Serum lipids, neuroendocrine, and cardiovascular responses to stress in men and women with mild hypertension

Parasympathetic Response Patterns are Associated with Metabolic Syndrome Among Older Women but Not Men

Background

Little is known about the role of physiological stress responses in metabolic syndrome (MetS).

Purpose

To examine whether patterns of autonomic response to psychological stress are associated with MetS and whether this association is moderated by sex

Methods

1121 men and women (M_age = 65.3 ± 6.77 years) with and without coronary artery disease (CAD) underwent an anger recall stressor task. Heart rate and heart-rate variability (HRV; HF, LF/HF) were assessed. Clusters of participants showing similar patterns of response across baseline, stress, and recovery periods were created using ACECLUS and FASTCLUS in SAS. Logistic regressions included clusters and interaction between clusters and sex as independent variables, controlling for relevant covariates. ANCOVAs were conducted in secondary analyses utilizing a continuous composite representation of MetS.

Results

Men and women showing greater tonic and phasic HR elevations were more likely to meet MetS criteria (OR = 1.45, [95% CI = 1.02–2.07], p = .037). HF-HRV cluster interacted significantly with sex (p < .001) to predict MetS. In women, those with significant parasympathetic withdrawal to stress and poor recovery were more likely to have MetS than women with a more moderate response (OR = 2.56, [95% CI = 1.23–5.41], p = .013). Women who displayed stress-related parasympathetic activation were also at greater risk of MetS (OR = 2.30, [95% CI = 1.30–4.07], p = .004). Results using a continuous measure of MetS were generally consistent with these findings.

Conclusion

Among older participants with CAD or other noncardiovascular disease, hyperreactivity to stress was associated with greater prevalence of MetS, particularly in women. Consistent with emerging literature, women who showed blunting or activation of parasympathetic responses to stress were similarly at greater risk.

Effect of a 30-Month Health-Promoting Program on the Prevalence of Cardiovascular Risk Factors in Patients With First Episode Schizophrenia

BACKGROUND

Lifestyle interventions aimed at reducing cardiovascular risk factors in patients with first-episode schizophrenia (FES) have shown modest efficacy, probably owing to a short observation period and the presumption of linear trajectories of cardiovascular risk factors.

STUDY QUESTION

How prevalent are abnormal cardiovascular values in patients with FES and how do cardiovascular risk factors develop during a 30-month program?

STUDY DESIGN

A 30-month naturalistic longitudinal study of 136 consecutively referred patients with FES from 2 outpatient clinics. The health-promoting program consisted of individual guidance, group sessions, and normal treatment and care.

MEASURES AND OUTCOMES

The prevalence of abnormal cardiovascular risk factors (body mass index, waist circumference (WC), body fat percentage, systolic and diastolic blood pressure, pulse, total cholesterol, high- and low-density lipoproteins, triglycerides, mean glucose, and visceral adiposity index) was estimated at index. The cardiovascular risk factor trajectories were analyzed with longitudinal mixed-effect models.

RESULTS

The patient with FES showed elevated cardiovascular risk factors at index. Thus, 56.8% of the patients were overweight in different grades and 50.4% had increased WC. A total of 81.8% had high level of body fat and hypertension prevalence with only 20% with normal blood pressure. Important changes during the intervention period were that the risk factors weight and WC were increasing the first 581 and 646 days, after which they decreased. Almost all cardiovascular risk factors worsened initially, improving after 1-2 years.

CONCLUSIONS

Patients with FES show increases in cardiovascular risk factors at index. Short observation periods and the presumption of linear trajectories may indicate that the effect of health-promoting programs is ineffective, as the effects are curvilinear and improvements appear only after 1 year. The implication clinically is the importance of a long intervention period regarding lifestyle modifications to ascertain improvement among patients with FES.

Population differences in associations of serotonin transporter promoter polymorphism (5HTTLPR) di- and triallelic genotypes with blood pressure and hypertension prevalence

Based on prior research finding the 5HTTLPR L allele associated with increased cardiovascular reactivity to laboratory stressors and increased risk of myocardial infarction, we hypothesized that the 5HTTLPR L allele will be associated with increased blood pressure (BP) and increased hypertension prevalence in 2 large nationally representative samples in the United States and Singapore.

METHODS

Logistic regression and linear models tested associations between triallelic (L'S', based on rs25531) 5HTTLPR genotypes and hypertension severity and mean systolic and diastolic blood pressure (SBP and DBP) collected during the Wave IV survey of the National Longitudinal Study of Adolescent to Adult Health (Add Health, N=11,815) in 2008-09 and during 2004-07 in 4196 Singaporeans.

RESULTS

In US Whites, L' allele carriers had higher SBP (0.9 mm Hg, 95% CI=0.26-1.56) and greater odds (OR=1.23, 95% CI=1.10-1.38) of more severe hypertension than those with S'S' genotypes. In African Americans, L' carriers had lower mean SBP (-1.27mm Hg, 95% CI=-2.53 to -0.01) and lower odds (OR = 0.78, 95% CI=0.65-0.94) of more severe hypertension than those with the S'S' genotype. In African Americans, those with L'L' genotypes had lower DBP (-1.13mm Hg, 95% CI=-2.09 to -0.16) than S' carriers. In Native Americans, L' carriers had lower SBP (-6.05mm Hg, 95% CI=-9.59 to -2.51) and lower odds of hypertension (OR = 0.34, 95% CI=0.13-0.89) than those with the S'S' genotype. In Asian/Pacific Islanders those carrying the L' allele had lower DBP (-1.77mm Hg, 95% CI=-3.16 to -0.38) and lower odds of hypertension (OR = 0.68, 95% CI=0.48-0.96) than those with S'S'. In the Singapore sample S' carriers had higher SBP (3.02mm Hg, 95% CI=0.54-5.51) and DBP (1.90mm Hg, 95% CI=0.49-3.31) than those with the L'L' genotype.

CONCLUSIONS

These findings suggest that Whites carrying the L' allele, African Americans and Native Americans with the S'S' genotype, and Asians carrying the S' allele will be found to be at higher risk of developing cardiovascular disease and may benefit from preventive measures.

Dysregulation of the autonomic nervous system predicts the development of the metabolic syndrome

CONTEXT

Stress is suggested to lead to metabolic dysregulations as clustered in the metabolic syndrome. Although dysregulation of the autonomic nervous system is found to associate with the metabolic syndrome and its dysregulations, no longitudinal study has been performed to date to examine the predictive value of this stress system in the development of the metabolic syndrome.

OBJECTIVE

We examined whether autonomic nervous system functioning predicts 2-year development of metabolic abnormalities that constitute the metabolic syndrome.

DESIGN

Data of the baseline and 2-year follow-up assessment of a prospective cohort: the Netherlands Study of Depression and Anxiety was used.

SETTING

Participants were recruited in the general community, primary care, and specialized mental health care organizations.

PARTICIPANTS

A group of 1933 participants aged 18-65 years.

MAIN OUTCOME MEASURES

The autonomic nervous system measures included heart rate (HR), respiratory sinus arrhythmia (RSA; high RSA reflecting high parasympathetic activity), pre-ejection period (PEP; high PEP reflecting low sympathetic activity), cardiac autonomic balance (CAB), and cardiac autonomic regulation (CAR). Metabolic syndrome was based on the updated Adult Treatment Panel III criteria and included high waist circumference, serum triglycerides, blood pressure, serum glucose, and low high-density lipoprotein (HDL) cholesterol.

RESULTS

Baseline short PEP, low CAB, high HR, and CAR were predictors of an increase in the number of components of the metabolic syndrome during follow-up. High HR and low CAB were predictors of a 2-year decrease in HDL cholesterol, and 2-year increase in diastolic and systolic blood pressure. Short PEP and high CAR also predicted a 2-year increase in systolic blood pressure, and short PEP additionally predicted 2-year increase in diastolic blood pressure. Finally, a low baseline RSA was predictive for subsequent decreases in HDL cholesterol.

CONCLUSION

Increased sympathetic activity predicts an increase in metabolic abnormalities over time. These findings suggest that a dysregulation of the autonomic nervous system is an important predictor of cardiovascular diseases and diabetes through dysregulating lipid metabolism and blood pressure over time.

Effects of 5HTTLPR on cardiovascular response to an emotional stressor

OBJECTIVES

To replicate a prior main effect of the serotonin transporter gene promoter (5HTTLPR) genotype on cardiovascular reactivity (CVR) and explore caregiver stress as a potential moderator of 5HTTLPR effects on CVR. On the basis of prior findings, we hypothesized that the more transcriptionally active allele variants would be associated with increased CVR.

METHODS

Expression of the serotonin transporter is affected by the genotype of the 5HTTLPR (S-short and L-long forms) as well as the genotype of the SNP rs25531 within this region. Based on the combined genotypes for these polymorphisms, we designated each allele as a Hi or Lo expressing allele according to expression levels-resulting in HiHi, HiLo, and LoLo groups. We examined the relationship between 5HTTLPR genotype and CVR in 164 caregivers and 158 noncaregivers. Main effects of 5HTTLPR on baseline adjusted blood pressure (systolic and diastolic blood pressures) and heart rate (HR) reactivity were examined, along with moderation by caregiving.

RESULTS

The 5HTTLPR × Caregiver Stress interaction moderated both systolic blood pressure (p < .02) and HR (p < .02) reactivity. In controls, the Hi activity allelic variants were associated with greater systolic blood pressure and HR reactivity as compared with the Lo activity variants. In caregivers, 5HTTLPR genotype was not associated with CVR.

CONCLUSIONS

Replication in this study's control group of our prior finding that 5HTTLPR alleles associated with Hi activity are associated with increased CVR to an emotion recall stressor strengthens the case that this association is real and could be partially responsible for the increased cardiovascular disease observed in persons carrying the 5HTTLPR L allele.

Psychosocial and biobehavioral factors and their interplay in coronary heart disease

Recent epidemiological research has confirmed that psychosocial factors are associated with increased risk of developing coronary heart disease (CHD), a major cause of death and disability worldwide. This association is probably mediated by changes in health risk behaviors and neuroendocrine and autonomic functions that affect metabolic, hemostatic, inflammatory, and cardiovascular functions that are the proximal agents in CHD pathogenesis over time as well as the precipitation of acute disease events. Recent developments in genomics have now made it possible to begin the process of identifying specific genetic variants that act either independently or via moderation of the impact of exposures to stressful environmental situations to increase the expression of these health-damaging psychosocial factors and the accompanying behavioral and physiological changes that lead to disease. It will be possible ultimately to use the knowledge emerging from research on gene x environment interactions that affect expression of psychosocial risk factors, health risk behaviors, and biological changes inside the body to speed the development of a new field of prospective medicine-a field where instead of spending the majority of health care resources on the treatment of chronic diseases at the end of life, it will be possible to allocate more resources to develop, test, and implement earlier in the disease process cost-effective, proactive interventions that target persons at high risk.

Childhood socioeconomic status and serotonin transporter gene polymorphism enhance cardiovascular reactivity to mental stress

OBJECTIVE

To test the hypothesis that low socioeconomic status (SES) and the 5HTTLPR L allele are associated with increased cardiovascular reactivity (CVR) to stress in a larger sample and that SES and 5HTTLPR genotypes interact to enhance CVR to stress. CVR to mental stress has been proposed as one mechanism linking stress to the pathogenesis of cardiovascular disease. The more transcriptionally efficient long (L) allele of a polymorphism of the serotonin transporter gene promoter (5HTTLPR) has been found associated with increased risk of myocardial infarction. We found the long allele associated with larger CVR to mental stress in a preliminary study of 54 normal volunteers.

METHODS

Subjects included 165 normal community volunteers stratified for race, gender, and SES, who underwent mental stress testing.

RESULTS

Childhood SES as indexed by Father's Education Level was associated with larger systolic blood pressure (SBP) (p < .05) and diastolic blood pressure (DBP) (p = .01) responses to mental stress. The L allele was associated with larger SBP (p = .04), DBP (p < .0001), and heart rate (p = .04) responses to mental stress compared with the short (S) allele. Subjects with the SS genotype and high Father's Education exhibited smaller SBP (5.2 mm Hg) and DBP (2.9 mm Hg) responses than subjects with LL genotype and low Father's Education (SBP = 13.3 mm Hg, p = .002; DBP = 9.7 mm Hg, p < .0001).

CONCLUSIONS

Both the 5HTTLPR long allele and low SES, particularly during childhood, are associated with increased CVR to mental stress, which could account, at least in part, for the increased cardiovascular disease risk associated with these characteristics. If confirmed in further research, these characteristics could be used to identify persons who might benefit from preventive interventions.

Renal function and cardiovascular response to mental stress

BACKGROUND/AIMS

Cardiovascular reactivity (CVR), defined as an exaggerated hemodynamic response to mental stress, is a putative vascular risk factor and may reflect sympathetic hyperactivity. Chronic kidney disease (CKD) is also associated with sympathetic hyperactivity and vascular risk, but its relationship with CVR is unknown.

METHODS

CVR was assessed in 107 individuals without overt cardiovascular disease or diabetes. Blood pressure and heart rate responses were elicited by three experimental tasks designed to evoke mental stress. Glomerular filtration rate (eGFR) was estimated using the MDRD formula. General linear models estimated the association between renal function and CVR, adjusting for potential confounders.

RESULTS

Mean age was 66 years and 11% had eGFR of <60 ml/min/1.73 m2. After multivariate adjustment, a low eGFR was associated with a greater stress response of systolic blood pressure, heart rate, and pulse pressure. Associations were only partially attenuated after adjustment for lipids and glucose tolerance. When considered as a continuous variable, lower eGFR was associated with a greater blood pressure response after adjustment for glycemia.

CONCLUSION

Although there were relatively few participants with CKD, these results suggest a relationship between CKD and greater CVR. Further investigation is warranted into factors that mediate this relationship and potential clinical consequences of this exaggerated response to stress in CKD.

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.

Marital status and quality in middle-aged women: Associations with levels and trajectories of cardiovascular risk factors

The current study compared cardiovascular risk profiles and trajectories (i.e., within-person changes) of women who were married or cohabitating and who had high relationship satisfaction with those of women with moderate or low satisfaction and with those of women who were single, divorced, and widowed. Participants were 493 women from the Healthy Women Study, a prospective investigation of health during and after the menopausal transition. Risk factors were measured across more than 5 occasions and 13 years, on average. Data were analyzed using a multilevel modeling technique. Overall, women in relationships with high satisfaction had lower levels of biological, lifestyle, and psychosocial risk factors when compared with the other groups. In some cases, women in satisfying marriages also showed a lower risk trajectory on risk factors relative to other women. Hence, marriage appears to confer health benefits for women, but only when marital satisfaction is high.

Marital status, marital quality, and atherosclerotic burden in postmenopausal women

Marriage confers health benefits for men, but the evidence for women is less consistent. Inconsistent findings may be attributed, in part, to the confounding of marital status and marital quality.

OBJECTIVES

The authors examined whether women in satisfying marriages evidence lesser atherosclerosis relative to women in low-satisfying marriages and relative to unmarried women.

MATERIALS AND METHODS

Three hundred ninety-three women from the Healthy Women Study participated in this study. Marital status and quality were assessed at baseline when women were premenopausal. Cardiovascular risk factors were also assessed at baseline to determine potential mediators. Markers of atherosclerotic burden--B-Mode ultrasound measures of intima-media thickness and plaque in the carotid arteries and electron beam computed tomography assessments of calcification in the aorta and coronary arteries--were performed, on average, 11 years and 14 years later, respectively. A subset of women underwent a second ultrasound scan approximately 3 years after their first scan.

RESULTS

Women in satisfying marriages had the least atherosclerosis in the carotid arteries and aorta, especially relative to those in low-satisfying marriages. Women in satisfying marriages also tended to show less rapid progression of carotid atherosclerosis relative to women in low-satisfying marriages. Women who did not have a partner had intermediate levels of atherosclerosis. Risk factors measured at baseline contributed to the differences between the satisfied and low-satisfied groups, but not those between the satisfied and unmarried groups.

CONCLUSIONS

High-quality marriages may protect against cardiovascular disease for women. Studies concerning marriage and cardiovascular health in women should, therefore, concurrently examine marital quality and marital status.

Toxic cocaine- and convulsant-induced modification of forced swimming behaviors and their interaction with ethanol: comparison with immobilization stress

BACKGROUND

Swimming behaviors in the forced swimming test have been reported to be depressed by stressors. Since toxic convulsion-inducing drugs related to dopamine [cocaine (COC)], benzodiazepine [methyl 6,7-dimethoxy-4-ethyl-beta-carboline-carboxylate (DMCM)], gamma-aminobutyric acid (GABA) [bicuculline (BIC)], and glutamate [N-methyl-D-aspartate (NMDA)] receptors can function as stressors, the present study compared their effects on the forced swimming behaviors with the effects of immobilization stress (IM) in rats. Their interactions with ethanol (EtOH), the most frequently coabused drug with COC which also induces convulsions as withdrawal symptoms but interferes with the convulsions caused by other drugs, were also investigated.

RESULTS

Similar to the IM (10 min) group, depressed swimming behaviors (attenuated time until immobility and activity counts) were observed in the BIC (5 mg/kg IP) and DMCM (10 mg/kg IP) groups at the 5 h time point, after which no toxic behavioral symptoms were observed. However, they were normalized to the control levels at the 12 h point, with or without EtOH (1.5 g/kg IP). In the COC (60 mg/kg IP) and NMDA (200 mg/kg IP) groups, the depression occurred late (12 h point), and was normalized by the EtOH cotreatment. At the 5 h point, the COC treatment enhanced the swimming behaviors above the control level.

CONCLUSIONS

Although the physiological stress (IM), BIC, and DMCM also depressed the swimming behaviors, a delayed occurrence and EtOH-induced recovery of depressed swimming were observed only in the COC and NMDA groups. This might be correlated with the previously-reported delayed responses of DA and NMDA neurons rather than direct effects of the drugs, which could be suppressed by EtOH. Furthermore, the characteristic psychostimulant effects of COC seemed to be correlated with an early enhancement of swimming behaviors.

Influence of cholesterol and fasting insulin levels on blood pressure reactivity

OBJECTIVE

This study examined how cholesterol and fasting insulin levels are related to blood pressure reactivity to behavioral stressors.

METHODS

Subjects (N = 116) were 20 to 52 years old, at 80% to 150% of ideal weight, and had an average fasting cholesterol level of 183 mg/dl. Stressor tasks included mirror star tracing and a videotaped speech task. Changes from baseline were calculated for systolic and diastolic blood pressure.

RESULTS

Neither cholesterol nor insulin was independently related to blood pressure change scores. However, after controlling for body mass, a two-way analysis of variance revealed a significant cholesterol-by-insulin interaction for change in diastolic blood pressure (p = .022). Subjects in the high-cholesterol/high-insulin group showed the greatest increase in diastolic blood pressure reactivity.

CONCLUSIONS

In a general population, people with a below-average cholesterol level experience only moderate cardiovascular reactivity to mental stressors regardless of their fasting insulin level. However, for people with an above-average cholesterol level, fasting insulin level is an important factor in determining potential reactivity to mental stressors. These findings highlight the importance of adequate sample size to allow for the analysis of such interactions in future studies of cholesterol, insulin, and blood pressure reactivity.

Self-reported health in relation to medical health and gender-specific problems in women

Self-reported health was studied in relation to physiological measures, gender-specific problems, and clinical evaluation in 61 middle-aged women employed in a male-dominated industry. Using self-reported somatic health as the dependent variable, 50% of the variability was explained by the dimension workplace culture and the ratio low-density lipoprotein/high-density lipoprotein. Some women who reported good health were diagnosed with distress but showed no ill-health factors. However, they reported experiences of gender-specific problems more often than the women who were diagnosed as being healthy. We concluded that self-report scales seem not to be enough to identify people who look healthy on standard health scales but who use psychological defenses. Differentiating methods such as gender-specific questions, physiological ratio-measures, and clinical judgment seem to be important for distinguishing genuine from illusory mental or physical health.

Cholesterol concentrations and cardiovascular reactivity to stress in African American college volunteers

Cholesterol levels and cardiovascular responses to emotionally arousing stimuli were examined in 60 healthy African American males and females. Cardiac output, stroke volume, contractile force, heart rate, and blood pressure were measured as the participants viewed two racially noxious scenes on videotape. Total serum cholesterol, high-density lipoproteins (HDL), low-density lipoproteins (LDL), and triglycerides were measured within 2 weeks of viewing the scenes. Multiple regression analysis showed that LDL and HDL were significant predictors of blood pressure responses. A correlation analysis revealed that total serum cholesterol and LDL were positively correlated with stroke volume, contractile force, and blood pressure reactivity. A possible relationship among stress, beta-adrenergic activity, and nonmetabolized free fatty acids is discussed. These findings suggest that cardiovascular reactivity to stress may be a new risk factor for heart and vascular diseases.

Serum lipids and cardiovascular reactivity to stress

Several studies have reported an association between serum lipid levels and cardiovascular reactivity to laboratory stressors. Their findings, however, are equivocal. The inconsistencies may be due to shortcomings such as the small number of subjects, the inclusion of patient groups, no control for medication, and no control for age effects. Two studies are presented investigating the relationship in large groups of adolescent and middle-aged males and females. Cholesterol, triglycerides and HDL were measured. Subjects were exposed to mental stressors, and in one study also to a cold pressor test. In addition to heart rate and blood pressure, in one study impedance cardiography was used to measure pre-ejection period, stroke volume and total peripheral resistance. Canonical correlation analysis suggested an association between triglycerides and decreased cardiac reactivity to mental stressors in middle-aged females. Trends in the same direction were found in both middle-aged males and females with respect to reactivity to the cold pressor. These associations, however, were not confirmed when the extreme deciles of the triglyceride distributions were compared with respect to stress reactivity. The fact that associations were completely absent in youngsters but sometimes showed up in older persons suggested an age dependency of the association. In post hoc analyses, indeed, some evidence was found for stronger cardiac responsivity being associated with cholesterol specifically in relatively older males. In females, in contrast to this, the association between triglycerides and cardiac responsivity was stronger in the younger group. More detailed measurement techniques, of specifically vascular processes, may be needed to explore further the effects of sex and age on the association between lipids and stress reactivity.

Apolipoprotein E phenotypes and cardiovascular responses to experimentally induced mental stress in adolescent boys

We investigated the relationship between apolipoprotein E (apoE) polymorphism and cardiovascular responses to experimentally induced mental stress. Mental stress was induced in 28 healthy 16-year-old boys with a series of stressors (e.g., mental arithmetic, Stroop Color-Word Interference Test). Heart rate (HR), finger blood volume, and skin conductance level were recorded continuously during the task performance. We found that boys with apoE3/2 or apoE3/3 showed marginally significantly greater HR reactivity and significantly greater task levels of HR and HR variability (HRV) during the mental stress than subjects with apoE4/2, apoE4/3, or apoE4/4. In addition, E4/2, E4/3, and E4/4 subjects manifested a distinct stress-related decrease in HRV relative to baseline values while E3/2 and E3/3 subjects showed a slight increase. The results suggests that apoE polymorphism is associated with cardiovascular responsivity to mental stress in adolescent boys.