Table 3.
Associations of UKV with continuous serum potassium (mEq/l) on the basis of 3-time and 7-time measurements in patients with CKD G3, G4, and G5 by GEE regression analyses
| Models |
CKD stage |
P-for-interaction |
|||
|---|---|---|---|---|---|
| CKD stage | G3 | G4 | G5 | G3 vs. G4 | G3 vs. G5 |
| Analyzed patients (N = 290) with 3-time measurements (870 observations) | |||||
| UKV on the basis of 24-hour urine collections, mEq/d, mean (SD) | 41.85 (14.66) | 33.5 (14.64) | 27.45 (13.97) | ||
| N of observations | 347 | 261 | 262 | ||
| Mean differences (95% CI) in serum potassium per 10 mEq/d increase in continuous UKVa | |||||
| Model 1b | 0.06 (0.02–0.10) | 0.10 (0.04–0.16) | 0.17 (0.12–0.22) | 0.27 | 0.001 |
| Model 2c | 0.07 (0.03–0.11) | 0.11 (0.05–0.16) | 0.17 (0.12–0.23) | 0.29 | 0.002 |
| Model 3d | 0.08 (0.05–0.12) | 0.12 (0.08–0.16) | 0.16 (0.12–0.20) | 0.13 | 0.002 |
| Analyzed patients (N = 220) with 7-time measurements (1540 observations) | |||||
| UKV on the basis of 24-hour urine collections, mEq/d, mean (SD) | 42.05 (14.67) | 34.07 (14.53) | 28.02 (14.22) | ||
| N of observations | 644 | 474 | 422 | ||
| Mean differences (95% CI) in serum potassium per 10 mEq/d increase in continuous UKV a | |||||
| Model 1b | 0.04 (0.01–0.07) | 0.12 (0.07–0.17) | 0.18 (0.12–0.24) | 0.003 | P < 0.001 |
| Model 2c | 0.04 (0.01–0.07) | 0.12 (0.07–0.18) | 0.18 (0.12–0.25) | 0.003 | P < 0.001 |
| Model 3d | 0.07 (0.04–0.10) | 0.11 (0.07–0.14) | 0.13 (0.09–0.17) | 0.06 | 0.004 |
CKD, chronic kidney disease; GEE, generalized estimating equation; UKV, 24-hour urinary potassium excretion; CI, confidence interval; SBP, systolic blood pressure; DBP, diastolic blood pressure; ACE, angiotensin-converting-enzyme inhibitor; ARB, angiotensin II receptor blocker; MRA, mineralocorticoid receptor antagonists; SGLT2i, sodium-glucose cotransporter 2 inhibitors.
This corresponds to a β-coefficient of a continuous UKV on serum potassium. Interaction term between CKD stage and continuous UKV, and their main effect terms in relation to serum potassium were included in statistical models.
Model 1 was unadjusted.
Model 2 was adjusted for age, sex, and urine creatinine.
Model 3 was adjusted for Model 2 covariates, urine protein, diabetes (defined by any medication use of diabetes and diabetic nephropathy as an underlying disease for CKD), hypertension (defined by any use of antihypertensive, or SBP ≥ 140 mm Hg or DBP ≥ 90 mm Hg, or nephrosclerosis as an underlying disease for CKD), medication use that could increase serum potassium level (including ACEi/ARB, MRA, renin inhibitors, potassium supplement medication), medication use that could decrease serum potassium level (including diuretics except MRA, SGLT2i, potassium binder, liquorice extract, and bicarbonate), and previous values of serum potassium and UKV.