Patient characteristics
. | Screening population (SD) . | LDH isoenzyme subgroup (SD) . | Blood flow study subgroup (SD) . |
|---|---|---|---|
| No. | 213 | 33 | 27 |
| Sex, female | .62 | .48 | .44 |
| Hydroxyurea treatment | .36 | .85* | .64* |
| Pulmonary hypertension | .34 | .67* | .26 |
| Hemoglobin SC | .18 | .06 | .07 |
| Age, y | 36 (11) | 35 (9.8) | 33 (8) |
| Leukocyte count, × 109/L | 10.1 (3.7) | 9.6 (3.9) | 9.4 (4.2) |
| Hemoglobin, g/L | 95 (19) | 90 (15) | 93 (19) |
| Platelet count, × 109/L | 357 (140) | 335 (155) | 373 (162) |
| Reticulocyte count, × 109/L | 233 (126) | 226 (123) | 274 (145) |
| Creatinine, μM | 80 (124) | 115 (186) | 53 (18) |
| Lactate dehydrogenase, IU/L | 351 (161) | 533 (701)† | 328 (90) |
| AST, IU/L | 39 (20) | 55 (45)† | 37 (18) |
| ALT, IU/L | 26 (13) | 41 (55)† | 25 (16) |
| Fetal hemoglobin | .075 (.066) | .099 (.061) | .106 (.094)† |
| Hemoglobin S | .66 (.19) | .67 (.20) | .73 (.15) |
| Serum haptoglobin, g/L | 0.10 (0.22) | ND | 0.08 (0.12) |
. | Screening population (SD) . | LDH isoenzyme subgroup (SD) . | Blood flow study subgroup (SD) . |
|---|---|---|---|
| No. | 213 | 33 | 27 |
| Sex, female | .62 | .48 | .44 |
| Hydroxyurea treatment | .36 | .85* | .64* |
| Pulmonary hypertension | .34 | .67* | .26 |
| Hemoglobin SC | .18 | .06 | .07 |
| Age, y | 36 (11) | 35 (9.8) | 33 (8) |
| Leukocyte count, × 109/L | 10.1 (3.7) | 9.6 (3.9) | 9.4 (4.2) |
| Hemoglobin, g/L | 95 (19) | 90 (15) | 93 (19) |
| Platelet count, × 109/L | 357 (140) | 335 (155) | 373 (162) |
| Reticulocyte count, × 109/L | 233 (126) | 226 (123) | 274 (145) |
| Creatinine, μM | 80 (124) | 115 (186) | 53 (18) |
| Lactate dehydrogenase, IU/L | 351 (161) | 533 (701)† | 328 (90) |
| AST, IU/L | 39 (20) | 55 (45)† | 37 (18) |
| ALT, IU/L | 26 (13) | 41 (55)† | 25 (16) |
| Fetal hemoglobin | .075 (.066) | .099 (.061) | .106 (.094)† |
| Hemoglobin S | .66 (.19) | .67 (.20) | .73 (.15) |
| Serum haptoglobin, g/L | 0.10 (0.22) | ND | 0.08 (0.12) |
The demographic, hematologic, and hepatic laboratory characteristics of the overlapping patient populations for each of the 3 studies are shown. All patients are included in the screening population. Two subgroups were recruited from this initial population for additional studies of LDH isoenzymes and forearm blood flow. For the categorical variables of sex, hydroxyurea treatment, pulmonary hypertension, hemoglobin SC, mean fetal hemoglobin, and mean hemoglobin S, the fraction of each population with the indicated characteristic is provided. For the continuous variables, the numbers are presented as means, with the SD indicated in parentheses. Characteristics that are significantly different in the 2 subgroups compared to the screening population are indicated.
ND indicates not done.
P < .05, χ2 versus screening population.
P < .05, unpaired t-test versus screening population.