Table 5. Associations between the concentrations of testosterone (T) or dihydrotestosterone (DHT) and agonist-dependent whole blood platelet aggregation (WBA) or the expression of the markers of resting platelet activation (FC).
| Associated variable |
Coefficient of association (RS) |
Value of a posteriori probablility (P1α) |
|
testosterone membrane expression of P-selectin on resting platelets |
-0.146 (-0.138) | 0.035 (0.043) |
| m -0.387 | <<0.0001 | |
| f -0.144 | 0.037 | |
| membrane expression of GPII/IIIa on resting platelets | -0.170 (-0.120) | 0.017 (0.068) |
| m -0.313 | <<0.0001 | |
| f -0.152 | 0.029 | |
| AA-dependent aggregation | -0.371 (-0.287) | <<0.0001 (0.0001) |
| m -0.131 | 0.054 | |
| f -0.343 | <<0.0001 | |
| COL-dependent aggregation | -0.269 (-0.173) | 0.0004 (0.016) |
| m 0.050 | 0.268 | |
| f -0.185 | 0.011 | |
| ADP-dependent aggregation | -0.437 (-0.157) | <<0.0001 (0.026) |
| m -0.137 | 0.045 | |
| f -0.104 | 0.098 | |
|
dihydrotestosterone membrane expression of P- selectin on resting platelets |
-0.162 (-0.149) | 0.022 (0.032) |
| m -0.394 | <<0.0001 | |
| f -0.150 | 0.031 | |
| membrane expression of GPII/IIIa on resting platelets | -0.191 (-0.154) | 0.009 (0.028) |
| m -0.353 | <<0.0001 | |
| f -0.159 | 0.024 | |
| AA-dependent aggregation | -0.396 (-0.326) | <<0.0001 (<<0.0001) |
| m -0.161 | 0.023 | |
| f -0.396 | <<0.0001 | |
| COL-dependent aggregation | -0.292 (-0.161) | 0.0001 (0.023) |
| m -0.104 | 0.099 | |
| f -0.214 | 0.004 | |
| ADP-dependent aggregation | -0.456 (-0.179) | <<0.0001 (0.013) |
| m -0.147 | 0.034 | |
| f -0.148 | 0.033 |
Associations, estimated in the group composed of 73 men and 82 women, are presented as the LOO-boosted non-adjusted or sex-adjusted Spearman’s rank correlation coefficients; the values adjusted for sex, given in parentheses, were calculated with the partial Spearman’s correlation analysis. Spearman’s correlation coefficients, calculated separately for men (m) and women (f), were estimated by bootstrap resampling with replacement adjusted for the sample size of the complete group (n=155) (10000 iterations). Platelet aggregation was triggered by the addition of 0.5 mM AA, 1 µg/ml collagen (COL) or 10 µM ADP and monitored with the use of a whole blood impedance aggregometry. In flow cytometry, whole blood samples stained with the gating anti-CD61 MoAb and either anti-CD62 or PAC-1 MoAb, were fixed and monitored with flow cytometry (10000 events) (for details see ‘Materials and methods’).
Abbreviations used: AA, arachidonic acid; ADP, adenosine diphosphate; anti-CD61 MoAb, monoclonal antibody against surface membrane GPIIIa; anti-CD62 MoAb, monoclonal antibody against surface membrane P-selectin; COL, equine tendon collagen; FC, flow cytometry; LOO, the leave-one-out (‘jackknife’ or ‘d-jackknife’) algorithm of the calculus; PAC-1 MoAb, monoclonal antibody against surface membrane activated complex GPIIb/GPIIIa; WBA, whole blood impedance aggregometry.