Table 2.
Association of solute concentrations with RKF
| Solute | Overall (N = 1280) | RKF (n = 433) | No RKF (n = 847) | Mean difference | Relative differencea | Adjusted P-valueb | P-value for interactionc |
|---|---|---|---|---|---|---|---|
| Urea (mg/dL) | 59.7 ± 18.7 | 59.8 ± 18.5 | 59.6 ± 18.8 | 0.2 (−1.9–2.3) | 0.3 (−3.2–3.9) | 0.09 | 0.55 |
| PCS (mg/dL) | 3.3 ± 1.7 | 3.5 ± 1.7 | 3.3 ± 1.7 | 0.3 (0.1–0.5) | 8.2 (2.1–14.2) | 0.007 | 0.75 |
| IS (mg/dL) | 2.5 ± 1.2 | 2.3 ± 1.1 | 2.6 ± 1.2 | −0.3 (−0.4 to −0.2) | −11.1 (−16.0 to −6.2) | <0.001 | 0.57 |
| HIPP (mg/dL) | 5.4 ± 4.3 | 4.5 ± 3.7 | 5.9 ± 4.4 | −1.4 (−1.9 to −0.9) | −23.6 (−30.8 to −16.5) | <0.001 | 0.23 |
| PAG (mg/dL) | 4.5 ± 2.8 | 4.0 ± 2.6 | 4.7 ± 2.9 | −0.7 (−1.0 to −0.4) | −14.5 (−20.7 to −8.2) | <0.001 | 0.10 |
| TMAO (μM) | 102.2 ± 63.8 | 97.1 ± 61.4 | 104.8 ± 64.9 | −7.8 (−15.0 to −0.6) | −7.4 (−14.1 to −0.7) | 0.04 | 0.51 |
| MG (μM) | 7.7 ± 4.4 | 7.0 ± 3.8 | 8.1 ± 4.7 | −1.2 (−1.6 to −0.7) | −14.1 (−19.6 to −8.6) | <0.001 | 0.31 |
| ADMA (μM) | 0.9 ± 0.2 | 0.9 ± 0.2 | 0.9 ±0.2 | −0.03 (−0.06 to −0.01) | −3.7 (−6.4 to −0.9) | 0.01 | 0.95 |
| SDMA (μM) | 4.3 ± 1.4 | 4.1 ± 1.3 | 4.4 ± 1.4 | −0.3 (−0.5 to −0.2) | −7.0 (−10.5 to −3.5) | 0.001 | 0.16 |
Relative difference was calculated as {[(Mean solute level in those with RKF/mean solute level in those without RKF) − 1] × 100}; 95% CIs were calculated using bootstrapping with 2000 replicates. Negative values imply a lower concentration in the group with RKF compared with the group without RKF.
P-values are from a linear regression model of solute on RKF adjusting for age, sex, race and dialysis dose intervention group.
P-value of the interaction term between dialysis dose intervention group and RKF (present or absent), adjusted for age, sex and race. The presence of statistically significant interaction would suggest that the association between RKF and the individual solute levels was modified by dialysis dose.