TY - JOUR
T1 - Effects of sex and menstrual cycle on volume-regulatory responses to 24-h fluid restriction
AU - Giersch, Gabrielle E.W.
AU - Colburn, Abigail T.
AU - Morrissey, Margaret C.
AU - Butler, Cody R.
AU - Pruchnicki, Michaela L.
AU - Kavouras, Stavros A.
AU - Charkoudian, Nisha
AU - Casa, Douglas J.
N1 - Funding Information:
G.E.W.G., M.C.M., C.R.B., M.L.P., and D.J.C. were employed by the Korey Stringer Institute at the University of Connecticut at the time the research took place. S.A.K. has provided scientific consultation to Danone Research and Quest Diagnostics and has active research grants with Danone Research and Standard Process. D.J.C. has served as expert witness and received consulting honoraria from Clif Bar, Sports Innovation Laboratories, and the National Football League, funding from Gatorade, and royalties from Jones and Bartlett, Springer, LWW, Wolters-Kluwer Publishers, Up-to-Date, and Routledge/ Taylor & Francis Group. A.T.C. and N.C. have no conflicts, financial or otherwise, to disclose.
Publisher Copyright:
© 2020 American Physiological Society. All rights reserved.
PY - 2020/11/5
Y1 - 2020/11/5
N2 - Reproductive hormones have significant nonreproductive physiological effects, including altering fluid regulation. Our purpose was to explore the impact of sex and menstrual cycle (MC) phase on volume-regulatory responses to 24-h fluid restriction (24-h FR). Participants (men: n = 12, 20 ± 2 yr; women: n = 10, 20 ± 1 yr) were assigned two randomized and counterbalanced fluid prescriptions [Euhy: Euhydrated, urine specific gravity (USG) < 1.020; Dehy: 24-h FR, USG > 1.020]. Men completed both (MEuhy, MDehy), while women completed both in the late-follicular (days 10-13; FDehy, FEuhy) and midluteal (days 18-22; LDehy, LEuhy) phases. We measured body mass, plasma and urine osmolality (Posm, Uosm), urine specific gravity (USG), urine color (Ucol), and serum copeptin; 24-h FR yielded mild dehydration without influence of sex or MC (P > 0.05). Copeptin increased in men following Dehy (pre: 8.2 ± 5.2, post: 15.8 ± 12.6, P = 0.04) but not in women (FDehy pre: 4.3 ± 1.6, post: 10.5 ± 6.9, P = 0.06; LDehy pre: 5.6 ± 3.5, post: 10.4 ± 6.2, P = 0.16). In FDehy, Posm increased following FR (pre: 288 ± 2, post: 292 ± 1, P = 0.03) but not in men (pre: 292 ± 3, post: 293 ± 2, P = 0.46). No MC differences were observed between body mass loss, Posm, Uosm, USG, and copeptin (P > 0.05). These results suggest that volume-regulatory responses to 24-h FR were present in men but not in women, without apparent effects of the menstrual cycle.
AB - Reproductive hormones have significant nonreproductive physiological effects, including altering fluid regulation. Our purpose was to explore the impact of sex and menstrual cycle (MC) phase on volume-regulatory responses to 24-h fluid restriction (24-h FR). Participants (men: n = 12, 20 ± 2 yr; women: n = 10, 20 ± 1 yr) were assigned two randomized and counterbalanced fluid prescriptions [Euhy: Euhydrated, urine specific gravity (USG) < 1.020; Dehy: 24-h FR, USG > 1.020]. Men completed both (MEuhy, MDehy), while women completed both in the late-follicular (days 10-13; FDehy, FEuhy) and midluteal (days 18-22; LDehy, LEuhy) phases. We measured body mass, plasma and urine osmolality (Posm, Uosm), urine specific gravity (USG), urine color (Ucol), and serum copeptin; 24-h FR yielded mild dehydration without influence of sex or MC (P > 0.05). Copeptin increased in men following Dehy (pre: 8.2 ± 5.2, post: 15.8 ± 12.6, P = 0.04) but not in women (FDehy pre: 4.3 ± 1.6, post: 10.5 ± 6.9, P = 0.06; LDehy pre: 5.6 ± 3.5, post: 10.4 ± 6.2, P = 0.16). In FDehy, Posm increased following FR (pre: 288 ± 2, post: 292 ± 1, P = 0.03) but not in men (pre: 292 ± 3, post: 293 ± 2, P = 0.46). No MC differences were observed between body mass loss, Posm, Uosm, USG, and copeptin (P > 0.05). These results suggest that volume-regulatory responses to 24-h FR were present in men but not in women, without apparent effects of the menstrual cycle.
KW - Body mass loss
KW - Copeptin
KW - Estrogen
KW - Sex differences
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U2 - 10.1152/AJPREGU.00173.2020
DO - 10.1152/AJPREGU.00173.2020
M3 - Article
C2 - 32936680
AN - SCOPUS:85095861243
SN - 0363-6119
VL - 319
SP - R560-R565
JO - American Journal of Physiology - Regulatory Integrative and Comparative Physiology
JF - American Journal of Physiology - Regulatory Integrative and Comparative Physiology
IS - 5
ER -