TABLE 4.
Associations between mean grey matter CVR metrics and clinical and biological variables. Only results of variables that had at least one p ≤ 0.2 on univariate analysis in at least one outcome (grey matter CVR or tau) were presented.
| CVR Z-score | Tau Z-score | |||||
|---|---|---|---|---|---|---|
| Statistical test(n) = statistic a | p-value | Effect size b | Statistical test(n) = statistic a | p-value | Effect size b | |
| Age (years) | r(15) = −0.02 | 0.20 | −0.02 per additional year | r(15) = +0.01 | 0.66 | +0.01 per additional year |
| SCD genotype (SS/Sβ0 vs SC/Sβ+) | t(13) = −1.41 | 0.18 | +0.76 for SC/Sβ+genotype | t(13) = +0.82 | 0.43 | −0.39 for SC/Sβ+genotype |
| Systolic blood pressure (mmHg) | r(15) = +0.01 | 0.76 | +0.07 per 10 mmHg increase in SBP | r(15) = −0.06 | 0.11 | −0.6 per 10 mmHg increase in SBP |
| Hematocrit (L/L) | r(14) = +6.76 | 0.03 | +0.68 per 0.1 L/L increase in hematocrit | r(14) = 6.73 | 0.22 | −0.67 per 0.1 L/L increase in hematocrit |
| Hemoglobin (g/L) | r(14) = +0.02 | 0.05 | +0.20 per 10 g/L increase in hemoglobin | r(14) = −0.02 | 0.23 | −0.21 per 10 g/L increase in hemoglobin |
| White blood cells (109/L) | r(14) = +0.07 | 0.28 | +0.07 per 1 x 109/L increase in WBC | r(14) = −0.19 | 0.05 c | −0.19 per 1 x 109/L increase in WBC |
For binary and categorical variables, results of t- and F-statistic are shown, respectively. For continuous variables, unstandardized coefficients are shown.
For binary and categorical variables, effect sizes are reported with the Cohen d and η2 statistics, respectively.
Linear correlation for Tau Z-score and neutrophils: r(13) = 0.53, p = 0.05; monocytes: r(13) = 0.29, p = 0.32; lymphocytes r(13) = 0.35, p = 0.21.
Abbreviations: CVR, cerebrovascular reactivity; SBP, systolic blood pressure; SCD, sickle cell disease; WBC = white blood cells.