Table 2.
Clinical and laboratory factors associated with plasma endothelin-1 concentration
| Variable | Univariate Analysis | Multivariable Analysis | Stepwise Selection | |||
|---|---|---|---|---|---|---|
| Difference in Plasma Endothelin-1 Concentration (%) (95% CI) | P Value | Difference in Plasma Endothelin-1 Concentration (%) (95% CI) | P Value | Difference in Plasma Endothelin-1 Concentration (%) (95% CI) | P Value | |
| Age, per 10 yr older | −3.8% (−5.9% to −1.6%) | <0.001 | −2.6% (−4.9% to −0.1%) | 0.04 | −2.6% (−4.9% to −0.2%) | 0.03 |
| Sex, men versus women | −2.0% (−8.0% to 4.4%) | 0.66 | −5.6% (−11.7% to 0.9%) | 0.09 | −5.4% (−11.1% to 0.7%) | 0.08 |
| BMI, per 10 kg/m2 higher | −1.0% (−4.9% to 3.1%) | 0.62 | −5.2% (−9.2% to −0.9%) | 0.02 | −5.0% (−8.7% to −1.1%) | 0.01 |
| Systolic BP, per 10 mm Hg higher | 1.6% (0.5% to 2.7%) | 0.004 | 1.1% (−0.2% to 2.4%) | 0.11 | 1.1% (−0.2% to 2.4%) | 0.10 |
| Diastolic BP, per 10 mm Hg higher | 3.5% (1.6% to 5.4%) | <0.001 | 1.8% (−0.6% to 4.4%) | 0.15 | 1.9% (−0.5% to 4.5%) | 0.12 |
| Hemoglobin, per 1 g/dl higher | −5.5% (−7.8% to −3.2%) | <0.001 | −4.6% (−7.0% to −2.1%) | <0.001 | −4.9% (−7.1% to −2.6%) | <0.001 |
| WBC, per 1×10−3 per mm3 higher | −1.6% (−2.9% to −0.4%) | 0.02 | −0.3% (−1.7% to 1.1%) | 0.65 | — | — |
| Platelet count, per 100×10−3 per mm3 higher | −7.2% (−10.7% to −3.5%) | <0.001 | −9.4% (−13.2% to −5.5%) | <0.001 | −9.8% (−13.2% to −6.3%) | <0.001 |
| RDW, per 1% higher | 7.7% (5.6% to 9.8%) | <0.001 | 4.6% (2.4% to 6.9%) | <0.001 | 5.1% (3.1% to 7.2%) | <0.001 |
| Albumin, per 1 g/dl higher | −0.4% (−1.2% to 0.4%) | 0.42 | 0.1% (−0.7% to 1.0%) | 0.77 | — | — |
| Calcium, per 1 mg/dl higher | −0.6% (−5.2% to 4.2%) | 0.55 | −0.5% (−4.8% to 4.1%) | 0.83 | — | — |
| Phosphorus, per 1 mg/dl higher | 3.2% (1.2% to 5.4%) | 0.001 | 2.2% (0.1% to 4.3%) | 0.04 | 2.2% (0.2% to 4.3%) | 0.03 |
| PTH, per 100 pg/ml higher | 0.4% (−0.6% to 1.4%) | 0.40 | −0.8% (−1.8% to 0.2%) | 0.12 | −0.8% (−1.8% to 0.2%) | 0.10 |
| Iron, per 10 μg/dl higher | −2.0% (−3.0% to −0.9%) | <0.001 | 11.0% (−0.1% to 23.3%) | 0.05 | 2.4% (0.1% to 4.8%) | 0.04 |
| Iron saturation, per 10 μg/dl higher | −5.0% (−7.3% to −2.6%) | <0.001 | −12.2% (−21.9% to −1.4%) | 0.03 | −9.5% (−14.1% to −4.6%) | <0.001 |
| TIBC, per 100 μg/dl higher | 0.4% (−6.7% to 8.1%) | 0.81 | −50.6% (−80.7% to 26.1%) | 0.14 | — | — |
| UIBC, per 100 μg/dl higher | 9.9% (2.4% to 17.9%) | 0.007 | 93.3% (−23.8% to 390.2%) | 0.16 | — | — |
| LDH, per 100 IU/L higher | 20.0% (12.7% to 27.7%) | <0.001 | 14.1% (7.1% to 21.6%) | <0.001 | 13.8% (7.0% to 21.0%) | <0.001 |
| eKt/V, per 1 unit higher | 1.0% (−11.1% to 14.7%) | 0.10 | −9.2% (−33.8% to 24.7%) | 0.55 | — | — |
| URR, per 10 units higher | −1.4% (−6.7% to 4.2%) | 0.53 | 3.4% (−9.4% to 18.1%) | 0.62 | — | — |
| Hours per week treated, per 1 h/wk longer | 0.2% (−1.1% to 1.4%) | 0.30 | 0.4% (−1.1% to 1.9%) | 0.63 | — | — |
| Average EPO dose, per 1000 unit higher | 2.3% (1.5% to 3.1%) | <0.001 | 0.5% (−0.4% to 1.5%) | 0.30 | — | — |
| Ultrafiltration volume, per 1 L higher | 5.4% (3.3% to 7.5%) | <0.001 | 5.2% (3.0% to 7.5%) | <0.001 | 5.0% (2.9% to 7.1%) | <0.001 |
| Dialysis vintage, per 10 mo longer | 0.7% (0.1% to 1.4%) | 0.02 | 0.6% (0.03% to 1.2%) | 0.04 | 0.7% (0.1% to 1.3%) | 0.03 |
EPO dosage was calculated as the average EPO dosage per prescription received 1 month before the baseline time. 95% CI, 95% confidence interval; BMI, body mass index; WBC, white blood cell; —, not included in the stepwise selection model; RDW, red blood cell distribution width; PTH, parathyroid hormone; TIBC, total iron binding capacity; UIBC, unsaturated iron binding capacity; LDH, lactate dehydrogenase; eKt/V, equilibrated Kt/V; URR, urea reduction ratio, EPO, erythropoietin.