title: Influence of menopause status and age on integrated central and peripheral hemodynamic responses to subsystolic cuffing during submaximal exercise.
abstract: Although pathophysiological links between postmenopause and healthy aging remain unclear, both factors are associated with increased blood pressure and sympathetic nerve activity (SNA) in women. Activation of polymodal musculoskeletal neural afferents originating within adventia of venules modulates SNA and blood pressure control during exercise in healthy adults. We hypothesized transient subsystolic regional circulatory occlusion (RCO) during exercise sensitizes these afferents leading to augmented systemic vascular resistance (SVR)-mediated increased mean arterial pressure (MAP) in postmenopause vs. premenopause. Normotensive women in premenopause or postmenopause (n = 14 and 14; ages: 30 ± 9 and 55 ± 7 yr, respectively; P < 0.01) performed: 1) peak exercise testing and 2) fixed-load cycling at 30% peak workload (48 ± 11 and 38 ± 6 W, respectively; P < 0.01), whereby the initial 3 min were control exercise without RCO (CTL), thereafter including 2 min of bilateral-thigh RCO to 20, 40, 60, 80, or 100 mmHg (randomized), with 2 min deflation between RCO. Both MAP (17 ± 4 vs. 4 ± 4%, P = 0.02) and SVR (16 ± 8 vs. -3 ± 8%, P = 0.04) increased at 80 mmHg from CTL in postmenopause vs. premenopause, respectively. However, cardiac index was similar in postmenopause vs. premenopause at 80 mmHg from CTL (1 ± 6 vs. 7 ± 6%, respectively; P = 0.15). There was no continuous effect of aging in MAP (P = 0.12), SVR (P = 0.07), or cardiac index (P = 0.18) models. These data suggest transient locomotor subsystolic RCO sensitizes musculoskeletal afferents, which provoke increased SVR to generate augmented MAP during exercise in postmenopause. These observations provide a novel approach for understanding the age-independent variability in exercise blood pressure control across the normotensive adult pre- to postmenopause spectrum.
authors.affiliation: Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota vaniterson.erik@mayo.edu.
authors.forename: Erik H
authors.initials: EH
authors.lastname: Van Iterson
authors.affiliation: Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Courtney
authors.initials: C
authors.lastname: Gramm
authors.affiliation: Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Nicholas R
authors.initials: NR
authors.lastname: Randall
authors.affiliation: Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Olson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D062186:Arterial Pressure / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000098:blood supply; D017698:Postmenopause / Q000502:physiology*; D017697:Premenopause / Q000502:physiology*; D013318:Stroke Volume / Q000502:physiology*; D013564:Sympathetic Nervous System / Q000502:physiology*; D013848:Thigh; D014111:Tourniquets; D014655:Vascular Resistance / Q000502:physiology*; D055815:Young Adult
keywords: aging women; cardiac output; exercise pressor reflex; group III-Aδ and IV-C neural afferents; regional circulatory occlusion