Table 1.
Baseline demographic, clinical, and laboratory values in the cohort and according to quartiles of SF36 Mental Health Dimension in 705 maintenance hemodialysis patients
| Quartile 1 (worse scores) (n = 177) (1 to <37.2) | Quartile 2 (n = 176) (37.3 to <51.3) | Quartile 3 (n = 177) (51.4 to >69.4) | Quartile 4 (best scores) (n = 175) (69.5 to 100) | P for Trend | |
|---|---|---|---|---|---|
| Demographic | |||||
| age (years) | 55.2 ± 13.2 | 53.6 ± 14.4 | 52.51 ± 15.1 | 52.7 ± 16 | 0.08 |
| women (%) | 100 (56%) | 87 (49%) | 80 (45%) | 65 (37%) | <0.001 |
| marital status (% married) | 62 (44%) | 59 (46%) | 62 (46%) | 65 (46%) | 0.78 |
| race (% African American) | 65 (37%) | 45 (26%) | 58 (33%) | 55 (31%) | 0.58 |
| insurance (% Medicare) | 63 (59%) | 61 (53%) | 55 (49%) | 59 (43%) | 0.01 |
| diabetes mellitus (%) | 110 (64%) | 100 (58%) | 93 (54%) | 80 (46%) | 0.001 |
| Charlson comorbidity score | 2.14 ± 1.70 | 2.01 ± 1.62 | 1.70 ± 1.55 | 1.65 ± 1.63 | <0.001 |
| crude mortality (%) | 82 (46%) | 75 (43%) | 61 (34%) | 56 (32%) | 0.002 |
| Body composition | |||||
| body mass index (kg/m2) | 26.6 ± 6.0 | 26.7 ± 6.5 | 26.0 ± 5.8 | 26.0 ± 5.4 | 0.20 |
| triceps skinfold (mm) | 18.8 ± 10.2 | 18.0 ± 9.5 | 16.6 ± 9.3 | 16.3 ± 9.0 | 0.004 |
| midarm muscle circumference (cm) | 31.6 ± 6.1 | 31.8 ± 6.0 | 31.1 ± 6.2 | 31.1 ± 4.9 | 0.34 |
| NIR measured body fat (%) | 47.8 ± 27.1 | 47.4 ± 29.3 | 42.2 ± 25.5 | 41.3 ± 24.8 | 0.008 |
| Hemodialysis treatment | |||||
| dialysis vintage (month) | 28.8 ± 31.6 | 25.9 ± 28.2 | 32.0 ± 37.3 | 31.7 ± 31.5 | 0.23 |
| dialysis dose (Kt/V single pool) | 1.61 ± 0.31 | 1.62 ± 0.30 | 1.59 ± 0.26 | 1.62 ± 0.28 | 0.91 |
| nPNA (nPCR; g/kg/d) | 1.03 ± 0.24 | 1.11 ± 0.25 | 1.07 ± 0.23 | 1.06 ± 0.22 | 0.73 |
| erythropoietin dose (1000 U/wk) | 15.6 ± 14.5 | 12.9 ± 94.4 | 14.0 ± 12.0 | 12.3 ± 84.4 | 0.02 |
| active vitamin D dose (ug/mo) | 41 ± 34 | 39 ± 28 | 40 ± 32 | 44 ± 42 | 0.41 |
| Biochemical measurements | |||||
| serum albumin (g/dl) | 3.83 ± 0.38 | 3.89 ± 0.34 | 3.90 ± 0.37 | 3.97 ± 0.34 | <0.001 |
| prealbumin (mg/dl) | 27.4 ± 8.9 | 29.3 ± 10.07 | 29.5 ± 9.26 | 28.15 ± 9.2 | 0.76 |
| creatinine (mg/dl) | 9.58 ± 2.9 | 9.94 ± 2.9 | 10.46 ± 3.0 | 10.95 ± 3.3 | <0.001 |
| TIBC (mg/dl) | 207 ± 38 | 209 ± 37 | 207 ± 39 | 209 ± 38 | 0.79 |
| calcium (mg/dl) | 9.34 ± 0.72 | 9.34 ± 0.63 | 9.39 ± 0.74 | 9.38 ± 0.61 | 0.46 |
| iron saturation ratio | 31.9 ± 11.6 | 32.5 ± 11.2 | 31.6 ± 10.8 | 32.2 ± 10.7 | 0.99 |
| phosphorus (mg/dl) | 5.7 ± 1.5 | 5.7 ± 1.3 | 6.0 ± 1.4 | 5.7 ± 1.4 | 0.43 |
| ferritin (ng/ml) | 593 ± 425 | 614 ± 422 | 534 ± 358 | 558 ± 428 | 0.18 |
| total homocysteine (μmol/L) | 21.6 ± 9.5 | 22.8 ± 9.8 | 25.0 ± 13.1 | 24.6 ± 9.7 | 0.002 |
| C-reactive protein (mg/L) | 6.3 ± 6.3 | 5.1 ± 4.7 | 5.1 ± 5.5 | 6.0 ± 7.6 | 0.63 |
| IL6 (pg/ml) | 18.4 ± 54.8 | 13.6 ± 36.4 | 20.7 ± 68.6 | 14.0 ± 24.0 | 0.67 |
| TNF (pg/ml) | 8.5 ± 12.0 | 9.7 ± 13.4 | 8.3 ± 7.9 | 7.9 ± 9.7 | 0.34 |
| white blood cells | 7.1 ± 1.9 | 7.2 ± 1.7 | 7.2 ± 1.7 | 7.0 ± 2.0 | 0.93 |
| lymphocytes | 22.9 ± 8.1 | 22.2 ± 7.3 | 22.7 ± 7.5 | 23.1 ± 7.1 | 0.63 |
| blood hemoglobin (g/dl) | 12.1 ± 1.0 | 12.1 ± 0.9 | 12.0 ± 0.9 | 12.1 ± 0.9 | 0.77 |
Values expressed as mean ± SD or percent. Albumin in g/dl may be converted to g/L by multiplying by 10; creatinine in mg/dl to μmol/L by multiplying by 88.4; calcium in mg/dl to mmol/L by multiplying by 0.2495; phosphorus in mg/dl to mmol/L by multiplying by 0.3229. Ferritin levels expressed in ng/ml and μg/L are equivalent. White blood cell count in 103/μl and 109/L is equivalent. P for dialysis dose (vintage), ferritin level, vitamin D dose, CRP level, IL6 levels, and TNF level are based on logarithmic values of these measures. nPNA, normalized protein nitrogen appearance; nPCR, normalized protein catabolic rate; TIBC, total iron binding capacity.