Table 4. Clinical and laboratory characteristics of patients according to lowest nocturnal SpO2.
| >93% (n = 15) | ≤93% (n = 15) | P value | |
| Medical history | |||
| Age (yrs) | 10.1 (5.7–17.0) | 9.1 (6.3–16.8) | 0.65 |
| Male gender | 3 (20%) | 7 (46.7%) | 0.12 |
| BMI (Kg/m2) | 16.3 (13.3–19.6) | 15.7 (13.9–21.4) | 0.60 |
| Enlarged tonsils | 6 (42.9%) | 7 (46.7%) | 0.84 |
| N of VOC in the past year | 0 (0–7) | 0 (0–2) | 0.75 |
| Hydroxycarbamide treatment | 4 (26.7%) | 2 (13.3%) | 0.65 |
| History of at least one ACS episode | 5 (33.3%) | 6 (40%) | 0.70 |
| Abnormal lung function test | 2 (13.3%) | 10 (66.7%) | 0.003 |
| SpO2 values | |||
| Daytime SpO2 | 98 (89–100) | 95 (92–99) | 0.03 |
| Postexercise SpO2 | 97 (79–100) | 92 (72–100) | 0.04 |
| >10% of sleep time with SpO2<90% | 1 (6.7%) | 10 (66.7%) | 0.0007 |
| Laboratory tests | |||
| Hemoglobin (g/dL) | 8.4 (6.9–10.6) | 7.5 (5.2–9.5) | 0.006 |
| Leukocytes(Giga/L) | 9.4 (5.8–16) | 10.8 (5.7–21.5) | 0.19 |
| Reticulocyte count (Giga/L) | 220 (43–276) | 246 (121–443) | 0.07 |
| Lactate dehydrogenase (IU/L) | 1196 (901–1683) | 1456 (849–1893) | 0.66 |
| Total bilirubin (µmol/L) | 36(17–130) | 55 (22–163) | 0.12 |
| Aspartate aminotransferase (IU/L) | 51 (39–132) | 63 (48–93) | 0.10 |
| Fetal hemoglobin (%) | 12.4 (2.6–28) | 5.4 (0.8–11.7) | 0.01 |
| Creatinine (µmol/L) | 36 (20–43) | 36 (22–51) | 0.91 |
| 6 MWT distance (% predicted distance) | 86 (46–120) | 87 (50–119) | 0.66 |
BMI, body mass index; VOC, vasoocclusive crisis; ACS, acute chest syndrome; 6 MWT, 6-minute walking test.