Table 2.
Urine volume (UV), free water clearance (CH20), urine osmolarity (u-osm), urinary excretions of cyclic AMP (u-c-AMP) and aquaporin2 (AQP2) during urine diluting test.
| Baseline | Post 0-60 |
Post 60-120 |
Post 120-180 |
Post 180-240 |
Post 240-300 |
P (GLM-within) |
|
|---|---|---|---|---|---|---|---|
|
UV (ml/min) | |||||||
| Group 1 |
0.8(0.4) |
2.4(3.0) * |
10.7(6.3)* |
7.4(4.2) * |
2.1(4,1) * |
1.2(1.5) |
0.000 |
| Group 2 |
0.8(0.8) |
1.9(2.8) * |
7.2(5.7) * |
8.2(3.1) * |
3.5(2.2) * |
1.3(1.8) * |
|
| Group 3 |
1.1(1.0) |
3.0(1.8) * |
11.7(8.0)* |
8.0(8.3) * |
3.8(4.8) * |
1.4(0.8) |
|
| Group 4 |
1.3(0.9) |
2.0(1.4) * |
3.7(1.6) * |
4.1(2.8) * |
2.7(0.9) * |
2.2(1.6) * |
|
| P (GLM-between) |
0.002 |
||||||
| P (Kruskal-Wallis) |
0.016 |
0.869 |
0.000 |
0.001 |
0.246 |
0.016 |
|
|
CH20 (ml/min) | |||||||
| Group 1 |
-1.1(0.5) |
-0.1(3.0) * |
7.9(5.5) * |
5.0(3.9) * |
-0,43(4.0) * |
-0.8(1.4) |
0.000 |
| Group 2 |
-0.9(0.6) |
-0,4(2.5) |
4.4(5.7) * |
5.6(2.8) * |
1.5(3.0) * |
-0.3(1.9) * |
|
| Group 3 |
-1.1(1.0) |
-0.9(1.5) |
8.7(8.4) * |
5.4(8.2) * |
1.3(4.3) * |
-0.8(1.0) * |
|
| Group 4 |
-0.3(0.6) |
-0.4(0.5) |
1.6(0.9) * |
1.5(2.6) * |
0.9(1.4) * |
0.1(0.8) * |
|
| P (GLM-between) |
0.000 |
||||||
| P (Kruskal-Wallis) |
0.003 |
0.264 |
0.000 |
0.001 |
0.309 |
0.017 |
|
|
U-osm (mosmol/l) | |||||||
| Group 1 |
709(258) |
271(360)* |
72(46)* |
98(80)* |
394(334)* |
637(388)* |
0.000 |
| Group 2 |
678(175) |
372(386)* |
104(68)* |
95(33)* |
146(186)* |
355(403)* |
|
| Group 3 |
555(247) |
448(285)* |
86(148)* |
92(122)* |
219(265)* |
452(216)* |
|
| Group 4 |
397(145) |
352(101)* |
190(63)* |
166(116)* |
203(129)* |
262(90)* |
|
| P (GLM-between) |
0.000 |
||||||
| P (Kruskal-Wallis) |
0.000 |
0.484 |
0.000 |
0.001 |
0.100 |
0.027 |
|
|
U-c-AMP (μg/min) | |||||||
| Group 1 |
3.07(1.35) |
3.83(1.77) |
3.48(1.31) |
3.07(1.28) |
3.24(0.94) |
2.97(1.48) |
0.254 |
| Group 2 |
3.88(2.45) |
4.21(2.52) |
3.91(1.56) |
3.96(2.17) |
3.41(3.24) |
3.55(1.04) |
|
| Group 3 |
3.20(1.04) |
3.84(1.58)* |
4.43(2.33) |
3.82(2.88) |
3.34(2.31) |
3.00(1.31) |
|
| Group 4 |
1.74(1.18) |
1.99(1.34) |
1.20(2.02) |
1.20(1.24) |
1.91(0.85) |
2.50(1.33) |
|
| P (GLM-between) |
0.000 |
||||||
| P (Kruskal-Wallis) |
0.000 |
0.000 |
0.001 |
0.000 |
0.000 |
0.001 |
|
|
U-AQP2 (ng/min) | |||||||
| Group 1 |
1.01(0.20) |
1.05(0.19) |
0.91(0.51) |
0.78(0.27)* |
0.74(0.33) * |
0.74(0.33) * |
0.321 |
| Group 2 |
0.97(0.52) |
1.04(0.63) |
0.85(0.55) |
0.91(0.31) |
0.69(0.34) * |
0.65(0.21) * |
|
| Group 3 |
1.16(0.88) |
1.42(0.86) |
1.31(1.14) |
1.16(0.67) |
0.99(0.28) |
0.79(0.47) * |
|
| Group 4 |
1.28(0.78) |
1.74(0.82) |
1.40(0.52) |
1.14(0.49)* |
1.03(0.56) * |
1.21(0.58) |
|
| P (GLM-between) |
0.002 |
||||||
| P (Kruskal-Wallis) | 0.157 | 0.036 | 0.063 | 0.022 | 0.000 | 0.000 | |
Baseline was mean of two 60 minutes control periods before water loading. An oral water load of 20 ml/kg body weight was given during the first 15 minutes of the following 60 minute's period (Post 0-60). Urine was subsequently collected during four consecutive 60 minute's periods (Post 60-120, Post 120-180, Post 180-240, and Post 240-300. Group 1 comprised healthy control subjects (n = 10). Groups 2-4 comprised patients with chronic kidney disease or hypertension (Group 2 (n = 14), e-GFR ≥ 90 ml/min; Group 3 (n = 11), 60 ml/min ≤ e-GFR < 90 ml/min; and Group 4 (n = 16), 15 ml/min < e-GFR ≤ 60 ml/min).
Median with Interquartile Range in brackets. A General Linear Model (GLM) for Repeated Measures was used for comparison within and between groups. Kruskal-Wallis's test was used to analyze differences between groups during the diluting test. Wilcoxon's signed rank test was used in each group to analyze significant deviations from baseline (* = P < 0.05).