Table 2 Comparison of baseline clinical and laboratory characteristics between participants with CKD stage 3, 4, and 5

eGFR (ml/min/1.73m²)

24.0 ± 11.9

36 (33.0–38.8)

24.5 (19.0–28.0)

12.3 (8.3–14.0)

 < 0.001^b

Systolic BP (mmHg)

143.3 ± 19.2

146 ± 19.9

140 ± 15.7

142 ± 20.6

0.672^b

Diastolic BP (mmHg)

78.6 ± 11.9

80 ± 13.6

80 ± 8.4

76 ± 12.0

0.119^b

BMI (kg/m²)

28.8 ± 5.7

29.9 ± 5.34

27.2 ± 5.0

29.1 ± 6.6

0.143^b

UPCI (g/mmol) (range < 0.01)

0.27 ± 0.35

0.13 ± 0.2

0.22 ± 0.2

0.46 ± 0.3

0.001^b

HbA1c (%)

6.3 (5.5–7.2)

6.3 (5.5–7.1)

6.5 (5.4–7.5)

6.2 (5.5–7.2)

0.933^b

Haemoglobin (g/dl)

12.1 (10.1–13.7)

13.5 (12.1–14.9)

12.8 (10.9–14.4)

9.8 (9.1–11.1)

 < 0.001^b

Hs-CRP (mg/L) (range < 1)

3.8 (0.6–11.4)

2.95 (0.5–8.08)

1.9 (0.53- 8.0)

9.85 (1.18–21.73)

0.037^b

ADMA (ng/ml) (range 50–180) (28)

567.399 (410.382–710.177)

546.996 (450.619–652.805)

510.996 (374.337–658.227)

633.059 (426.677–933.278)

0.224^b

Tortuosity

1.026 (1.021–1.030)

1.0249 (1.020–1.032)

1.0235 (1.020–1.0263)

1.0261 (1.0228–1.0372)

0.032^b

CRVE (µm)

159.776 (128.500 -208.733)

159.776 (128.545–170.242)

140.651 (107.926–190.413)

200.359 (144.377–258.980)

0.01^b

CRAE (µm)

151.166 (136.578–166.995)

149.798 (136.578–161.398)

150.222 (124.130–174.568)

153.819 (142.429–166.407)

0.612^b

Macula volume (mm³)

9.6 (9.2–10.1)

9.75 (9.15–10.1)

9.58 (9.13–10.30)

9.58 (9.2–10.0)

0.755^b