Table 2.
Baseline demographic, clinical, and laboratory values in the cohort and according to quartiles of SF36 Physical Health Dimension in 703 maintenance hemodialysis patients
| Quartile 1 (worse scores) (n = 177) (1 to <28.4) | Quartile 2 (n = 176) (28.4 to <43.6) | Quartile 3 (n = 176) (43.8 to <62.2) | Quartile 4 (best scores) (n = 174) (62.2 to 100) | P for Trend | |
|---|---|---|---|---|---|
| Demographic | |||||
| age (years) | 56.9 ± 12.6 | 55.0 ± 14.2 | 51.8 ± 14.5 | 50.0 ± 16.4 | <0.001 |
| women (%) | 95 (54%) | 86 (49%) | 87 (49%) | 63 (36%) | 0.002 |
| marital status (% married) | 55 (41%) | 70 (51%) | 67 (49%) | 55 (41%) | 0.85 |
| race (% African American) | 64 (37%) | 52 (30%) | 56 (32%) | 52 (30%) | 0.27 |
| insurance (% Medicare) | 70 (62%) | 61 (53%) | 54 (52%) | 54 (39%) | <0.001 |
| diabetes mellitus (%) | 122 (70%) | 103 (59%) | 89 (52%) | 67 (39%) | <0.001 |
| Charlson comorbidity score | 2.3 ± 1.70 | 2.15 ± 1.58 | 1.61 ± 1.53 | 1.44 ± 1.58 | <0.001 |
| crude mortality (%) | 89 (51%) | 75 (43%) | 56 (32%) | 54 (31%) | <0.001 |
| Body composition | |||||
| body mass index (kg/m2) | 27.2 ± 6.5 | 26.4 ± 6.2 | 26.4 ± 5.2 | 25.4 ± 6.1 | 0.012 |
| triceps skinfold (mm) | 19.2 ± 10.1 | 17.5 ± 9.6 | 17.6 ± 9.1 | 15.6 ± 9.5 | <0.001 |
| midarm muscle circumference (cm) | 32.3 ± 6.3 | 31.1 ± 6.1 | 31.3 ± 5.0 | 30.6 ± 5.6 | 0.016 |
| NIR measured body fat (%) | 50.0 ± 28.6 | 45.5 ± 26.9 | 44.9 ± 22.6 | 37.8 ± 27.3 | <0.001 |
| Hemodialysis treatment | |||||
| dialysis vintage (month) | 28.8 ± 31.6 | 25.9 ± 28.2 | 31.9 ± 37.3 | 31.7 ± 31.3 | 0.013 |
| dialysis dose (Kt/V single pool) | 1.58 ± 0.32 | 1.64 ± 0.32 | 1.61 ± 0.28 | 1.62 ± 0.28 | 0.41 |
| nPNA (nPCR; g/kg/d) | 1.05 ± 0.24 | 1.07 ± 0.24 | 1.08 ± 0.24 | 1.07 ± 0.22 | 0.44 |
| erythropoietin dose (1000 U/wk) | 15.6 ± 13.8 | 14.0 ± 12.2 | 12.9 ± 91 | 12.4 ± 96.6 | 0.005 |
| active vitamin D dose (ug/mo) | 38 ± 26 | 44 ± 37 | 41 ± 42 | 41 ± 30 | 0.56 |
| Biochemical measurements | |||||
| serum albumin (g/dl) | 3.81 ± 0.34 | 3.84 ± 0.38 | 3.96 ± 0.34 | 3.99 ± 0.35 | <0.001 |
| prealbumin (mg/dl) | 27.4 ± 8.9 | 28.2 ± 9.4 | 29.4 ± 9.79 | 29.19 ± 9.5 | 0.05 |
| creatinine (mg/dl) | 9.2 ± 2.9 | 9.9 ± 3.1 | 10.6 ± 3.1 | 11.3 ± 3.4 | <0.001 |
| TIBC (mg/dl) | 210 ± 40 | 209 ± 42 | 207 ± 39 | 206 ± 38 | 0.30 |
| calcium (mg/dl) | 9.33 ± 0.70 | 9.33 ± 0.75 | 9.40 ± 0.63 | 9.40 ± 0.62 | 0.26 |
| iron saturation ratio | 30.0 ± 9.55 | 33.3 ± 11.3 | 32.6 ± 11.8 | 33.2 ± 11.1 | 0.002 |
| phosphorus (mg/dl) | 5.71 ± 1.54 | 5.70 ± 1.26 | 5.78 ± 1.55 | 5.89 ± 1.43 | 0.21 |
| ferritin (ng/ml) | 583 ± 435 | 599 ± 430 | 577 ± 398 | 542 ± 438 | 0.32 |
| total homocysteine (μmol/L) | 22.8 ± 11.9 | 23.5 ± 11.9 | 24.1 ± 10.1 | 24.0 ± 9.5 | 0.28 |
| C-reactive protein (mg/L) | 6.8 ± 6.0 | 5.8 ± 5.9 | 4.4 ± 4.7 | 5.8 ± 7.6 | 0.05 |
| IL6 (pg/ml) | 17.9 ± 44.9 | 19.2 ± 64.0 | 18.2 ± 59.7 | 13.9 ± 21.9 | 0.40 |
| TNF (pg/ml) | 8.8 ± 12.2 | 8.0 ± 10.5 | 9.5 ± 10.6 | 8.6 ± 11.3 | 0.85 |
| white blood cells | 7.3 ± 1.9 | 7.2 ± 1.9 | 7.2 ± 1.9 | 6.8 ± 1.9 | 0.02 |
| lymphocytes | 21.4 ± 8.2 | 23.1 ± 8.1 | 23.5 ± 7.4 | 22.9 ± 7.2 | 0.06 |
| blood hemoglobin (g/dl) | 12.1 ± 1.0 | 12.1 ± 1.0 | 12.2 ± 0.9 | 12.1 ± 0.9 | 0.68 |
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.