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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.

From: Abnormal function of the vasopressin-cyclic-AMP-aquaporin2 axis during urine concentrating and diluting in patients with reduced renal function. A case control study

 

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

 

C H20 (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

 
  1. 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).
  2. 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).
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BMC Nephrology

ISSN: 1471-2369

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