title: Increased postflight carotid artery stiffness and inflight insulin resistance resulting from 6-mo spaceflight in male and female astronauts.
abstract: Removal of the normal head-to-foot gravity vector and chronic weightlessness during spaceflight might induce cardiovascular and metabolic adaptations related to changes in arterial pressure and reduction in physical activity. We tested hypotheses that stiffness of arteries located above the heart would be increased postflight, and that blood biomarkers inflight would be consistent with changes in vascular function. Possible sex differences in responses were explored in four male and four female astronauts who lived on the International Space Station for 6 mo. Carotid artery distensibility coefficient (P = 0.005) and β-stiffness index (P = 0.006) reflected 17-30% increases in arterial stiffness when measured within 38 h of return to Earth compared with preflight. Spaceflight-by-sex interaction effects were found with greater changes in β-stiffness index in women (P = 0.017), but greater changes in pulse wave transit time in men (P = 0.006). Several blood biomarkers were changed from preflight to inflight, including an increase in an index of insulin resistance (P < 0.001) with a spaceflight-by-sex term suggesting greater change in men (P = 0.034). Spaceflight-by-sex interactions for renin (P = 0.016) and aldosterone (P = 0.010) indicated greater increases in women than men. Six-month spaceflight caused increased arterial stiffness. Altered hydrostatic arterial pressure gradients as well as changes in insulin resistance and other biomarkers might have contributed to alterations in arterial properties, including sex differences between male and female astronauts.
authors.affiliation: Schlegel-University of Waterloo Research Institute for Aging, Waterloo, Ontario, Canada; hughson@uwaterloo.ca.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Hughson
authors.affiliation: Schlegel-University of Waterloo Research Institute for Aging, Waterloo, Ontario, Canada;
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Robertson
authors.affiliation: Unite Medecine Physiologie Spatiale, CERCOM, EFMP, CHU Trousseau, Tours, France;
authors.forename: Philippe
authors.initials: P
authors.lastname: Arbeille
authors.affiliation: School of Kinesiology and Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada; and.
authors.forename: J Kevin
authors.initials: JK
authors.lastname: Shoemaker
authors.affiliation: Faculty of Applied Health Sciences, University of Waterloo, Waterloo, Ontario.
authors.forename: James W E
authors.initials: JW
authors.lastname: Rush
authors.affiliation: Schlegel-University of Waterloo Research Institute for Aging, Waterloo, Ontario, Canada;
authors.forename: Katelyn S
authors.initials: KS
authors.lastname: Fraser
authors.affiliation: Schlegel-University of Waterloo Research Institute for Aging, Waterloo, Ontario, Canada;
authors.forename: Danielle K
authors.initials: DK
authors.lastname: Greaves
mesh_terms: D000328:Adult; D000450:Aldosterone / Q000097:blood; D062186:Arterial Pressure; D018480:Astronauts; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D002340:Carotid Artery Diseases / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D063177:Pulse Wave Analysis; D012083:Renin / Q000097:blood; D012084:Renin-Angiotensin System; D012737:Sex Factors; D013026:Space Flight; D013997:Time Factors; D014463:Ultrasonography; D059289:Vascular Stiffness; D014893:Weightlessness / Q000009:adverse effects*
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D007328:Insulin; D000450:Aldosterone; D012083:Renin
keywords: arterial stiffness; sex differences; spaceflight