title: Sympathetic Neural and Hemodynamic Responses During Cold Pressor Test in Elderly Blacks and Whites.
abstract: The sympathetic response during the cold pressor test (CPT) has been reported to be greater in young blacks than whites, especially in those with a family history of hypertension. Because blood pressure (BP) increases with age, we evaluated whether elderly blacks have greater sympathetic activation during CPT than age-matched whites. BP, heart rate, cardiac output, and muscle sympathetic nerve activity were measured during supine baseline, 2-minute CPT, and 3-minute recovery in 47 elderly (68 ± 7 [SD] years) volunteers (12 blacks and 35 whites). Baseline BP, heart rate, cardiac output, or muscle sympathetic nerve activity did not differ between races. Systolic and diastolic BP and heart rate increased during CPT (all P<0.001) with no racial differences (all P > 0.05). Cardiac output increased during CPT and ≤ 30 s of recovery in both groups, but was lower in blacks than whites. Muscle sympathetic nerve activity increased during CPT in both groups (both P<0.001); the increase in burst frequency was similar between groups, whereas the increase in total activity was smaller in blacks (P=0.030 for interaction). Peak change (Δ) in diastolic BP was correlated with Δ total activity at 1 minute into CPT in both blacks (r=0.78,P=0.003) and whites (r=0.43,P=0.009), whereas the slope was significantly greater in blacks (P=0.007). Thus, elderly blacks have smaller sympathetic and central hemodynamic (eg, cardiac output) responses, but a greater pressor response for a given sympathetic activation during CPT than elderly whites. This response may stem from augmented sympathetic vascular transduction, greater sympathetic activation to other vascular bed(s), or enhanced nonadrenergically mediated vasoconstriction in elderly blacks.
authors.affiliation: From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (Y.O., S.S.J., S.A.B., J.G.E., B.D.L., Q.F.); Departments of Internal Medicine (Y.O., S.S.J., S.A.B., B.A.-H., W.V., B.D.L., Q.F.) and Anesthesiology and Pain (J.M.H.), UT Southwestern Medical Center, Dallas, TX; Department of Special Care Dentistry, Matsumoto Dental University, Nagano, Japan (Y.O.); and Department of Biological Sciences, Northern Arizona University, Flagstaff (S.S.J.).
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Okada
authors.affiliation: From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (Y.O., S.S.J., S.A.B., J.G.E., B.D.L., Q.F.); Departments of Internal Medicine (Y.O., S.S.J., S.A.B., B.A.-H., W.V., B.D.L., Q.F.) and Anesthesiology and Pain (J.M.H.), UT Southwestern Medical Center, Dallas, TX; Department of Special Care Dentistry, Matsumoto Dental University, Nagano, Japan (Y.O.); and Department of Biological Sciences, Northern Arizona University, Flagstaff (S.S.J.).
authors.forename: Sara S
authors.initials: SS
authors.lastname: Jarvis
authors.affiliation: From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (Y.O., S.S.J., S.A.B., J.G.E., B.D.L., Q.F.); Departments of Internal Medicine (Y.O., S.S.J., S.A.B., B.A.-H., W.V., B.D.L., Q.F.) and Anesthesiology and Pain (J.M.H.), UT Southwestern Medical Center, Dallas, TX; Department of Special Care Dentistry, Matsumoto Dental University, Nagano, Japan (Y.O.); and Department of Biological Sciences, Northern Arizona University, Flagstaff (S.S.J.).
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Best
authors.affiliation: From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (Y.O., S.S.J., S.A.B., J.G.E., B.D.L., Q.F.); Departments of Internal Medicine (Y.O., S.S.J., S.A.B., B.A.-H., W.V., B.D.L., Q.F.) and Anesthesiology and Pain (J.M.H.), UT Southwestern Medical Center, Dallas, TX; Department of Special Care Dentistry, Matsumoto Dental University, Nagano, Japan (Y.O.); and Department of Biological Sciences, Northern Arizona University, Flagstaff (S.S.J.).
authors.forename: Jeffrey G
authors.initials: JG
authors.lastname: Edwards
authors.affiliation: From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (Y.O., S.S.J., S.A.B., J.G.E., B.D.L., Q.F.); Departments of Internal Medicine (Y.O., S.S.J., S.A.B., B.A.-H., W.V., B.D.L., Q.F.) and Anesthesiology and Pain (J.M.H.), UT Southwestern Medical Center, Dallas, TX; Department of Special Care Dentistry, Matsumoto Dental University, Nagano, Japan (Y.O.); and Department of Biological Sciences, Northern Arizona University, Flagstaff (S.S.J.).
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Hendrix
authors.affiliation: From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (Y.O., S.S.J., S.A.B., J.G.E., B.D.L., Q.F.); Departments of Internal Medicine (Y.O., S.S.J., S.A.B., B.A.-H., W.V., B.D.L., Q.F.) and Anesthesiology and Pain (J.M.H.), UT Southwestern Medical Center, Dallas, TX; Department of Special Care Dentistry, Matsumoto Dental University, Nagano, Japan (Y.O.); and Department of Biological Sciences, Northern Arizona University, Flagstaff (S.S.J.).
authors.forename: Beverley
authors.initials: B
authors.lastname: Adams-Huet
authors.affiliation: From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (Y.O., S.S.J., S.A.B., J.G.E., B.D.L., Q.F.); Departments of Internal Medicine (Y.O., S.S.J., S.A.B., B.A.-H., W.V., B.D.L., Q.F.) and Anesthesiology and Pain (J.M.H.), UT Southwestern Medical Center, Dallas, TX; Department of Special Care Dentistry, Matsumoto Dental University, Nagano, Japan (Y.O.); and Department of Biological Sciences, Northern Arizona University, Flagstaff (S.S.J.).
authors.forename: Wanpen
authors.initials: W
authors.lastname: Vongpatanasin
authors.affiliation: From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (Y.O., S.S.J., S.A.B., J.G.E., B.D.L., Q.F.); Departments of Internal Medicine (Y.O., S.S.J., S.A.B., B.A.-H., W.V., B.D.L., Q.F.) and Anesthesiology and Pain (J.M.H.), UT Southwestern Medical Center, Dallas, TX; Department of Special Care Dentistry, Matsumoto Dental University, Nagano, Japan (Y.O.); and Department of Biological Sciences, Northern Arizona University, Flagstaff (S.S.J.).
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Levine
authors.affiliation: From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (Y.O., S.S.J., S.A.B., J.G.E., B.D.L., Q.F.); Departments of Internal Medicine (Y.O., S.S.J., S.A.B., B.A.-H., W.V., B.D.L., Q.F.) and Anesthesiology and Pain (J.M.H.), UT Southwestern Medical Center, Dallas, TX; Department of Special Care Dentistry, Matsumoto Dental University, Nagano, Japan (Y.O.); and Department of Biological Sciences, Northern Arizona University, Flagstaff (S.S.J.). QiFu@TexasHealth.org.
authors.forename: Qi
authors.initials: Q
authors.lastname: Fu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology; D000704:Analysis of Variance; D044383:Black People / Q000706:statistics & numerical data*; D001795:Blood Pressure Determination / Q000379:methods; D002302:Cardiac Output / Q000502:physiology; D016009:Chi-Square Distribution; D015331:Cohort Studies; D003080:Cold Temperature; D003955:Diagnostic Tests, Routine / Q000379:methods; D004562:Electrocardiography / Q000379:methods; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000208:ethnology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D018709:Statistics, Nonparametric; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D014655:Vascular Resistance / Q000502:physiology; D014661:Vasoconstriction / Q000502:physiology; D044465:White People / Q000706:statistics & numerical data*
keywords: aging; blood pressure; cardiac output; heart rate; hypertension