TABLE 3.
Platelet reactivity and blood-borne microvesicles averaged across baseline, 18-, 36-, and 48-month visits
| Measurements (averaged over treatment period) | Placebo pills or patch (n = 36) | Transdermal 17β-estradiol (n = 30) | Oral conjugated equine estrogen (n = 29) |
| Platelet reactivity | |||
| Platelet count (×103/μL) | 235.60 (221.70, 260.10) | 246.75 (219.40, 287.60) | 239.60 (212.60, 264.20) |
| Platelet microaggregates (% difference) | 1.90 (−0.30, 5.04) | 2.79 (−0.14, 4.72) | 3.58 (0.64, 7.72) |
| ATP secretion, (attomoles/platelet) | 25.78 (22.68, 29.46) | 23.96 (20.28, 28.10) | 28.90 (23.10, 32.36) |
| PGE1 sensitivity of ATP secretion (% suppression) | 24.92 (15.16, 31.96) | 22.05 (16.00, 29.74) | 20.30 (14.10, 27.94) |
| Basal expression of membrane P-selectin (%) | 1.61 (1.38, 2.02) | 1.40 (1.09, 1.67) | 1.72 (1.30, 1.99) |
| Basal expression of membrane fibrinogen receptor (antibody PAC-1 binding, %) | 0.72 (0.64, 0.89) | 0.76 (0.61, 0.87) | 0.81 (0.64, 0.92) |
| Microvesicles (MV)/μL plasma | |||
| Phosphatidylserine positive MV | 208.84 (170.60, 294.23) | 226.94 (141.74, 354.53) | 252.54 (178.44, 381.23) |
| Tissue factor positive MV | 22.96 (14.24, 28.62) | 23.67 (18.06, 39.35) | 17.05 (14.32, 24.97) |
| Leukocyte (CD45)-derived MV | 5.72 (3.48, 10.10) | 6.71 (4.83, 8.58) | 4.74 (3.73, 6.85) |
| Monocyte (CD14)-derived MV | 16.75 (11.30, 25.42) | 16.92 (11.42, 26.96) | 17.54 (10.16, 19.07) |
| Platelet (CD42a)-derived MV | 170.95 (132.38, 257.48) | 214.58 (135.23, 314.32) | 194.14 (141.75, 313.66) |
| Endothelium (CD62-E)-derived MV | 11.17 (8.13, 17.32) | 12.96 (8.38, 20.55) | 11.96 (9.44, 17.50) |
| ICAM-1-positive MV | 11.16 (7.57, 18.75) | 10.45 (5.90, 16.67) | 8.98 (5.99, 16.79) |
| VCAM-1-positive MV | 1.18 (0.84, 3.08) | 2.02 (0.89, 3.40) | 0.91 (0.59, 1.58) |
Results reported as median (25th, 75th percentile).
ATP, adenosine triphosphate; ICAM-1, intracellular adhesion molecule 1; MV, microvesicle; PGE1, prostaglandin E1; VCAM-1, vascular cell adhesion protein 1.