Data are depicted as mean (SD), unless marked with * (median and 95% CI of the median)
| Patients with type 1 diabetes (n=8) | Healthy controls (n=12) | |||||
| LSD | HSD | P value | LSD | HSD | P value | |
| Weight (kg) | 75.6 (8.8) | 78.2 (9.6) | <0.001 | 74.0 (6.6) | 76.5 (6.7) | <0.001 |
| Extracellular fluid volume (L) | 14.6 (2.2) | 16.1 (2.8) | 0.32 | 15.1 (3.6) | 17.1 (2.6) | 0.09 |
| Plasma volume (L) | 3.2 (0.5) | 3.5 (0.6) | <0.05 | 3.4 (0.6) | 3.6 (0.6) | 0.23 |
| Hemodynamics | ||||||
| Systolic BP (mm Hg) | 120.0 (4.5) | 126.4 (7.4) | <0.05 | 117.3 (7.8) | 118.8 (5.5) | 0.33 |
| Diastolic BP (mm Hg) | 60.4 (5.2) | 63.6 (5.0) | <0.05 | 58.3 (5.4) | 57.4 (5.4) | 0.28 |
| MAP (mm Hg) | 80.3 (3.5) | 84.6 (5.1) | <0.05 | 78.0 (4.8) | 77.8 (4.8) | 0.85 |
| Cardiac output (L/min) | 6.6 (0.8) | 7.2 (0.7) | <0.05 | 6.5 (1.0) | 7.0 (1.3) | 0.10 |
| Heart rate (beats/min) | 57.5 (10.1) | 63.1 (10.7) | <0.01 | 54.7 (8.0) | 58.9 (11.2) | 0.06 |
| Stroke volume (mL) | 116.2 (14.3) | 116.7 (18.9) | 0.87 | 118.9 (12.0) | 120.5 (8.4) | 0.67 |
| Systemic vascular resistance (dyn·s·cm−5) | 991.3 (127.6) | 940.2 (94.6) | 0.21 | 983.4 (174.0) | 907.3 (154.6) | 0.09 |
| Plasma | ||||||
| PRA (pmol AngI/mL/hour)* | 0.48 (0.24–0.70) | 0.08 (0.04–0.13) | <0.01 | 0.36 (0.17–0.63) | 0.04 (0.00–0.07) | <0.001 |
| Aldosterone (pg/mL)* | 142.6 (130.7–272.9) | 34.4 (20.8–52.1) | <0.001 | 204.2 (49.3–455.3) | 28.0 (15.2–64.2) | <0.001 |
| Aldosterone:PRA ratio* (pg/mL/pmol AngI/mL/hour) | 699.5 (216.1–959.8) | 667.7 (415.8–5067) | 0.31 | 410.4 (361.6–512.9) | 443.3 (263.0–566.7) | 0.68 |
| NT-proBNP (ng/L) | 10.3 (6.2) | 51.8 (45.4) | <0.05 | 12.7 (13.4) | 20.8 (15.7) | 0.15 |
| Sodium (mmol/L) | 137.3 (2.4) | 139.8 (2.1) | <0.05 | 137.5 (1.6) | 140.3 (1.8) | <0.01 |
| Potassium (mmol/L) | 4.3 (0.3) | 4.2 (0.3) | 0.41 | 3.9 (0.3) | 3.9 (0.2) | 0.76 |
| Chloride (mmol/L) | 98.0 (2.3) | 101.9 (1.6) | <0.05 | 99.6 (1.5) | 103.3 (2.0) | <0.001 |
| Bicarbonate (mmol/L) | 25.2 (2.5) | 25.6 (2.0) | 0.77 | 25.5 (2.0) | 25.4 (1.6) | 0.88 |
| Creatinine (μmol/L) | 75.1 (10.1) | 70.6 (9.9) | 0.12 | 83.9 (10.0) | 77.0 (9.2) | <0.001 |
| eGFR (CKD-EPI) | 116.9 (10.6) | 120.9 (10.2) | 0.08 | 111.7 (14.1) | 119.9 (11.7) | <0.01 |
| Osmolality (mOsm/kg) | 290.3 (2.1) | 297.6 (6.1) | <0.01 | 284.9 (3.1) | 289.6 (3.8) | <0.01 |
| Glucose (mmol/L) | 10.7 (4.0) | 11.0 (2.9) | 0.88 | 4.9 (0.3) | 5.0 (0.4) | 0.70 |
| 24-hour urine | ||||||
| Volume (mL/24 hours) | 2246 (1044) | 2809 (788) | <0.05 | 1702 (551) | 1909 (544) | 0.24 |
| Osmolality (mOsm/kg) | 447.1 (209.5) | 650.3 (222.1) | <0.05 | 430.9 (164.4) | 743.7 (164.8) | <0.001 |
| Creatinine (mmol/24 hours) | 16.5 (2.6) | 17.9 (3.4) | <0.05 | 15.8 (2.4) | 17.3 (2.5) | <0.05 |
| FeNa (%) | 0.1 (0.03) | 1.0 (0.2) | <0.001 | 0.1 (0.03) | 1.1 (0.5) | <0.001 |
| Sodium (mmol/24 hours) | 23.3 (13.0) | 352.7 (72.6) | <0.001 | 19.1 (9.5) | 340.8 (104) | <0.001 |
| Potassium (mmol/24 hours) | 113.8 (36.3) | 105.8 (38.9) | 0.51 | 90.4 (25.4) | 89.5 (19.7) | 0.93 |
| Solute-free water clearance (L/day) | −0.8 (1.6) | −3.0 (1.8) | <0.01 | −0.7 (0.7) | −2.8 (0.5) | <0.001 |
| Solute-mediated water clearance (L/day) | 3.1 (0.8) | 5.8 (1.8) | <0.001 | 2.4 (0.5) | 4.7 (0.6) | <0.001 |
| Electrolyte-free water clearance (L/day) | 1.2 (0.9) | −0.5 (1.0) | <0.001 | 0.9 (0.6) | −1.2 (0.3) | <0.001 |
Data are tested using paired t-test (LSD vs HSD) or Wilcoxon test if marked with *.
BP, blood pressure; CKD-EPI, Chronic Kidney Disease Epidemiology Collaboration; eGFR, estimated glomerular filtration rate; FeNa, fractional excretion of sodium; HSD, high-salt diet; LSD, low-salt diet; MAP, mean arterial pressure; NT-proBNP, N-terminal pro-B-type natriuretic peptide; PRA, plasma–renin activity.