Table 1 Characteristics of study population by level of eGFR (ml/min/1.73 m²)

Mean age, years, mean (SD)

58.4 ± 10.9

58.8 ± 11.2

59.8 ± 10.6

58.6 ± 10.3

51.6 ± 11.0

<0.001

Men (%)

55.0

47.8

53.5

60.4

57.0

<0.001

Race/Ethnicity

<0.001

 White/Caucasian (%)

43.3

37.6

43.2

47.6

40.8

 Black/African American (%)

41.4

40.3

40.4

41.0

48.9

 Hispanic (%)

11.4

18.3

12.9

7.2

5.9

 Other (%)

3.9

3.8

3.5

4.2

4.3

Diabetes mellitus (%)

48.1

54.2

54.0

42.1

33.2

<0.001

Myocardial Infarcation/Prior Revasculization (%)

22.2

24.7

24.2

21.4

13.0

<0.001

Peripheral Vascular Disease (%)

6.7

11.0

7.1

4.9

2.7

<0.001

Stroke (%)

9.7

10.6

10.7

9.9

4.1

0.001

BMI, kg/m², mean (SD)

32.2 ± 7.8

32.1 ± 8.3

32.5 ± 7.7

32.1 ± 7.9

31.4 ± 7.1

0.1

Serum creatinine, mg/dL, mean (SD)

1.74 ± 0.57

2.56 ± 0.56

1.78 ± 0.32

1.39 ± 0.22

1.14 ± 0.20

eGFR, ml/min/1.73 m², mean (SD)

42.9 ± 13.4

24.9 ± 3.51

37.8 ± 4.22

51.6 ± 4.23

67.5 ± 7.55

Albumin level, g/dL, mean (SD)

3.95 ± 0.46

3.86 ± 0.47

3.90 ± 0.47

4.01 ± 0.44

4.07 ± 0.40

<0.001

Hypoalbuminemia (%)

12.7

16.6

15.6

9.0

6.2

<0.001

Dietary Protein Intake, g/kg/day, mean (SD)

0.81 ± 0.31

0.78 ± 0.31

0.80 ± 0.30

0.83 ± 0.30

0.87 ± 0.35

<0.001

CRP, mg/L, median (IQR)

2.59 (1.07, 6.33)

2.83 (1.08, 6.97)

2.90 (1.20, 6.71)

2.38 (1.00, 6.23)

1.85 (0.89, 4.07)

<0.001

Urine albumin, g/24 h, median (IQR)

0.06 (0.01, 0.55)

0.34 (0.05, 1.52)

0.10 (0.02, 0.71)

0.03 (0.01, 0.21)

0.01 (0.01, 0.08)

<0.001

4-variable^a GI symptom score, mean (SD) median (range)

11.1 ± 25.9 0(0,348)

14.0 ± 27.9 2(0, 250)

12.2 ± 27.1 0(0,348)

8.7 ± 24.1 0(0,282)

9.0 ± 22.2 0(0,150)

<0.001