Stress and lipoprotein metabolism: modulators and mechanisms

Effects of Environmental Noise Stress on Mouse Metabolism

Environmental noise is associated with various health outcomes. However, the mechanisms through which these outcomes influence behavior and metabolism remain unclear. This study investigated how environmental noise affects the liver, adipose tissue, and brain metabolic functions, leading to behavioral and body weight changes. Mice were divided into a noise group exposed to construction noise and an unexposed (control) group. Behavior and body weight changes were monitored over 50 days. Early changes in response to noise exposure were assessed by measuring plasma cortisol and glial fibrillary acidic protein expression in brain tissues on days 1, 15, and 30. Chronic responses, including changes in lipoprotein and fat metabolism and neurotransmitters, were investigated by analyzing serum lipoprotein levels and body fat mass and evaluating liver, fat, and brain tissue after 50 days. The noise group showed higher locomotor activity and reduced anxiety in the open-field and Y-maze tests. Noise exposure caused an initial weight loss; however, chronic noise increased fat mass and induced adipocyte hypertrophy. Our findings underscore the role of environmental noise-induced stress in augmenting locomotor activity and reducing anxiety in mice through neurotransmitter modulation while increasing the risk of obesity by decreasing HDL cholesterol levels and promoting adipocyte hypertrophy.

Independent relationship between sleep apnea-specific hypoxic burden and glucolipid metabolism disorder: a cross-sectional study

OBJECTIVES

Obstructive sleep apnea (OSA) is associated with abnormal glucose and lipid metabolism. However, whether there is an independent association between Sleep Apnea-Specific Hypoxic Burden (SASHB) and glycolipid metabolism disorders in patients with OSA is unknown.

METHODS

We enrolled 2,173 participants with suspected OSA from January 2019 to July 2023 in this study. Polysomnographic variables, biochemical indicators, and physical measurements were collected from each participant. Multiple linear regression analyses were used to evaluate independent associations between SASHB, AHI, CT90 and glucose as well as lipid profile. Furthermore, logistic regressions were used to determine the odds ratios (ORs) for abnormal glucose and lipid metabolism across various SASHB, AHI, CT90 quartiles.

RESULTS

The SASHB was independently associated with fasting blood glucose (FBG) (β = 0.058, P = 0.016), fasting insulin (FIN) (β = 0.073, P < 0.001), homeostasis model assessment of insulin resistance (HOMA-IR) (β = 0.058, P = 0.011), total cholesterol (TC) (β = 0.100, P < 0.001), total triglycerides (TG) (β = 0.063, P = 0.011), low-density lipoprotein cholesterol (LDL-C) (β = 0.075, P = 0.003), apolipoprotein A-I (apoA-I) (β = 0.051, P = 0.049), apolipoprotein B (apoB) (β = 0.136, P < 0.001), apolipoprotein E (apoE) (β = 0.088, P < 0.001) after adjustments for confounding factors. Furthermore, the ORs for hyperinsulinemia across the higher SASHB quartiles were 1.527, 1.545, and 2.024 respectively, compared with the lowest quartile (P < 0.001 for a linear trend); the ORs for hyper-total cholesterolemia across the higher SASHB quartiles were 1.762, 1.998, and 2.708, compared with the lowest quartile (P < 0.001 for a linear trend) and the ORs for hyper-LDL cholesterolemia across the higher SASHB quartiles were 1.663, 1.695, and 2.316, compared with the lowest quartile (P < 0.001 for a linear trend). Notably, the ORs for hyper-triglyceridemia{1.471, 1.773, 2.099} and abnormal HOMA-IR{1.510, 1.492, 1.937} maintained a consistent trend across the SASHB quartiles.

CONCLUSIONS

We found SASHB was independently associated with hyperinsulinemia, abnormal HOMA-IR, hyper-total cholesterolemia, hyper-triglyceridemia and hyper-LDL cholesterolemia in Chinese Han population. Further prospective studies are needed to confirm that SASHB can be used as a predictor of abnormal glycolipid metabolism disorders in patients with OSA.

TRIAL REGISTRATION

ChiCTR1900025714 { http://www.chictr.org.cn/ }; Prospectively registered on 6 September 2019; China.

Effects of portable pedal machines at work on lipoprotein subfraction profile in sedentary workers - the REMOVE study

BACKGROUND

Sedentary behaviour at work is a major cause of atherosclerosis, particularly in tertiary workers. However, no studies have ever assessed the effect of active workstation on lipoprotein subfraction profile. This study aimed to evaluate the effect of 12-week portable pedal machines (PPMs) on lipoprotein subfraction profile among healthy sedentary workers.

METHODS

Healthy administrative workers were randomized into an intervention group using PPMs for 12 weeks or a control group using normal-desk. Lipoprotein subfractions were assessed using Lipoprint® electrophoresis. Main outcomes were explored using mixed models with sensitivity analyses (four models).

RESULTS

We included 40 participants (43.7 ± 8.6 years old, 100% women, BMI 23.8 ± 3.4 kg/m2; sedentary time at work 7.7 ± 1.8 h/day). Groups did not differ at baseline in any outcomes. 32 participants finished the trial. Changes in lipoprotein subfractions were especially marked for LDL profile. There was an interaction time x group for all parameters related to LDL and their subfractions: total LDL-cholesterol (p = 0.012), LDL particle size (p = 0.027), large LDL subfractions 1 and 2 (p = 0.001), and small dense LDL subfractions 3 to 7 (p = 0.046), using the crude model. The interaction reflects difference in the direction of changes between groups. The LDL particle size significantly increased in the intervention group (from 271.9 ± 2.5 at t0 to 272.8 ± 1.9 Ångström at t1, p = 0.037) while it did not change in the control group (272.5 ± 1.7 at t0 to 271.8 ± 1.5Å at t1, p = 0.52). All interactions were constantly significant whatever the models. Influencing variables were mainly stress at work that was associated with an increase in total LDL-cholesterol (coefficient 3.15, 95CI 0.20 to 6.11 mg/dl, p = 0.038), and BMI that was associated with Large-LDL, Large-HDL, IDL-C and triglycerides.

CONCLUSIONS

Lipoprotein profile was improved after a 12-week PPMs intervention at work in healthy administrative workers. Changes were mainly showed for LDL and LDL subfractions. Lipoprotein profile was worsened by stress at work, BMI and age.

TRIAL REGISTRATION

NCT04153214.

Physiological reactivity to acute mental stress in essential hypertension-a systematic review

Objective

Exaggerated physiological reactions to acute mental stress (AMS) are associated with hypertension (development) and have been proposed to play an important role in mediating the cardiovascular disease risk with hypertension. A variety of studies compared physiological reactivity to AMS between essential hypertensive (HT) and normotensive (NT) individuals. However, a systematic review of studies across stress-reactive physiological systems including intermediate biological risk factors for cardiovascular diseases is lacking.

Methods

We conducted a systematic literature search (PubMed) for original articles and short reports, published in English language in peer-reviewed journals in November and December 2022. We targeted studies comparing the reactivity between essential HT and NT to AMS in terms of cognitive tasks, public speaking tasks, or the combination of both, in at least one of the predefined stress-reactive physiological systems.

Results

We included a total of 58 publications. The majority of studies investigated physiological reactivity to mental stressors of mild or moderate intensity. Whereas HT seem to exhibit increased reactivity in response to mild or moderate AMS only under certain conditions (i.e., in response to mild mental stressors with specific characteristics, in an early hyperkinetic stage of HT, or with respect to certain stress systems), increased physiological reactivity in HT as compared to NT to AMS of strong intensity was observed across all investigated stress-reactive physiological systems.

Conclusion

Overall, this systematic review supports the proposed and expected generalized physiological hyperreactivity to AMS with essential hypertension, in particular to strong mental stress. Moreover, we discuss potential underlying mechanisms and highlight open questions for future research of importance for the comprehensive understanding of the observed hyperreactivity to AMS in essential hypertension.

Obstructive Sleep Apnoea and Lipid Metabolism: The Summary of Evidence and Future Perspectives in the Pathophysiology of OSA-Associated Dyslipidaemia

Obstructive sleep apnoea (OSA) is associated with cardiovascular and metabolic comorbidities, including hypertension, dyslipidaemia, insulin resistance and atherosclerosis. Strong evidence suggests that OSA is associated with an altered lipid profile including elevated levels of triglyceride-rich lipoproteins and decreased levels of high-density lipoprotein (HDL). Intermittent hypoxia; sleep fragmentation; and consequential surges in the sympathetic activity, enhanced oxidative stress and systemic inflammation are the postulated mechanisms leading to metabolic alterations in OSA. Although the exact mechanisms of OSA-associated dyslipidaemia have not been fully elucidated, three main points have been found to be impaired: activated lipolysis in the adipose tissue, decreased lipid clearance from the circulation and accelerated de novo lipid synthesis. This is further complicated by the oxidisation of atherogenic lipoproteins, adipose tissue dysfunction, hormonal changes, and the reduced function of HDL particles in OSA. In this comprehensive review, we summarise and critically evaluate the current evidence about the possible mechanisms involved in OSA-associated dyslipidaemia.

Recent Progress of Chronic Stress in the Development of Atherosclerosis

With the development of the times, cardiovascular diseases have become the biggest cause of death in the global aging society, causing a serious social burden. Atherosclerosis is a chronic inflammatory disease, which can occur in large and medium-sized blood vessels in the whole body. It takes atherosclerotic plaque as the typical pathological change and endothelial injury as the core pathophysiological mechanism. It is the pathological basis of coronary heart disease, peripheral artery disease, cerebrovascular disease, and other diseases. Recent studies have shown that chronic stress plays an important role in the occurrence and development of atherosclerosis, endothelial injury, lipid metabolism, and chronic inflammation. This process involves a large number of molecular targets. It is usually the cause of atherosclerotic cardiovascular and cerebrovascular diseases. If chronic stress factors exist for a long time, patients have genetic susceptibility, and the combination of environmental factors triggers the pathogenesis, which may eventually lead to complete blockage of the blood vessels, unstable rupture of plaques, and serious adverse cardiovascular events. This paper reviews the role of chronic stress in the occurrence and development of atherosclerosis, focusing on the pathophysiological mechanism.

Effect of Continuous Positive Airway Pressure on Lipid Profiles in Obstructive Sleep Apnea: A Meta-Analysis

BACKGROUND

Obstructive sleep apnea (OSA) is associated with dyslipidemia. However, the effects of continuous positive airway pressure (CPAP) treatment on lipid profiles are unclear.

METHODS

PubMed/Medline, Embase and Cochrane were searched up to July 2021. Randomized controlled trials (RCTs) of CPAP versus controls with ≥4 weeks treatment and reported pre- and post-intervention lipid profiles were included. Weighted mean difference (WMD) was used to assess the effect size. Meta-regression was used to explore the potential moderators of post-CPAP treatment changes in lipid profiles.

RESULTS

A total of 14 RCTs with 1792 subjects were included. CPAP treatment was associated with a significant decrease in total cholesterol compared to controls (WMD = -0.098 mmol/L, 95% CI = -0.169 to -0.027, p = 0.007, I² = 0.0%). No significant changes in triglyceride, high-density lipoprotein nor low-density lipoprotein were observed after CPAP treatment (all p > 0.2). Furthermore, meta-regression models showed that age, gender, body mass index, daytime sleepiness, OSA severity, follow-up study duration, CPAP compliance nor patients with cardiometabolic disease did not moderate the effects of CPAP treatment on lipid profiles (all p > 0.05).

CONCLUSIONS

CPAP treatment decreases total cholesterol at a small magnitude but has no effect on other markers of dyslipidemia in OSA patients. Future studies of CPAP therapy should target combined treatment strategies with lifestyle modifications and/or anti-hyperlipidemic medications in the primary as well as secondary cardiovascular prevention models.

A Systematic Review and Meta-Analysis of Lipid Signatures in Post-traumatic Stress Disorder

BACKGROUND

Research assessing lipid levels in individuals diagnosed with post-traumatic stress disorder (PTSD) has yielded mixed results. This study aimed to employ meta-analytic techniques to characterize the relationship between the levels of lipid profiles and PTSD.

METHODS

We performed meta-analyses of studies comparing profiles and levels of lipids between PTSD patients and healthy individuals by searching Embase, Ovid Medline, Scopus, PsycINFO, and Cochrane databases for the studies until March 2021. Meta-analyses were performed using random-effects models with the restricted maximum-likelihood estimator to synthesize the effect size assessed by standardized mean difference (SMD) across studies.

FINDINGS

A total of 8,657 abstracts were identified, and 17 studies were included. Levels of total cholesterol (TC) (SMD = 0.57 95% CI, 0.27-0.87, p = 0.003), low-density lipoprotein (LDL) (SMD = 0.48, 95% CI, 0.19-0.76, p = 0.004), and triglyceride (TG) (SMD = 0.46, 95% CI, 0.22-0.70, p = 0.001) were found to be higher, while levels of high-density lipoprotein (HDL) (SMD = -0.47, -0.88 to -0.07, p = 0.026) were found to be lower in PTSD patients compared to healthy controls. Subgroup analysis showed that TG levels were higher in PTSD patients who were on or off of psychotropic medications, both < 40 and ≥ 40 years of age, and having body mass index of < 30 and ≥ 30 compared to healthy controls.

INTERPRETATION

This work suggested dysregulation of lipids in PTSD that may serve as biomarker to predict the risk. The study will be useful for physicians considering lipid profiles in PTSD patients to reduce cardiovascular morbidity and mortality.

Health problems associated with single, multiple, and the frequency of months of objectively measured long working hours: a cohort study by the National Institute of Occupational Safety and Health, Japan

Purpose

We aimed to examine the prospective associations of monthly working hours measured in a month, the 6-month averaged hours, and the frequency of long working hours (≥ 205 h/month) during the past 6 months with health indicators.

Methods

This study included 6,806 Japanese company workers (response rate = 86.6%). Data on the workers’ monthly attendance during the second half of fiscal year 2016 and annual health checkups in fiscal years 2016 and 2017 were collected. We evaluated the association of the above three types of monthly working hours with subsequent health checkup data in fiscal year 2017. We adjusted for the corresponding data in fiscal year 2016.

Results

Multivariate logistic regression analyses revealed significant associations between monthly working hours and workers’ systolic and diastolic blood pressure as well as aspartate aminotransferase, alanine aminotransferase, low-density lipoprotein cholesterol (LDL), and triglyceride levels. However, the associations were not consistent between months. The average monthly working hours were significantly associated with higher LDL levels for the 220–240 h/mo group (OR: 1.49, 95%CI: 1.07–2.08) and lower triglyceride levels for the < 140 h/mo group (OR: 0.15, 95%CI: 0.03–0.77), compared to the 140–180 h/mo group. The frequency of long working hours was significantly associated with higher LDL levels.

Conclusions

Working hours over several months produced various associations with health indicators compared to those measured in a single month. Our present data suggest that the effects of average or frequency of long working hours during the past 6 months are likely to appear in LDL levels.

Hepatocyte ATF3 protects against atherosclerosis by regulating HDL and bile acid metabolism

Activating transcription factor (ATF)3 is known to have an anti-inflammatory function, yet the role of hepatic ATF3 in lipoprotein metabolism or atherosclerosis remains unknown. Here we show that overexpression of human ATF3 in hepatocytes reduces the development of atherosclerosis in Western-diet-fed Ldlr^-/- or Apoe^-/- mice, whereas hepatocyte-specific ablation of Atf3 has the opposite effect. We further show that hepatic ATF3 expression is inhibited by hydrocortisone. Mechanistically, hepatocyte ATF3 enhances high-density lipoprotein (HDL) uptake, inhibits intestinal fat and cholesterol absorption and promotes macrophage reverse cholesterol transport by inducing scavenger receptor group B type 1 (SR-BI) and repressing cholesterol 12α-hydroxylase (CYP8B1) in the liver through its interaction with p53 and hepatocyte nuclear factor 4α, respectively. Our data demonstrate that hepatocyte ATF3 is a key regulator of HDL and bile acid metabolism and atherosclerosis.

Evaluation of Orally Administered Atorvastatin on Plasma Lipid and Biochemistry Profiles in Hypercholesterolemic Hispaniolan Amazon Parrots (Amazona ventralis)

Atorvastatin is a synthetic statin administered in its active form and used for the treatment of dyslipidemias. In the current study, the effects of atorvastatin were evaluated on plasma lipid profiles and the potential for adverse effects after once daily PO dosing of atorvastatin for 30 days in Hispaniolan Amazon parrots (Amazona ventralis). Sixteen adult parrots (10 female, 6 male) with hypercholesterolemia were used for this study. Birds were assigned to 2 groups (treatment and control) of 8 parrots each (3 male, 5 female) after balancing for age, sex, originating institution, and baseline plasma cholesterol values. Compounded atorvastatin oral suspension (10 mg/kg) was administered PO once daily via gavage into the crop. Equivalent volumes of placebo suspension were administered to the control group. Plasma biochemistry and plasma lipid profile analysis (total cholesterol, high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol [LDL-C], and triglycerides [TGs]) were analyzed on days 0, 14, and 30. Plasma samples and HDL-C fractions were evaluated for cholesterol and TG concentrations via enzymatic assays. Subtraction of HDL-C values from total cholesterol yielded the non-HDL-C concentration for each bird. Birds were routinely assessed for appetite, activity, and urofeces. Plasma atorvastatin concentrations were obtained from 7 of 8 birds in the treatment group from banked samples. Those samples were obtained on days 14 and 30, with drug administration 6 to 8 hours before collection. No significant differences were observed in total cholesterol, HDL-C, non-HDL-C, or TG between treatment and control groups at days 0, 14, and 30. Plasma atorvastatin concentrations were variable on day 14 (0.54-5.41 ng/ mL for 6 of 7 samples, with 1 outlier of 307 ng/mL) and on day 30 (0.79-6.74 ng/mL). No adverse effects were noted in any of the birds during the study period. When dosed PO at 10 mg/kg once daily, atorvastatin did not result in significant changes to plasma lipid profiles (eg, lowering of plasma total or non-HDL-C concentrations) at any time point during this study. Future studies to investigate pharmacokinetic and pharmacodynamic properties of atorvastatin in parrots may require increased doses and/or frequency of administration.

Loneliness as a risk factor for metabolic syndrome: results from the HUNT study

Objective

Metabolic syndrome (MetS) includes hyperglycaemia, hypertension, central adiposity, elevated triglyceride levels and low levels of high-density lipoprotein cholesterol. All factors are identified as risk factors for cardiovascular disease and mortality. This longitudinal study examined whether loneliness, which has been shown to predict a range of negative health outcomes, increases the risk for MetS.

Methods

We used data from ‘the Nord-Trøndelag Health Study’ (HUNT) which is a large longitudinal health study based on a Mid-Norway county population (n=26 990). Self-reports, physical examinations and blood samples were analysed to evaluate the associations between loneliness and incidents of MetS after 10 years (follow-up survey conducted during 2006–2008). We also investigated the role of depression as a potential mediating factor.

Results

Individuals who reported higher levels of loneliness had a higher odds for MetS (adjusted OR 1.09 (95% CI 1.02 to 1.16); p=0.007). This effect was mediated through depression.

Conclusions

Findings suggest that loneliness may be an important factor that increases the risk for MetS. The effect of loneliness on MetS is mediated through depressive symptoms. Reducing loneliness may help prevent the incidence of MetS and related diseases.

Long-term exposure to road traffic noise, ambient air pollution, and cardiovascular risk factors in the HUNT and lifelines cohorts

Aims

Blood biochemistry may provide information on associations between road traffic noise, air pollution, and cardiovascular disease risk. We evaluated this in two large European cohorts (HUNT3, Lifelines).

Methods and results

Road traffic noise exposure was modelled for 2009 using a simplified version of the Common Noise Assessment Methods in Europe (CNOSSOS-EU). Annual ambient air pollution (PM10, NO2) at residence was estimated for 2007 using a Land Use Regression model. The statistical platform DataSHIELD was used to pool data from 144 082 participants aged ≥20 years to enable individual-level analysis. Generalized linear models were fitted to assess cross-sectional associations between pollutants and high-sensitivity C-reactive protein (hsCRP), blood lipids and for (Lifelines only) fasting blood glucose, for samples taken during recruitment in 2006-2013. Pooling both cohorts, an inter-quartile range (IQR) higher day-time noise (5.1 dB(A)) was associated with 1.1% [95% confidence interval (95% CI: 0.02-2.2%)] higher hsCRP, 0.7% (95% CI: 0.3-1.1%) higher triglycerides, and 0.5% (95% CI: 0.3-0.7%) higher high-density lipoprotein (HDL); only the association with HDL was robust to adjustment for air pollution. An IQR higher PM10 (2.0 µg/m3) or NO2 (7.4 µg/m3) was associated with higher triglycerides (1.9%, 95% CI: 1.5-2.4% and 2.2%, 95% CI: 1.6-2.7%), independent of adjustment for noise. Additionally for NO2, a significant association with hsCRP (1.9%, 95% CI: 0.5-3.3%) was seen. In Lifelines, an IQR higher noise (4.2 dB(A)) and PM10 (2.4 µg/m3) was associated with 0.2% (95% CI: 0.1-0.3%) and 0.6% (95% CI: 0.4-0.7%) higher fasting glucose respectively, with both remaining robust to adjustment for air/noise pollution.

Conclusion

Long-term exposures to road traffic noise and ambient air pollution were associated with blood biochemistry, providing a possible link between road traffic noise/air pollution and cardio-metabolic disease risk.

Metformin potentiates cognitive and antidepressant effects of fluoxetine in rats exposed to chronic restraint stress and high fat diet: potential involvement of hippocampal c-Jun repression

Several hypotheses link high fat diet (HFD) with the pathophysiology of depression and its response to antidepressants. This study aimed to determine the effect of metformin (MET) on the cognitive and antidepressant activity of fluoxetine (FLU) through its effect on c-Jun expression. Behavioral, cognitive function, biochemical, and histopathological studies were performed in non-HFD- and HFD-fed rats exposed to chronic restraint stress (CRS). Stressed group showed cognitive impairment, depressive-like symptoms, disturbed glucose homeostasis and lipid profile, reduced adiponectin level, brain-derived neurotrophic factor (BDNF) expression, and increased corticosterone and c-Jun. All these were aggravated by HFD. MET, FLU and their combination produced significant improvement in lipid profile with significant increase in adiponectin and BDNF expression. Corticosterone, body weight and insulin resistance showed significant decrease in the treated groups. Moreover, there was a significant decrease in hippocampal c Jun expression. There was a significant preferable effect toward the combination. Conclusion, MET may decrease the refractoriness to FLU and improves the cognition in individuals who are fed on HFD.

Circulating PCSK9 is lowered acutely following surgery

BACKGROUND

A decrease in serum low-density lipoprotein cholesterol (LDL-C) is well documented after acute stress. Plasma proprotein convertase subtilisin kexin 9 (PCSK9), which promotes degradation of low-density lipoprotein receptor (LDL-R) resulting in reduced plasma clearance of low-density lipoproteins (LDL) and an increase in serum LDL-C, would be predicted to decrease. Yet, a few studies have demonstrated an increase 1-8 days after acute stress. Our objective was to assess the earlier status of plasma PCSK9, within the first 24 hours of onset of stress.

METHODS

We measured serum lipids and plasma PCSK9 in 39 patients before and soon after an elective surgical procedure (abdominal aortic aneurysm (AAA) repair).

RESULTS

We observed an early decrease in PCSK9 following surgery, as well as a decrease in total cholesterol (TC), LDL-C, high-density lipoprotein cholesterol (HDL-C), non-high-density lipoprotein cholesterol (non-HDL-C) and triglycerides (TG).

CONCLUSION

Unlike other studies which showed an increase in PCSK9 after the onset of stress, our study detected a fall in PCSK9 following acute surgical stress. The observed difference is likely due to the earlier timing of PCSK9 measurement in our study. Further studies involving serial poststress measurements for several days are needed to determine whether PCSK9 behaves as an acute-phase reactant, whether it displays a biphasic response to acute stress, and whether changes in circulating PCSK9 are responsible for lipoprotein changes observed after surgical stress. (Clinical Trial Registration: ClinicalTrials.gov study ID NCT00493389).

Parallel changes in serum proteins and diffusion tensor imaging in methamphetamine-associated psychosis

Methamphetamine-associated psychosis (MAP) involves widespread neurocognitive and molecular deficits, however accurate diagnosis remains challenging. Integrating relationships between biological markers, brain imaging and clinical parameters may provide an improved mechanistic understanding of MAP, that could in turn drive the development of better diagnostics and treatment approaches. We applied selected reaction monitoring (SRM)-based proteomics, profiling 43 proteins in serum previously implicated in the etiology of major psychiatric disorders, and integrated these data with diffusion tensor imaging (DTI) and psychometric measurements from patients diagnosed with MAP (N = 12), methamphetamine dependence without psychosis (MA; N = 14) and healthy controls (N = 16). Protein analysis identified changes in APOC2 and APOH, which differed significantly in MAP compared to MA and controls. DTI analysis indicated widespread increases in mean diffusivity and radial diffusivity delineating extensive loss of white matter integrity and axon demyelination in MAP. Upon integration, several co-linear relationships between serum proteins and DTI measures reported in healthy controls were disrupted in MA and MAP groups; these involved areas of the brain critical for memory and social emotional processing. These findings suggest that serum proteomics and DTI are sensitive measures for detecting pathophysiological changes in MAP and describe a potential diagnostic fingerprint of the disorder.

Independent Association between Sleep Fragmentation and Dyslipidemia in Patients with Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is independently associated with dyslipidemia. Previous studies have demonstrated that sleep fragmentation can impair lipid metabolism. The present study aimed to identify whether sleep fragmentation is independently associated with dyslipidemia, in a large-scale, clinic-based consecutive OSA sample. This cross-sectional study was conducted among 2,686 patients who underwent polysomnography (PSG) for suspicion of OSA from January 2008 to January 2013 at the sleep laboratory. Multivariate regression analyses were performed to evaluate the independent associations between the microarousal index (MAI) and lipid profiles adjusting for potential confounders, including metabolic syndrome components and nocturnal intermittent hypoxia. The adjusted odds ratios (ORs) for various types of dyslipidemia according to MAI quartiles, as determined by logistic regression were also evaluated. MAI was found positively associated with low-density lipoprotein cholesterol (LDL-c) but not with total cholesterol (TC), triglyceride (TG) or high-density lipoprotein cholesterol (HDL-c). Furthermore, the adjusted ORs (95% confidence interval) for hyper-LDL cholesterolemia increased across MAI quartiles, as follows: 1 (reference), 1.3 (1.1-1.7), 1.6 (1.2-2.0), and 1.6 (1.2-2.1) (p = 0.001, linear trend). Sleep fragmentation in OSA is independently associated with hyper-LDL cholesterolemia, which may predispose patients with OSA to a higher risk of cardiovascular disease.

Relationship among stress, depression, cardiovascular and metabolic changes and physical exercise

Abstract Introduction: Stress is considered one of the most significant health problems in modern society. It can be characterized as any changes in the homeostasis of an individual that require an adaptive response. An imbalance in the secretion of the primary stress mediators may be responsible for the onset and development of several diseases. Thus, chronic stress has been recognized as a risk factor for depression as well as cardiovascular and metabolic diseases. Given the pathophysiological mechanisms associated with chronic stress and related cardiovascular and metabolic changes, it is necessary to implement measures to prevent, control and/or avoid their development. Physical exercise is a non-pharmacological resource that is widely used for this purpose. Its beneficial effects include the improvement of the emotional state as well as lipid and glycemic control. Objective: The aim of this review is to discuss the relationship between stress, depression, cardiovascular and metabolic changes, and highlight the importance of physical exercise in the prevention and treatment of resulting disorders. Materials and Methods: We searched MEDLINE and SCIELO from 2000 through 2012, using the terms chronic stress, mood disorders, depression, cardiovascular and metabolic changes, and exercise. Results: Most of the studies found in our literature search have shown that exercise can attenuate and/or reverse the deleterious effects of chronic stress. Conclusion: Regular physical exercise is useful for maintaining health, especially with respect to improving mood and mental stress.

The association between mental health, chronic disease and sleep duration in Koreans: a cross-sectional study

Background

Sleep duration holds considerable importance as an indicator of mental/physical health. The objective of this study was to investigate the association between sleep duration, mental health, and chronic disease prevalence in Koreans.

Methods

Of 31,596 subjects eligible for the Korean National Health and Nutrition Examination Survey V (2010–2012), 17,638 participants who answered items on sleep duration (aged ≥19 yrs) were analyzed in a cross-sectional study. Association between sleep duration, mental health, and chronic disease prevalence was assessed using logistic regression, and adjusted for various socioeconomic and lifestyle characteristics.

Results

Short or long sleep duration showed correlations with mental health, and items of significance showed gender-specific patterns. Women displayed significant associations with stress and depressive symptoms, and men with stress, thoughts of suicide, and psychiatric counseling. While stress was related with short sleep duration in both genders, depressive symptoms showed a relationship with long duration in men, and short duration in women. Prevalence of any chronic disease was associated with ≤6 h sleep when adjusted for factors including mental health, and among chronic diseases, cancer and osteoarthritis showed associations with short sleep duration, while diabetes and dyslipidemia were associated with normal sleep duration.

Conclusions

Mental health problems were associated with sleep duration with gender-specific patterns. Associations with osteoarthritis, cancer, diabetes, dyslipidemia and abnormal sleep duration persisted after adjustment for mental health.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-2542-3) contains supplementary material, which is available to authorized users.

Perceived stress status and sympathetic nervous system activation in young male patients with coronary artery disease in China

BACKGROUND AND PURPOSE

Young Chinese male adults have faced increasing psychological stress. Whether this is associated with the increased risk of coronary artery disease (CAD) in young Chinese males remains unclear. This study aimed to evaluate the correlation and underlying mechanisms of perceived stress and CAD in young male patients.

METHODS

A total of 178 male patients diagnosed as young CAD (aged ≤ 55 years) by coronary angiography (CAG) were enrolled, and 181 age-matched non-CAD individuals were set as control group. Traditional cardiovascular risk factors and levels of epinephrine and norepinephrine were measured, and perceived stress status was accessed by Perceived Stress Scale (PSS).

RESULTS

The PSS score was correlated with levels of epinephrine (r=0.45), norepinephrine (r=0.41), high-sensitivity C-reactive protein (hs-CRP) (r=0.38, p<0.01), and current smoking (r=0.32) (all p<0.05). Multivariate logistic regression analysis showed that smoking (OR, 3.12; 95%CI, 1.23-7.91), triglycerides (OR, 1.42; 95%CI, 1.04-1.94), hs-CRP (OR, 3.57; 95%CI, 1.65-7.72), and PSS score (OR, 1.81; 95%CI, 1.23-2.66) were independently correlated with CAD in young patients. The association between PSS score and risk of CAD become insignificant (OR, 1.43; 95%CI, 0.96-2.13) when further adjusted for the levels of epinephrine and norepinephrine.

CONCLUSIONS

After adjustment for multiple cardiovascular risk factors, high perceived stress was an independent risk factor for CAD in young Chinese male patients. Abnormal activation of the sympathetic nervous system may play an important role linking perceived stress with the risk of CAD.

Dispositional depression and hostility are associated with inflammatory markers of cardiovascular disease in African Americans

Prior research has demonstrated that state depressive symptoms and hostility can modulate inflammatory immune responses and directly contribute to cardiovascular disease (CVD) onset and development. Previous studies have not considered the contribution of dispositional depressive symptoms to the inflammatory process. They have also largely excluded African Americans, despite their disproportionate risk for CVD. The first aim of the study was to examine the impact of state and dispositional depression and hostility on CVD-associated inflammatory biomarkers interleukin-6 (IL-6) and C-reactive protein (CRP) in an African American sample. The second aim was to examine synergistic influences of hostility and state and dispositional depression on IL-6 and CRP. The final aim was to examine whether the relations between state and dispositional depression, hostility, IL-6, and CRP varied as a function of gender and education. Anthropometric measures, blood serum samples, and psychosocial data were collected from 198 African Americans from the Washington, DC metropolitan area. Hierarchical and stepwise regression analyses indicated that (1) increased levels of hostility were associated with increased levels of CRP; (2) hostility and IL-6 were more strongly associated among participants with lower educational attainment; and (3) dispositional depression and CRP were more strongly associated among participants with greater hostility and lower educational attainment. Findings suggest that enduring personality dispositions, such as dispositional depression and hostility, are critical to a thorough assessment of cardiovascular profiles in African Americans. Future studies should investigate causal pathways that link depressive and hostile personality styles to inflammatory activity for African American men and women.

Cardiovascular reactivity and cardiometabolic risk in adolescents

BACKGROUND

Cardiovascular reactivity has been examined as a risk marker or factor in the pathogenesis of hypertension or cardiovascular disease, but few have examined the relationship with the metabolic syndrome.

PURPOSE

We examined whether cardiovascular reactivity to laboratory stress is associated with individual cardiometabolic risk factors and their co-occurrence. A significant positive relationship was hypothesized for both individual and clustered risk factors in their cross-sectional associations with reactivity to multiple stressors.

METHODS

A sample of 144, 15-17-year-old adolescents (74 % boys) largely from ethnic minority groups (54 % Hispanic White, 26 % Black) were identified at annual blood pressure (BP) screening (39 % with elevated BP) at high schools in Miami, Florida, USA. Participants completed the evaluated speaking, mirror star tracing, and cold pressor tasks, as well as cardiometabolic risk factor blood sampling. Participants were classified into metabolic syndrome criterion groups (0, 1, 2, or ≥3 criteria) based on American Heart Association adult criteria.

RESULTS

Multiple regression analyses with individual metabolic syndrome variables demonstrated that diastolic (D)BP reactivity during the mirror star tracing task accounted for 1.3 %, 3.8 %, and 5.1 % of the respective variances in casual systolic BP, waist circumference, and triglycerides (ps < 0.05). In multinomial logistic regression models, increased DBP reactivity during mirror star tracing and cold pressor tasks, and decreased HR reactivity during the cold pressor, were associated with greater likelihood of risk factor co-occurrence (ranging from 8.3 % to 15.8 %).

CONCLUSIONS

Findings indicate that autonomic reactivity to the mirror star tracing and cold pressor tasks, but not the evaluated speaking task, is associated with risk factor co-occurrence, and reactivity may be a clinical prognosticator of cardiometabolic disease risk.

Role of sudarshan kriya and pranayam on lipid profile and blood cell parameters during exam stress: A randomized controlled trial

BACKGROUND

Yoga is a science practiced in India over thousands of years. It produces constituent physiological changes and has sound scientific basis.

AIM

Since exam stress modifies lipid profile and hematological parameters, we conducted an investigation on the effect of sudarshan kriya (SK and P) program on these parameters.

MATERIALS AND METHODS

Blood samples of 43 engineering students were collected at four intervals namely baseline (BL), exam stress (ES), three and six weeks practice of SK and P during exam stress. Lipid profile and hematological parameters were measured at all four intervals.

RESULTS

ES elevated total cholesterol (TC), triglycerides (TGL) and very low density lipoprotein (VLDL) levels. Hematological parameters affected by ES included neutrophil, lymphocytes, platelet count, packed cell volume (PCV) and mean cell volume (MCV). Three and six weeks practice of SK and P reduced the elevated lipid profile, hematological parameters and improved lymphocyte levels.

CONCLUSION

Our study indicates that SK and P practice has the potential to overcome ES by improving lipid profile and hematological parameters.

Chronic stress, but not hypercaloric diet, impairs vascular function in rats

The aim of this study was to evaluate vascular and metabolic effects of chronic mild unpredictable stress (CMS) and hypercaloric diet (HD) without carbohydrate supplementation in rats. Male Sprague-Dawley rats were randomly assigned to four groups: Control, HD, CMS, and HD plus CMS. CMS consisted of the application of different stressors for 3 weeks. The rats were killed 15 days after CMS exposure. The HD group presented higher plasma lipid concentrations, without changes in fasting glucose concentration, glucose tolerance test, and vascular function and morphology, in comparison with the control group. Stressed rats presented higher fasting blood concentration of insulin, higher homeostasis model assessment index values and area under the curve in an oral glucose tolerance test, in comparison with non-stressed rats. CMS increased the plasma concentrations of corticosterone and lipids, and the atherogenic index values, without change in high-density lipoprotein level. CMS increased intima-media thickness and induced endothelium-dependent supersensitivity to phenylephrine, and lowered the relaxation response to acetylcholine in the thoracic aorta isolated from rats fed with control or HD, in comparison with non-stressed groups. CMS effects were independent of diet. In non-stressed rats, the HD induced dyslipidemia, but did not change glucose metabolism, vascular function, or morphology. The data from this study indicate that CMS promotes a set of events which together can contribute to impair function of the thoracic aorta.

Expression of the chicken peptide transporter 1 and the peroxisome proliferator-activated receptor α following feed restriction and subsequent refeeding

The peptide transporter 1 (PepT1) transports di- and tripeptides from the lumen of the small intestine into the enterocyte. Expression of this transporter is affected by numerous factors, including feed restriction. During a fasting state, PepT1 is thought to be regulated by peroxisome proliferator-activated receptor α (PPARα). The objective of this study was to evaluate the effects of a feed restriction-refeeding regimen on expression of chicken PepT1 and PPARα. Ten-day-old broiler chicks were placed on a 24-h feed restriction with 6 birds sampled before and after the restriction. Following feed restriction, the remaining birds were divided into 3 groups: continuously fasted, refed-food withdrawn, and refed ad libitum. The duodenum, jejunum, and ileum were sampled 1, 2, 3, 5, and 7 h post feed restriction. Expression of PepT1 and PPARα increased almost 2-fold post feed restriction (P < 0.002). A significant group × time interaction was observed for PPARα, with the continuously fasted group showing a peak at 29 h postrestriction (P = 0.002). A group × segment interaction was found for both PepT1 (P = 0.002) and PPARα (P = 0.01); within the continuously fasted group, PepT1 expression was greatest in the jejunum (P < 0.001) and ileum (P = 0.01) when compared with the duodenum. No difference was observed between the jejunum and ileum. The PPARα expression was greatest in the jejunum (P = 0.03) when compared with the duodenum, with no difference between the jejunum and ileum or between the duodenum and ileum. The increase in PepT1 expression during a time of reduced feed intake suggests the importance of having transporters ready to scavenge any available luminal nutrients. The concurrent increase in PPARα suggests a possible regulatory role for this receptor in the regulation of PepT1 during feed restriction.

Psychological factors and subclinical atherosclerosis in postmenopausal Chinese women in Hong Kong

BACKGROUND

Substantial evidence shows that psychological factors are associated with cardiovascular diseases. However, data on the association between psychological factors and subclinical atherosclerosis is lacking in postmenopausal Chinese women.

OBJECTIVES

To examine the associations of perceived stress and trait anxiety with subclinical atherosclerosis in postmenopausal Chinese women in Hong Kong. Their relationships with biological and behavioral risk factors were also examined.

METHODS

Between 2002 and 2004, we recruited 518 postmenopausal women aged 50-64 years. Perceived stress and trait anxiety were evaluated by the perceived stress scale and the state-trait anxiety inventory, respectively. Subclinical atherosclerosis was determined by measuring carotid intima-media thickness (IMT) and plaque using B-mode ultrasonography.

RESULTS

Perceived stress and trait anxiety showed no significant association with IMT or plaque. Multivariate analyses showed high perceived stress scores were associated with an increased risk of elevated total cholesterol (OR=2.10; 95% CI=1.17-3.77) and elevated low-density lipoprotein cholesterol (LDL-C) (OR=2.39; 95% CI=1.36-4.21). High trait anxiety scores were associated with a 2.7-fold risk of elevated LDL-C (OR=2.74; 95% CI=1.56-4.80). Women with high perceived stress or trait anxiety scores were more likely to be physically inactive.

CONCLUSIONS

Perceived stress and trait anxiety were associated with atherogenic lipid levels, but not subclinical atherosclerosis. Maintaining high physical activity may help alleviate psychological stress and anxiety.

Proatherosclerotic effects of chronic stress in male rats: altered phenylephrine sensitivity and nitric oxide synthase activity of aorta and circulating lipids

The aim of this study was to analyze the effects of chronic mild unpredictable stress (CMS) on the vasoconstrictor response and morphology of the thoracic aorta and serum lipid profiles in rats. Male Sprague-Dawley rats were submitted to CMS, which consisted of the application of different stressors for 7 days per week across 3 weeks. The rats were sacrificed 15 days after CMS exposure. CMS induced supersensitivity to the vasoconstrictor effect of phenylephrine in endothelium-intact thoracic aortic rings without changes in aortic rings without endothelium, or pre-incubated with nitric oxide (NO) synthesis inhibitor. Rats submitted to CMS showed hypertrophy of the intima and tunica media of thoracic aorta, increased serum levels of triglycerides, total cholesterol, very low-density lipoprotein cholesterol, low-density lipoprotein cholesterol and atherogenic index, without changes in high-density lipoprotein cholesterol levels, when compared with control rats. These data indicate that CMS induces physiological and morphological changes that may contribute to the development of atherosclerosis by mechanisms related to deficiency in NO production and dyslipidemia.

Effects of social isolation and environmental enrichment on atherosclerosis in ApoE-/- mice

Social support and a stimulating environment have been suggested to reduce stress reactions and cardiovascular risk. The aim of this study was to assess the role of environmental enrichment and social interaction for development of atherosclerosis in atherosclerosis prone mice. Male ApoE-/- mice were divided into four groups and followed during 20 weeks: (i) enriched environment (E, n=12), (ii) deprived environment (ED, n=12), (iii) enriched environment with exercise (E-Ex, n=12) and (iv) socially deprived by individual housing (SD, n=10). Plasma lipid and cytokine concentrations were measured. Atherosclerosis was quantified in cross-sections of innominate artery and en face in thoracic aorta. Plaque area was significantly increased in SD mice in the innominate artery (P<0.05 vs. all other groups), but not in the thoracic aorta. Plasma lipids were increased in SD mice (P<0.001 vs. all for total cholesterol, P<0.05 vs. E and P<0.01 vs. ED for triglycerides). Plasma concentration of granulocyte-colony stimulating factor (G-CSF) was decreased in SD mice compared to E mice (P<0.05). Thus, social isolation increased atherosclerosis and plasma lipids in ApoE-/- mice. Reduction in plasma G-CSF levels may hamper endothelial regeneration in the atherosclerotic process. While environmental enrichment did not affect atherosclerosis, social isolation accelerated atherosclerosis.

Menopausal Complaints Are Associated With Cardiovascular Risk Factors

It has been hypothesized that women with vasomotor symptoms differ from those without with respect to cardiovascular risk factors or responses to exogenous hormone therapy. We studied whether the presence and extent of menopausal complaints are associated with cardiovascular risk profile. Data were used from a population-based sample of 5523 women, aged 46 to 57 years, enrolled between 1994 and 1995. Data on menopausal complaints and potential confounders were collected by questionnaires. Total cholesterol, systolic and diastolic blood pressures, and body mass index were measured. Linear and logistic regression analyses were used to analyze the data. Night sweats were reported by 38% and flushing by 39% of women. After multivariate adjustment, women with complaints of flushing had a 0.27-mmol/L (95% CI: 0.15 to 0.39) higher cholesterol level, a 0.60-kg/m 2 (95% CI: 0.35 to 0.84) higher BMI, a 1.59-mm Hg (95% CI: 0.52 to 2.67) higher systolic blood pressure, and a 1.09-mm Hg (95% CI: 0.48 to 1.69) higher diastolic blood pressure compared with asymptomatic women. Flushing was also associated with hypercholesterolemia (odds ratio: 1.52; 95% CI: 1.25 to 1.84) and hypertension (OR: 1.20; 95% CI: 1.07 to 1.34). Results were similar for complaints of night sweating. The findings support the view that menopausal complaints are associated with a less favorable cardiovascular risk profile. These findings substantiate the view that differences in the presence of menopausal symptoms as a reason for using hormone therapy could explain discrepant findings between observational research and trials.

Effects of a stress management program on vital exhaustion and depression in women with coronary heart disease: a randomized controlled intervention study

OBJECTIVES

Psychosocial factors, including depression and vital exhaustion (VE) are associated with adverse outcome in coronary heart disease (CHD). Women with CHD are poor responders to psychosocial treatment and knowledge regarding which treatment modality works in them is limited. This randomized controlled clinical study evaluated the effect of a 1-year stress management program, aimed at reducing symptoms of depression and VE in CHD women.

DESIGN

Patients were 247 women, < or =75 years, recruited consecutively after a cardiac event and randomly assigned to either stress management (20 2-h sessions) and medical care by a cardiologist, or to obtaining usual health care as controls. Measurements at; baseline (6-8 weeks after randomization), 10 weeks (after 10 intervention sessions), 1 year (end of intervention) and 1-2 years follow-up.

RESULTS

For VE, intention to treat analysis showed effects for time (P < 0.001) and time x treatment interaction (P = 0.005), reflecting that both groups improved over time, and that the decrease of VE was more pronounced in the intervention group. However, the level of VE was higher in the intervention group than amongst controls at baseline, 22.7 vs. 19.4 (P = 0.036) but it did not differ later. The change in depressive symptoms did not differ between the groups.

CONCLUSIONS

CHD women attending our program experienced a more pronounced decrease in VE than controls. However, as they had higher baseline levels, due to regression towards the mean we cannot attribute the decrease in VE to the intervention. Whether the program has long-term beneficial effects needs to be evaluated.

Social stress profoundly affects lipid metabolism: Over-expression of SR-BI in liver and changes in lipids and lipases in plasma and tissues of stressed mice

We examined the effect of chronic social stress, similar to that endured by humans, on lipid metabolism of mice. The activity of the lipoprotein lipase (LPL) enzyme increased in adrenals, while in plasma it diminished significantly. Hepatic lipase (HL) was strongly affected in liver and adrenal glands, increasing four-fold and three-fold, respectively. At the same time, scavenger receptor class-B type-I (SR-BI), which are considered the high-density lipoprotein (HDL) receptor in the liver, increased significantly. Although the adrenals do not synthesise HL, the increase in HL may facilitate the uptake of HDL cholesterol for the synthesis of corticoids, which increase significantly following chronic stress. The volume of adrenal glands in control animals was significantly higher than in stressed animals (1.23+/-0.12 mm3 versus 0.29+/-0.06 mm3, p<0.001), corresponding with the weight difference of these organs. Medulla volume was also different in the two groups (0.27+/-0.10 mm3 versus 0.04+/-0.02 mm3, p<0.05). Despite this, corticosterone in plasma was significantly higher in stressed animals. Our results shows, for the first time, the effect of chronic social stress on lipid metabolism in general, and in particular on the SR-BI receptor and HL, which is directly involved in cholesterol reverse transport.

The effect of chronic psychological stress on corticosterone, plasma metabolites, and immune responsiveness in European starlings

Although increases in glucocorticoid concentrations during acute stress are believed to help animals survive stressful events, chronic changes in glucocorticoid concentrations can alter metabolism and lead to disease. We studied the effect of chronic psychological stress on corticosterone (CORT), corticosterone binding globulin (CBG), glucose, and triglyceride concentrations as well as immune responsiveness to a T-cell mitogen challenge in European starlings, Sturnus vulgaris. To induce chronic stress we used a chronic stress protocol consisting of five stressors (loud radio, cage tapping, cage rolling, human voice, and bag restraint) administered in random order for 30 min for 4 times/day over 18 days. Total CORT decreased throughout the chronic stress period, which parallels a previous study with starlings. CBG capacity did not significantly change with chronic stress, thus free CORT followed the same pattern of attenuation as total CORT during chronic stress. Despite the change in regulation of CORT release, daytime glucose and triglyceride concentrations did not change with chronic stress. In addition, immune responsiveness in chronically stressed and unstressed birds was similar. Our results, together with a previous study using a similar CSP in European starlings, suggest that starlings physiologically dampen the HPA axis during chronic psychological stress to avoid pathology associated with chronically augmented CORT concentrations such as hyperglycemia and impaired immune function.

New and improved glucocorticoid receptor ligands

The therapeutic and prophylactic use of glucocorticoids is widespread due to their powerful anti-inflammatory, antiproliferative and immunomodulatory activity. However, long-term use of these drugs can result in severe dose-limiting side effects. One of the most critical and debilitating side effects is osteoporosis, which leads to increased risk of fractures. Glucocorticoids damage bone through several different mechanisms. The search for novel glucocorticoids that have reduced side effects in bone and other tissues is being driven by the identification of new mechanisms of action of the glucocorticoid receptor. This may facilitate the detection of new, safer therapies with efficacies equivalent to currently prescribed steroids.

Possible connections among job stress, depressive symptoms, lipid modulation and antioxidants

BACKGROUND

Oxidative/antioxidative status may be related to psychological stress or pathogenesis of depression.

SUBJECTS AND METHODS

Participants were selected from 381 female nurses working in a university hospital, and the Brief Job Stress Questionnaire was utilized to assess them. Nurses with high job stress (JS) (n = 18) and with low JS (n = 15) consented to participate in this study. Depressive symptoms were assessed by the Centre for Epidemiologic Studies Depression scale (CES-D). Cholesterols, lipid peroxidation (malondialdehyde, MDA) and antioxidants in the plasma were measured.

RESULTS

High JS participants exhibited significantly higher CES-D scores (t = 3.34, p < 0.005), and significantly lower concentrations of total cholesterol (TC), low density+very low density lipoprotein cholesterols (LDL+VLDL), alpha-tocopherol, and beta-carotene compared with low JS participants (t = 2.69, p < 0.05; t = 3.46, p < 0.005; t = 2.96, p < 0.05; t = 2.98, p < 0.05, respectively). However, the reductions in plasma indicators were substantially weakened after controlling for lifestyle factors with the exception of LDL+VLDL and alpha-tocopherol. In addition, the significance of alpha-tocopherol concentrations appeared to depend on cholesterol levels. CES-D scores correlated positively with plasma MDA levels, the MDA/TC ratio and the MDA/LDL+VLDL ratio among the low JS group (r = 0.69, p < 0.001; r = 0.79, p < 0.001; r = 0.75, p < 0.005, respectively), whereas there were no correlations among the high JS group. After controlling for lifestyle covariates, the relationship between CES-D scores and the MDA/LDL+VLDL ratio remained significant (beta = 0.95, p < 0.05) using a multiple linear regression model (F = 3.61, p < 0.05).

LIMITATIONS

Sample numbers in each JS group were relatively small.

CONCLUSIONS

Psychological stress may reduce the plasma levels of LDL+VLDL accompanying an alpha-tocopherol decrease. There appeared to be a correlation between elevated MDA and depressive symptoms in low JS participants.

Effects of academic examination stress on eating behavior and blood lipid levels

The influence of academic examination stress on eating behavior and lipid profiles and the moderating effect of dietary restraint, trait anxiety, and social support availability was assessed in university students. One hundred and seventy-nine students were divided into exam-stress groups (51 women, 64 men) and control groups (48 women, 16 men) and were assessed at baseline and then within 2 weeks of exams or an equivalent point for the control group. Perceived stress, emotional well-being, and fasting lipid profiles were measured, and dietary information was collected by interview. The exam-stress group reported significant increases in perceived stress and deterioration in emotional well-being at the exam sessions compared with baseline sessions. No general effects of exam stress on food intake were observed, and there was no interaction between stress and dietary restraint. However, students in the exam-stress group with high trait anxiety and low social support showed significant increases in total energy intake between baseline and exam sessions, whereas individuals with low trait anxiety and high social support showed a reduction in energy intake. Students with high trait anxiety and low social support showed increases between baseline and exam sessions in the amount of fat and saturated fat consumed. Women in the exam-stress group taking oral contraceptives showed a significant increase in total cholesterol between baseline and exam sessions. The results are discussed in relation to the effects of naturally occurring episodic stress on health behavior and on lipid profiles.

Associations between acute lipid stress responses and fasting lipid levels 3 years later

The authors assessed the association between lipid responses to acute mental stress and fasting serum lipid levels 3 years later in 199 middle-aged men and women. Total cholesterol, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) cholesterol increased following moderately stressful behavioral tasks. LDL cholesterol, HDL cholesterol, and total:HDL ratio measured 3 years later were predicted by acute stress responses independent of gender, age, socioeconomic position, change in body mass, smoking, alcohol consumption, or hormone replacement therapy baseline lipid levels. The odds of clinically elevated cholesterol were significantly greater in the highest compared with the lowest stress tertile, independent of baseline levels and covariates. Acute lipid stress responsivity may reflect processes that contribute to the development of elevated blood cholesterol concentration.

Microarousals during sleep are associated with increased levels of lipids, cortisol, and blood pressure

OBJECTIVE

Previous work has demonstrated a link between restricted sleep and risk indicators for cardiovascular and metabolic disease, such as levels of cortisol, lipids, and glucose. The present study sought to identify relations between polysomnographic measures of disturbed sleep (frequency of arousals from sleep, total sleep time, and sleep efficiency) and a number of such indicators. A second purpose was to relate the number of arousals to mood, stress, work characteristics, and other possible predictors in daily life.

METHODS

Twenty-four people (10 men, 14 women; mean age 30 years), high vs. low on burnout, were recruited from a Swedish IT company. Polysomnographically recorded sleep was measured at home before a workday. Blood pressure, heart rate, morning blood sample, and saliva samples of cortisol were measured the subsequent working day. They were also recorded for diary ratings of sleep and stress, and a questionnaire with ratings of sleep, stress, work conditions, and mood was completed.

RESULTS

A stepwise regression analysis using sleep parameters as predictors brought out number of arousals as the best predictor of morning cortisol (serum and saliva), heart rate, systolic and diastolic blood pressure, total cholesterol, high-density lipoprotein (HDL)-, low-density lipoprotein (LDL)-cholesterol, and LDL/HDL-ratio. Work stress/unclear boundaries between work and leisure time was the best predictor of arousals among the stress variables.

CONCLUSION

Consistent with sleep restriction experiments, sleep fragmentation was associated with elevated levels of metabolic and cardiovascular risk indicators of stress-related disorders. Number of arousals also seems to be related to workload/stress.

Cynical hostility, depressive symptoms, and the expression of inflammatory risk markers for coronary heart disease

Although the prognostic significance of depression and hostility has been established, little is known about how they operate together to influence disease processes. This study explored the independent and interactive relationships between these constructs and the expression of inflammatory markers implicated in the pathogenesis of coronary heart disease. One hundred adults completed measures of cynical hostility and depressive symptoms, and had blood drawn to assess serum levels of interleukin-1 beta, interleukin-6, and tumor necrosis factor-alpha. Depression was directly related to inflammatory markers, but hostility was not. A significant interaction between hostility and depression emerged. Among participants scoring low in depressive symptoms, hostility was positively associated with interleukin-6 and tumor necrosis factor-alpha concentrations. Hostility's association with these inflammatory markers was much weaker among participants with moderate depressive symptoms, however, and virtually nil among participants with severe depressive symptoms. Neither depression nor hostility was associated with interleukin-1 beta concentrations. These findings highlight the importance of considering both the independent and interactive relationships among psychosocial characteristics involved in disease.

Vital exhaustion in relation to lifestyle and lipid profile in healthy women

"Vital exhaustion," characterized by fatigue, irritability, and demoralization, precedes new and recurrent coronary events. Biological mechanisms explaining this association are not fully understood. The objective was to investigate the relationship between vital exhaustion, lifestyle, and lipid profile. Vital exhaustion, smoking, body mass index (BMI), alcohol consumption, exercise capacity, and serum lipids were determined in 300 healthy women, aged 56.4 +/- 7.1 years. No statistically significant associations were found between vital exhaustion and lifestyle variables. Divided into quartiles, vital exhaustion was inversely related to high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A1 in a linear fashion after adjustment for age, BMI, exercise capacity, and alcohol consumption. A multivariate-adjusted vital exhaustion-score in the top quartile, as compared to one in the lowest, was associated with 12% lower HDL-C and 8% lower apolipoprotein A1 (p < .05). In conclusion, alterations in lipid metabolism may be a possible mediating mechanism between vital exhaustion and coronary heart disease. The impact of lifestyle variables was weak.

Stress and the inflammatory response: a review of neurogenic inflammation

The subject of neuroinflammation is reviewed. In response to psychological stress or certain physical stressors, an inflammatory process may occur by release of neuropeptides, especially Substance P (SP), or other inflammatory mediators, from sensory nerves and the activation of mast cells or other inflammatory cells. Central neuropeptides, particularly corticosteroid releasing factor (CRF), and perhaps SP as well, initiate a systemic stress response by activation of neuroendocrinological pathways such as the sympathetic nervous system, hypothalamic pituitary axis, and the renin angiotensin system, with the release of the stress hormones (i.e., catecholamines, corticosteroids, growth hormone, glucagons, and renin). These, together with cytokines induced by stress, initiate the acute phase response (APR) and the induction of acute phase proteins, essential mediators of inflammation. Central nervous system norepinephrine may also induce the APR perhaps by macrophage activation and cytokine release. The increase in lipids with stress may also be a factor in macrophage activation, as may lipopolysaccharide which, I postulate, induces cytokines from hepatic Kupffer cells, subsequent to an enhanced absorption from the gastrointestinal tract during psychologic stress. The brain may initiate or inhibit the inflammatory process. The inflammatory response is contained within the psychological stress response which evolved later. Moreover, the same neuropeptides (i.e., CRF and possibly SP as well) mediate both stress and inflammation. Cytokines evoked by either a stress or inflammatory response may utilize similar somatosensory pathways to signal the brain. Other instances whereby stress may induce inflammatory changes are reviewed. I postulate that repeated episodes of acute or chronic psychogenic stress may produce chronic inflammatory changes which may result in atherosclerosis in the arteries or chronic inflammatory changes in other organs as well.

Cortisol and vital exhaustion in relation to significant coronary artery stenosis in middle-aged women with acute coronary syndrome

BACKGROUND

The role of chronic stress in coronary artery disease (CAD) is not well known. Conflicting results have been obtained with regard to the stress hormone cortisol and 'vital exhaustion', a psychological construct defining the effects of long-term stress. We investigated the relationship between chronic stress, assessed by serum cortisol and vital exhaustion, and coronary artery stenosis and the importance of chronic stress in relation to standard risk factors of CAD.

METHODS AND RESULTS

Women, <or=65 years, consecutively admitted to coronary care units presenting with acute coronary syndrome, were examined after 3-6 months regarding morning serum cortisol, vital exhaustion, lifestyle, clinical variables, and coronary artery stenosis. Evaluated from coronary angiography in 238 patients, coronary stenosis was dichotomized to significant vs non-significant luminal narrowing (<50%). Women with coronary stenosis (>or=50%) had elevated cortisol levels compared to the others (p=0.009). A 25% increase of cortisol increased the probability of significant coronary stenosis by 41% (p=0.005). Compared to standard risk variables of CAD, only high-density lipoprotein cholesterol (HDL-C) was a more important predictor. Each 25% decrease of HDL-C increased the probability of significant coronary stenosis by 65% (p=0.0021). Vital exhaustion was not related to coronary stenosis (p=0.47). However, it appeared to have an additive effect as women with both a cortisol level and vital exhaustion score above the sample median, had a near three-fold risk of having CAD, OR=2.85 (95% CI 1.31-6.18), compared to those who did not have this combination. The results remained after adjusting for age, glucose, and use of calcium channel- and beta-blockers.

CONCLUSION

Cortisol, but not vital exhaustion, was independently related to coronary stenosis in women with acute coronary syndrome. The influence of cortisol was important compared to standard risk factors of CAD.

A path model of chronic stress, the metabolic syndrome, and coronary heart disease

OBJECTIVE

We tested a theoretical stress model cross-sectionally and prospectively that examined whether relationships of chronic stress, psychophysiology, and coronary heart disease (CHD) varied in older adult men (N = 47), older adult women not using hormone replacement therapy (HRT) (N = 64), and older adult women using HRT (N = 41).

METHOD

Structural equations examined relationships of CHD with 1) chronic stress (caring for a spouse with Alzheimer's disease and patient functioning), 2) vulnerability (anger and hostility), 3) social resources (supports), 4) psychological distress (burden, sleep problems, and low uplifts), 5) poor health habits (high-caloric, high-fat diet and limited exercise), and 6) the metabolic syndrome (MS) (blood pressure, obesity, insulin, glucose, and lipids).

RESULTS

Caregiver men had a greater prevalence of CHD (13/24) than did noncaregiver men (6/23) (p <.05) 27 to 30 months after study entry. This was influenced by pathways from caregiving to distress, distress to the MS, and the MS to CHD. In men, poor health habits predicted the MS 15 to 18 months later, and the MS predicted new CHD cases over 27 to 30 months. In women, no "caregiving-CHD" relationship occurred; however, 15 to 18 months after study entry women not using HRT showed "distress-MS" and "MS-CHD" relationships. In women using HRT, associations did not occur among distress, the MS, and CHD, but poor health habits and the MS were related.

CONCLUSIONS

In older men, pathways occurred from chronic stress to distress to the metabolic syndrome, which in turn predicted CHD. Older women not using HRT showed fewer pathways than men; however, over time, distress, the MS, and CHD were related. No psychophysiological pathways occurred in older women using HRT.

Stress, inflammation and cardiovascular disease

Various psychosocial factors have been implicated in the etiology and pathogenesis of certain cardiovascular diseases such as atherosclerosis, now considered to be the result of a chronic inflammatory process. In this article, we review the evidence that repeated episodes of acute psychological stress, or chronic psychologic stress, may induce a chronic inflammatory process culminating in atherosclerosis. These inflammatory events, caused by stress, may account for the approximately 40% of atherosclerotic patients with no other known risk factors. Stress, by activating the sympathetic nervous system, the hypothalamic-pituitary axis, and the renin-angiotensin system, causes the release of various stress hormones such as catecholamines, corticosteroids, glucagon, growth hormone, and renin, and elevated levels of homocysteine, which induce a heightened state of cardiovascular activity, injured endothelium, and induction of adhesion molecules on endothelial cells to which recruited inflammatory cells adhere and translocate to the arterial wall. An acute phase response (APR), similar to that associated with inflammation, is also engendered, which is characterized by macrophage activation, the production of cytokines, other inflammatory mediators, acute phase proteins (APPs), and mast cell activation, all of which promote the inflammatory process. Stress also induces an atherosclerotic lipid profile with oxidation of lipids and, if chronic, a hypercoagulable state that may result in arterial thromboses. Shedding of adhesion molecules and the appearance of cytokines, and APPs in the blood are early indicators of a stress-induced APR, may appear in the blood of asymptomatic people, and be predictors of future cardiovascular disease. The inflammatory response is contained within the stress response, which evolved later and is adaptive in that an animal may be better able to react to an organism introduced during combat. The argument is made that humans reacting to stressors, which are not life-threatening but are "perceived" as such, mount similar stress/inflammatory responses in the arteries, and which, if repetitive or chronic, may culminate in atherosclerosis.