Table 1.
Ocular and cardiovascular measurements by experimental condition
Preflight |
Spaceflight |
||||
---|---|---|---|---|---|
Seated | Supine | HDT | Without LBNP | LBNP | |
IOP, mmHg | 14.4 (13.5–15.2) | 15.6 (14.8–16.4) | 18.6 (17.8–19.4) | 15.6 (14.9–16.4) | 14.2 (13.4–15.0) |
Choroidal thickness, µm | 339 (289–388) | 340 (290–390) | 344 (294–393) | 374 (325–423) | 381 (331–430) |
Systolic BP, mmHg | 117 (113–122) | 114 (109–118) | 119 (115–124) | 124 (120–128) | 119 (115–123) |
Diastolic BP, mmHg | 78 (74–83) | 72 (67–76) | 71 (67–76) | 78 (74–82) | 63 (59–68) |
MAP, mmHg | 93 (88–97) | 86 (82–91) | 87 (83–92) | 93 (89–97) | 82 (78–86) |
Heart rate, beats/min | 59 (56–62) | 54 (51–57) | 53 (50–56) | 59 (56–62) | 70 (67–73) |
Marginal means for ocular and cardiovascular measures for each posture on the ground and during spaceflight, without and with application of LBNP. 95% CI is shown in parenthesis. Hand-calculated differences of the means may diverge slightly from the estimates of the statistical model reported in the results. BP, blood pressure; CI, confidence interval; HDT, head-down tilt; IOP, intraocular pressure; LBNP, lower body negative pressure; MAP, mean arterial pressure.