Table 1.
Hypergravity‐Induced Changes of the Cellular Hemostatic System
| Pre | Post | Post+30 | P Value | |
|---|---|---|---|---|
| Plasma volume change (%) | … | −12.5 (−14.5 to −8.9) | −0.2 (−2.9 to 2.8) | 0.002 |
| Blood volume change (%) | … | −6.9 (−7.8 to −6.1) | −0.1 (−1.4 to 1.9) | 0.003 |
| Blood count | ||||
| Hematocrit, % | 43.2±3.1 | 46.3±3.6 | 43.5±3.2 | <0.001 |
| Hemoglobin, g/dL | 15.4±1.0 | 16.4±1.2 | 15.4±1.1 | <0.001 |
| Red blood cells, ×106/µL | 5.0±0.4 | 5.3±0.4 | 5.0±0.4 | <0.001 |
| Mean corpuscular hemoglobin concentration, g/dL | 35.6±0.4 | 35.5±0.3 | 35.4±0.4 | 0.015 |
| Platelets, ×109/L | 219±35 | 242±35 | 213±29 | 0.023 |
| 228±34 † | 214±31 † | 0.431 † | ||
| White blood cells, ×109/L | 5.1±1.2 | 6.5±2.0 | 5.0±1.3 | 0.006 |
| 6.1±1.9 † | 5.0±1.3 † | 0.045 *,† | ||
| Blood rheology | ||||
| Red blood cell aggregation index, % | 62.4±5.9 | 67.7±6.5 | 60.4±6.8 | 0.001 |
| Shear rate balancing red blood cell aggregation and disaggregation (y at dIsc min [1/s]) | 75.8±18.7 | 320.0±349.7 | 119.7±172.0 | 0.003 |
| Red blood cell deformability (SS1/2:EImax) | 3.69±0.4 | 3.68±0.6 | 3.80±0.6 | 0.668 |
| Platelet function | ||||
| ADP induced, velocity | 16 (14–21) | 18 (14–22) | 17 (12–21) | 0.022 |
| ADP, induced aggregation | 163±28 | 172±31 | 163±32 | 0.622 |
| ADP induced, AUC (U) | 81±18 | 90±21 | 82±22 | 0.387 |
| Arachidonic acid induced, velocity | 19 (17–22) | 21 (19–24) | 18 (15–21) | 0.021 |
| Arachidonic acid induced, aggregation | 188 (149–219) | 199 (162–218) | 175 (143–200) | 0.182 |
| Arachidonic acid induced, AUC (U) | 91 (79–113) | 105 (81–111) | 86 (75–104) | 0.045 |
| Thrombin receptor activating peptide‐6 induced, velocity | 25±4 | 26±5 | 26±5 | 0.852 |
| Thrombin receptor activating peptide‐6 induced, aggregation | 221±35 | 226±34 | 218±35 | 0.799 |
| Thrombin receptor activating peptide‐6 induced, AUC (U) | 119±2 | 124±20 | 119±21 | 0.736 |
| Ristocetin induced, velocity | 30 (24–38) | 30 (23–38) | 31 (26–32) | 0.846 |
| Ristocetin induced, aggregation | 223±49 | 226±43 | 221±52 | 0.951 |
| Ristocetin induced, AUC (U) | 100±28 | 101±26 | 99±32 | 0.963 |
| Collagen induced, velocity | 18 (17–21) | 20 (17–23) | 19 (16–22) | 0.278 |
| Collagen induced, aggregation | 166±38 | 174±34 | 174±44 | 0.762 |
| Collagen induced, AUC (U) | 75±18 | 80±18 | 78±21 | 0.658 |
| Microparticles | ||||
| CD42 (events/µL plasma) | 984 (468–2043) | 1216 (753–3382) | 957 (633–2098) | 0.327 |
| CD61 (events/µL plasma) | 539 (145–1442) | 1363 (420–2368) | 784 (212–1451) | 0.494 |
| CD62P (events/µL plasma) | 462 (205–975) | 1075 (345–2274) | 615 (174–1032) | 0.113 |
| Annexin (events/µL plasma) | 447 (235–811) | 933 (338–1952) | 704 (207–1387) | 0.028 |
Pre, baseline values registered after 30 minutes of sitting in the centrifuge gondola; post, values registered immediately after the centrifuge had stopped; post+30, values registered 30 minutes after the centrifuge run. During this half hour the participants were allowed to move freely inside the centrifuge facility. EImax, the ratio of maximum deformability of red blood cells, SS1/2: EImax, shear stress required for one‐half of EImax with lower values representing higher red blood cell deformability. Normal distributed values are shown as mean±SD. Nonnormal distributed values are shown as median (first–third percentile). ADP indicates adenosine diphosphate; AUC, area under the curve.
Concentration measures corrected for plasma volume changes.