Table 1.
Descriptive statistics
| Combined | Female | Male | |||
|---|---|---|---|---|---|
| n = 416 | n = 293 | ||||
| n | Mean (SD) or n (%) | Mean (SD) or n (%) | Mean (SD) or n (%) | p value | |
| Age, years | 709 | 65.4 (9) | 64.6 (8.9) | 66.5 (9) | 0.05 |
| Weight, kg | 709 | 87.7 (19.1) | 81.3 (17.5) | 96.8 (17.5) | <.0001 |
| BMI, kg/m2 | 709 | 31 (5.9) | 30.9 (6.5) | 31 (5) | 1.00 |
| SBP, mmHg | 705 | 149 (25) | 150 (25) | 147 (25) | 0.09 |
| DBP, mmHg | 705 | 84 (11) | 82 (11) | 86 (11) | 0.95 |
| Serum creatinine, mg/dL | 612 | 0.9 (0.2) | 0.8 (0.2) | 1.0 (0.2) | <.0001 |
| eGFRCys, ml/min/1.73 m2 | 601 | 85.6 (24.7) | 87.9 (25.8) | 82.5 (22.8) | 0.02 |
| Diabetes status | 625 | 0.21 | |||
| Yes | 87 (13.9) | 45 (12.4) | 42 (16.1) | ||
| No | 538 (86.1) | 319 (87.6) | 219 (83.9) | ||
| Blood glucose, mg/dL | 612 | 96.1 (22.9) | 94.8 (23.0) | 98.0 (22.7) | 0.24 |
| Dietary measures | |||||
| Oxalate, mg/day | 511 | 215.8 (126.3) | 217.9 (121.3) | 212.9 (133.3) | 0.64 |
| Animal protein, g/day | 521 | 52.9 (25.4) | 48.9 (21.4) | 58.7 (29.4) | <.0001 |
| Sodium, mg/day | 521 | 3140 (1407) | 2947 (1313) | 3419 (1491) | <0.0001 |
| Water intake, g | 521 | 2950 (1119) | 3004 (1050) | 2873 (1211) | <0.0001 |
| Total protein, g/day | 521 | 80.4 (33.9) | 75.5 (29.9) | 87.3 (37.9) | <0.0001 |
| Sucrose, g/day | 519 | 37.2 (20.7) | 38 (20.4) | 36 (21.1) | 0.34 |
| Calcium, mg/day | 521 | 1059 (542) | 1060 (517) | 1057 (578) | <0.0001 |
| Diuretic use | |||||
| Loop | 709 | 0.61 | |||
| Yes | 35 (4.9) | 22 (5.3) | 13 (4.4) | ||
| No | 674 (95.1) | 394 (94.7) | 280 (95.6) | ||
| Thiazide | 709 | 0.99 | |||
| Yes | 259 (36.5) | 152 (36.5) | 107 (36.5) | ||
| No | 450 (63.5) | 264 (63.5) | 186 (63.5) | ||
| Urinary traits | |||||
| Urine osmolality, mOsm/kg | 709 | 511.3 (188.6) | 456.1 (165.7) | 589.8 (191.7) | <0.0001 |
| Urine volume, mL/day | 709 | 1971.1 (690.77) | 1967.65 (675.26) | 1975.99 (713.36) | 0.8743 |
| Total mOsm/day | 709 | 932 (314) | 829 (257) | 1078 (329) | <0.0001 |
| Urine sodium, mmol/day | 705 | 143 (58) | 123 (48) | 170 (61) | <0.0001 |
| Urine potassium, mmol/day | 709 | 59 (23) | 52 (19) | 70 (23) | <0.0001 |
| Electrolyte contribution to urine osmole load, mmol/day | 705 | 403 (145) | 349 (116) | 478 (148) | <0.0001 |
| Urea contribution to urine osmole load, mmol/day | 705 | 523 (242) | 476 (212) | 591 (264) | <0.0001 |
p values were testing for sex differences, using linear mixed models to account for sibships. Water intake includes water from food consumption
SD standard deviation, BMI body mass index, SBP systolic blood pressure, DBP diastolic blood pressure, eGFR estimated glomerular filtration rate (cystatin calculation)