43.1 | 302 (5.2) | 18 (0.3) | 30.1 |
a
ACEi = angiotensin-converting enzyme inhibitor; ARB = angiotensin receptor blocker; CKD = chronic kidney disease; eGFR = estimated glomerular filtration rate; HDL = high-density lipoprotein; HF = heart failure; LDL = low-density lipoprotein; MRA = mineralocorticoid receptor antagonist; RAASi = renin-angiotensin-aldosterone system inhibitor; S-K = serum potassium.
b
SI conversion factors: To convert total, HDL, and LDL cholesterol values to mmol/L, multiply by 0.0259.
c
Other drugs associated with hyperkalemia include nonsteroidal anti-inflammatory drugs, azole antifungals, β-blockers, calcium channel blockers, cyclosporin, digoxin, heparin, potassium supplements, tacrolimus, trimethoprim, and systemic corticosteroids.
d
Standardized difference greater than 0.1 was considered a non-negligible difference.