Kristen Salomon

Cardiovascular Reactivity to Stress Predicts Future Blood Pressure in Adolescence

Objective This study evaluated the prospective relationship between cardiovascular reactivity to psychological stress and increases in resting blood pressure across a 3-year period among a multiethnic pediatric sample (N = 149). Methods Systolic and diastolic blood pressure; EKG heart rate, pre-ejection period, and mean successive difference of R to R intervals; and impedance-derived measures of cardiac output, stroke volume, and total peripheral resistance were collected during performance of four tasks that elicited different hemodynamic response patterns. Changes from baseline to each task were standardized and averaged to form eight composite scores. Analyses adjusted for time 1 baseline blood pressure and age, body mass index at baseline and change to follow-up, and duration of follow-up. Results Rises in SBP over the follow-up period were independently predicted by SBP (&bgr; = 0.161, p = .009), DBP (&bgr; = 0.132, p = .02), and CO (&bgr; = 0.144, p = .02) composite measures of reactivity. Rises in DBP over the follow-up period were predicted by DBP (&bgr; = 0.292, p = .003, respectively), and MSD (&bgr; = −0.176, p < .03) composite measures of reactivity. TPR reactivity was not related prospectively to blood pressure rises. Conclusions This study adds to the pediatric literature documenting an association between cardiovascular reactivity to stress and subsequent risk for hypertension. It is the first to show that impedance-derived measures of myocardial function during stress are related to future blood pressure levels.

Major depressive disorder is associated with attenuated cardiovascular reactivity and impaired recovery among those free of cardiovascular disease.

OBJECTIVE To examine cardiovascular reactivity and recovery to laboratory stress among a naturalistic sample of individuals diagnosed with major depressive disorder (MDD) and healthy control participants. Prospective evidence suggests that MDD confers risk for cardiovascular disease equal to or greater than the risk associated with depressed mood. Enhanced cardiovascular reactivity has been proposed as a mechanism explaining increased risk, but data are inconsistent as to whether depressed individuals exhibit enhanced or attenuated reactivity. Further, few studies have examined appraisal and recovery differences. DESIGN Participants diagnosed with MDD (N = 25) and healthy control participants (N = 25) engaged in a cardiovascular reactivity protocol including 2 tasks, each followed by a brief recovery period. MAIN OUTCOME MEASURES Blood pressure, heart rate, pre-ejection period, cardiac output and total peripheral resistance were assessed. Appraisals of tasks were assessed prior to each task. RESULTS Depressed participants exhibited significantly less systolic blood pressure, heart rate, and cardiac output reactivity during speech, less heart rate reactivity during mirror tracing, and less heart rate recovery after speech and mirror tracing than controls. Depressed participants appraised the tasks as more demanding, threatening, and stressful and reported being less able to cope than controls. Appraisals were related to heart rate reactivity, but appraisals did not mediate the relationship between depression group and reactivity. CONCLUSION Impaired recovery rather than exaggerated cardiovascular reactivity may partially explain the increased prospective cardiovascular disease risk in depressed individuals.

Patterns of sympathetic and parasympathetic reactivity in a sample of children and adolescents

We hypothesized that patterns of sympathetic and parasympathetic reactivity observed in adults would be apparent in a sample of children and adolescents and that these patterns would be consistent across tasks. We explored the relationship between these patterns and psychosocial risk factors for cardiovascular disease. We measured preejection period (PEP) and an index of respiratory sinus arrhythmia (mean successive difference [MSD] statistic) during three reactivity tasks. We classified participants into four groups based on increases or decreases in PEP and MSD. Ninety percent of the sample exhibited the same pattern during at least two of the tasks. PEP and MSD demonstrated consistency, suggesting individual response stereotypy. Exhibiting a consistent pattern of decreased PEP and increased MSD was associated with less child- and parent-reported family conflict. These results are discussed in the context of vagal regulation of environmental demands.

The Robust Nature of the Biopsychosocial Model Challenge and Threat: A Reply to Wright and Kirby

This article responds to Wright and Kirbys (this issue) critique of our biopsychosocial (BPS) analysis of challenge and threat motivation. We counter their arguments by reviewing the current state of our theory as well as supporting data, then turn to their specific criticisms. We believe that Wright and Kirby failed to accurately represent the corpus of our work, including both our theoretical model and its supporting data. They critiqued our model from a contextual, rational-economic perspective that ignores the complexity and subjectivity of person-person and person-environmental interactions as well as nonconscious influences. Finally, they provided criticisms regarding possible underspecificity of antecedent components of our model that do not so much indicate theoretical flaws as provide important and interesting questions for future research. We conclude by affirming that our BPS model of challenge and threat is an evolving, generative theory directed toward understanding the complexity of personality and social psychological factors underlying challenge and threat states.

Hostility Predicts Metabolic Syndrome Risk Factors in Children and Adolescents

The authors tested in 134 African American and European American children whether hostility measured at study entry predicted the metabolic syndrome risk factors an average of 3 years later. Hostility was measured with the Cook-Medley Hostility Scale (W. W. Cook & D. M. Medley, 1954) and with ratings of Potential for Hostility from interview responses. Metabolic syndrome was based on having at least 2 of the following risk factors above the 75th percentile of scores for their age, race, and gender group: body mass index, insulin resistance index, ratio of triglycerides to high-density lipoprotein cholesterol, and mean arterial blood pressure. Children who exhibited high hostility scores at baseline were likely to exhibit the metabolic syndrome at the follow-up. The results highlight the potential importance of early prevention and intervention of behavioral risk factors for cardiovascular disease.

Unfair treatment, discrimination, and ambulatory blood pressure in black and white adolescents

The authors tested the hypotheses that unfair treatment and its attribution to race, physical appearance, and peer group were related to elevated ambulatory blood pressure (ABP). During 2 school days, 207 Black and White adolescents wore an ABP monitor and answered questions about mood, posture, location, and activity level at the time of the ABP assessment. At a separate session, in-clinic resting blood pressure and perceptions of unfair treatment were measured. Multilevel mixed models showed that unfair treatment and its attribution to race were not associated with ABP. However, adolescents who indicated that the primary reason for unfair treatment was their physical appearance had elevated ABP. Feeling unfairly treated because of physical appearance may impact blood pressure uniquely during the adolescent transition.

A greater reduction in high-frequency heart rate variability to a psychological stressor is associated with subclinical coronary and aortic calcification in postmenopausal women.

Objective: Reduced cardiac parasympathetic activity, as indicated by a reduced level of clinic or ambulatory high-frequency heart rate variability (HF-HRV), is associated with an increased risk for atherosclerosis and coronary artery disease. We tested whether the reduction in HF-HRV to a psychological stressor relative to a baseline level is also associated with subclinical coronary or aortic atherosclerosis, as assessed by calcification in these vascular regions. Method: Spectral estimates of 0.15 to 0.40 Hz HF-HRV were obtained from 94 postmenopausal women (61–69 years) who engaged in a 3-minute speech-preparation stressor after a 6-minute resting baseline. A median of 282 days later, electron beam tomography (EBT) was used to measure the extent of coronary and aortic calcification. Results: In univariate analyses, a greater reduction in HF-HRV from baseline to speech preparation was associated with having more extensive calcification in the coronary arteries (rho = −0.29, p = .03) and in the aorta (rho = −0.22, p = .06). In multivariate analyses that controlled for age, education level, smoking status, hormone therapy use, fasting glucose, high-density lipoproteins, baseline HF-HRV, and the stressor-induced change in respiration rate, a greater stressor-induced reduction in HF-HRV was associated with more calcification in the coronary arteries (B = −1.21, p < .05), and it was marginally associated with more calcification in the aorta (B = −0.92, p = .09). Conclusion: In postmenopausal women, a greater reduction in cardiac parasympathetic activity to a psychological stressor from baseline may be an independent correlate of subclinical atherosclerosis, particularly in the coronary arteries. ANOVA = analysis of variance; BMI = body mass index; BPM = beats per minute; DBP = diastolic blood pressure; EBT = electron beam tomography; HDL = high-density lipoproteins; HF-HRV = high-frequency heart rate variability; HT = hormone therapy; IBI = interbeat interval; LDL = low-density lipoproteins; ln = natural log; SBP = systolic blood pressure.

Chronic Life Stress, Cardiovascular Reactivity, and Subclinical Cardiovascular Disease in Adolescents

Objective: To examine cross-sectional and longitudinal relationships between chronic life stress, cardiovascular reactivity, and a marker of subclinical cardiovascular disease in a multiethnic sample of adolescents. Methods: Participants were 158 healthy adolescents who completed self-report measures of chronic negative life stress as well as assessments of heart rate and blood pressure reactivity to acute laboratory stressors at two time points, approximately 3.3 years apart. At Time 2, intima-media thickness (IMT), a measure of subclinical atherosclerosis, was also measured. Results: In hierarchical regression models adjusting for demographic variables and body mass index, chronic negative life stress at Time 2 was concurrently associated with greater diastolic blood pressure (DBP) reactivity to stress (&bgr; = 0.18, p = .016), but neither chronic stress nor cardiovascular reactivity was associated concurrently with IMT. Increasing life stress from Time 1 to Time 2 was accompanied by increasing cardiovascular reactivity (&bgr; = 0.14–0.20, p < .05), and increasing DBP reactivity over time was also associated with IMT (&bgr; = 0.24, p = .03), although increasing chronic life stress was not directly related to IMT. Conclusions: Adolescents exposed to chronic, negative stressors that worsen over time may show heightened cardiovascular reactivity that puts them at risk for subclinical atherosclerosis. BMI = body mass index; CVD = cardiovascular disease; DBP = diastolic blood pressure; ECG = electrocardiogram; HR = heart rate; IMT = intima media thickness; SBP = systolic blood pressure.

Central adiposity is associated with cardiovascular reactivity to stress in adolescents

The current study examined the association between central adiposity, measured by waist circumference, and cardiovascular reactivity to stress among 106 White and 105 Black adolescents, approximately 50% of whom were girls. Participants engaged in 4 laboratory tasks while cardiovascular reactivity measures were taken. Independent of body mass index, race, and gender, participants with a greater waist circumference exhibited greater systolic blood pressure reactivity and diastolic blood pressure reactivity (boys only). Race did not affect the results. Results from the present study suggest that central adiposity is associated with blood pressure reactivity early in life, especially in adolescent boys.

Respiratory sinus arrhythmia during stress predicts resting respiratory sinus arrhythmia 3 years later in a pediatric sample.

The author examined whether respiratory sinus arrhythmia (RSA) responses to stress predicted resting RSA approximately 3 years later in children and adolescents. A total of 149 children and adolescents (49% girls and women, 44% African Americans) participated in 2 laboratory protocols approximately 3 years apart. RSA reactivity during tasks was consistent within participants across tasks during each session. Resting RSA at Visit 1 explained 17% of the variance in resting RSA at Visit 2 when body mass index, duration between visits, race, gender, and age were controlled for. Visit 1 RSA reactivity explained an additional 5% of the variance in resting RSA at Visit 2. The positive relationship between Visit 1 reactivity and Visit 2 resting levels suggests that larger decreases in RSA during stress predicted lower resting RSA. Conversely, increases in RSA during stress were associated with higher resting RSA an average of 3 years later.