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. 2023 Jan 2;9:3. doi: 10.1186/s40795-022-00660-2

Table 3.

Comparison between the mean biomarker values at four different time periods of the day and the mean of the four 24-collections of urine performed during the preceding days. Time was missing for 3 spot samples. Data are the mean (SD)

(1)
0–7 h
(2)
7–14 h
(3)
14–20 h
(4)
20–24 h
ANOVA
P-value
Normal water intake
 Sample count 49 116 111 72
 Osmolality (mosmol/kg) Spot 529 (234) 564 (283) 557 (305) 562 (293) 0.90
 Spot – 24 h -14 (243)  + 67 (239)  + 46 (237)  + 45 (212) 0.26
 Creatinine (mmol/L) Spot 9.7 (5.7) 9.3 (6.7) 8.2 (6.1) 8.5 (5.7) 0.36
 Spot – 24 h  + 1.3 (5.7)  + 2.0 (5.5) 0.0 (4.9)  + 0.6 (3.7) 0.03 1
Increased water intake
 Sample count 62 130 131 88
 Osmolality (mosmol/kg) Spot 519 (211) 462 (234) 419 (252) 397 (232) 0.01 2
 Spot – 24 h  + 72 (214)  + 44 (221) -12 (208) -48 (198) 0.02 3
 Creatinine (mmol/L) Spot 10.5 (6.3) 7.8 (5.5) 6.5 (5.6) 5.9 (4.7) 0.001 4
 Spot – 24 h  + 3.9 (6.0)  + 1.6 (5.3) -0.1 (4.4) -0.7 (4.1) 0.001 5

Scheffé post hoc test shows differences by P < 0.05; 1 3 < 2; 2 4 < 1; 3 4 < 1, 2; 4 4 < 1, 2; 5 3,4 < 1, 2