Table 4 Diurnal variation of kidney biomarkers

All participants (n = 50)

 BUN

15.0 ± 3.5

14.6 ± 3.6

0.360

 Creatinine

0.84 ± 0.17

0.83 ± 0.15

0.641

 Cystatin C

0.84 ± 0.11

0.83 ± 0.11

0.065

Without severe OSA (n = 24)

 BUN

15.3 ± 3.7

14.6 ± 3.0

0.386

 Creatinine

0.83 ± 0.18

0.83 ± 0.15

0.890

 Cystatin C

0.84 ± 0.11

0.81 ± 0.11

0.005

With severe OSA (n = 26)

 BUN

14.7 ± 3.3

14.5 ± 4.1

0.704

 Creatinine

0.84 ± 0.16

0.83 ± 0.16

0.633

 Cystatin C

0.85 ± 0.11

0.85 ± 0.10

0.841