Table 3.
| Variable | Urine volume |
P value | |
|---|---|---|---|
| <2.5 L on the subsequent collection (n=165) | ≥2.5 L on the subsequent collection (n=108) | ||
| Sex (n=273) | .67 | ||
| Female (n=118) | 73/165 (44.2) | 45/108 (41.7) | |
| Male (n=155) | 92/165 (55.8) | 63/108 (58.3) | |
| Age (y) | 60.8±14.4 | 59.4±14.4 | .40 |
| BMI (kg/m2) | |||
| Initial collections | 27.5±6.2 | 28.0±6.1 | .45 |
| Subsequent collection | 27.2±6.3 | 28.4±6.1 | .12 |
| Change | −0.2±2.3 | 0.0±1.5 | .93 |
| Insurance | .69 | ||
| Medicare | 79/156 (50.6) | 51/106 (48.1) | |
| Not Medicare | 77/156 (49.4) | 55/106 (51.9) | |
| Urine volume | |||
| Initial collections | 1.5±0.5 | 1.9±0.4 | <.0001c |
| Subsequent collection | 1.7±0.5 | 3.3±0.5 | <.0001c |
| Change | 0.3±0.5 | 1.4±0.6 | <.0001c |
| Urine dietary factors | |||
| Urine sodium level (mmol/dL) | |||
| Initial collections | 147.2±54.4 | 168.0±66.3 | .025c |
| Subsequent collection | 159.5±67.7 | 191.2±80.1 | .0026c |
| Change | 12.3±58.2 | 23.2±67.2 | .16 |
| Urine phosphorus level (g/d) | |||
| Initial collections | 0.8±0.3 | 0.9±0.3 | .052 |
| Subsequent collection | 0.8±0.3 | 0.9±0.3 | .22 |
| Change | 0.0±0.3 | 0.0±0.3 | .28 |
| Urine calcium level (mg/d) | |||
| Initial collections | 185.9±99.1 | 223.3±102.3 | .0016c |
| Subsequent collection | 173.0±96.8 | 197.2±112.0 | .15 |
| Change | −12.9±78.0 | −26.1±98.0 | .1806 |
| SSCaOx | |||
| Initial collections | 8.0±3.3 | 7.0±2.7 | .012c |
| Subsequent collection | 6.6±3.2 | 3.1±1.5 | <.0001c |
| Change | −1.4±3.5 | −3.9±2.4 | <.0001c |
| UUN level (g/d) | |||
| Initial collections | 9.4±3.3 | 11.0±4.0 | .0055c |
| Subsequent collection | 9.9±3.8 | 11.9±4.1 | <.0001c |
| Change | 0.5±2.6 | 1.0±3.3 | .079 |
| PCR (g/kg per day) | |||
| Initial collections | 0.9±0.2 | 1.0±0.3 | .0016c |
| Subsequent collections | 1.0±0.3 | 1.1±0.2 | <.0001c |
| Change | 0.1±0.2 | 0.1±0.3 | .43 |
| Comorbidities (n=262) | |||
| Heart failure | 6/156 (3.8) | 4/106 (3.8) | .98 |
| Hyponatremia | 9/156 (5.8) | 0/106 (0) | <.05c |
| Cirrhosis | 3/156 (1.9) | 3/106 (2.8) | .63 |
| Medications at presentation (n=262) | |||
| Hydrochlorothiazide | 7/156 (4.5) | 2/106 (1.9) | .26 |
| Chlorthalidone | 48/156 (30.8) | 44/106 (41.5) | .074 |
| Indapamide | 3/156 (1.9) | 1/106 (0.9) | .53 |
| Amiloride | 4/156 (2.6) | 2/106 (1.9) | .72 |
| Furosemide | 5/156 (3.2) | 2/106 (1.9) | .52 |
| Bumetanide | 0/156 (0) | 1/106 (0.9) | .22 |
| Torsemide | 1/156 (0.6) | 0/106 (0) | .41 |
| Potassium citrate | 31/156 (19.9) | 31/106 (29.2) | .080 |
| Sodium bicarbonate | 1/156 (0.6) | 0/106 (0) | .41 |
| Collection day | .59 | ||
| Sunday | 13/165 (7.9) | 6/108 (5.6) | |
| Monday | 48/165 (29.1) | 34/108 (31.5) | |
| Tuesday | 30/165 (18.2) | 22/108 (20.4) | |
| Wednesday | 25/165 (15.2) | 16/108 (14.8) | |
| Thursday | 26/165 (15.8) | 12/108 (11.1) | |
| Friday | 20/165 (12.1) | 12/108 (11.1) | |
| Saturday | 3/165 (1.8) | 6/108 (5.6) | |
| Weekday vs weekend | .71 | ||
| Weekday | 149/165 (90.3) | 96/108 (88.9) | |
| Weekend | 16/165 (9.7) | 12/108 (11.1) | |
a
BMI = body mass index; PCR = protein catabolic rate; SSCaOx = supersaturation of calcium oxalate; UUN = urine urea nitrogen.
b
Data are presented as mean ± SD or as number/total number (percentage).
c
Any P value less than .05.