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Vascular Responses to Hypovolemic Pressure Challenge in Individuals with Down Syndrome
Author(s) -
Wee Sang Ouk,
Rosenberg Alexander J.,
Kanokwan Bunsawat,
Griffith Garett,
Baynard Tracy,
Fernhall Bo
Publication year - 2016
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.30.1_supplement.763.9
Subject(s) - arterial stiffness , medicine , cardiology , blood pressure , hemodynamics
Aging is associated with altered vascular and autonomic function. Individuals with Down Syndrome (DS), experience premature aging, and exhibit autonomic dysfunction. Moreover, limited evidence suggests a link between autonomic dysfunction, arterial stiffness and vascular responsiveness to sympathoexcitation in individuals with DS, but this still remains unclear. Purpose To examine the differences in vascular responsiveness, specifically changes in arterial elastic properties, during sympathoexcitation using lower body negative pressure (LBNP) in individuals with and without DS. Methods Twenty four volunteers (DS=12, 24 yrs; Control=12, 23 yrs) participated in this study. Changes in vascular indices (β‐stiffness and elastic modulus (Ep) by carotid ultrasonography) were measured before, during and after LBNP (−20 mmHg). Results Individuals with DS showed lower VO 2peak (25.0 ± 1.7 vs. 42.5 ± 1.7 ml/kg/min for DS and controls, respectively) and higher BMI (23.1± 1.7 vs. 31.9 ± 1.8 kg/m 2 for controls and DS, respectively) ( p <0.05). However, there was no group differences and no changes with LBNP in vascular or hemodynamics indices. Conclusions Our results demonstrated a lack of vascular responsiveness to sympathoexcitation in both individuals with and without DS. These findings may have been influenced by a lack of statistical power. Hemodynamics and Arterial StiffnessDS (N = 12) Control (N = 12)Baseline LBNP (‐20mm Hg) Recovery Baseline LBNP (‐20mm Hg) RecoveryCarotid SBP (mmHg) 132 ± 6 129 ± 5 131 ± 5 125 ± 6 119 ± 5 124 ± 4Carotid DBP (mmHg) 73 ± 3 74 ± 3 71 ± 3 75±3 74 ± 2 76 ± 3Carotid MAP (mmHg) 94 ± 4 94 ± 3 93 ± 3 96 ± 3 93 ± 3 97 ± 3β‐stiffness 5.44 ± 0.59 5.48 ± 0.37 5.78 ± 0.60 6.02 ± 0.56 6.59 ± 0.35 5.99 ± 0.57Ep 71.22 ± 7.65 71.72 ± 4.57 72.94 ± 6.88 78.70 ± 7.26 82.80 ± 4.34 77.75 ± 6.52Mean ± SEM, Significance level, p <0.05