Stress-induced cardiac autonomic reactivity and preclinical atherosclerosis: does arterial elasticity modify the association?

The effect of acute mental stress on atherosclerosis can be estimated using arterial elasticity measured by carotid artery distensibility (Cdist). We examined the interactive effect of acute stress-induced cardiac reactivity and Cdist to preclinical atherosclerosis assessed by carotid intima-media thickness (IMT) in 58 healthy adults aged 24-39 years participated in the epidemiological Young Finns Study. Cdist and IMT were measured ultrasonographically. Impedance electrocardiography was used to measure acute mental stress-induced cardiac autonomic responses: heart rate (HR), respiratory sinus arrhythmia and pre-ejection period after the mental arithmetic and the public speaking tasks. Interactions between HR reactivity and Cdist in relation to preclinical atherosclerosis were found. The results imply that elevated HR reactivity to acute mental stress is related to less atherosclerosis among healthy participants with higher arterial elasticity. Possibly, increased cardiac reactivity in response to challenging tasks is an adaptive reaction related to better cardiovascular health.

Interleukin-6 gene polymorphism, chronic stress and atherosclerosis: interleukin-6-174G>C polymorphism, chronic stress and risk of early atherosclerosis in the Cardiovascular Risk in Young Finns Study.

OBJECTIVE: Interleukin-6 protein has been suggested as a mediator connecting chronic stress and cardiovascular diseases. We investigated whether the functional G174C polymorphism (rs1800795) of interleukin-6 gene is associated with vital exhaustion, a measure of chronic stress, or with preclinical atherosclerosis. METHODS: Associations between the interleukin-6-174G>C polymorphism, preclinical atherosclerosis, and vital exhaustion were examined in 1673 women and men aged 24-39years participating in the Cardiovascular Risk in Young Finns study. Vital exhaustion was measured using Maastricht Questionnaire. Preclinical atherosclerosis was assessed by carotid intima-media thickness using ultrasound techniques. DNA was genotyped for the interleukin-6-174G>C polymorphism (rs1800795). RESULTS: The GG genotype of the interleukin-6-174G>C polymorphism was associated with higher vital exhaustion. Moreover, higher vital exhaustion was associated with greater intima-media thickness in men carrying G alleles, adjusted for cardiovascular risk factors. CONCLUSION: Our findings support a role for the interleukin-6-174G>C polymorphism in increased risk of atherosclerosis in individuals with chronic stress. In addition, individuals carrying the G allele of the interleukin-6-174G>C polymorphism may be more prone to adverse effects of psychosocial stress.

Sex differences in the combined effect of chronic stress with impaired vascular endothelium functioning and the development of early atherosclerosis: the Cardiovascular Risk in Young Finns study.

BACKGROUND: The syndrome of vital exhaustion (VE), characterized by fatigue and irritability, may contribute to an increased risk of atherosclerosis. The aim of the study was to explore sex differences in the interactions of VE with endothelial dysfunction and VE with reduced carotid elasticity, the important contributors to the development of early atherosclerosis, on preclinical atherosclerosis. METHODS: The participants were 1002 women and 719 men aged 24-39 examined in the Cardiovascular Risk in Young Finns study. Vital exhaustion was measured using the Maastricht Questionnaire. Preclinical atherosclerosis was assessed by carotid intima-media thickness (IMT), endothelial function was measured by brachial flow-mediated dilatation (FMD), and arterial elasticity by carotid artery compliance (CAC) using ultrasound techniques. RESULTS: We found a significant CAC x VE interaction for IMT only for the men. Our results imply that high VE level significantly related to high IMT levels among the men with low CAC, but not among the women with low CAC or among the women or men with high CAC. No significant FMD x VE interactions for IMT for the women or men were found. CONCLUSIONS: High VE may exert an effect on IMT for men with impaired arterial elasticity. The results suggest that high vitally exhausted men with reduced arterial elasticity are at increased risk of atherosclerosis in early life and imply men's decreased stress coping in relation to stressful psychological coronary risk factors.

Early atherosclerosis and cardiac autonomic responses to mental stress: a population-based study of the moderating influence of impaired endothelial function.

BACKGROUND: Acute mental stress may contribute to the cardiovascular disease progression via autonomic nervous system controlled negative effects on the endothelium. The joint effects of stress-induced sympathetic or parasympathetic activity and endothelial function on atherosclerosis development have not been investigated. The present study aims to examine the interactive effect of acute mental stress-induced cardiac reactivity/recovery and endothelial function on the prevalence of carotid atherosclerosis. METHODS: Participants were 81 healthy young adults aged 24-39 years. Preclinical atherosclerosis was assessed by carotid intima-media thickness (IMT) and endothelial function was measured as flow-mediated dilatation (FMD) using ultrasound techniques. We also measured heart rate, respiratory sinus arrhythmia (RSA), and pre-ejection period (PEP) in response to the mental arithmetic and speech tasks. RESULTS: We found a significant interaction of FMD and cardiac RSA recovery for IMT (p = 0.037), and a significant interaction of FMD and PEP recovery for IMT (p = 0.006). Among participants with low FMD, slower PEP recovery was related to higher IMT. Among individuals with high FMD, slow RSA recovery predicted higher IMT. No significant interactions of FMD and cardiac reactivity for IMT were found. CONCLUSIONS: Cardiac recovery plays a role in atherosclerosis development in persons with high and low FMD. The role of sympathetically mediated cardiac activity seems to be more important in those with impaired FMD, and parasympathetically mediated in those with relatively high FMD. The development of endothelial dysfunction may be one possible mechanism linking slow cardiac recovery and atherosclerosis via autonomic nervous system mediated effect.

Chronic stress and the development of early atherosclerosis: moderating effect of endothelial dysfunction and impaired arterial elasticity.

This study aims to explore the interactive effect of vital exhaustion (VE) and endothelial dysfunction on preclinical atherosclerosis, assessed by carotid intima-media thickness (IMT). Furthermore, interaction between VE and carotid elasticity is examined. Participants were 1,596 young healthy adults from the Cardiovascular Risk in Young Finns study. Endothelial dysfunction was measured by brachial flow-mediated dilatation (FMD), and carotid elasticity by carotid artery compliance (CAC). Significant interactions between FMD and VE, and between CAC and VE, for IMT were found in participants with the very lowest FMD and CAC. Thus, VE may be harmful if the endothelium is not working properly.

Interactive effect of long-term mental stress and cardiac stress reactivity on carotid intima-media thickness: the Cardiovascular Risk in Young Finns study.

The present study examined the interaction between vital exhaustion and cardiac reactivity and recovery on preclinical atherosclerosis assessed by carotid intima-media thickness (IMT) in young men and women. We measured heart rate (HR), respiratory sinus arrhythmia (RSA), and pre-ejection period (PEP) in response to mental arithmetic and speech tasks. Vital exhaustion and carotid IMT were also measured. Significant associations were observed for men aged 28-37 years, but not for men aged 22-25 years, nor for women in these age groups. It was shown that, among highly exhausted men in the older age group, lower HR reactivity was related to greater IMT. Our results also imply that, among non-exhausted men in this age group, slow HR and RSA recovery after acute stress predicted higher IMT. These results suggest that long-term stress as assessed by vital exhaustion is a risk only if it has resulted in ineffective cardiac stress reactivity. Autonomic imbalance resulting from chronic stress may be the common mechanism linking vital exhaustion and cardiac responsiveness to an increased risk of atherosclerosis.