Table 2.
Baseline characteristics by category of serum uncorrected calcium in patients undergoing HD
| Characteristic | Uncorrected Serum Calcium Category, mg/dl (n) | |||||
|---|---|---|---|---|---|---|
| Total (n=118,955) | <8.5 (n=12,844) | 8.5 to <9.0 (n=27,436) | 9.0 to <9.5 (n=40,841) | 9.5 to <10.2 (n=31,849) | ≥10.2 (n=5985) | |
| Age (yr) | 62±16 | 60±16 | 63±15 | 62±15 | 61±15 | 61±15 |
| Sex (% women) | 45 | 41 | 42 | 45 | 49 | 52 |
| Diabetes mellitus (%) | 58 | 61 | 64 | 60 | 51 | 42 |
| Body mass index (kg/m2) | 26.6±6.6 | 26±6.9 | 26.3±6.5 | 26.8±6.6 | 26.9±6.4 | 25.9±6.0 |
| Race/ethnicity (%) | ||||||
| White | 43 | 40 | 45 | 44 | 41 | 39 |
| Black | 33 | 30 | 27 | 31 | 38 | 41 |
| Hispanic | 15 | 18 | 18 | 16 | 12 | 10 |
| Asian | 3 | 3 | 3 | 30 | 3 | 3 |
| Other | 7 | 8 | 7 | 6 | 6 | 7 |
| Vintage (time on dialysis; %) | ||||||
| 0–6 mo | 57 | 63 | 66 | 61 | 48 | 29 |
| 6–24 mo | 17 | 14 | 16 | 17 | 18 | 16 |
| 2–5 yr | 16 | 12 | 13 | 15 | 21 | 27 |
| >5 yr | 10 | 10 | 6 | 7 | 13 | 28 |
| Marital status (%) | ||||||
| Married | 47 | 44 | 48 | 48 | 48 | 46 |
| Single | 28 | 32 | 27 | 27 | 29 | 29 |
| Widoweda | 16 | 15 | 16 | 16 | 15 | 16 |
| Divorceda | 8 | 9 | 8 | 8 | 8 | 9 |
| Comorbid conditions (%) | ||||||
| Atherosclerotic heart disease | 21 | 19 | 23 | 22 | 19 | 18 |
| Congestive heart failure | 28 | 28 | 31 | 29 | 25 | 22 |
| Other cardiac diseases | 6 | 6 | 6 | 6 | 5 | 5 |
| Cerebrovascular disease | 8 | 7 | 8 | 8 | 7 | 7 |
| Peripheral vascular disease | 11 | 13 | 13 | 12 | 9 | 8 |
| Chronic obstructive pulmonary disease | 6 | 6 | 7 | 6 | 5 | 4 |
| Cancer | 4 | 5 | 5 | 4 | 4 | 4 |
| Current smoker | 5 | 6 | 5 | 5 | 5 | 4 |
| Laboratory data | ||||||
| Serum albumin (g/dl) | 3.7±0.4 | 3.3±0.6 | 3.6±0.4 | 3.7±0.4 | 3.9±0.3 | 3.9±0.4 |
| Serum creatinine (mg/dl) | 8.1±3.0 | 7.7±3.2 | 7.5±2.8 | 8.0±3.0 | 8.8±3.0 | 9.2±3.0 |
| Blood hemoglobin (g/dl) | 12.0±1.0 | 11.5±1.2 | 11.8±1.0 | 12.0±0.9 | 12.1±0.8 | 12.0±1.0 |
| Serum ferritin (ng/ml) | 507 (306–721) | 455 (256–683) | 468 (276–684) | 501 (311–709) | 547 (342–751) | 582 (380–834) |
| Serum total iron binding capacity (mg/dl) | 204±40 | 188±46 | 201±50 | 207±39 | 209±38 | 203±39 |
| Serum phosphorus (mg/dl) | 5.5±1.3 | 5.8±1.7 | 5.5±1.3 | 5.4±1.2 | 5.6±1.2 | 5.7±1.2 |
| Serum bicarbonate (mg/dl) | 23±3.0 | 22±2.9 | 23±3.0 | 23±3.0 | 23±3.0 | 23±3 |
| Serum parathyroid hormone (pg/ml) | 300 (193–386) | 342 (200–406) | 279 (186–368) | 275 (185–368) | 321 (204–430) | 372 (274–663) |
| Serum alkaline phosphatase (units/L) | 107 (84.5–182) | 117 (89.6–162) | 109 (86.1–146) | 105 (83.4–136) | 104 (82.7–136) | 112 (87.2–152) |
| White blood cell count (×103/μl) | 7.5±2.4 | 7.7±2.9 | 7.6±2.5 | 7.5±2.3 | 7.3±2.2 | 7.4±2.3 |
| Percent lymphocyte | 20±7 | 19±7 | 19±7 | 20±7 | 21±7 | 21±3 |
Data presented as means±SDs, medians (interquartile ranges), or percentages.
a
P value for difference among categories ≥0.05. All other P values are <0.05.