Synergistic Effect of Dietary Supplementation with Sodium Butyrate, ß-Glucan and Vitamins on Growth Performance, Cortisol Level, Intestinal Microbiome and Expression of Immune-Related Genes in Juvenile African Catfish (Clarias gariepinus).

The effect of dietary supplementation with sodium butyrate, ß-glucan and vitamins (A, D3, E, K, C) on breeding indicators and immune parameters of juvenile African catfish was examined. The fish were fed with unenriched (group C) and enriched feed with a variable proportion of sodium butyrate/ß-glucan, and constant content of vitamins (W1-W3). After the experiment, blood and the middle gut were collected. The microbiome of the gut was determined using Next Generation Sequencing (NGS). Liver tissue was collected for determination of expression of immune-related genes (HSP70, IL-1ß, TNFα). W2 and W3 were characterized by the most favorable values of breeding indicators (p < 0.05). The highest blood cortisol concentration was in group C (71.25 ± 10.45 ng/mL), and significantly the lowest in W1 (46.03 ± 7.01 ng/ mL) (p < 0.05). The dominance of Cetobacterium was observed in all study groups, with the largest share in W3 (65.25%) and W1 (61.44%). Gene expression showed an increased number of HSP70 genes in W1. IL-1ß and TNFα genes peaked at W3. The W3 variant turns out to be the most beneficial supplementation, due to the improvement of breeding and immunological parameters. The data obtained can be used to create a preparation for commercial use in the breeding of this species.

Effect of cortisol and glycosylated-hemoglobin levels on mortality in intensive care unit.

OBJECTIVES: To research the effects of blood cortisol and hemoglobinA1c (HBA1C) levels on mortality in patients admitted to the intensive care unit (ICU) and whether these factors could be used as reliable indicators for mortality risk assessment in these patients. METHODS: After receiving approval from the ethics committee, 79 patients admitted to ICU were included in the study. From patient files, we collected data on demographics (age, gender), presence of diabetes mellitus, and levels of cortisol, HbA1C, glucose, and lactate measured during hospitalization, along with acute physiology and chronic health evaluation (APACHE) II scores calculated within the first 24 hours. In our study, we planned to investigate the relationship between patients' cortisol and HbA1C levels and mortality. RESULTS: A total of 79 patients were included in the study. The mortality rate of the patients included in the study was 65.8%. In the model established with all variables, only cortisol level (p=0.017) and APACHE II score (p=0.005) were defined to affect mortality. CONCLUSION: Cortisol levels at the time of admission to the ICU were found to affect mortality and can be considered a predictive factor, while HBA1C levels showed no such effect. Our findings indicate that neither cortisol nor HBA1C levels had an impact on the duration of mechanical ventilation or length of stay in the ICU.

Preliminary investigation into long-term stress by isolated captivity-related changes of reproduction hormones in Cynomolgus monkey.

BACKGROUND: Stress profoundly affects physical and emotional well-being, extending its physiological influence to the female menstrual cycle, impeding the hypothalamus-pituitary-gonadal (HPG) axis, and affecting fertility by suppressing sex-stimulating hormones. METHODS: In this study, we meticulously analyzed menstrual cycles and corresponding hormonal fluctuations in three female Cynomolgus monkeys. RESULTS: The preliminary findings indicated lower-than-normal levels of cortisol, follicle-stimulating hormone (FSH), and estradiol. Anovulatory bleeding occurred in one monkey, which could be linked to stress. In contrast to cortisol, alkaline phosphatase (ALP), which is correlated to cortisol levels, was consistently elevated in menstruating monkeys, suggesting its potential as a stress indicator. The non-menstruating group exhibited stress-related weight loss, emphasizing the observed ALP trends. CONCLUSIONS: Non-menstruating monkeys may experience more stress than menstruating monkeys. The implications of this study extend beyond the confines of primate studies and offer a valuable method for enhancing the welfare of female Cynomolgus monkeys.

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.

Radiation-induced DNA double-strand breaks in cortisol exposed fibroblasts as quantified with the novel foci-integrated damage complexity score (FIDCS).

Without the protective shielding of Earth's atmosphere, astronauts face higher doses of ionizing radiation in space, causing serious health concerns. Highly charged and high energy (HZE) particles are particularly effective in causing complex and difficult-to-repair DNA double-strand breaks compared to low linear energy transfer. Additionally, chronic cortisol exposure during spaceflight raises further concerns, although its specific impact on DNA damage and repair remains unknown. This study explorers the effect of different radiation qualities (photons, protons, carbon, and iron ions) on the DNA damage and repair of cortisol-conditioned primary human dermal fibroblasts. Besides, we introduce a new measure, the Foci-Integrated Damage Complexity Score (FIDCS), to assess DNA damage complexity by analyzing focus area and fluorescent intensity. Our results show that the FIDCS captured the DNA damage induced by different radiation qualities better than counting the number of foci, as traditionally done. Besides, using this measure, we were able to identify differences in DNA damage between cortisol-exposed cells and controls. This suggests that, besides measuring the total number of foci, considering the complexity of the DNA damage by means of the FIDCS can provide additional and, in our case, improved information when comparing different radiation qualities.

The influence of cortisol co-secretion on clinical characteristics and postoperative outcomes in unilateral primary aldosteronism.

Context: The prevalence of unilateral primary aldosteronism (UPA) with cortisol co-secretion varies geographically. Objective: To investigate the prevalence and clinical characteristics of UPA with cortisol co-secretion in a Chinese population. Design: Retrospective cohort study. Methods: We recruited 580 patients with UPA who underwent cosyntropin stimulation test (CST) after the 1-mg dexamethasone suppression test (DST) and retrospectively analyzed the clinical characteristics and postoperative outcomes of UPA with and without cortisol co-secretion. Results: UPA with cortisol co-secretion (1 mg DST>1.8 ug/dL) was identified in 65 of 580 (11.2%) patients. These patients were characterized by older age, longer duration of hypertension, higher concentration of plasma aldosterone and midnight cortisol, lower adrenocorticotropic hormone (ACTH) and dehydroepiandrosterone sulfate (DHEAS), larger tumor diameter, and more history of diabetes mellitus. Cortisol and aldosterone levels were higher and DHEAS level was lower in UPA with cortisol co-secretion at 0-120 min after CST. Among 342 UPA patients with KCNJ5 gene sequencing and follow-up results, the complete clinical success rate was lower in UPA with cortisol co-secretion (33.3% vs. 56.4%, P<0.05); the complete biochemical success rate and KCNJ5 mutation did not differ between the two groups. Age, tumor size, and ACTH were independent predictors of UPA with cortisol co-secretion. Sex, BMI, duration of hypertension, KCNJ5 mutation, and cortisol co-secretion were independent predictors for complete clinical success in UPA after surgery. Conclusions: UPA with cortisol co-secretion is not uncommon in China, but the clinical features were distinctly different from those without co-secretion. Cortisol co-secretion is an independent risk factor for incomplete clinical success after surgery in UPA.

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.

Pebble to the Metal: A Boulder Approach to Enrichment for Danio rerio.

Zebrafish are an established and widely used animal model, yet there is limited understanding of their welfare needs. Despite an increasing number of studies on zebrafish enrichment, in-tank environmental enrichment remains unpopular among researchers. This is due to perceived concerns over health/hygiene when it comes to introducing enrichment into the tank, although actual evidence for this is sparse. To accommodate this belief, regardless of veracity, we tested the potential benefits of enrichments presented outside the tank. Thus, we investigated the preferences and physiological stress of zebrafish with pictures of pebbles placed underneath the tank. We hypothesized that zebrafish would show a preference for enriched environments and have lower stress levels than barren housed zebrafish. In our first experiment, we housed zebrafish in a standard rack system and recorded their preference for visual access to a pebble picture, with two positive controls: visual access to conspecifics, and group housing. Using a crossover repeated-measures factorial design, we tested if the preference for visual access to pebbles was as strong as the preference for social contact. Zebrafish showed a strong preference for visual access to pebbles, equivalent to that for conspecifics. Then, in a second experiment, tank water cortisol was measured to assess chronic stress levels of zebrafish housed with or without a pebble picture under their tank, with group housing as a positive control. Cortisol levels were significantly reduced in zebrafish housed with pebble pictures, as were cortisol levels in group housed zebrafish. In fact, single housed zebrafish with pebble pictures showed the same cortisol levels as group housed zebrafish without pebble pictures. Thus, the use of an under-tank pebble picture was as beneficial as being group housed, effectively compensating for the stress of single housing. Pebble picture enrichment had an additive effect with group housing, where group housed zebrafish with pebble pictures had the lowest cortisol levels of any treatment group.

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.

The loneliness factor in eating disorders: Implications for psychopathology and biological signatures.

OBJECTIVES: Eating disorders (ED) are severe psychiatric conditions. While the biological consequences of EDs are well established, including an increase in inflammatory biomarkers, the influence of psychological factors, such as loneliness, has only recently gained attention in research. Loneliness has been associated with more severe psychopathology in ED patients, while its association with inflammatory biomarkers has only been explored in the general population. For these reasons, we aimed to investigate any possible associations between psychological features, trauma, and inflammatory biomarkers with loneliness in people with ED. METHODS: This study examined the interaction between loneliness, eating psychopathology, and biological markers in people with EDs. A group of 97 female patients with various diagnoses of ED was assessed for loneliness, general and eating psychopathology, traumatic history during childhood, and clinical biomarkers such as C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and urinary-free cortisol (UFC). RESULTS: The results indicated that individuals with ED who reported moderate to severe loneliness also displayed greater general psychopathology (p = 0.001), weight concerns (p = 0.007), and physical neglect during childhood (p = 0.006). Furthermore, people with higher levels of loneliness also had higher inflammatory indexes (ESR p = 0.001, CRP p = 0.027) and were positively correlated with markers of stress reaction such as UFC (p < 0.05). CONCLUSION: The findings underscore the importance of considering loneliness in the assessment of individuals with an ED. We observed notable associations between loneliness and increased psychopathology (both general and specific to eating), as well as higher levels of inflammation and childhood physical neglect. Addressing loneliness may contribute to improving overall well-being and potentially support recovery. This consideration encompasses both psychological and physical factors that interplay in the clinical presentation of individuals.

Multivariate analysis and mathematical modeling of the informativeness of patients cases data in chronic pancreatitis associated with concomitant pathology.

OBJECTIVE: Aim: To investigate and analyze homeostatic disorders in patients with a combination of Chronic Pancreatitis(CP) and Arterial Hypertension (AH) and to develop correcting ways of the detected changes. PATIENTS AND METHODS: Materials and Methods: General clinical, laboratory-instrumental examination of 121 patients, who were undergoing inpatient treatment with a diagnosis of Chronic Pancreatitis in combination with Arterial Hypertension of the II stage during 2021-2022. RESULTS: Results: In the majority of cases of patients signs the increasing in IL-1,6 and Cortisol levels were found. A decrease in Ca to the lower limit of the norm was observed (2.18 ± 0.26 mmol/l to the data of control group patients (2.32 ± 0.12 mmol/l, p= 0.01 ), the levels of trace elements Zn and Se were determined within the reference values. The Atherogenic Index was increased 1.8 times and was significantly different from the control group date. During the FE-1 study, a decrease in the level of this indicator was revealed by 151.71±13.91 mg/g of feces, both to the values of reference values and a significant difference to the data of the control group (241.28±29.17 mg/g of feces, p<0 .05). CONCLUSION: Conclusions: Based on the multivariate linear regression analysis of the obtained data, formulas have been developed that can be used to predict the dynamics of the dependent variable (FE-1, IL-1, Selenium level, Glutathione Peroxidase, blood pressure) according to changes in the studied influencing factors.

Unique and interactive effects of threat and deprivation on latent trait cortisol among emerging adults.

Though considerable work supports the Dimensional Model of Adversity and Psychopathology, prior research has not tested whether the dimensions-threat (e.g., abuse) and deprivation (e.g., neglect)-are uniquely related to salivary trait indicators of hypothalamic pituitary adrenal (HPA) axis activity. We examined the unique and interactive effects of threat and deprivation on latent trait cortisol (LTC)-and whether these effects were modified by co-occurring adversities. Emerging adults (n = 90; Mage = 19.36 years; 99.88% cisgender women) provided salivary cortisol samples four times a day (waking, 30 min and 45 min postwaking, bedtime) over three 3-day measurement waves over 13 weeks. Contextual life stress interviews assessed early adversity. Though the effects varied according to the conceptualization of early adversity, overall, threat-but not deprivation, nor other co-occurring adversities-was uniquely associated with the across-wave LTC. Specifically, the incidence and frequency of threat were each negatively related to the across-wave LTC. Threat severity was also associated with the across-wave LTC, but only among those with no deprivation. Finally, the effects of threat were modified by other co-occurring adversities. Findings suggest that threat has unique implications for individual differences in HPA axis activity among emerging adults, and that co-occurring adversities modify such effects.

[A rare cause of hypercorticism: ACTH-secreting pheochromocytoma (a case report)]. / Une cause rare d'hypercorticisme: un phéochromocytome sécrétant l'ACTH (à propos d'un cas).

Ectopic ACTH-secreting pheochromocytoma is a very rare cause of Cushing´s syndrome, posing diagnostic and therapeutic challenges. We here report the case of a female patient with suspected severe Cushing´s syndrome associated with melanoderma, arterial hypertension resistant to triple therapy and unbalanced diabetes treated with insulin therapy. Biologically, urinary ethoxylated, 24-hour urinary free cortisol and ACTH were very high. Imaging showed a 3.5 cm left adrenal mass. The patient underwent left adrenalectomy after medical preparation, with good clinico-biological outcome. Anatomopathological examination confirmed the diagnosis of pheochromocytoma. This case study highlights the importance of measuring methoxylated derivatives in any patient with ACTH-dependent Cushing´s syndrome associated with an adrenal mass. The aim is to ensure early treatment and avoid life-threatening complications.

Seasonal Variation in Vitamin D Status Does Not Interfere with Improvements in Aerobic and Muscular Endurance in Conscripts during Basic Military Training.

Considering a lack of respective data, the primary objective of this study was to assess whether seasonal variation in vitamin D status (D-status) affects the extent of improvement in physical performance (PP) in conscripts during basic military training (BMT). D-status, PP and several blood parameters were measured repeatedly in conscripts whose 10-week BMT started in July (cohort S-C; n = 96) or in October (cohort A-C; n = 107). D-status during BMT was higher in S-C compared to A-C (overall serum 25(OH)D 61.4 ± 16.1 and 48.5 ± 20.7 nmol/L, respectively; p < 0.0001). Significant (p < 0.05) improvements in both aerobic and muscular endurance occurred in both cohorts during BMT. Pooled data of the two cohorts revealed a highly reliable (p = 0.000) but weak (R2 = 0.038-0.162) positive association between D-status and PP measures both at the beginning and end of BMT. However, further analysis showed that such a relationship occurred only in conscripts with insufficient or deficient D-status, but not in their vitamin D-sufficient companions. Significant (p < 0.05) increases in serum testosterone-to-cortisol ratio and decreases in ferritin levels occurred during BMT. In conclusion, a positive association exists between D-status and PP measures, but seasonal variation in D-status does not influence the extent of improvement in PP in conscripts during BMT.

Cortisol Levels During First Admission Day Are Associated With Clinical Outcomes in Surgical Critically Ill Patients.

IMPORTANCE: To explore the correlation between cortisol levels during first admission day and clinical outcomes. OBJECTIVES: Although most patients exhibit a surge in cortisol levels in response to stress, some suffer from critical illness-related corticosteroid insufficiency (CIRCI). Literature remains inconclusive as to which of these patients are at greater risk of poor outcomes. DESIGN: A retrospective study. SETTING: A surgical ICU (SICU) in a tertiary medical center. PARTICIPANTS: Critically ill patients admitted to the SICU who were not treated with steroids. MAIN OUTCOMES AND MEASURES: Levels of cortisol taken within 24 hours of admission (day 1 [D1] cortisol) in 1412 eligible patients were collected and analyzed. Results were categorized into four groups: low (0-10 µg/dL), normal (10-25 µg/dL), high (25-50 µg/dL), and very high (above 50 µg/dL) cortisol levels. Primary endpoint was 90-day mortality. Secondary endpoints were the need for organ support (use of vasopressors and mechanical ventilation [MV]), ICU length of stay (LOS), and duration of MV. RESULTS: The majority of patients (63%) had high or very high D1 cortisol levels, whereas 7.6% had low levels and thus could be diagnosed with CIRCI. There were statistically significant differences in 90-day mortality between the four groups and very high levels were found to be an independent risk factor for mortality, primarily in patients with Sequential Organ Failure Assessment (SOFA) less than or equal to 3 or SOFA greater than or equal to 7. Higher cortisol levels were associated with all secondary endpoints. CIRCI was associated with favorable outcomes. CONCLUSIONS AND RELEVANCE: In critically ill surgical patients D1 cortisol levels above 50 mcg/dL were associated with mortality, need for organ support, longer ICU LOS, and duration of MV, whereas low levels correlated with good clinical outcomes even though untreated. D1 cortisol level greater than 50 mcg/dL can help discriminate nonsurvivors from survivors when SOFA less than or equal to 3 or SOFA greater than or equal to 7.

Surgical versus medical management of patients with primary hyperaldosteronism and indeterminate adrenal vein sampling: A 10-year experience of the Cleveland Clinic.

In patients with primary hyperaldosteronism (PA), adrenal vein sampling (AVS) can identify patients suitable for unilateral adrenalectomy. However, in AVS with an indeterminate aldosterone-to-cortisol lateralization (ACL) ratio of 3.0-4.0, clinical guidance is unclear. The authors screened all patients undergoing AVS at the Cleveland Clinic from October 2010 to January 2021 and identified 18 patients with indeterminate ACL results. Ten underwent adrenalectomy and eight continued medical management. The surgical group was younger (58.5 vs. 68 years, p = .17), and more likely to have a unilateral imaging adrenal abnormality (90% vs. 38%, p = .043) and a lower contralateral suppression index (0.63 vs. 1.1, p = .14). Post-treatment, the surgical group had a significant reduction in diastolic blood pressure (-5.5 mmHg, p = .043) and aldosterone (4.40 vs. 35.80 ng/mL, p = .035) and required fewer anti-hypertensive medications (2 vs. 3, p = .015). These findings may support the benefit of adrenalectomy in a select group of patients with indeterminate ACL.

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.

The Importance of PET Imaging to Understanding Whole-Body Cortisol Metabolism in Alzheimer's Disease.

Excess cortisol is associated with more severe cognitive decline, Alzheimer's disease, and related dementia phenotypes. The intracellular enzyme 11ß-HSD1 regenerates active cortisol from inactive cortisone. In this current issue, high regional brain occupancy of Xanamemtrademark, determined by [11C]TARACT PET imaging of 11ß-HSD1, in cognitively normal individuals and mild cognitive impartment/Alzheimer's disease (AD) patients is presented. In the future, comprehensive kinetic modeling using arterial sampling for occupancy studies, and whole-body PET imaging of 11ß-HSD1 enzyme levels, in combination with stable isotope studies of cortisol metabolism, can provide broad insight into enzyme levels and activity in AD and other relevant diseases.