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Baroreflex sensitivity during static exercise in individuals with Down Syndrome.

Kevin S Heffernan·Tracy Baynard·Styliani Goulopoulou·Ifigenia Giannopoulou·Scott R Collier·Arturo Figueroa·Bo Fernhall
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Abstract

INTRODUCTION: Individuals with Down syndrome (DS) have altered heart rate (HR) and blood pressure (BP) responses to orthostatic challenges and isometric handgrip (IHG) exercise, suggesting possible alteration in baroreflex sensitivity. PURPOSE: This study investigated baroreflex sensitivity (BRS) as a potential mechanism contributing to chronotropic incompetence during IHG in persons with DS. METHODS: Heart rate and BP were continually recorded in 12 individuals with DS and 10 controls, at rest and during 2 min of IHG, at 30% of maximal voluntary contraction (MVC). Spontaneous BRS was derived via the sequence method. RESULTS: No differences were seen in HR at rest between groups. Systolic BP (SBP) was significantly lower in the DS group at rest (106.1+/- 2.9 vs 116.5+/- 3.9 mm Hg, P < 0.05) and during IHG (123.9+/- 4.6 vs 150.1+/- 5.3 mm Hg, P<0.001). A significant group-by-task interaction was found for both change in HR and change in SBP with IHG, because of an attenuated HR and SBP response to IHG in participants with DS (P<0.05). When controlling for resting SBP, the DS group had a lower BRS at rest (16.0+/-1.7 vs 21.2+/-4.2 ms.mm Hg, P< 0.05) and during IHG (7.8 +/-1.0 vs 12.1+/- 2.6 ms.mm Hg, P< 0.05). CONCLUSIONS: Individuals with DS have lower BRS at rest and during IHG than controls and this may be related to their attenuated HR response during perturbation.

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AdultArrhythmias, CardiacBaroreflexBlood PressureCase-Control StudiesDown SyndromeExerciseFemaleHeart RateHumansMalePressoreceptorsSystoleTime FactorsJournal ArticleResearch Support, Non-U.S. Gov't

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Kevin S Heffernan, Tracy Baynard, Styliani Goulopoulou, Ifigenia Giannopoulou, Scott R Collier, Arturo Figueroa, Bo Fernhall. 2005. Baroreflex sensitivity during static exercise in individuals with Down Syndrome.. https://doi.org/10.1249/01.mss.0000179217.59831.41

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