Table 1.
Demographics, comorbidities and medications by kidney stone group among 1957 potential kidney donors evaluated at the Mayo Clinic between 2000 and 2008
| Group 1: no radiographic or past symptomatic stones (N = 1719) | Group 2: asymptomatic radiographic stones only (N = 185) | Group 3: past symptomatic stones (N = 53)a | P-value | ||
| Characteristic | Mean ± SD or n (%) | Mean ± SD or n (%) | Mean ± SD or n (%) | Group 1 versus 2 | Groups 1 and 2 versus 3 |
| Age, years | 43 ± 12 | 44 ± 12 | 48 ± 11 | 0.83 | 0.007 |
| Male gender | 724 (42) | 75 (41) | 728 (53) | 0.68 | 0.12 |
| White race | 1514 (87) | 172 (96) | 747 (92) | 0.045 | 0.89 |
| Hypertension | 247 (14) | 26 (14) | 13 (25) | 0.91 | 0.038 |
| History of urinary tract infection | 109 (6.3) | 16 (8.6) | 6 (11) | 0.23 | 0.17 |
| Daily alcohol use | 108 (6.3) | 8 (4.3) | 3 (5.7) | 0.29 | 0.90 |
| Current smoker | 370 (22) | 33 (18) | 12 (23) | 0.24 | 0.80 |
| Chronic diarrhea | 15 (0.9) | 0 (0) | 1 (1.9) | 0.20 | 0.38 |
| Gastric bypass | 8 (0.5) | 1 (0.5) | 1 (1.9) | 0.89 | 0.15 |
| Body mass index > 30 kg/m2 | 602 (35) | 52 (28) | 17 (32) | 0.06 | 0.73 |
| Metabolic syndrome | 480 (28) | 41 (22) | 14 (26) | 0.10 | 0.85 |
| Calcium supplement | 191 (11) | 23 (12) | 9 (17) | 0.59 | 0.20 |
| Multivitamin | 444 (26) | 44 (24) | 16 (30) | 0.55 | 0.45 |
| Vitamin C supplement | 108 (6.3) | 8 (4.3) | 5 (9.4) | 0.29 | 0.32 |
| Thiazide diuretic | 65 (3.8) | 6 (3.2) | 3 (5.7) | 0.71 | 0.47 |
a
Subjects included those with and without current radiographic stones.