Table 1. Demographic characteristics, markers of mineral metabolism, and measures of cognitive function of the whole population and by kidney disease status.
| Total (n = 605) | CKD (n = 247) | ESRD (n = 358) | p-value | |
|---|---|---|---|---|
| Age (y) | 67 ± 12 | 69 ± 12 | 66 ± 11 | 0.001 |
| Male sex | 595 (98%) | 243 (98%) | 352 (98%) | 0.9 |
| Race | 0.0002 | |||
| White | 304 (50%) | 67 (27%) | 149 (42%) | |
| Black | 216 (36%) | 148 (60%) | 156 (44%) | |
| Other | 85 (14%) | 32 (13%) | 53 (15%) | |
| Education (y) | 13 ± 3 | 13 ± 3 | 13 ± 3 | 0.5 |
| Cause of CKD | 0.01 | |||
| Diabetes | 233 (39%) | 73 (30%) | 160 (45%) | |
| GN | 38 (6%) | 17 (7%) | 21 (6%) | |
| HTN | 211 (35%) | 96 (39%) | 115 (32%) | |
| OU | 13 (2%) | 4 (2%) | 9 (3%) | |
| PKD | 26 (4%) | 14 (6%) | 12 (3%) | |
| Other | 84 (14%) | 43 (18%) | 41 (11%) | |
| Diabetes | 299 (49%) | 98 (40%) | 201 (56%) | < 0.0001 |
| Hypertension | 585 (97%) | 240 (97%) | 345 (96%) | 0.7 |
| CVD | 299 (49%) | 116 (47%) | 183 (51%) | 0.3 |
| Smoking | ||||
| Current | 106 (18%) | 40 (16%) | 66 (18%) | 0.9 |
| Former | 334 (55%) | 137 (56%) | 197 (55%) | 0.5 |
| BMI (kg/m2) | 28 ± 5 | 27 ± 5 | 29 ± 5 | 0.003 |
| SBP (mmHg) | 142 ± 23 | 141 ± 23 | 142 ± 23 | 0.4 |
| DBP (mmHg) | 75 ± 13 | 74 ± 13 | 76 ± 13 | 0.08 |
| Homocysteine (mmol/L) | 24 ± 7 | 23 ± 7 | 24 ± 7 | 0.10 |
| Calcium* (mg/dL) | 8.98 ± 0.85 | 9.00 ± 0.91 | 8.96 ± 0.80 | 0.5 |
| Phosphorus (mg/dL) | 4.74 ± 1.57 | 4.27 ± 1.37 | 5.07 ± 1.62 | < 0.0001 |
| 25(OH)D (ng/mL) | 18 [12 – 25] | 19 [13 – 28] | 17 [11 – 24] | 0.001 |
| 1,25(OH)2D (pg/mL) | 16 [11 – 23] | 19 [13 – 27] | 14 [10 – 20] | < 0.0001 |
| iPTH (pg/mL) | 154 [93 – 280] | 111 [75 – 186] | 185 [114 – 345] | < 0.0001 |
| FGF-23 (RU/mL) | 657 [254 – 2,959] | 288 [181 – 1,003] | 1,135 [390 – 4,238] | 0.0001 |
| Total TICSm score | 32.04 ± 5.12 | 32.01 ± 5.30 | 32.06 ± 5.00 | 0.9 |
| Global cognitive z-score composite | 0.01 ± 0.71 | 0.03 ± 0.68 | 0.00 ± 0.72 | 0.7 |
| Memory z-score composite | 0.01 ± 0.82 | –0.03 ± 0.86 | 0.03 ± 0.79 | 0.3 |
Data are expressed as number (%), mean ± SD, or median [interquartile range]. *Corrected for serum albumin concentration. GN = glomerulonephritis; HTN = hypertension; OU = obstructive nephropathy; PKD = polycystic kidney disease; CVD = cardiovascular disease; BMI = body mass index; SBP = systolic blood pressure; DBP = diastolic blood pressure; 25(OH)D = 25-hydroxyvitamin D; 1,25(OH)2D = 1,25-dihydroxvitamin D; iPTH = intact parathyroid hormone; FGF-23 = fibroblast growth factor-23; TICSm = Telephone Interview of Cognitive Status-modified.