Table 1. Patient characteristics by sickle cell disease genotype.
| Patient characteristics | HbSS patients | HbSC patients | |||
| n | median (IQR)* | n | median (IQR)* | p† | |
| Age, years | 500 | 34 (25–45) | 161 | 41 (28–51) | 0.002 |
| Male gender, N (%) | 500 | 245 (49.0) | 161 | 66 (41.0) | 0.08 |
| SBP, mmHg | 500 | 117 (109–127) | 161 | 120 (112–132) | 0.01 |
| DBP, mmHg | 500 | 67 (60–74) | 161 | 71 (67–80) | <0.0001 |
| MAP, mmHg | 500 | 83 (77–90) | 161 | 88 (82–96) | <0.0001 |
| Pulse pressure, mmHg | 500 | 50 (42–59) | 161 | 48 (41–55) | 0.02 |
| Body mass index (BMI) | 492 | 23.0 (20.8–25.8) | 160 | 26.7 (22.7–30.5) | <0.0001 |
| Oxygen saturation‡, % | 497 | 97 (95–98) | 160 | 98 (97–99) | <0.0001 |
| Hydroxyurea use, N (%) | 500 | 225 (45.0) | 161 | 21 (13.0) | <0.0001 |
| Transfusions§, N (%) | 499 | 72 (14.4) | 159 | 6 (3.8) | 0.0003 |
| Chronic pain, N (%) | 499 | 184 (36.9) | 161 | 78 (48.4) | 0.009 |
| Six minute walk, m | 492 | 438 (384–504) | 159 | 440 (363–495) | 0.32 |
| WBC, × 109/L | 490 | 9.7 (7.5–4.3) | 156 | 8.1 (6.4–10.0) | <0.0001 |
| Hemoglobin, mmol/L | 489 | 5.4 (4.7–6.1) | 157 | 6.9 (6.4–7.6) | <0.0001 |
| Hematocrit, % | 490 | 25.2 (22.0–28.4) | 157 | 32.4 (29.4–35.3) | <0.0001 |
| Platelets, × 109/L | 489 | 364 (285–456) | 156 | 296 (193–362) | <0.0001 |
| Hemoglobin F, % | 445 | 6.3 (2.6–12.4) | 139 | 1.5 (0.8–3.2) | <0.0001 |
| Reticulocytes, % | 461 | 9.1 (6.1–13.4) | 153 | 3.3 (2.5–4.7) | <0.0001 |
| LDH, IU/L | 453 | 422 (299–600) | 154 | 240 (200–321) | <0.0001 |
| Total Bilirubin, µmol/L | 490 | 46.2 (32.5–70.1) | 159 | 22.2 (15.4–34.2) | <0.0001 |
| Hemolytic Component | 420 | 0.6 (−0.4–1.4) | 148 | −1.6 (−2.3–1.0) | <0.0001 |
| AST, IU/L | 477 | 42 (31–59) | 157 | 26 (21–35) | <0.0001 |
| Ferritin, pmol/L | 450 | 643 (254–1539) | 141 | 263 (148–483) | <0.0001 |
| Albumin, g/L | 489 | 42 (39–44) | 157 | 42 (39–44) | 0.59 |
| ALT, IU/L | 491 | 23 (17–33) | 159 | 18 (14–26) | <0.0001 |
| ALP, IU/L | 489 | 90 (70–122) | 157 | 76 (65–102) | 0.0002 |
| Creatinine, µmol/L | 492 | 61.9 (50.4–79.6) | 159 | 70.7 (61.9–86.6) | <0.0001 |
| Proteinuria, N (%) | 474 | 162 (34.2) | 147 | 28 (19.0) | 0.0005 |
| ACR | 306 | 32 (7.3–220.0) | 81 | 15.2 (4.2–68.4) | 0.004 |
| eGFR (ml/min/1.73 m2) | 492 | 138 (109–153) | 157 | 119 (95–137) | <0.0001 |
| CKD||, N (%) | 313 | 173 (55.3) | 82 | 35 (42.7) | 0.04 |
| TRV, m/sec | 449 | 2.6 (2.3–2.7) | 139 | 2.4 (2.2–2.7) | 0.003 |
| NT-proBNP, pmol/L | 464 | 9.1 (4.0–19.9) | 146 | 5.3 (2.2–12.5) | <0.0001 |
*Unless otherwise indicated; † From Wilcoxon two-sample test for difference in medians or Pearson chi-square test of independence of groups. p values <0.002 remained significant after Bonferroni's adjustment for multiple comparisons; ‡Hemoglobin oxygen saturation; §Chronic transfusion therapy; ||Stage I or higher.
SBP = systolic blood pressure; DBP = diastolic blood pressure; MAP = mean arterial pressure; WBC = white blood cell count; LDH = lactate dehydrogenase; AST = aspartate aminotransferase; ALT = alanine aminotransferase; ALP = alkaline phosphatase; ACR = urine albumin-to-creatinine ratio; eGFR = estimated glomerular filtration rate; CKD = chronic kidney disease; TRV = tricuspid regurgitant jet velocity; NT-proBNP = N-terminal prohormone of brain natriuretic peptide.