Laboratory Stress Reactivity and Ambulatory Blood Pressure Variability

2.50
Hdl Handle:
http://hdl.handle.net/10755/150407
Type:
Presentation
Title:
Laboratory Stress Reactivity and Ambulatory Blood Pressure Variability
Abstract:
Laboratory Stress Reactivity and Ambulatory Blood Pressure Variability
Conference Sponsor:Sigma Theta Tau International
Conference Year:2001
Conference Date:November 10 - 14, 2001
Author:Yucha, Carolyn, PhD
P.I. Institution Name:University of Florida
Title:Associate Professor
Objective: To determine whether laboratory stress reactivity and recovery can predict ambulatory blood pressure (ABP) variability. Design: Cross-Sectional design. Sample: To date, 8 subjects (2 male, 6 female), aged 34-57 years, with stages 1 or 2 essential hypertension (systolic blood pressure between 140 & 180 and diastolic blood pressure between 90 & 110) have been studied. Data collection is ongoing. Setting: Biofeedback laboratory. Variables: The laboratory stress protocol consisted of a 5-min adaptation period, a 3-min baseline period, a 6-min stress period using the Stroop Color Word Test (SCWT), and a 3-min recovery period. The SCWT consists of a color name reading task, a color naming task and an interference task and has been utilized in laboratory studies of reactivity. Dependent variables include continuous non-invasive blood pressure (CNIBP), forearm muscle tension (EMG), heart rate (HR), skin temperature (ST), and skin conductance (SC) during the laboratory stress protocol. Measures of reactivity were calculated as the difference between the stress level during the SCWT and the resting baseline. Measures of recovery were calculated as the difference between the stress level and the recovery level. The above variables were compared with ABP variability, defined as the standard deviation of the BP measured every 30-60 minutes over 24 hours. Measures: CNIBP was measured using a Tonometric Patient Monitor (Colin Medical Instruments Corp, San Antonio, TX). EMG, HR, ST, and SC were measured using the Procomp+/Multitrace Biofeedback Instrument (Thought Technology LTD, West Chazy, N.Y.). Ambulatory blood pressure and heart rate were recorded using the Spacelabs ABPM (Model 90207), Spacelabs Medical Inc., Redmond, WA. Findings: Correlational analyses were performed. HR during the lab stress period was significantly associated with ambulatory SBP during waking hours (r = 0.87, p = 0.0116). SBP during lab stress, EMG during lab stress, SBP lab reactivity, and SBP lab recovery predicted ambulatory daytime SBP variability with an R-square for the regression equation of 0.998 (p = 0.0035). Conclusions: Ninety-nine percent of the variance in ambulatory daytime SBP variability is accounted for by the independent variables in this regression model, with SBP during lab stress having the most profound contribution to the regression model. Implications: Exaggerated cardiovascular responses to stress may contribute to the initiation and maintenance of essential hypertension. An important question with regard to reactivity is: Do those people who show exaggerated responses to laboratory stressors also show large responses to stress in the natural environment during normal daily activities? This research shows that those with high EMG and SBP during lab stress, high SBP lab reactivity, and low SBP lab recovery have greater BP variability over 24 hours.
Repository Posting Date:
26-Oct-2011
Date of Publication:
10-Nov-2001
Sponsors:
Sigma Theta Tau International

Full metadata record

DC FieldValue Language
dc.typePresentationen_GB
dc.titleLaboratory Stress Reactivity and Ambulatory Blood Pressure Variabilityen_GB
dc.identifier.urihttp://hdl.handle.net/10755/150407-
dc.description.abstract<table><tr><td colspan="2" class="item-title">Laboratory Stress Reactivity and Ambulatory Blood Pressure Variability</td></tr><tr class="item-sponsor"><td class="label">Conference Sponsor:</td><td class="value">Sigma Theta Tau International</td></tr><tr class="item-year"><td class="label">Conference Year:</td><td class="value">2001</td></tr><tr class="item-conference-date"><td class="label">Conference Date:</td><td class="value">November 10 - 14, 2001</td></tr><tr class="item-author"><td class="label">Author:</td><td class="value">Yucha, Carolyn, PhD</td></tr><tr class="item-institute"><td class="label">P.I. Institution Name:</td><td class="value">University of Florida</td></tr><tr class="item-author-title"><td class="label">Title:</td><td class="value">Associate Professor</td></tr><tr class="item-email"><td class="label">Email:</td><td class="value">yuchacb@nursing.ufl.edu</td></tr><tr><td colspan="2" class="item-abstract">Objective: To determine whether laboratory stress reactivity and recovery can predict ambulatory blood pressure (ABP) variability. Design: Cross-Sectional design. Sample: To date, 8 subjects (2 male, 6 female), aged 34-57 years, with stages 1 or 2 essential hypertension (systolic blood pressure between 140 &amp; 180 and diastolic blood pressure between 90 &amp; 110) have been studied. Data collection is ongoing. Setting: Biofeedback laboratory. Variables: The laboratory stress protocol consisted of a 5-min adaptation period, a 3-min baseline period, a 6-min stress period using the Stroop Color Word Test (SCWT), and a 3-min recovery period. The SCWT consists of a color name reading task, a color naming task and an interference task and has been utilized in laboratory studies of reactivity. Dependent variables include continuous non-invasive blood pressure (CNIBP), forearm muscle tension (EMG), heart rate (HR), skin temperature (ST), and skin conductance (SC) during the laboratory stress protocol. Measures of reactivity were calculated as the difference between the stress level during the SCWT and the resting baseline. Measures of recovery were calculated as the difference between the stress level and the recovery level. The above variables were compared with ABP variability, defined as the standard deviation of the BP measured every 30-60 minutes over 24 hours. Measures: CNIBP was measured using a Tonometric Patient Monitor (Colin Medical Instruments Corp, San Antonio, TX). EMG, HR, ST, and SC were measured using the Procomp+/Multitrace Biofeedback Instrument (Thought Technology LTD, West Chazy, N.Y.). Ambulatory blood pressure and heart rate were recorded using the Spacelabs ABPM (Model 90207), Spacelabs Medical Inc., Redmond, WA. Findings: Correlational analyses were performed. HR during the lab stress period was significantly associated with ambulatory SBP during waking hours (r = 0.87, p = 0.0116). SBP during lab stress, EMG during lab stress, SBP lab reactivity, and SBP lab recovery predicted ambulatory daytime SBP variability with an R-square for the regression equation of 0.998 (p = 0.0035). Conclusions: Ninety-nine percent of the variance in ambulatory daytime SBP variability is accounted for by the independent variables in this regression model, with SBP during lab stress having the most profound contribution to the regression model. Implications: Exaggerated cardiovascular responses to stress may contribute to the initiation and maintenance of essential hypertension. An important question with regard to reactivity is: Do those people who show exaggerated responses to laboratory stressors also show large responses to stress in the natural environment during normal daily activities? This research shows that those with high EMG and SBP during lab stress, high SBP lab reactivity, and low SBP lab recovery have greater BP variability over 24 hours.</td></tr></table>en_GB
dc.date.available2011-10-26T10:23:44Z-
dc.date.issued2001-11-10en_GB
dc.date.accessioned2011-10-26T10:23:44Z-
dc.description.sponsorshipSigma Theta Tau Internationalen_GB
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