The use of bioluminescent enzyme bioassay for the analysis of human saliva: Advantages and disadvantages.

The purpose of the work was to find optimal conditions for bioluminescent enzymatic analysis of saliva (based on the use of NADH:FMN oxidoreductase + luciferase) and then to determine the biological effect of using bioluminescence assay of saliva to study the physiological state of the body under normal and pathological conditions. The saliva of snowboarders and students were studied in the "rest-training" model. The saliva of patients diagnosed with acute pharyngitis was examined in the "sick-healthy" model. Bioluminescence assay was performed with a lyophilized and immobilized bi-enzyme system using cuvette, plate, and portable luminometers. The concentrations of secretory immunoglobulin A (sIgA) and cortisol were determined by enzyme immunoassay, and the total protein content was measured by spectrophotometric method. The activity of the bioluminescent system enzymes increased as the amount and volume of saliva in the sample was decreased. The cuvette and plate luminometers were sensitive to changes in the luminescence intensity in saliva assay. Luminescence intensity correlated with the concentrations of sIgA and cortisol. The integrated bioluminescent index for saliva was reduced in the "rest-training" model and increased in the "sick-healthy" model. Thus, the non-invasive bioluminescent saliva analysis may be a promising tool for assessing the health of the population.

Rank, stress, and risk: A conjecture.

A perception at the core of studies that consider the link between social rank and stress (typically measured by the so-called stress hormone cortisol) is that the link is direct. Examples of such studies are Bartolomucci (2007), Beery and Kaufer (2015), and Koolhaas et al. (2017). A recent and stark representation of this body of work is a study by Smith-Osborne et al. (2023), who state that "social hierarchies directly influence stress status" (Smith-Osborne et al. p. 1537, italics added). In the present paper, we reflect on this "direct" perspective. We conjecture that the link between social rank and stress involves an intervening variable: an indirect relationship arises when the loss of rank triggers a behavioral response in the form of risk taking aimed at regaining rank, and it is the engagement in risk-taking behavior that is the cause of an elevated level of cortisol. Smith-Osborne et al., as well as others whose papers are cited by Smith-Osborne et al. and who, like Creel (2001) and Avitsur et al. (2006), conducted comprehensive research on the association between rank (social standing) and stress, do not refer to risk taking at all. We present four strands of research that lend support to our conjecture: evidence that in response to losing rank, individuals are stressed; evidence that in response to losing rank, individuals resort to risk-taking behavior aimed at regaining their lost rank; evidence that there exists a link between engagement in risky activities or exposure to risk and elevated levels of cortisol; and an analytical perspective on incidence and intensity, namely a perspective that shows how the willingness to take risks responds to a change in rank, specifically, how a loss of rank triggers a greater willingness to take risks and how this trigger is stronger for individuals whose rank is higher.

Salivary analysis to unveil the paradigma of stress of domestic horses reared in the wild.

Horse welfare is the product of multiple factors, including behavioral and physiological adjustments to cope with stressful situation regarding environment and housing condition. Collectively, it is supposed that a horse kept in the wild has a lower level of stress than other housing system, and the aim of the present study was to investigate the level of stress in domestic horses reared in the wild and then moved to human controlled housing, through saliva analysis. Twelve clinically healthy Catria (Italian local breed) mares, usually reared in the wild, were moved into collective paddocks for a folkloric event. Saliva samples were obtained before and after the change of housing condition to evaluate stress biomarkers including salivary cortisol, salivary alpha-amylase, and butyrylcholinesterase (BChol). The mares were also scored using the Welfare Aggregation and Guidance (WAG) Tool to highlight the presence of abnormal behaviors. Despite the absence of differences in behavioral scores between wild and paddocks, salivary cortisol and BChol were found to be higher in the wild and lower when mares were moved to paddocks. The highest concentrations in stress biomarkers like salivary cortisol and BChol in the wild was unexpected, but the need for managing hierarchical relationships, and the exposure to feral animals, predators, and weather changes, might explain these findings. The overall results of the present study may provide further knowledge toward stress response in domesticated horses living in the wild moved to human controlled housing system.

Long-term, medium-term and acute stress response of urban populations of Eurasian red squirrels affected by different levels of human disturbance.

Animals in urban areas often encounter novel and potentially stressful conditions. It is important to understand how wildlife cope with anthropogenic disturbance. To investigate this specific adaptation we live-trapped squirrels in two study sites in Warsaw: a forest reserve and an urban park and we estimated stress responses at three levels: long-term and medium-term stress (the level of stress hormones, i.e. cortisol and cortisone concentrations, in hair and feces) and acute reaction to human-induced stress (measured during handling with the aid of the three indices: breath rate, struggle rate, and vocalization). According to GLMM models no difference in the stress hormones level was found between the two populations. The only differences in cortisol concentrations clearly depended on the season, i.e. being higher in autumn and winter comparying to other seasons. There was no influence of sex, or reproductive status on stress hormones. Forest squirrels had significantly higher breath rates, suggesting they were more stressed by handling. There was no difference in the struggle rate between study areas, this index was mostly affected by season (i.e. being highest in winter). First-trapped squirrels vocalized less than during the subsequent trappings. Assumingly, during the first, and more stressful trapping, squirrels used 'freezing' and/or little vocalization, while during next captures they used alarm calls to warn conspecifics. Overall, we showed that the two squirrel populations differed only in terms of their breath rate. This suggests that they did not differ in medium-term and long-term stress in general, but they can differ in acute response to handling. This also suggests that both populations were similarly affected by environmental factors. The lack of clear effects may also be due to population heterogeneity. Thus, in order to assess the effects of anthropogenic stressors a broader range of indicators and diverse analytical methods, including behavioral analyses, should be employed.

Psychophysiological effects of walking in forests and urban built environments with disparate road traffic noise exposure: study protocol of a randomized controlled trial.

BACKGROUND: Stress is a widespread phenomenon and reality of everyday life, entailing negative consequences for physical and psychological wellbeing. Previous studies have indicated that exposure to greenspaces and nature-based interventions are promising approaches to reducing stress and promoting restoration. However, an increasing percentage of the population lives in urban regions with limited opportunities to spend time in greenspaces. In addition, urban settings typically feature increased levels of noise, which represents a major environmental stressor. Although various studies have compared the effects of exposure to greenspaces versus urban built environments, evidence of the effects of noise in this context is very limited. Psychophysiological benefits of exposure to greenspaces compared to urban built environments reported in earlier studies might be less (or at least not only) due to features of the greenspaces than to additional stressors, such as road traffic noise in the urban built environment. Hence, differences in the effects attributed to greenness in previous studies may also be due to potentially detrimental noise effects in comparison settings. This paper reports the study protocol for a randomized, controlled intervention study comparing the effects of walking in forest versus urban built environments, taking road traffic noise exposure during walks in the respective settings into account. METHODS: The protocol envisages a field study employing a pretest-posttest design to compare the effects of 30-min walks in urban built environments and forests with different road traffic noise levels. Assessments will consist of self-reported measures, physiological data (salivary cortisol and skin conductance), an attention test, and noise, as well as greenness measurements. The outcomes will be restoration, stress, positive and negative affect, attention, rumination, and nature connectedness. DISCUSSION: The results will inform about the restorative effect of walking in general, of exposure to different types of environments, and to different noise levels in these sites. The study will provide insights into the benefits of walking and nature-based interventions, taking into account the potential detrimental effects of noise exposure. It will thus facilitate a better understanding of low-threshold interventions to prevent stress and foster wellbeing. TRIAL REGISTRATION: ISRCTN48943261 ; Registered 23.11.2023.

A low-fouling electrochemical biosensor based on BSA hydrogel doped with carbon black for the detection of cortisol in human serum.

Electrochemical biosensors with high sensitivity can detect low concentrations of biomarkers, but their practical detection applications in complex biological environments such as human serum and sweat are severely limited by the biofouling. Herein, a conductive hydrogel based on bovine serum albumin (BSA) and conductive carbon black (CCB) was prepared for the construction of an antifouling biosensor. The BSA hydrogel (BSAG) was doped with CCB, and the prepared composite hydrogel exhibited good conductivity originated from the CCB and antifouling capability owing to the BSA hydrogel. An antifouling biosensor for the sensitive detection of cortisol was fabricated by drop-coating the conductive hydrogel onto a poly(3,4-ethylenedioxythiophene) (PEDOT) modified electrode and further immobilizing the cortisol aptamer. The constructed biosensor showed a linear range of 100 pg mL-1 - 10 µg mL-1 and a limit of detection of 26.0 pg mL-1 for the detection of cortisol, and it was capable of assaying cortisol accurately in complex human serum. This strategy of preparing antifouling and conductive hydrogels provides an effective way to develop robust electrochemical biosensors for biomarker detection in complex biological media.

Aptamer-aided plasmonic nano-urchins for reporter-free surface-enhanced Raman spectroscopy analysis of cortisol.

Cortisol is a vital glucocorticoid hormone reflecting stress levels and related disease processes. In this study, we report an aptamer-functionalized plasmonic nano-urchin (α-FeOOH@Au-aptamer)-aided cortisol-capturing and surface-enhanced Raman spectroscopy (SERS) analysis approach. The designed α-FeOOH@Au-aptamer exhibits a well-patterned plasma structure, which combines the good SERS enhancement ability of reduced nanogaps between the Au plasma and the hot spot-favored structure of anisotropic tips from α-FeOOH urchins, with the high affinity of the aptamer towards cortisol molecules. The α-FeOOH@Au-aptamer achieved reporter-free SERS quantification for cortisol with good sensitivity (limit of detection <0.28 µmol L-1), robust salt (1.0 mol per L NaCl) and protein (5.0 mg per mL bovine serum protein) tolerance, favorable reproducibility, as well as good reusability. We further demonstrated the good cortisol-capturing ability and SERS efficacy of the α-FeOOH@Au-aptamer profiling in the serum and urine samples. Our approach provides an alternative tool for cortisol analysis and a reference strategy for report-free SERS detection of small molecules.

Chronic stress, social support, and symptoms at midlife. Is there a buffering effect?

OBJECTIVES: This study was designed to examine associations among measures of stress, social support, and symptoms at midlife. Specifically, the study examined whether support buffered against the negative effects of stress on severity of symptoms grouped via factor analyses into emotional instability, vaso-somatic symptoms, mood disturbances, and aches and pains. METHODS: We used cross-sectional data from n = 119 women aged 40-55 in Nagaland, India. Midlife symptoms were measured with the help of questionnaires, and factor analysis was used to identify latent factors. Stress and social support were measured by Perceived Stress Scale and Multidimensional Scale of Perceived Social Support, respectively. Chronic stress was measured by fingernail cortisol. RESULTS: After adjusting for menopausal status, tobacco use, body mass index, and socioeconomic status, cortisol level was positively associated with emotional instability (p < 0.01), vaso-somatic symptom score (p < 0.05), and total symptoms at midlife (p < 0.05). Familial support was negatively associated with emotional instability (p < 0.05) and total symptoms at midlife (p < 0.05). However, no significant associations were observed with spousal or friend support. Although no significant interactions between stress, social support, and symptoms at midlife were observed, spousal support when stratified as high and low support using the means, perceived stress and vaso-somatic symptoms indicated an interaction. CONCLUSION: Cortisol level and support from family were independently associated with symptoms at midlife. The study highlights the importance of family ties and support for navigating the stressors of everyday life among women in Nagaland.

A dilute and shoot method for urinary free cortisol analysis by LC-MS/MS.

24-hour urinary free cortisol (UFC) is considered as the first-line test for screening and diagnosis of Cushing's syndrome. Although 24-hour UFC assay has been extensively studied by liquid chromatography-tandem mass spectrometry (LC-MS/MS), an accurate assay coupled with a reliable sample preparation procedure and a method-specific reference interval would be very important for reasonable diagnosis. In this study, a simple dilute and shoot method has been proposed for UFC determination by LC-MS/MS. Namely, 50 µL of urine sample was mixed with 200 µL of a 50 % methanol/water solution containing the internal standard cortisol-13C3. The mixture was centrifuged and the supernatant was used for direct analysis by LC-MS/MS. This method was validated with wide linear range from 0.625 to 500 ng/ml with coefficients of variation (CVs) ≤ 3.64 %, excellent precision (intra-day CVs ≤ 5.70 % and inter-day CVs ≤ 5.33 %) and good recovery in the range of 93.3-109 %. The preservatives were further evaluated for urine storage. It was recommended that no preservatives could be used in collection of 24-hour urine for good detecting peaks. The investigation of reference interval and diagnostic performance finally confirmed the potential usage of this LC-MS/MS assay in routing clinical testing.

Feeding under fire: Relations between parental stress hormones and controlling feeding behaviors.

Under stress, parents tend to use more controlling feeding behaviors toward their children (Berge et al., 2017; Doan et al., 2022; Loth et al., 2016). However, the majority of prior work focuses on subjective reports of stress, and there is a dearth of research examining parental physiological stress and its impact on feeding behaviors. In the current study, we examined how parental physiological stress reactivity would influence their feeding behaviors under mild stress in a lab-based setting. Parents (n = 83, 50 % females) and their children (59% female, Mage = 42 months, SD = 4.48) participated. Stress was induced using the Trier Social Stress Test in the laboratory (Kirshbaum et al., 1993). Salivary samples were collected at 4 time points during the visit to index stress reactivity and later assayed for cortisol and DHEA. Parent-child interactions during the anticipatory period of the stress test were observationally coded for parent use of controlling feeding behaviors. To examine whether parent stress physiology predicts their feeding behaviors, we ran a Poisson regression using income, parent ethnicity, parent sex (mom/dad), time of day, and DHEA/cortisol ratio as predictors of controlling feeding behavior. Latinx parents used less controlling feeding behaviors, b = -0.323, p = 0.041 than non-Latinx parents. Parents with a higher DHEA/Cortisol ratio were less likely to use controlling feeding behaviors, b = -0.231, p = 0.008. To our knowledge, this is the first study to show that for both mothers and fathers, DHEA relative to cortisol has a protective role in controlling feeding practices, and lends support to the role of acute stress reactivity in predicting behavioral outcomes.

Wearable Sensing Device Integrated with Prestored Reagents for Cortisol Detection in Sweat.

Wearable sweat sensors have achieved rapid development since they hold great potential in personalized health monitoring. However, a typical difficulty in practical processes is the control of working conditions for biorecognition elements, e.g., pH level and ionic strength in sweat may decrease the affinity between analytes and recognition elements. Here, we developed a wearable sensing device for cortisol detection in sweat using an aptamer as the recognition element. The device integrated functions of sweat collection, reagent prestorage, and signal conversion. Especially, the components of prestored reagents were optimized according to the inherent characteristics of sweat samples and electrodes, which allowed us to keep optimal conditions for aptamers. The sweat samples were transferred from the inlet of the device to the reagent prestored chamber, and the dry preserved reagents were rehydrated with sweat and then arrived at the aptamer-modified electrodes. Sweat samples of volunteers were analyzed by the wearable sensing device, and the results showed a good correlation with those of the ELISA kit. We believe that this convenient and reliable wearable sensing device has significant potential in self-health monitoring.

Interplay of Adolescents' and Parents' Mindsets of Socioeconomic Status on Adolescents' Stress-Related Outcomes.

The reciprocity and variation of values and beliefs are dynamic features of the parent-child relationship. Parents and adolescents may hold congruent or incongruent views regarding the malleability of socioeconomic status (mindset of SES), potentially influencing adolescents' psychological and physiological stress outcomes, as reflected in stress perceptions and the hypothalamic-pituitary-adrenal (HPA) axis functioning. The current study investigated how patterns of parent-adolescent congruence and incongruence in mindset of SES were associated with adolescents' perceived stress and diurnal cortisol patterns four months later. A total of 253 adolescents (Mage = 12.60, 46.2% girls) and their parents (Mage = 40.09 years, 59.5% mothers) participated in this study. Polynomial regression analyses and response surface analyses showed that adolescents perceived lower levels of stress when they themselves or their parents reported a stronger growth mindset of SES. Additionally, adolescents with a stronger growth mindset of SES also exhibited a steeper diurnal cortisol slope. Moreover, parents' mindset significantly interacted with adolescents' mindset to influence adolescents' diurnal cortisol patterns such that when adolescents hold weaker growth mindset of SES, those with higher parental growth mindsets had significantly higher cortisol awakening response and steeper diurnal cortisol slope. Furthermore, adolescents who showed incongruence with their parents but had averagely stronger growth mindsets of SES reported a significantly steeper diurnal cortisol slope than those who had averagely weaker growth mindsets with their parents. The findings point to the beneficial impacts of the growth mindset of SES on stress-related outcomes among adolescents, as well as the significance of considering both parents' and adolescents' mindsets when exploring these associations.

Systematic evaluation of benzoylation for liquid chromatography-mass spectrometry analysis of different analyte classes.

LC-MS is an indispensable tool for small molecule analysis in many fields; however, many small molecules require chemical derivatization to improve retention on commonly used reversed-phase columns and increase ionization. Benzoyl chloride (BzCl) derivatization is commonly used for derivatization of primary and secondary amines and phenolic alcohols, though evidence exists that with proper reaction conditions (i.e., specific bases), other hydroxyl groups may be derivatized too. Previous studies have examined BzCl concentration, reaction times, and reaction temperatures for derivatization of amines and phenols for LC-MS analysis; however, use of different bases, base concentration, and extending to conditions to hydroxyl groups for LC-MS analysis has not been well-studied. To address this understudied area and identify reaction conditions for both amino and hydroxyl groups, we performed a systematic study of reaction conditions on multiple classes of potential targets. For selected derivatization methods, detection limits and performance in a variety of biological matrices were assessed. Results highlight the importance of tailoring derivatization methods for a given application as they varied by molecule and/or molecule class. Compared to the standard BzCl method commonly used, alternative methods were identified to better derivatize challenging analytes (glucosamine, choline, cortisol, uridine, cytidine) with detection limits reaching 1100, 9, 38, 170, and 67 nM compared to undetectable, 170, 86, 1000, and 86 nM respectively. Sub-nanomolar detection limits were achieved for norepinephrine with alternative derivatization approaches. Improved derivatization methods for several classes and molecules including nucleosides, steroids, and molecules containing hydroxyl groups were also identified.

Intra and interspecific audience effect on domestic dogs' behavioural displays and facial expressions.

The aim of the current study was to investigate the influence of both intra- and interspecific audiences on dogs' facial expressions and behaviours. Forty-six dogs were exposed to three test conditions in which a food reward, initially available, was denied when in the presence of either a human (Human condition) or a dog audience (Dog condition), or in the absence of a visible audience (Non-social condition). Salivary cortisol was collected to evaluate the stress/arousal activation in the different conditions. Compared to the Non-social condition, the presence of a conspecific evoked more facial expressions, according to the DogFACS (Facial Action Coding System, an anatomically based tool to analyze facial expressions in domestic dogs), (EAD105-Ears downward), displacement behaviours (AD137-Nose licking, AD37-Lip wiping), tail wagging, whining, and panting (AD126). When facing a conspecific, dogs assumed a more avoidant attitude, keeping a distance and not looking at the stimuli, compared to when in the presence of the human partner. Dogs also exhibited more facial expressions (EAD102-Ears Adductor, EAD104-Ears Rotator), displacement behaviours (AD137-Nose licking, AD37-Lip wiping), panting (AD126) and whining when facing the conspecific than the human partner. Post-test cortisol was not influenced by any condition, and no association between pre-test cortisol and behavioural variables was found, thus strong differences in the levels of stress/arousal were unlikely to be responsible for differences in behavior between conditions. Considering the current results in the context of the available literature, we suggest that the higher displacement behaviors exhibited with the conspecifics were likely due to an increased level of uncertainty regarding the situations.

Canine and feline foetal fluids: Volume, hormonal and biochemical characterization during pregnancy.

BACKGROUND AND OBJECTIVES: This study aimed to evaluate the volume, the concentration of steroid hormones, and biochemical composition of the foetal fluids at different gestational ages in dogs and cats. METHODS: Following the ovariohysterectomy, the allantoic and amniotic fluid samples were collected from pregnant bitches and queens and were assigned to different groups according to their gestational age. RESULTS: The canine and feline allantoic fluid volume increased during pregnancy, reached its maximum values on days 40-49 and then decreased. The canine and feline amniotic fluid volume increased steadily by the last days of pregnancy. In spite of significant changes of sex hormones in the foetal fluids, their concentration and ratios were not significantly different between male and female fetuses. The canine amniotic cortisol concentration increased until days 40-49 and decreased significantly afterwards. The maximum cortisol concentrations in the feline allantoic and amniotic fluids were observed on days 50-60 and 40-49, respectively. During the canine pregnancy, the concentrations of calcium, phosphorus, chloride, sodium, triglyceride, cholesterol, total protein, albumin and the activities of aminotransferase (AST), alkaline phosphatase (ALP), amylase and gamma-glutamyl transferase (GGT) in the amniotic fluid were higher than the allantoic fluid. The magnesium, potassium, lactate dehydrogenase (LDH) activity, creatine and lipase were higher in the allantoic fluid. In the feline allantoic fluid, potassium, magnesium, phosphorus, creatinine, albumin and glucose concentrations and the activities of creatine kinase (CK), GGT, LDH and lipase were higher. The ALP, AST activities, sodium and calcium concentrations were higher in the amniotic fluid (p < 0.05). CONCLUSION: Volume of foetal fluids was determined in dogs and cats. Concentration of sex hormones did not different between male and female fetuses.

Monitoring adrenal insufficiency through salivary steroids: a pilot study.

BACKGROUND: Various glucocorticoid replacement therapies (GRTs) are available for adrenal insufficiency (AI). However, their effectiveness in restoring glucocorticoid rhythm and exposure lacks adequate biochemical markers. We described the diurnal salivary cortisol (SalF) and cortisone (SalE) rhythm among different GRTs and analysed the associations between saliva-derived parameters and life quality questionnaires. METHODS: Control subjects (CSs, n = 28) and AI patients receiving hydrocortisone (HC, n = 9), cortisone acetate (CA, n = 23), and dual-release hydrocortisone once (DRHC-od, n = 10) and twice a day (DRHC-td, n = 6) collected 9 saliva samples from 07:00 to 23:00. Patients compiled Pittsburgh Sleep Quality Index, Hospital Anxiety and Depression Scale, and Addison disease-specific quality-of-life questionnaires. SalE and SalF were measured by liquid chromatography-mass spectrometry. Exposure was monitored using SalE for HC and DRHC and SalF for CA. Area under the curve (AUC) was computed. Different GRTs were compared by Z-scores calculated from saliva-derived parameters. Questionnaire results predictors were evaluated with multiple regression analysis. RESULTS: Compared with controls, all GRTs resulted in glucocorticoid overexposure in the morning. Hydrocortisone, CA, and DRHC-td caused overexposure also in afternoon and evening. Compared with other treatments, CA determined increased Z-score-07:00 (P < .001), DRHC-td determined increased Z-score-AUC07:00→14:00 (P = .007), and DRHC-od induced lower Z-score-AUC14:00→23:00 (P = .015). Z-scores-AUC14:00→16:00 ≥ .619 best predicted questionnaire scores. CONCLUSIONS: None of the GRTs mimics normal glucocorticoid rhythmicity and exposure. SalE, SalF, and Z-score may be useful markers for monitoring and comparing different GRTs. Excess glucocorticoid in early afternoon best associated with depressive symptoms and worse life and sleep quality.

Hair cortisol levels are associated with overweight and obesity in the ELSA-Brasil cohort.

Introduction: Hair cortisol level has recently been identified as a promising marker for detecting long-term cortisol levels and a marker of hypothalamic-pituitary-adrenal cortex (HPA) axis activity. However, research on the association between obesity and an altered cortisol metabolism remains controversial. Objective: This study aimed to investigate the relationship between hair cortisol levels and overweight and obesity in participants from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). Methods: This was a cross-sectional study involving 2,499 participants from the second follow-up (visit 3, 2017-2019) attending research centers in Rio de Janeiro and Rio Grande do Sul states. Hair samples were collected, and cortisol levels were analyzed using enzyme-linked immunosorbent assay (ELISA) kits. Cortisol levels were classified as low (< 40 pg/mg), medium (40-128 pg/mg), or high (> 128 pg/mg). The participants were classified as eutrophic, overweight, or obese according to their weight (kg) and height (m2). Odds ratios (ORs) with 95% confidence intervals (95%CI) were estimated. Results: Of the 2499 individuals, 30% had eutrophic weight, 40% were overweight, and 30% were obese. Notably, cortisol levels gradually increased with increasing body weight. Among participants with high hair cortisol levels, 41.2% were classified as overweight and 34.2% as obese. Multinomial logistic regression analysis indicated that participants with high cortisol levels were 43% (OR =1.43; 95%CI: 1.02-2.03) more likely to be overweight and 72% (OR =1.72; 95%CI:1.20-2.47) more likely to be obese than participants with low hair cortisol levels. After adjustment for all covariates, high cortisol levels remained associated with obesity (OR = 1.54; 95%CI:1.02-2.31) and overweight (OR =1.33; 95%CI:0.91-1.94). Conclusion: In the ELSA-Brazil cohort, hair stress were positively associated with overweight and obesity. These results underscore the importance of considering stress and cortisol as potential factors in obesity prevention and intervention efforts, and highlight a novel aspect of the complex relationship between stress and obesity in the Brazilian population.

Prenatal stress and hair cortisol in a sample of Latina women.

BACKGROUND: Stress during pregnancy adversely impacts maternal and infant health. Dysregulation of the hypothalamic pituitary axis is a mediator of the relationship between stress and health. Evidence supporting an association between prenatal chronic stress and cortisol is limited, and the majority of research published has been conducted amongst White participants, who experience less chronic stress than people of color. AIM: This study investigated associations between various measures of prenatal stress and hair cortisol concentrations which is a biomarker of the integrated stress response in a sample of Latina participants during the third trimester of pregnancy. METHOD: Pregnant women (n=45) were surveyed with scales measuring chronic stress, perceived stress, pregnancy-related and pregnancy-specific anxiety. Hair samples were collected as an objective neuroendocrine measure of chronic stress. Linear regression analyses were performed to assess associations between stress measures and hair cortisol. Pre-pregnancy BMI, smoking during pregnancy, and steroid use during pregnancy were used as covariates in adjusted models. RESULTS: Chronic stress, operationalized as maternal reports of neighborhood/housing strain, daily activities and relationship strain, discrimination, and financial strain, was significantly associated with higher hair cortisol concentrations. No significant associations were found between hair cortisol and perceived stress, pregnancy-related anxiety, nor pregnancy-specific anxiety in adjusted models. CONCLUSION: Chronic stress may be a more robust correlate of physiological stress, as measured by hair cortisol in pregnancy, than other common measures of prenatal stress and anxiety.

Cumulative environmental stress and emerging cardiometabolic risk during childhood.

OBJECTIVE: To prospectively evaluate the relationship between cumulative environmental stress and cardiometabolic risk in middle childhood, and to examine whether hair cortisol, a measure of hypothalamic pituitary adrenal-axis activity, mediates this relationship. METHODS: In a cohort of children from low-income households (n = 320; 59% Hispanic, 23% Black, body mass index (BMI) percentile >50th at enrollment), environmental stressors including family and neighbourhood factors representing disadvantage/deprivation, and cortisol concentrations from hair samples, were measured over five timepoints beginning when children were 2-4 years old. Cardiometabolic risk factors (i.e., BMI, blood pressure, lipids, blood sugar, C-reactive protein) were measured at the final timepoint when children were 7-11 years of age. RESULTS: In adjusted logistic regression models, greater cumulative environmental stress was associated with a higher likelihood of elevated cardiometabolic risk in middle childhood (p = 0.01). Children from minoritized racial/ethnic groups had a higher prevalence of both stressors and cardiometabolic risk factors. Cumulative environmental stress was associated with higher hair cortisol concentrations (p < 0.01). However, hair cortisol was not directly associated with cardiometabolic risk factors and did not explain the association between environmental stress and cardiometabolic risk in causal mediation analysis. CONCLUSIONS: The influence of cumulative stress on cardiometabolic health can be observed in middle childhood and may contribute to cardiometabolic health disparities, highlighting the importance of public health interventions to mitigate disadvantage.

An LC-MS/MS-based method for the simultaneous quantification of melatonin, cortisol and cortisone in saliva.

Disturbances in the diurnal pattern are associated with several clinical and psychological conditions, including depression and fatigue. Salivary sampling for melatonin, cortisol and cortisone provides a non-invasive method for frequent sampling and obtaining biochemical insight into the diurnal pattern of individuals. Therefore, a new liquid chromatography-tandem mass spectrometry-based method for the measurement of salivary melatonin, cortisol and cortisone was developed and validated. The method required 250 µl saliva, used isotope dilution methodology and was based on a liquid-liquid extraction for sample preparation, reversed-phase chromatography and multiple reaction monitoring on a mass spectrometer for quantitation. The lower limits of quantification obtained were 0.010 nmol/L for melatonin, 0.5 nmol/L for cortisol and 1.00 nmol/L for cortisone and the limits of detection were 0.003 nmol/L, 0.15 nmol/L and 0.1 nmol/L respectively. The method imprecision was ≤14% for all measurands, and the method comparison showed highly comparable results with high correlation coefficients (all ≥0.964). Potential interference of cortisol and cortisone by prednisolone was observed and could be detected by chromatogram review. Typical diurnal patterns for melatonin, cortisol and cortisone were observed in the saliva of 20 cancer survivors who collected saliva throughout the day.