TABLE 1.
Characteristics of patients stratified by 50th percentile of betaine.
| Variables | Total patients (N = 216) | Low betaine (N = 108) | High betaine (N = 108) | p value |
| Age, years | 36 (27, 54) | 32 (25, 46) | 43 (30, 56) | 0.001 |
| Female sex, n (%) | 141 (65.3) | 79 (73.1) | 62 (57.4) | 0.022 |
| BMI, kg/m2 | 22.0 ± 3.9 | 21.5 ± 4.2 | 22.6 ± 3.4 | 0.067 |
| WHO-FC, n (%) | ||||
| I–II | 132 (61.1) | 76 (70.4) | 56 (51.9) | 0.008 |
| III–IV | 84 (38.9) | 32 (29.6) | 52 (48.1) | 0.008 |
| Laboratories | ||||
| Betaine, μM | 49.8 (39.0, 68.3) | 39.0 (33.5, 44.7) | 68.1 (57.8, 88.7) | <0.001 |
| NT-proBNP, pg/ml | 446.3 (144.3, 1563.0) | 304.0 (127.0, 659.8) | 821.6 (194.5, 2328.5) | <0.001 |
| Albumin, g | 42.3 ± 4.8 | 42.8 ± 4.5 | 41.8 ± 5.1 | 0.203 |
| Triglycerides | 1.1 (0.8, 1.5) | 1.1 (0.8, 1.5) | 1.1 (0.8, 1.5) | 0.687 |
| Total cholesterol, mM | 4.2 ± 1.1 | 4.2 ± 1.1 | 4.1 ± 1.1 | 0.975 |
| Creatinine, μM | 75.0 (65.5, 90.0) | 71.0 (62.4, 81.9) | 82.3 (71.0, 95.0) | <0.001 |
| Echocardiography | ||||
| LVEF, % | 65.0 (60.0, 70.0) | 65.0 (60.0, 69.3) | 65.0 (60.0, 70.0) | 0.533 |
| RVD, mm | 32.0 (27.0, 37.0) | 30.0 (26.8, 36.0) | 33.0 (27.5, 38.0) | 0.04 |
| TAPSE, mm | 16.5 (14.0, 18.0) | 18.0 (15.0, 19.0) | 15.0 (13.0, 18.0) | 0.005 |
| Exercise capacity | ||||
| PeakVO2, mL/min/kg | 47.4 ± 15.3 | 15.0 ± 4.1 | 14.1 ± 3.7 | 0.249 |
| VO2% | 1.5 ± 0.4 | 1.5 ± 0.4 | 1.4 ± 0.3 | 0.045 |
| 6MWD, m | 422.3 ± 96.5 | 426.4 ± 86.8 | 417.3 ± 107.5 | 0.096 |
| Hemodynamics | ||||
| mRAP, mmHg | 6.0 (4.0, 8.3) | 6.0 (3.5, 8.5) | 7.0 (4.0, 8.5) | 0.538 |
| mPAP, mmHg | 57.0 (47.0, 70.0) | 57.5 (46.8, 70.5) | 56.5 (47.0, 70.8) | 0.726 |
| Cardiac output index, L/min*m2 | 3.2 ± 1.0 | 3.4 ± 1.1 | 2.9 ± 0.9 | 0.002 |
| PAWP, mmHg | 8.0 (6.0, 11.0) | 8.0 (6.0, 11.0) | 9.0 (6.0, 11.0) | 0.452 |
| PVR, WU | 6.7 (5.0, 11.2) | 6.8 (5.0, 10.0) | 6.6 (4.9, 11.7) | 0.861 |
Betaine represents plasma betaine concentrations and patients were stratified into low betaine and high betaine groups by 50th percentile of betaine (49.8 μM). BMI, body mass index; WHO-FC, World Health Organization Function Class; NT-proBNP, N-terminal pro-brain natriuretic peptide; LVEF, left ventricular ejection fraction; RVD, right ventricular diameter; TAPSE, tricuspid annular plane systolic excursion; 6MWD, 6-min walk distance; mRAP, mean right atrial pressure; mPAP, mean pulmonary atrial pressure; PAWP, pulmonary arterial wedge pressure; PVR, pulmonary vascular resistance.