An oscillometric approach in assessing early vascular ageing biomarkers following long-term space flights.

Purpose: The environmental conditions in space, particularly exposure to cosmic radiation, coupled with decreased mobility, altered glucose metabolism, and hemodynamic changes may promote cardiovascular disease Therefore, we assessed early vascular aging markers and hemodynamics using a novel oscillometric blood pressure device.

Methodology: In eight cosmonauts (46.5 ​± ​5.3 ​yrs, 77.6 ​± ​8.2 ​kg, 176 ​± ​6.2 ​cm, 7 men/1woman), we determined heart rate, peripheral blood pressure, central blood pressure, and pulse wave velocity in the supine position using an oscillometric brachial device coupled with transfer function analysis. We obtained measurements at baseline (65-90 days before flight) and four days (R+4) and eight days (R+8) after return from six months mission onboard the International Space Station.

Results: Compared to baseline, heart rate increased significantly on R+4 (58.6 ​± ​6.4 vs. 70.3 ​± ​5.2 bpm) but did not differ on R+8. Central systolic blood pressure increased from 112.5 ​± ​13.5 on baseline to 125.6 ​± ​18.5 on R+4 and 121.6 ​± ​9.5 ​mmHg, albeit showing no statistical significance compared to baseline (p ​= ​0.243/0.295). Peripheral diastolic and systolic as well as central diastolic blood pressure measurements followed this trend. Pulse wave velocity increased non-significantly from baseline (6.7 ​± ​0.8 ​m/s) to R+4 (7.2 ​± ​0.8 ​m/s, p ​= ​0.499) and stayed elevated on R+8 (7.1 ​± ​0.5 ​m/s, p ​= ​0.614).

Conclusion: The important finding of our study is that six months in a near-earth orbit do not lead to clinically significant changes in early vascular ageing biomarkers. However, these findings cannot be extrapolated to the conditions encountered in deep space. Non-invasive testing of vascular biomarkers may have utility in detecting vascular risks during space travel at an early stage.