Table 1 Main demographic, clinical and functional data: mean ± SD [range]

General characteristics

 Gender (M / W)

6 / 2

6 / 3

8 / 1

4 / 6

4 / 5

 Age (years)

60.4 ± 13.7 [40–83]

74.7 ± 9.1 [63–92]

77.1 ± 10.5 [53–85]

72.1 ± 4.4 [65–79]

75.9 ± 7.2 [62–86]

 BMI (kg/m²)

25.3 ± 2.4 [22–28.7]

27.4 ± 4.0 [22.2–33.7]

28.4 ± 3.7 [23.5–36.4]

28.9 ± 5.5 [16.7–34.3]

29.2 ± 3.3 [22.6–35.1]

18.5 – 24.9

 Schooling (years)

11.5 ± 3.0 [8–16]

9.6 ± 2.6 [5–14]

10.1 ± 4.0 [5–17]

6.9 ± 2.8 [3–13]

8.7 ± 3.3 [5–17]

CKD specific parameters

 eGFR (ml/min/1.73 m²)

68.8 ± 16.2 [56–108]

35.1 ± 5.9 [26–44]

22.1 ± 4.9 [16–29]

10.3 ± 1.7 [7–13]

9.4 ± 4.0 [4–17]

 Time on HD (weeks)

-

-

-

-

81 ± 43 [13–131]

Health status

 Physical health

52.1 ± 7.7 [36.5–60.9]

45.5 ± 10.1 [25.0–55.3]

49.7 ± 8.6 [34.2–62.4]

40.3 ± 7.8 [25.0–52.5]

37.6 ± 10.2 [19.9–50.6]

 > 40

 Mental health

53.8 ± 7.0 [40.0–60.7]

52.7 ± 7.9 [38.1–62.0]

49.5 ± 12.9 [23.3–60.6]

54.4 ± 7.9 [37.9–65.1]

48.7 ± 8.0 [39.3–59.7]

 > 40

 Autonomy

100 ± 0.0 [100–100]

99.4 ± 1.7 [95–100]

100 ± 0.0 [100–100]

98.5 ± 3.4 [90–100]

91.7 ± 8.3 [80–100]

 ≥ 75

 Independence

21.0 ± 1.5 [18–22]

20.4 ± 1.4 [17–22]

18.4 ± 1.6 [16–21]

17.1 ± 3.2 [10–22]

12.8 ± 3.9 [7–19]

 ≥ 17

 General fatigue

6.0 ± 1.9 [4–9]

10.4 ± 4.2 [4–16]

9.6 ± 3.8 [5–17]

11.5 ± 3.1 [7–15]

11.1 ± 4.4 [4–17]

 < 10

 Pain

17.5 ± 27.1 [0–80]

17.8 ± 18.4 [0–50]

13.9 ± 18.2 [0–50]

51.0 ± 33.8 [0–100]

29.4 ± 24.8 [0–60]

 < 40

 GDS-10

0.9 ± 0.6 [0–2]

1.1 ± 1.2 [0–4]

2.6 ± 2.9 [0–7]

2.6 ± 3.4 [0–10]

3.7 ± 1.7 [1–6]

 ≤ 5

 Comorbidity severity Index

2.0 ± 0.1 [1.8–2.0]

2.5 ± 0.3 [2.3–3.0]

2.2 ± 0.3 [1.7–2.5]

2.0 ± 0.2 [1.6–2.2]

2.0 ± 0.3 [1.5–2.5]

 ≤ 2

 Comorbidity index

0.0 ± 0.0 [0–0]

1.3 ± 0.5 [1, 2]

1.7 ± 1.1 [1–4]

1.6 ± 1.1 [1–4]

1.6 ± 0.5 [1, 2]

 ≤ 2

Physical Performance

 SPPB

11.1 ± 1.1 [9–12]

11.6 ± 0.7 [10–12]

10.3 ± 1.3 [8–12]

9.4 ± 2.5 [4–12]

6.3 ± 2.4 [3–10]

 > 6

 ETGUG (seconds)

18.7 ± 1.8 [16.3–21.4]

20.7 ± 3.7 [14.8–26.7]

22.6 ± 3.3 [16.9–26.3]

27.5 ± 9.6 [16.4–43.8]

36.7 ± 13.5 [20.5–55.6]

 < 34

 POMA

27.0 ± 0.9 [26–28]

26.0 ± 2.3 [21–28]

25.6 ± 1.9 [23–28]

24.7 ± 2.8 [21–28]

21.7 ± 4.4 [16–28]

 > 19

 Steps/day^a

10,876 ± 3,419 [5,843–16,881]¹

9,979 ± 5,432 [3,664–22,027]

6,251 ± 2,779 [3,576–11,463]¹

7,144 ± 3,639 [2,839–15,862]

3,406 ± 3,257 [402–11,145]

 > 5,000

 Handgrip (kg)^b

 -Male

 -Female

47.7 ± 9.0 [38–58]

36.0 ± 4.2 [33–39]

41.7 ± 13.1 [21–58]

28.0 ± 0.0 [28–28]

29.0 ± 7.6 [20–44]

24.0 ± 0.0 [24–24]

28.3 ± 9.6 [19–40]

10.4 ± 3.3 [8–16]

21.3 ± 4.3 [15–25]

12.4 ± 3.9 [8–18]

 ≥ 27

 ≥ 16

Hip flexion (kg)^c

-Male

-Female

23.0 ± 6.9 [14.0–31.3]

16.1 ± 0.9 [15.4–16.7]

23.2 ± 7.6 [18.8–36.7]

11.9 ± 1.5 [10.1–12.9]

19.6 ± 3.1 [14.6–23.2]

12.0 ± 0.0 [12.0–12.0]

18.9 ± 13.5 [9.3–42.4]

14.3 ± 2.1 [11.4–17.4]

12 ± 3.6 [8.2–15.3]

11.4 ± 3.4 [7–15.3]

 > 11

 > 10

Cognitive Status

 MMSE

28.9 ± 1.1 [27–30]

28.3 ± 0.7 [27–29]

26.7 ± 2.3 [23–29]

26.2 ± 4.1 [16–29]

25.9 ± 1.6 [24–28]

 > 24

 FAB^d

3.3 ± 0.7 [2–4]

2.9 ± 1.1 [1–4]

0.7 ± 1.1 [0–3]

1.9 ± 1.5 [0–4]

1.3 ± 1.5 [0–4]

 ≥ 1

 TMT_A^d

3.8 ± 0.7 [2–4]

3.3 ± 1.1 [1–4]

2.2 ± 1.8 [0–4]

2.2 ± 1.9 [0–4]

2.7 ± 1.6 [0–4]¹

 ≥ 1

 TMT_B^d

3.6 ± 0.7 [2–4]

2.7 ± 1.7 [0–4]

2.8 ± 1.9 [0–4]

2.3 ± 2.1 [0–4]¹

1.7 ± 2.0 [0–4]¹

 ≥ 1

Haematology parameters

 Calcium (mmol/L)

2.4 ± 0.1 [2.3–2.5]²

2.3 ± 0.1 [2.2–2.4]¹

2.3 ± 0.2 [2.0–2.5]¹

2.3 ± 0.2 [2.0–2.5]

2.2 ± 0.1 [2.0–2.4]

2.15 – 2.55

 Phosphates (mmol/L)

1.0 ± 0.2 [0.8–1.2]²

1.1 ± 0.1 [0.9–1.3]¹

1.2 ± 0.2 [0.9–1.4]¹

1.6 ± 0.2 [1.3–1.8]

1.7 ± 0.5 [1.0–2.9]

0.81 – 1.45

 Haemoglobin (g/L)

142.3 ± 9.5 [124–154]¹

133.8 ± 13.6 [115–156]

130.0 ± 20.1 [99–171]¹

101.5 ± 10.5 [84–119]

103.8 ± 11.2 [87–122]

140 – 180

 Haematocrit (L/L)

0.44 ± 0.03 [0.38–0.48]¹

0.41 ± 0.05 [0.36–0.50]

0.40 ± 0.07 [0.29–0.53]¹

0.31 ± 0.04 [0.26–0.38]

0.31 ± 0.04 [0.26–0.39]

0.45 – 0.55