The relationship between carotid blood pressure reactivity to mental stress and carotid intima-media thickness

Social isolation and subclinical vascular pathways to cerebrovascular disease

Social isolation and lack of social support are risk factors for cardiovascular and cerebrovascular disease (CVD). This study explored the relationship between measures of social support and subclinical measures of CVD risk. 58 healthy adults ages 18 to 85 years participated in this study. The Berkman-Syme Social Network Inventory (SNI) was used to assess social isolation, with higher scores signifying less isolation. Social support was defined using the 12-Item Interpersonal Support Evaluation List (ISEL-12) with a higher score signifying higher social support. Subclinical CVD measures included carotid-femoral pulse wave velocity (cfPWV), carotid beta-stiffness index, and middle cerebral artery (MCA) pulsatility index. Path analysis models for both the SNI and ISEL appraisal domain predicting cfPWV and cerebrovascular pulsatility fit the data well. Path analyses showed significant direct paths from the SNI (β = -.363, t = -2.91) and ISEL appraisal domain (β = -.264, t = -2.05) to cfPWV. From cfPWV, both models revealed significant direct paths to carotid stiffness (β = .488, t = 4.18) to carotid pulse pressure (β = .311, t = 2.45) to MCA pulsatility (β = .527, t = 4.64). Social isolation and appraisal of social support are related to unfavorably higher aortic stiffness, with subsequent detrimental effects on cerebrovascular hemodynamic pulsatility.

Is stressor-evoked cardiovascular reactivity a pathway linking positive and negative emotionality to preclinical cardiovascular disease risk?

Stressor-evoked cardiovascular reactivity, trait positive emotionality, and negative emotionality are all associated with cardiovascular disease. It is unknown, however, whether cardiovascular reactivity may constitute a pathway by which trait positive or negative emotionality relates to disease risk. Accordingly, this study modeled the cross-sectional relationships between trait positive and negative emotionality, stressor-evoked cardiovascular reactivity, and severity of a subclinical vascular marker of cardiovascular risk, carotid artery intima-media thickness (CA-IMT). The sample consisted of healthy, midlife adults free from clinical cardiovascular disease (N = 286; ages 30-54; 50% female). Trait positive and negative emotionality were measured by three questionnaires. Heart rate and blood pressure reactivity were assessed across three stressor tasks. CA-IMT was assessed by ultrasonography. Latent factors of positive and negative emotionality, blood pressure reactivity, heart rate reactivity, and CA-IMT were created using structural equation modeling. Greater negative emotionality was marginally associated with more CA-IMT (β = .21; p = .049), but lower blood pressure reactivity (β = -.19; p = .03). However, heightened blood pressure (β = .21; p = .03), but not heart rate reactivity (β = -.05; p = .75), associated with greater CA-IMT. Positive emotionality was uncorrelated with cardiovascular reactivity (blood pressure: β = -.04; p = .61; heart rate: β = .16; p = .11) and CA-IMT (β = .16; p = .07). Although trait negative emotionality associates with a known marker of cardiovascular disease risk, independent of positive emotionality, it is unlikely to occur via a stressor-evoked cardiovascular reactivity pathway.

Developmental origins of cardiovascular disease: Impact of early life stress in humans and rodents

The Developmental Origins of Health and Disease (DOHaD) hypothesizes that environmental insults during childhood programs the individual to develop chronic disease in adulthood. Emerging epidemiological data strongly supports that early life stress (ELS) given by the exposure to adverse childhood experiences is regarded as an independent risk factor capable of predicting future risk of cardiovascular disease. Experimental animal models utilizing chronic behavioral stress during postnatal life, specifically maternal separation (MatSep) provides a suitable tool to elucidate molecular mechanisms by which ELS increases the risk to develop cardiovascular disease, including hypertension. The purpose of this review is to highlight current epidemiological studies linking ELS to the development of cardiovascular disease and to discuss the potential molecular mechanisms identified from animal studies. Overall, this review reveals the need for future investigations to further clarify the molecular mechanisms of ELS in order to develop more personalized therapeutics to mitigate the long-term consequences of chronic behavioral stress including cardiovascular and heart disease in adulthood.

Racial Differences in Aortic Stiffness in Children

OBJECTIVE

To investigate racial differences in central blood pressure and vascular structure/function as subclinical markers of atherosclerotic cardiovascular disease in children.

STUDY DESIGN

This cross-sectional study recruited 54 African American children (18 female, 36 male; age 10.5 ± 0.9 years) and 54 white children (27 female, 26 male; age 10.8 ± 0.9 years) from the Syracuse City community as part of the Environmental Exposures and Child Health Outcomes study. Participants underwent blood lipid and vascular testing on 2 separate days. Carotid artery intima-media thickness and aortic stiffness were measured by ultrasonography and carotid-femoral pulse wave velocity, respectively. Blood pressure was assessed at the brachial artery and estimated in the carotid artery using applanation tonometry.

RESULTS

African American children had significantly higher pulse wave velocity (4.8 ± 0.8 m/s) compared with white children (4.2 ± 0.7 m/s; P < .05), which remained significant after adjustment for confounding variables including socioeconomic status. African American children had significantly higher intima-media thickness (African American 0.41 ± 0.06, white 0.39 ± 0.05 mm), and carotid systolic blood pressure (African American 106 ± 11, white 102 ± 8 mm Hg; P < .05) compared with white children, although these racial differences were no longer present after covariate adjustments for height.

CONCLUSIONS

Racial differences in aortic stiffness are present in childhood. Our findings suggest that racial differences in subclinical cardiovascular disease occur earlier than previously recognized.

Relation between exercise central haemodynamic response and resting cardiac structure and function in young healthy men

BACKGROUND

Left ventricular (LV) structure and function are predictors of cardiovascular (CV) morbidity and mortality and are related to resting peripheral haemodynamic load in older adults. The central haemodynamic response to exercise may reveal associations with LV structure and function not detected by traditional peripheral (brachial) measures in a younger population.

PURPOSE

To examine correlations between acute exercise-induced changes in central artery stiffness and wave reflections and measures of resting LV structure and function.

METHODS

Sixteen healthy men (age 26 ± 6 year; BMI 25·3 ± 2·7 kg m^-2 ) had measures of central haemodynamic load measured before/after a 30-s Wingate anaerobic test (WAT). Common carotid artery stiffness and reflected wave intensity were assessed via wave intensity analysis as a regional pulse wave velocity (PWV) and negative area (NA), respectively. Resting LV structure (LV mass) and function [midwall fractional shortening (mFS)] were assessed using M-mode echocardiography in the parasternal short-axis view.

RESULTS

There was a significant association between mFS and WAT-mediated change in carotid systolic BP (r = -0·57, P = 0·011), logNA (r = -0·58, P = 0·009) and PWV (r = -0·44, P = 0·045). There were no significant associations between resting mFS and changes in brachial systolic BP (r = -0·26, P>0·05). There were no associations between resting LV mass and changes in any haemodynamic variable (P>0·05).

CONCLUSION

Exercise-induced increases in central haemodynamic load reveal associations with lower resting LV function in young healthy men undetected by traditional peripheral haemodynamics.

Carotid artery stiffness and hemodynamic pulsatility during cognitive engagement in healthy adults: a pilot investigation

BACKGROUND

The matching of vascular supply to neuronal metabolic demand during cognitive engagement is known as neurovascular coupling (NVC). Arterial stiffness is a prominent determinant of pulsatility in the systemic circulation and may thus indirectly impact NVC. In this pilot investigation, we explored changes in carotid artery stiffness and cerebrovascular hemodynamic pulsatiltiy during cognitive engagement in healthy adults.

METHODS

Twenty-seven adults (age 39 ± 3 years, BMI 24 ± 1 kg/m(2)) underwent Doppler ultrasonography of the common carotid artery (CCA) combined with applanation tonometry to derive (i) CCA elastic modulus (Ep) and β-stiffness index; (ii) CCA flow pulsatility index (PI); (iii) CCA pulse pressure, (iv) CCA augmentation index (AIx). Cerebral PI was assessed using transcranial Doppler at the middle cerebral artery (MCA). All measures were made at rest and during an incongruent Stroop task.

RESULTS

CCA PI was reduced (1.75 ± 0.06 to 1.57 ± 0.06, P < 0.05) while MCA PI was unchanged (0.75 ± 0.02 to 0.75 ± 0.02, P > 0.05) during Stroop. Brachial pulse pressure increased during Stroop (43 ± 1 to 46 ± 1 mm Hg, P < 0.05) while CCA pulse pressure was unchanged (36 ± 1 to 35 ± 1 mm Hg, P > 0.05). Similarly, CCA Ep (54.5 ± 5.5 to 53.8 ± 4.9 kPa, P > 0.05) and β-stiffness index (4.4 ± 0.4 to 4.2 ± 0.3 aU, P > 0.05) were unchanged. CCA AIx increased (1 ± 4 to 13 ± 4%, P < 0.05).

CONCLUSION

Carotid pressure pulsatility is unaltered while carotid flow pulsatility is reduced during cognitive engagement. Carotid artery stiffness does not change suggesting that factors other than the dynamic elastic properties of the CCA buffer cerebrovascular hemodynamic pulsatility during cognitive engagement.