Table 1.
Cohort characteristics overall and by urine ammonium excretion rate tertiles
| Variable | Total Cohort, n=144 | NH4+ Tertile 1 (0.3–0.8 mEq/h), n=48 | NH4+ Tertile 2 (0.9–1.3 mEq/h), n=48 | NH4+ Tertile 3 (1.4–5.3 mEq/h), n=48 |
|---|---|---|---|---|
| Age, yr | 65 (13) | 68 (14) | 65 (12) | 62 (13) |
| Non-Hispanic white, no. (%) | 137 (95) | 46 (96) | 45 (94) | 46 (96) |
| Men, no. (%) | 112 (78) | 32 (67) | 36 (75) | 44 (92) |
| Diabetes, no. (%) | 89 (62) | 30 (63) | 27 (56) | 32 (67) |
| Hypertension, no. (%) | 115 (80) | 42 (88) | 34 (71) | 39 (81) |
| Coronary artery disease, no. (%) | 30 (21) | 8 (17) | 16 (33) | 6 (13) |
| Congestive heart failure, no. (%) | 13 (9) | 5 (10) | 3 (6) | 5 (10) |
| Systolic BP, mmHg | 125 (16) | 124 (15) | 126 (15) | 127 (18) |
| Systolic BP <140 mmHg, no. (%) | 119 (83) | 43 (90) | 40 (83) | 36 (75) |
| Body mass index, kg/m2 | 33 (8) | 32 (8) | 32 (6) | 34 (9) |
| Dietary protein intake, g/d | 81 (31) | 65 (21) | 77 (23) | 100 (36) |
| ACE-i/ARB use, no. (%) | 113 (78) | 40 (83) | 36 (75) | 37 (77) |
| Diuretic use, no. (%) | 73 (51) | 29 (60) | 25 (52) | 19 (40) |
| Alkali use, no. (%) | 25 (17) | 14 (29) | 7 (15) | 4 (8) |
| eGFR, ml/min per 1.73 m2, no. (%) | 42 (17) | 35 (15) | 40 (16) | 51 (16) |
| eGFR 60–89 | 20 (14) | 3 (6) | 6 (13) | 11 (23) |
| eGFR 45–59 | 41 (28) | 6 (13) | 14 (29) | 21 (44) |
| eGFR 30–44 | 45 (31) | 20 (42) | 13 (27) | 12 (25) |
| eGFR <30 | 38 (26) | 19 (40) | 15 (31) | 4 (8) |
| Urine protein-to-creatinine ratio, mg/ga | 184 (48–576) | 176 (24–488) | 233 (50–570) | 181 (46–842) |
| Serum K+, mEq/L | 4.4 (0.5) | 4.6 (0.5) | 4.4 (0.5) | 4.3 (0.4) |
| Urine TGF-β1/creatinine, ng/g | 102 (49) | 103 (48) | 97 (44) | 107 (54) |
Continuous variables are presented as mean (SD) unless noted otherwise, and categorical variables are presented as number (percentage). NH4+, ammonium; ACE-i, angiotensin-converting enzyme inhibitor; ARB, angiotensin receptor blocker.
a
Presented as median with interquartile range.