Table 1.
Baseline characteristics in relation to tertile stratification of dietary fiber intakea
| Variables | Total (n = 219) | Dietary fiber intake stratified in tertiles |
P for trend | ||
|---|---|---|---|---|---|
| Upper (n = 73) | Middle (n = 73) | Lower (n = 73) | |||
| Clinical and demographic | |||||
| Age (yr) | 556 ± 12 | 53 ± 13 | 56 ± 11 | 58 ± 10 | 0.009 |
| Men, n (%) | 109 (49.5) | 45 (61.6) | 35 (47.9) | 29 (39.7) | 0.3 |
| Diabetes mellitus, n (%) | 66 (30) | 22 (30.1) | 19 (26.0) | 25 (34.2) | 0.6 |
| Positive smoking history, n (%) | 54 (24.5) | 25 (34.2) | 13 (17.8) | 15 (20.5) | 0.5 |
| Body mass index (kg/m2) | 23.0 ± 3.4 | 23.1 ± 4.0 | 23.0 ± 3.0 | 23.0 ± 3.2 | 0.9 |
| Duration of dialysis (mo)b | 26.5 (15, 51) | 24 (12, 37.5) | 26 (16.5, 57.5) | 39 (16, 61.5) | 0.1 |
| Systolic BP (mm Hg) | 147 ± 17.2 | 144 ± 16 | 148 ± 18 | 148 ± 17 | 0.1 |
| Diastolic BP (mm Hg) | 82 ± 9 | 83 ± 10 | 82 ± 9 | 82 ±10 | 0.6 |
| Pulse pressure (mm Hg) | 64 ± 14 | 61 ± 12 | 66 ± 14 | 66 ± 15 | 0.02 |
| Hypertension, n (%) | 189 (85.9) | 61 (83.6) | 63 (86.3) | 64 (87.7) | 0.5 |
| Background AVD, n (%) | 52 (23.6) | 19 (26.0) | 12 (16.4) | 21 (28.8) | 0.7 |
| Coronary artery disease, n (%) | 44 (20) | 16 (21.9) | 11 (15.1) | 17 (23.3) | 0.8 |
| Echocardiographic | |||||
| LV mass index (g/m2) | 224 ± 85 | 207 ± 69 | 217 ± 81 | 247 ± 99 | 0.004 |
| LV volume index (ml/m2) | 66 ± 20 | 67 ± 22 | 63 ± 18 | 67 ± 21 | 0.2 |
| LV ejection fraction (%) | 53 ± 8 | 52 ± 10 | 53 ± 8 | 52 ± 8 | 0.2 |
| Dialysis | |||||
| Total weekly urea clearance | 1.81 ± 0.44 | 1.76 ± 0.46 | 1.87 ± 0.49 | 1.80 ± 0.36 | 0.6 |
| PD urea clearance | 1.53 ± 0.35 | 1.4 ± 0.4 | 1.6 ± 0.3 | 1.6 ± 0.3 | <0.001 |
| Renal urea clearance | 0.28 ± 0.41 | 0.38 ± 0.42 | 0.29 ± 0.50 | 0.16 ± 0.26 | 0.001 |
| Total weekly CrCl (l/wk per 1.73 m2) | 56.3 ± 21.6 | 61.1 ± 26.7 | 56.6 ± 22.9 | 51.2 ± 11.0 | 0.005 |
| PD CrCl (l/wk per 1.73 m2) | 39.8 ± 8.16 | 36.1 ± 7.21 | 40.3 ± 8.03 | 42.8 ± 7.74 | <0.001 |
| Renal CrCl (l/wk per 1.73 m2) | 16.5 ± 23.1 | 25.1 ± 27.9 | 16.3 ± 23.6 | 8.39 ± 12.2 | <0.001 |
| Normalized PCR (g/kg per d)b | 0.94 (0.82, 1.08) | 0.99 (0.85, 1.10) | 0.94 (0.86, 1.09) | 0.88 (0.78, 1.03) | 0.03 |
| % with RRF | 134 (60.9) | 57 (78.1) | 44 (60.3) | 32 (43.8) | <0.001 |
| Residual GFR (ml/min/1.73m2)b | 0.55 (0.00, 1.89) | 0.92 (0.17, 2.75) | 0.44 (0.0, 1.76) | 0.00 (0.00, 1.06) | <0.001 |
| Biochemical | |||||
| Hemoglobin (g/dl) | 9.18 ± 1.71 | 9.77 ± 2.01 | 8.92 ± 1.36 | 8.85 ± 1.54 | 0.001 |
| Serum albumin (g/dl) | 28.6 ± 5.2 | 29.7 ± 5.6 | 28.3 ± 5.4 | 27.7 ± 4.3 | 0.02 |
| Serum potassium (mmol/l) | 4.01 ± 0.62 | 4.16 ± 0.59 | 4.07 ± 0.62 | 3.80 ± 0.58 | 0.001 |
| Plasma calcium (mmol/l) | 2.56 ± 0.23 | 2.55 ± 0.22 | 2.55 ± 0.25 | 2.57 ± 0.21 | 0.7 |
| Plasma phosphate (mmol/l) | 1,67 ± 0.46 | 1.71 ± 0.50 | 1.69 ± 0.43 | 1.61 ± 0.47 | 0.2 |
| Intact PTH (pmol/l)b | 42.4 (18.7, 74.1) | 40.6 (18.9, 67.7) | 36.3 (16.7, 64.7) | 48.9 (19.9, 82.9) | 0.2 |
| Total cholesterol (mmol/l) | 5.39 ± 1.19 | 5.32 ± 1.07 | 5.60 ± 1.27 | 5.25 ± 1.22 | 0.06 |
| HDL-cholesterol (mmol/l) | 1.24 ± 0.42 | 1.19 ± 0.35 | 1.27 ± 0.48 | 1.25 ± 0.43 | 0.4 |
| LDL-cholesterol (mmol/l) | 2.18 ± 0.98 | 3.33 ± 0.90 | 3.41 ± 0.98 | 3.09 ± 1.05 | 0.2 |
| Triglyceride (mmol/l) | 2.08 ± 1.48 | 1.87 ± 0.99 | 2.24 ± 1.90 | 2.14 ± 1.40 | 0.3 |
| Hs-CRP (mg/l)b | 2.90 (0.90, 0.98) | 1.39 (0.77, 5.43) | 3.0 (0.95, 8.08) | 4.28 (1.25, 11.4) | 0.006 |
| Interleukin-6 (pg/ml)b | 9.7 (5.2, 18.1) | 6.9 (4.5, 14.6) | 10.7 (5.4, 18.6) | 10.3 (7.0, 18.80 | 0.05 |
| Fetuin-A (g/l) | 0.31 ± 0.07 | 0.32 ± 0.07 | 0.31 ± 0.06 | 0.29 ± 0.06 | 0.003 |
| Cardiac troponin T (μg/l)b | 0.06 (0.01, 0.15) | 0.03 (0.01, 0.09) | 0.03 (0.01, 0.15) | 0.1 (0.02, 0.18) | 0.002 |
| NT-pro-BNP (pg/ml)b | 5842 (1950, 17,533) | 3730 (1631, 13,304) | 4798 (1717, 13,872) | 9366 (2640, 35,000) | 0.02 |
| Dietary intake | |||||
| Total fiber intake (g/d) | 5.0 ± 2.5 | 7.7 ± 2.0 | 4.8 ± 0.7 | 2.5 ± 0.8 | <0.001 |
| Energy intake (kcal/kg per day) | 24.6 ± 8.8 | 29.9 ± 8.8 | 24.5 ± 7.3 | 19.6 ± 6.9 | <0.001 |
| Protein intake (g/kg per day) | 1.1 ± 0.5 | 1.3 ± 0.5 | 1.1 ± 0.4 | 0.9 ± 0.4 | <0.001 |
AVD, atherosclerotic vascular disease; BP, blood pressure; CrCl, creatinine clearance; GFR, glomerular filtration rate; HDL, high-density lipoprotein; hs-CRP, high sensitive C-reactive protein; LDL, low-density lipoprotein; LV, left ventricular; NT-pro-BNP, N-terminal pro-brain natriuretic peptide; PCR, protein catabolic rate; PD, peritoneal dialysis; PTH, parathyroid hormone; RRF, residual renal function.
Dietary fiber intake >5.88 g/d as upper tertile (reference group), 3.71 g to 5.88 g/d as middle tertile, and <3.71 g/d as lower tertile.
a
Continuous data are expressed as mean ± SD unless specified otherwise.
b
Median (interquartile range).