Impact of chronic psychological stress on platelet membrane fatty acid composition in a rat model of type 1 diabetes Mellitus.

BACKGROUND: Chronic stress and diabetes mellitus are highly associated with oxidative stress and inflammation, resulting in cell membrane disruption and platelet activity. This study aims to evaluate the impact of chronic psychological stress on the composition of the platelet phospholipid membrane and platelet activation in type 1 diabetes mellitus (T1DM). METHODS: We enrolled 35 mature healthy female Wistar rats and randomly divided them into 4 groups, namely the control group (n = 9), stress group (n = 10), T1DM group (n = 8), and T1DM + Stress group (n = 8). The Wistar rats were treated in different experimental conditions for 28 days while being provided free access to feed and water. The concentration of corticosterone in blood serum and hair samples was measured using a competitive enzyme-linked immunosorbent assay. Gas chromatography-mass spectrometry was conducted to identify the methyl esters of fatty acids (FAs) in the platelet phospholipid membrane. A quantitative determination of 11-dehydro-thromboxane B2 in the blood serum was also performed using a competitive enzyme-linked immunosorbent assay. RESULTS: After 28 days, the concentration of corticosterone in blood serum (ng/mL) was observed to be higher in the stress group as compared to the T1DM and T1DM + Stress groups (P = 0.031 and P = 0.008, respectively). The percentage of C 16:0 FA in the platelet membrane was greater in the T1DM + Stress group, but its levels of C 20:1 omega (ω) 9 FA, including C 18:3ω3 FA, C 20:5ω3 FA, and the total sum of ω3 FAs, were lower as compared to the control group (P = 0.016; P = 0.016; P = 0.031; P = 0.016, P = 0.031). The concentration of 11-dehydro-thromboxane B2 in blood serum (pg/mL) was observed to be higher in the stress group than in rats with T1DM (P = 0.063). CONCLUSION: Chronic psychological stress is related to higher levels of corticosterone, saturated FAs acids in the platelet membrane, and greater platelet activation. This study proves how a low percentage of unsaturated fatty acids in the DM and stress groups indicates the disturbing impact of the oxidative/inflammatory environment to lipid metabolism and neuroendocrine response.

Malondialdehyde, Antioxidant Defense System Components and Their Relationship with Anthropometric Measures and Lipid Metabolism Biomarkers in Apparently Healthy Women.

Cardiovascular diseases are the leading cause of mortality worldwide. Since atherosclerosis, an inflammatory, lipid-driven disease, is an underlying basis for the development of cardiovascular disease, it is important to understand its relationship with confounding factors, such as oxidative lipid degradation. In contrast, circulating antioxidants prevent oxidative lipid damage, and therefore, may be associated with reduced development of atherosclerosis. We aimed to assess oxidative lipid degradation biomarker malondialdehyde (MDA) and antioxidant defense system components, total antioxidant capacity (TAC) and superoxide dismutase (SOD) inhibition rate levels, in healthy women and evaluate their relationships with age, anthropometric measures, and lipid metabolism biomarkers. The study included 86 healthy middle-aged women. MDA in human serum samples was evaluated by HPLC, and the TAC and SOD inhibition rates were measured by photometric methods. MDA was found to be associated with age, total cholesterol, non-HDL cholesterol, apolipoprotein B and triacylglycerols. TAC was shown to be associated with age, BMI, and waist circumference, as well as lipid metabolism biomarkers apolipoprotein B and triacylglycerol, while SOD inhibition rate was only associated with total cholesterol, apolipoprotein B and triacylglycerols. In conclusion, the association of oxidative status indices, MDA, TAC and SOD, with cardiovascular risk factors suggests that they could be additional useful biomarkers in the research of aging, obesity, and atherosclerosis pathogenesis.

Association of hair glucocorticoid levels with sleep quality indicators: a pilot study in apparently healthy perimenopausal and menopausal women.

Background: Poor sleep quality is associated with different physical and mental health diseases. It is proposed that increased hypothalamic-pituitary-adrenal axis activity is a potential contributor affecting sleep pattern and quality. We aimed to analyze the relationship between subjective sleep quality indicators and hair glucocorticoid levels among relatively healthy perimenopausal and postmenopausal women. Methods: A total of 145 women aged 50-64 y.o. were enrolled in the cross-sectional pilot study. Sleep quality was evaluated using the Pittsburgh Sleep Quality Index, while stress level was measured using the Perceived Stress Scale. Hair cortisol and cortisone levels were determined by ultra-high-performance liquid chromatography-tandem mass spectrometry. Results: Statistically significant positive relationship was found between hair cortisol concentration and Pittsburgh sleep quality index score. Similarly, statistically significant positive associations were observed between hair total glucocorticoid level and Pittsburgh sleep quality index, sleep disturbance, and Perceived Stress Scale scores. Subjects with prolonged sleep latency had significantly higher hair cortisol and total hair glucocorticoid concentrations compared with individuals whose sleep latency is not disturbed. Additionally, Chi-squared test indicated that lower hair cortisol concentration was significantly related to better sleep efficiency. Conclusion: Increased hair glucocorticoid (cortisol, cortisone) levels were found to be related with worse sleep quality measured by Pittsburgh sleep quality index score.

Relationship between Oxidative Stress and Left Ventricle Markers in Patients with Chronic Heart Failure.

Oxidative stress is proposed in the literature as an important player in the development of CHF and correlates with left ventricle (LV) dysfunction and hypertrophy in the failing heart. In this study, we aimed to verify if the serum oxidative stress markers differ in chronic heart failure (CHF) patients' groups depending on the LV geometry and function. Patients were stratified into two groups according to left ventricular ejection fraction (LVEF) values: HFrEF (<40% (n = 27)) and HFpEF (≥40% (n = 33)). Additionally, patients were stratified into four groups according to LV geometry: NG-normal left ventricle geometry (n = 7), CR-concentric remodeling (n = 14), cLVH-concentric LV hypertrophy (n = 16), and eLVF-eccentric LV hypertrophy (n = 23). We measured protein (protein carbonyl (PC), nitrotyrosine (NT-Tyr), dityrosine), lipid (malondialdehyde (MDA), oxidizes (HDL) oxidation and antioxidant (catalase activity, total plasma antioxidant capacity (TAC) markers in serum. Transthoracic echocardiogram analysis and lipidogram were also performed. We found that oxidative (NT-Tyr, dityrosine, PC, MDA, oxHDL) and antioxidative (TAC, catalase) stress marker levels did not differ between the groups according to LVEF or LV geometry. NT-Tyr correlated with PC (rs = 0.482, p = 0.000098), and oxHDL (rs = 0.278, p = 0.0314). MDA correlated with total (rs = 0.337, p = 0.008), LDL (rs = 0.295, p = 0.022) and non-HDL (rs = 0.301, p = 0.019) cholesterol. NT-Tyr negatively correlated with HDL cholesterol (rs = -0.285, p = 0.027). LV parameters did not correlate with oxidative/antioxidative stress markers. Significant negative correlations were found between the end-diastolic volume of the LV and the end-systolic volume of the LV and HDL-cholesterol (rs = -0.935, p < 0.0001; rs = -0.906, p < 0.0001, respectively). Significant positive correlations between both the thickness of the interventricular septum and the thickness of the LV wall and the levels of triacylglycerol in serum (rs = 0.346, p = 0.007; rs = 0.329, p = 0.010, respectively) were found. In conclusions, we did not find a difference in serum concentrations of both oxidant (NT-Tyr, PC, MDA) and antioxidant (TAC and catalase) concentrations in CHF patients' groups according to LV function and geometry was found. The geometry of the LV could be related to lipid metabolism in CHF patients, and no correlation between oxidative/antioxidant and LV markers in CHF patients was found.

Prevalence and Variability of Allergen-Specific Immunoglobulin E in Patients with Elevated Tryptase Levels.

BACKGROUND In this paper we report on the link between increased tryptase levels and prevalence of allergen-specific immunoglobulin E (IgE) in patients with anaphylaxis. The main aim of the study was to assess the corelation between elevated tryptase levels and allergen-specific immunoglobulin E (IgE) in anaphylactic reactions, mastocytosis, and other types of allergic reactions. MATERIAL AND METHODS We enrolled 60 adult patients, aged 18-68 years (mean age 45±8 years). The subjects were divided into 3 groups (20 patients in each group) according to the serum tryptase changes: group 1 consisted of patients with anaphylaxis (serum tryptase level ≥11.4 µg/l), group 2 consisted of patients with mastocytosis (serum tryptase level ≥20.0 µg/l), and group 3 consisted of patients with other allergic reactions with no anaphylaxis as an atopic control group (serum tryptase level <11.4 µg/l). The test material was venous blood serum samples. The allergen-specific IgE assay was carried out by immunoblot. Tryptase concentration was determined by immunoenzymatic assay. RESULTS Allergen-specific IgE was found in 73% of all subjects: 75% in the anaphylactic group, 55% in the mastocytosis group, and 90% in the atopic control group. Polysensitization was common and was significantly different among groups. In the atopic group, there were more patients allergic to 4-7 allergens (P<0.05). CONCLUSIONS We did not find a strong correlation between allergen-specific IgE levels and elevated tryptase levels.

Dynamics of Physiological, Biochemical and Psychological Markers during Single Session of Virtual Reality-Based Respiratory Biofeedback Relaxation.

Psychological stress exposure is associated with long-lasting health effects including memory problems, depression, aches and pains, eating disorders, and alcohol or drug use. Thus, there is a need to develop effective stress management strategies that are easy to learn and practice. Respiratory biofeedback is an evidence-based stress management technique presenting breathing-related information to help subjects learn specific breathing skills for relaxation. It is suggested that the use of biofeedback techniques in conjunction with virtual reality makes biofeedback training an even more effective tool for stress management. The current study aimed to investigate dynamics of distinct stress indicators before, after, as well as during one brief virtual reality-based respiratory biofeedback session. Thirty-nine healthy volunteers participated in the study. Individuals provided their saliva samples and evaluated their mood status, fatigue, and strain level before and after the session. The subjects' heart and respiratory rate, heart rate variability, and galvanic skin response measures were recorded during the session. The results showed that after single 12 min relaxation session, there was a significant decrease in salivary cortisol concentration, heart and respiratory rate, as well as decrease in skin conductance values. Self-reported strain, fatigue level, and mood status also significantly improved. VR-based respiratory-biofeedback-assisted relaxation sessions might serve as an effective stress management strategy, as even single session had positive effects on subjects' autonomic nervous system (ANS) and hypothalamic-pituitary-adrenal (HPA) axis activity, as well as self-reported fatigue, strain level, and mood status.

Self-Sampled Gargle Water Direct RT-LAMP as a Screening Method for the Detection of SARS-CoV-2 Infections.

We assessed the viability of self-sampled gargle water direct RT-LAMP (LAMP) for detecting SARS-CoV-2 infections by estimating its sensitivity with respect to the gold standard indirect RT-PCR of paired oro-nasopharyngeal swab samples. We also assessed the impact of symptom onset to test time (STT)-i.e., symptom days at sampling, on LAMP. In addition, we appraised the viability of gargle water self-sampling versus oro-nasopharyngeal swab sampling, by comparing paired indirect RT-PCR results. 202 oro-nasopharyngeal swab and paired self-sampled gargle water samples were collected from hospital patients with COVID-19 associated symptoms. LAMP, indirect and direct RT-PCR were performed on all gargle water samples, and indirect RT-PCR was performed on all oro-nasopharyngeal samples. LAMP presented a sensitivity of 80.8% (95% CI: 70.8-90.8%) for sample pairs with sub-25 Ct oro-nasopharyngeal indirect RT-PCR results, and 77.6% (66.2-89.1%) sensitivity for sub-30 Ct samples with STT ≤ 7 days. STT, independently of Ct value, correlated negatively with LAMP performance. 80.7% agreement was observed between gargle water and oro-nasopharyngeal indirect RT-PCR results. In conclusion, LAMP presents an acceptable sensitivity for low Ct and low STT samples. Gargle water may be considered as a viable sampling method, and LAMP as a screening method, especially for symptomatic persons with low STT values.

Oxidative Properties of Blood-Derived Extracellular Vesicles in 15 Patients After Myocardial Infarction.

BACKGROUND In this study, we investigated the yield and composition of extracellular vesicles (EVs) derived from 40- to 60-year-old healthy male controls and post-myocardial infarction (post-MI) patients' blood samples and assessed their pro-inflammatory and oxidative-related properties. Our study aimed to determine the EV yield and composition differences between both groups and to find out if there were differences between EV-mediated oxidative stress reactions. MATERIAL AND METHODS Fifteen post-MI patients and 25 healthy individuals were included. EVs were isolated by ultracentrifugation and analyzed using nanotracking analysis (NTA), western blotting and fluorescent flow cytometry (FFC). Oxidative stress (OS) in blood samples was identified by measuring malondialdehyde concentration from serum, while EVs-induced OS was measured in the human vein endothelium cells (HUVEC) using H2DCFDA (2',7'-dichlorodihydrofluorescein diacetate) fluorescence as a marker. RESULTS We found higher EVs concentration in healthy controls than in the post-MI group (7.07±3.1 E+10 ml vs 3.1±1.9 E+10 ml, P<0.001) and a higher level of CD9-positive exosomes (MFI 275±39.5 vs 252±13, P<0.001). Post-MI patients' EVs carry pro-oxidative nicotinamide adenine dinucleotide phosphate (NADPH) oxidases isoforms NOX1 (NADPH oxidase 1), NOX5 (NADPH oxidase 5) and NOX2 (NADPH oxidase 2) and anti-oxidative thioredoxin, extracellular signal-regulated kinases 1/2 (ERK1/2), and protein kinase B (Akt B). In the post-MI EVs, there was a higher predominance of enzymes with anti-oxidative effects, leading to weaker OS-inducing properties in the HUVEC cells. CONCLUSIONS We conclude that post-MI patient blood sample EVs have stronger anti- than pro-oxidative properties and these could help fight against post-MI consequences.

Higher Levels of Stress-Related Hair Steroid Hormones Are Associated with the Increased SCORE2 Risk Prediction Algorithm in Apparently Healthy Women.

Cardiovascular diseases (CVDs) are the major cause of death worldwide. Although the importance of conventional CVD risk factors, including older age, male gender, hypertension, obesity, dyslipidemia and hyperglycemia, is well-studied, psychosocial stress, which is considered an independent CVD risk factor, requires further investigation. Thus, we aimed to investigate the association between long-term secretion of stress-related steroid hormones, including cortisol, cortisone and dehydroepiandrosterone, and the 10-year fatal and non-fatal CVD risk estimated by the SCORE2 risk prediction algorithm, as well as traditional CVD risk factors in a group of apparently healthy women. A total of 145 women (aged 50-64 years) participating in the national CVD prevention program were enrolled in the study. Sociodemographic, lifestyle, health-related characteristics, stress, anxiety and sleep quality indicators were evaluated using specific questionnaires. Anthropometric and arterial blood pressure measures were assessed by trained personnel, lipid and glucose metabolism biomarkers were measured using routine methods, and hair steroid hormone levels were determined by ultra-high-performance liquid chromatography-tandem mass spectrometry. The results showed that higher levels of hair cortisol and cortisone are associated with increased SCORE2 values. Moreover, significant associations between hair glucocorticoids and individual cardiovascular risk factors, including obesity, hypertension, dyslipidemia and hyperglycemia, were found. These findings indicate that stress-related hair steroid hormones might be valuable biomarkers for CVD prediction and prevention.

Hair Cortisol, Perceived Stress, and the Effect of Group Dynamics: A Longitudinal Study of Young Men during Compulsory Military Training in Lithuania.

Previous research shows a nonlinear dependency between hair cortisol concentrations and perceived stress levels. This may be due to stress being targeted at the individual level despite it also being a social phenomenon which is often affected by group dynamics. Therefore, the objective of this study was to determine the influence of perceived stress on the hair cortisol level, considering the impact of the variables of group dynamics (interpersonal, task, and norm cohesion). Information was collected on 11 groups of, in total, 112 young men in three phases of time during their compulsory military training (covering nine months in total). The classification and regression tree (C&RT) method was used to predict hair cortisol concentrations in groups. The results show that the variability of the hair cortisol level in young men groups can be explained by perceived stress only when the groups were in formation process (47.7% normalised importance in Model 1) and when the groups were working on their final tasks (37.80% normalised importance in Model 3); meanwhile, the importance of perceived stress in explaining hair cortisol concentrations is low when the group is in a routine period of a group life-span (28.9% normalised importance in Model 2). Interpersonal cohesion (normalised importance 100% in Model 1 and 80.0% in Model 3) and task cohesion (normalised importance 78.6% in Model 2) were the most important predictors in the study area. These results point to the importance of the elements of group dynamics when it comes to explaining the nature of hair cortisol as accumulated stress biomarkers in young men.

Perceived stress and hair cortisol levels amongst conscripts during basic military training: A repeated measures study.

The aim was to examine hair cortisol levels and self-reported stress amongst conscripts during their basic military training, and how they are related to four types of theory-derived determinants. The following prediction was made: lower levels of perceived stress and hair cortisol will be associated with: (1) higher levels of emotional stability (the individual nonmilitary aspect); (2) a lower degree of private life problems (the contextual nonmilitary aspect); (3) more positive attitudes toward the military, higher engagement in military service, and higher adaptability to military conditions (the individual-military aspect); and (4) stronger group cohesion and better leadership (the contextual-military aspect). The sample consisted of a total of 107 male Lithuanian conscripts. Assessments were made at the beginning of their basic military training, in the middle, and at the end. Established instruments were used on all self-reported scales. Hair cortisol levels were established through analyses of hair samples. Low to moderate levels of stress were found throughout the basic training period regarding perceived stress levels. Hair cortisol levels were mainly unrelated to the self-rating scales. Regarding perceived stress, the prediction was fully confirmed. The future value of the theoretical model is discussed.

Effects of Virtual Reality-Based Relaxation Techniques on Psychological, Physiological, and Biochemical Stress Indicators.

Various relaxation techniques could benefit from merging with virtual reality (VR) technologies, as these technologies are easily applicable, involving, and user-friendly. To date, it is unclear which relaxation technique using biofeedback combined with VR technology is the most effective. The study aimed to compare the effectiveness of brief VR-based biofeedback-assisted relaxation techniques including electroencephalographic biofeedback, mindfulness-based biofeedback, galvanic skin response biofeedback, and respiratory biofeedback. Forty-three healthy volunteers (age 34.7 ± 7.2 years), comprising 28 (65%) women and 15 (35%) men, were enrolled in the study. All the participants were exposed to four distinct relaxation sessions according to a computer-generated random sequence. The efficacy of relaxation methods was evaluated by examining psychological, physiological, and biochemical stress indicators. All VR-based relaxation techniques reduced salivary steroid hormone (i.e., cortisol, cortisone, and total glucocorticoid) levels and increased galvanic skin response values. Similarly, all interventions led to a significantly reduced subjectively perceived psychological strain level. Three out of the four interventions (i.e., electroencephalographic, respiratory, and galvanic skin response-based biofeedback relaxation sessions) resulted in a decreased self-reported fatigue level. We suggest that newly developed VR-based relaxations techniques are potential tools for stress reduction and might be particularly suitable for individuals who are not capable of adhering to a strict and time-consuming stress management intervention schedule.

The Association between Endogenous Hair Steroid Hormones and Social Environmental Factors in a Group of Conscripts during Basic Military Training.

This study aimed to analyse the association between endogenous hair steroid hormones as reliable biological indicators of an individual's stress level and the social environmental factors experienced during military training that are manifested at the beginning of compulsory military service. Hair steroid hormone concentrations-cortisol, cortisone, dehydroepiandrosterone (DHEA), and testosterone-in a group of 185 conscripts were measured using the ultra-high performance liquid chromatography-tandem mass spectrometry method. Six subjective social environmental factors in the military-attitude towards the military and military service, adaptation to the military environment, team, task, and norm cohesion, as well as psychological (un)safety in the group-were evaluated using military-specific research questionnaires. Weak but significant negative correlations were identified between cortisol and adaptation (r = -0.176, p < 0.05), attitude (r = -0.147, p < 0.05) as well as between testosterone and task cohesion (r = -0.230, p < 0.01) levels. Additionally, a multiple forward stepwise regression analysis highlighted that cortisone variation might be partially explained by task cohesion; the DHEA-determined by psychological (un)safety in the group, attitude towards the military and military service, and norm cohesion; and the testosterone-determined by task cohesion and adaptation to the new military environment. The results of this study suggest that subjective measures of social factors can be used to predict hair steroid hormone levels as objective measures of the chronic stress perceived by conscripts during their basic military training.

Association between hair cortisol concentration and metabolic syndrome.

Metabolic syndrome (MetS) is a highly prevalent disorder defined as a cluster of cardiometabolic risk factors including obesity, hyperglycemia, hypertension, and dyslipidemia. It is believed that excessive cortisol secretion due to psychosocial stress-induced hypothalamic-pituitary-adrenal axis activation might be involved in the pathogenesis of MetS. We sought to explore the association between MetS and psychosocial risk factors, as well as cortisol concentration measured in different biological specimens including saliva, blood serum, and hair samples. The study was conducted on a sample of 163 young and middle-aged men who were divided into groups according to the presence of MetS. Hair cortisol concentration (HCC) was determined using high performance liquid chromatography with UV detection, while blood serum and salivary cortisol levels were measured by enzyme-linked immunoassay. Lipid metabolism biomarkers were determined using routine laboratory methods. Anthropometric and lifestyle characteristics, as well as self-reported psychosocial indicators, were also examined. Significantly higher HCC and lower social support level among participants with MetS compared with individuals without MetS were found. However, no significant differences in blood serum and salivary cortisol levels were observed between men with and without MetS. In conclusion, chronically elevated cortisol concentration might be a potential contributing factor to the development of MetS.

Association of salivary steroid hormones and their ratios with time-domain heart rate variability indices in healthy individuals.

BACKGROUND: Stress system consists of the hypothalamicpituitary-adrenal (HPA) axis and the locus caeruleus/norepinephrine-autonomic nervous system (ANS). Traditionally, HPA axis activity is evaluated by measuring its end-product cortisol, while the activity of ANS is assessed using heart rate variability (HRV) indices. Alterations in cortisol levels and HRV measures during laboratory-based stress tasks were extensively studied in previous research. However, scarce data exist on the associations of HRV measures with the levels of other adrenal steroid hormones under baseline conditions. Thus, we aimed to evaluate the activity of the HPA axis by measuring salivary cortisol, cortisone, dehydroepiandrosterone (DHEA) levels, and their ratios and to examine its association with HRV measures in a sample of healthy young and middle-aged adults. METHODS: For each participant (n=40), three data collection sessions taking place at the same time of the day were scheduled within five working days. Participants completed a self-reported questionnaire on sociodemographic and lifestyle characteristics, filled out t h e Perceived Stress Scale and State-Trait Anxiety Inventory. Also, saliva samples were collected, and physiological measures, including resting HR and HRV, were recorded during three data collection sessions. RESULTS: Statistically significant associations between diminished parasympathetic vagal tone evaluated by time domain HRV measures and higher salivary cortisol, lower DHEA levels, as well as decreased DHEA to cortisol ratio, were found. Also, physiological stress indicators (i.e., HRV) showed greater intraindividual stability compared with biochemical biomarkers (i.e., salivary steroid hormones) within five days. CONCLUSIONS: Our findings suggest that both cortisol and DHEA mediate the link between two stress-sensitive homeostatic systems.

Relationship Between Composition of Fatty Acid in Platelet Phospholipid Membrane and Markers of Oxidative Stress in Healthy Men and Men After a Myocardial Infarction.

BACKGROUND Oxidative stress (OS) is known to be extremely damaging for phospholipids in cell membranes, especially their polyunsaturated fatty acids (PUFAs). OS is known to be associated with increased platelet activation and thrombosis, which lead to cardiovascular lesions. The aim of this study was to investigate how changes in the composition of fatty acids (FAs) in the platelet phospholipid membrane correlate with OS in healthy men and in men who have experienced a myocardial infarction (post-MI men). MATERIAL AND METHODS FA methyl esters from the platelet phospholipid membrane of 79 apparently healthy and 20 post-MI men were identified using gas chromatography/mass spectrometry. Malondialdehyde (MDA) was measured in the blood serum using high-performance liquid chromatography, and platelet-white blood cell aggregates (PWAs) were analysed based on whole-blood flow cytometry. The composition of platelet membrane FAs was compared to MDA concentration (µg/l) and the percentage of PWA formation between healthy men and individuals who had suffered a myocardial infarction (MI). RESULTS Statistically, post-MI patients had a significantly higher concentration of blood serum MDA than those in the control group (p=0.000). The level of PUFAs was also higher in the platelet phospholipid membrane of post-MI patients than in healthy individuals (p=0.016). However, the percentage of PWA formation was lower in patients compared with the control group (p<0.05). CONCLUSIONS A higher level of blood serum MDA concentration due to OS stimulates platelets to incorporate more PUFAs into the phospholipid membrane, thereby affecting platelet activation. This may lead the individual to develop cardiovascular diseases in the future.

Changes in circulating endothelial microvesicles in men after myocardial infarction.

PURPOSE: The objective of the study was to determine the differences in the numbers of endothelial microvesicles (EMV) after myocardial infarction (MI) and their association with oxidative stress. MATERIALS AND METHODS: We included 15 post MI patients and 28 healthy controls. Samples were analysed by flow cytometry. We examined four EMV populations: 1) CD144+, CD42a-, CD61-, 2) CD144+, CD42a+, CD61-, 3) CD105+, CD42a-, CD61-and 4) CD31+, CD42a-, CD61-and determined a percentage of CD62e + EMV. Malondialdehyde concentration was determined by ultra-high performance liquid chromatography. RESULTS: The median of EMV counts differed between controls and patients in: CD105+ (10.91 microvesicles/µl vs. 33.68 microvesicles/µl, P = 0.006), CD144+, CD42a+ (312.87 microvesicles/µl vs. 73.29 microvesicles/µl, P < 0.001) and CD31+ (2 microvesicles/µl vs. 1.38 microvesicles/µl, P = 0.021). The median of percentage of CD62e expression differed between controls and patients in: CD105+ (1.35% vs. 14.8%, P < 0.001), CD144+, CD42a+ (56.45% vs. 98.99%, P < 0.001) and CD144+, CD42a- (173.03% vs. 215.56%) EMV. In patients, EMV counts correlated with low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C) concentrations: CD105+: R = -0.69, P = 0.004 (LDL-C), R = -0.64, P = 0.01 (TC); CD144+, CD42a-: R = -0.68, P = 0.005 (LDL-C), R = -0.63, P = 0.011 (TC); CD144+: R = -0.54, P = 0.038 (HDL-C) and CD144+, CD42a-, CD62e+: R = 0.78, P = 0.001 (HDL-C). In controls, HDL-C concentration correlated with CD105+ (R = -0.395, P = 0.038) and CD105+, CD62e+ (R = -0.716, P < 0.001) counts. Malondialdehyde concentration correlated with CD144+, CD42a- (P = 0.01, R = 0.48) and CD105+, CD62e+ (P = 0.012, R = 0.47) counts. CONCLUSIONS: Changes in EMV levels after the MI period were observed. Counts of EMV and their CD62e expression correlated with dyslipidaemia and oxidative stress.

Lower than average HDL cholesterol efflux capacity in Lithuanian population.

BACKGROUND: The aim of our study was to evaluate high-density lipoprotein cholesterol (HDL-C) efflux capacity in healthy controls and patients with severe dyslipidemia. Evaluation of HDL function may be beneficial for better understanding of cardiovascular diseases, as well as for taking actions to minimize residual cardiovascular risk. METHODS: During 2016-2017 a total of 93 participants - 48 (51.6%) women and 45 (48.4%) men - were included in this cross-sectional study. Data of 45 (48.4%) participants with severe dyslipidemia (SD) and 48 (51.6%) controls without dyslipidemia was used for statistical analysis. Total lipid panel, concentration of lipoprotein (a) and apolipoproteins were measured, data about cardiovascular risk factors were collected and detailed evaluation of HDL-C quality was performed for all patients. RESULTS: Increased HDL-C concentration was associated with higher ApoA1 (r = 0.866 in controls, r = 0.63 in SD group), ApoA2 (r = 0.41 in controls, r = 0.418 in SD group) and LDL-C concentrations (r = - 0.412 in SD group), lower ApoE (r = - 0.314 in SD group) and TG concentrations (r = - 0.38 in controls, r = - 0.608 in SD group), lower ApoB/ApoA1 ratio (r = - 0.567 in control group), below average HDL-C efflux capacity (r = - 0.335 in SD group), lower BMI (r = - 0.327 in controls, r = - 0.531 in SD group) and abdominal circumference (r = - 0.309 in women with SD). Below-average HDL-C efflux capacity was found in 67.7% (N = 63) of participants. It was more often found among patients with normal weight or BMI 30-31 kg/m2. HDL-C efflux capacity was inversely associated with HDL-C concentration (r = - 0.228). CONCLUSION: Abnormal HDL function may be associated with residual cardiovascular risk in Lithuanian population.

Association of Platelet Membrane Fatty Acid Composition with Markers of Oxidative Stress in Healthy Men.

BACKGROUND Platelet membranes are extremely susceptible to peroxidation, forming a variety of lipid peroxides, including malondialdehyde (MDA), which has been implicated in the etiology of cardiovascular diseases. Moreover, platelet-leukocyte aggregates (PLAs) are known to contribute to advanced endothelial injury and atherogenesis. MATERIAL AND METHODS Fatty acid (FA) methyl esters of the platelet membranes of 79 apparently healthy men without any acute clinical condition at the time of the study were identified by GC/MS. MDA was measured by HPLC in blood serum, and PLAs were analyzed by whole-blood flow cytometry. Individuals were divided into quartiles according to MDA concentration and percentage of PLAs formation. The composition of platelet membrane FAs was compared to MDA concentration and the percentage of PLAs formation in apparently healthy individuals. RESULTS In quartiles (Q) with higher MDA concentration, percentage of C 16: 1ω7 (Q1 vs. Q3, p=0.021), C 20: 1ω9 (Q2 vs. Q4, p=0.028) and C 20: 5ω3 (Q2 vs. Q4, p=0.046) was lower. However, C 22: 5ω3 (Q1 vs. Q4, p=0.038) and total ω3 (Q1 vs. Q2, p=0.024) were higher. CONCLUSIONS MDA and the formation of platelet-monocyte aggregates stimulate the incorporation of monounsaturated fatty acids and polyunsaturated fatty acids in platelet phospholipid membranes, which may be a hallmark for a changed level of biologically active compounds required for the activation of future platelets.

Association of Hair Cortisol Concentration with Prevalence of Major Cardiovascular Risk Factors and Allostatic Load.

BACKGROUND The high prevalence of cardiovascular diseases cannot be explained completely by conventional risk factors such as older age, smoking, diabetes mellitus, hypertension, obesity, and dyslipidemia. Results of recent studies indicate that chronic stress may be an independent risk factor for cardiovascular morbidity and mortality. Thus, the aim of our study was to investigate the associations between the hair cortisol concentration (HCC), which is considered as a potential biomarker of long-term psychosocial stress, and traditional cardiovascular risk factors, including smoking, dyslipidemia, hypertension, and obesity. MATERIAL AND METHODS Fasting blood samples and anthropometric and lifestyle data were collected from 163 apparently healthy men. HCC was determined using high-performance liquid chromatography. Allostatic load (AL) index, defined as an integrated score of multiple interacting systems involved in the adaptation to adverse physical or psychosocial situations, was also calculated. RESULTS We found that many prevalent cardiovascular risk factors, including hypertension, smoking, higher than recommended waist circumference (WC), and low-density lipoprotein cholesterol (LDL-C) median values, are associated with higher HCC. Hair cortisol level was also positively associated with the manifestation of individual cardiovascular risk factors such as higher-than-recommended total cholesterol, LDL-C, non-high-density lipoprotein cholesterol, body mass index, and WC median values. Moreover, a significant positive relationship between HCC and AL index was observed. CONCLUSIONS The results of this study suggest that increased prevalence of traditional cardiovascular risk factors is associated with higher HCC. Also, both HCC and AL index might be appropriate markers for the evaluation of chronic stress level.