Table 3 Urine biomarkers of renal water conservation in the four groups of subjects. Data are the median (25th -75th percentile range)

Group Nr

1

2

3

4

N

354

286

316

360

Age (years)

43 (32–54)

66 (56–74)

80 (73–86)

83 (77–89)

0.0001

All differ

Body weight (kg)

71 (62–80)

67 (58–79)

-

69 (57–79)

0.034

1 < 3, 4

Urine osmolality (mosmol/kg)

686 (486–893)

543 (378–705)

-

454 (364–589)

0.0001

All differ

Urine creatinine

(mmol/L)

10.1 (6.4–14.6)

7.5 (4.8–12.1)

6.6 (3.9–10.9)

7.6 (5.6–9.7)

0.0001

1 < 2, 3

Urine < 1 L (%)

 U-osmolality

42%

20%

-

5%

0.0001

1 > 2 > 3

 U-creatinine

33%

21%

17%

8% ¹

0.0001

1 > 2–4

 Agreement

81%

82%

-

85%

-

-

Males / females

 U-osmolality

54% / 36%

27% / 13%

-

10% / 2%

-

 U-creatinine

45% / 28%

25% / 17

21% / 14%

6% / 9%

-

U-albumin / U-creatinine ratio

(mg/mmol/L)

0.7 (0.5–1.1)

2.1 (0.9–7.1)

3.8 (1.6–11.5)

2.4 (1.2–4.7) ¹

0.0.0001 ²

1 < 2–4,

3 > 2, 4

Thirst (VAS scale 0-100)

21 (14–38)

40 (20–50)

-

30 (21–45).

0.0.0003 ²

1 < 2, 4