Adrenal gland volume, intra-abdominal and pericardial adipose tissue in major depressive disorder

Associations between adrenal gland volume and adipose tissue compartments - a whole body MRI study

BACKGROUND

Obesity is associated with alterations in the hypothalamic-pituitary-adrenal (HPA) axis. Effects of glucocorticoids on adipose tissues appear to depend on the specific adipose depot, in which they take place. In this study, we aimed to investigate the role of MRI-based adrenal gland volume as an imaging marker in association with different adipose tissue compartments.

METHODS

The study cohort derives from the population-based research platform KORA (Cooperative Health Research in the Augsburg Region, Germany) MRI sub-study, a cross-sectional sub-study investigating the interactions between subclinical metabolic changes and cardiovascular disease in a study sample of 400 participants. Originally, eligible subjects underwent a whole-body MRI. MRI-based segmentations were performed manually and semi-automatically for adrenal gland volume, visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), epi- and pericardial fat and renal sinus fat. Hepatic and pancreatic lipid content were measured as pancreatic proton density fraction (PDFF) and MR-spectroscopic hepatic fat fraction (HFF). Multivariable linear regression analyses were performed.

RESULTS

A number of 307 participants (56.2 ± 9.1 years, 60.3% male, 14.3% with type 2 diabetes (T2DM), 30.6% with obesity, 34.2% with hypertension) were included. In multivariable analyses, strong positive associations between adrenal gland volume and VAT, total adipose tissue (TAT) as well as HFF persisted after extensive step-wise adjustment for possible metabolic confounders (VAT: beta = 0.31, 95%-CI [0.71, 0.81], p < 0.001; TAT: beta = 0.14, 95%-CI [0.06, 0.23], p < 0.001; HFF: beta = 1.17, 95%-CI [1.04, 1.31], p = 0.009). In contrast, associations between adrenal gland volume and SAT were attenuated in multivariate analysis after adjusting for BMI. Associations between pancreatic PDFF, epi- and pericardial fat and renal sinus fat were mediated to a great extent by VAT (pancreatic PDFF: 72%, epicardial adipose tissue: 100%, pericardial adipose tissue: 100%, renal sinus fat: 81.5%).

CONCLUSION

Our results found MRI-based adrenal gland volume as a possible imaging biomarker of unfavorable adipose tissue distribution, irrespective of metabolic risk factors. Thus, adrenal gland volume may serve as a potential MRI-based biomarker of metabolic changes and contributes to an individual characterization of metabolic states and individual risk stratification. Future studies should elucidate in a longitudinal study design, if and how HPA axis activation may trigger unfavorable adipose tissue distribution and whether and to which extent this is involved in the pathogenesis of manifest metabolic syndrome.

The Role of the Adrenal-Gut-Brain Axis on Comorbid Depressive Disorder Development in Diabetes

Diabetic patients are more affected by depression than non-diabetics, and this is related to greater treatment resistance and associated with poorer outcomes. This increase in the prevalence of depression in diabetics is also related to hyperglycemia and hypercortisolism. In diabetics, the hyperactivity of the HPA axis occurs in parallel to gut dysbiosis, weakness of the intestinal permeability barrier, and high bacterial-product translocation into the bloodstream. Diabetes also induces an increase in the permeability of the blood-brain barrier (BBB) and Toll-like receptor 4 (TLR4) expression in the hippocampus. Furthermore, lipopolysaccharide (LPS)-induced depression behaviors and neuroinflammation are exacerbated in diabetic mice. In this context, we propose here that hypercortisolism, in association with gut dysbiosis, leads to an exacerbation of hippocampal neuroinflammation, glutamatergic transmission, and neuronal apoptosis, leading to the development and aggravation of depression and to resistance to treatment of this mood disorder in diabetic patients.

Cardiovascular risk in bipolar disorder - A case for the hypothalamus-pituitary-adrenal axis?

BACKGROUND

Unipolar major depressive disorder (MDD) and bipolar disorder (BD) are associated with elevated mortality risk secondary to natural causes. Cardiovascular disease (CVD) constitutes the most prevalent underlying condition. Patients with BD display higher CVD-associated excess mortality than MDD patients. Epicardial adipose tissue (EAT) volume, a known predictor of premature CV morbidity and adrenal gland (AG) volume, an indicator for chronic hypothalamus-pituitary-adrenal (HPA) axis activation, were compared in BD and MDD patients.

METHODS

Magnetic resonance imaging was performed to assess EAT and AG volume in age-, gender-, and body mass index (BMI)-matched MDD (N = 27) and BD (N = 27) patients. Ten-year CV mortality risk and diabetes risk were assessed by PROCAM, ESC-SCORE, and FINDRISK, respectively; metabolic syndrome (MetS) was determined following NCEP/ATP III criteria.

RESULTS

Cardiometabolic risk scores and frequency of MetS were comparable, and scores of cardiometabolic risk indices did not significantly differ in both groups. After adjustment for age, BMI, and physical activity, EAT and AG volumes were significantly higher in BD compared to MDD. Partial correlation analyses showed a significant positive association of EAT and AG volumes in BD but not in the MDD.

LIMITATIONS

The modest sample size warrants confirmation in a larger cohort and the cross-sectional design does not allow for temporal or causal inferences.

CONCLUSION

Our study indicates increased EAT accumulation in BD patients. This was associated with HPA axis dysregulation. Therapeutic lifestyle interventions that reduce EAT volume should be considered in clinical BD management.

Plasma complement C3 and C3a are increased in major depressive disorder independent of childhood trauma

BACKGROUND

Dysregulated complement system is linked to pathophysiology of major depressive disorder (MDD). Childhood trauma has been associated with an increased incidence of adult depression via a putative mechanism of immune activation. This study aimed to measure and compare peripheral levels of complement C3, C3a, C1q and C-reactive protein (CRP) in MDD patients and healthy controls and explore the relationship between these molecule levels and childhood trauma history in the participants.

METHODS

The participants were 49 medication-free MDD patients and 45 healthy controls. All participants were asked to finish the Childhood Trauma Questionnaire, followed by blood sampling for measurement of plasma complement C3, C3a, C1q and CRP by means of enzyme-linked immunosorbent assay.

RESULTS

Peripheral plasma concentration of C3 and C3a in medication-free MDD group was significantly higher than that in the healthy controls; whereas the concentration of plasma C1q and CRP in depressed patients was comparable to that in healthy controls. All these inflammatory factors were not associated to childhood trauma experience in patients with MDD.

CONCLUSION

Our data suggest that complement C3 and C3a may be implicated in the pathophysiology of MDD, although traumatic childhood experiences were not associated with the circulating levels of complement C3, C3a, C1q and CRP.

Effects of dopamine modulation on chronic stress-induced deficits in reward learning

Anhedonia is characteristically preceded by chronic stress, likely involving downstream effects of glucocorticoid alterations on dopamine (DA) function. To elucidate the neural underpinnings of this interaction, we examined whether acute pharmacological modulation of DA alters reward learning after chronic mild stress (CMS). Forty-eight male Wistar rats were exposed to a 21-day CMS regime (n = 48 no stress controls) before completing the probabilistic reward task (PRT), a well-validated cross-species test of reward learning. We first examined whether stress-induced reward dysfunction could be restored by systemic injections of low-dose amisulpride (AMI), which increases DA transmission via D2-like autoreceptor blockade. Then, we investigated region-specific effects through bilateral infusions of quinpirole (QUIN), a D2-like receptor agonist, into either the nucleus accumbens core (NAcc) or medial prefrontal cortex (mPFC). Blunted reward learning in CMS animals was reversed by acute AMI administration, but this treatment did not alter reward learning in the no stress group. Elevated adrenal gland weight, a proxy for stress reactivity, predicted lower reward learning in the untreated CMS group. This effect was extinguished following AMI treatment. These findings might be attributed to significantly higher D2 receptor density in the NAcc of high stress reactive animals. To this end, NAcc QUIN infusions potentiated reward learning relative to mPFC QUIN infusions in CMS rats, but there was no effect in no stress control rats. Collectively, these findings suggest that DA modulation reverses stress-induced reward dysfunction, even among the most stress-reactive animals. The effect might depend on D2-like receptor activation in the mesolimbic system.

Association of MRI-based adrenal gland volume and impaired glucose metabolism in a population-based cohort study

OBJECTIVES

The aim of this study was to assess adrenal gland volume by using magnetic resonance imaging (MRI) and to study its role as an indirect marker of impaired glucose metabolism and hypothalamic-pituitary-adrenal (HPA) axis activation in a population-based cohort.

METHODS

Asymptomatic participants were enrolled in a nested case-control study and underwent a 3-T MRI, including T1w-VIBE-Dixon sequences. For the assessment of adrenal gland volume, adrenal glands were manually segmented in a blinded fashion. Impaired glucose metabolism was determined using fasting glucose and oral glucose tolerance test. Cardiometabolic risk factors were also obtained. Inter- and intrareader reliability as well as univariate and multivariate associations were derived.

RESULTS

Among 375 subjects included in the analysis (58.5% male, 56.1 ± 9.1 years), 25.3% participants had prediabetes and 13.6% had type 2 diabetes (T2DM). Total adrenal gland volume was 11.2 ± 4.2 ml and differed significantly between impaired glucose metabolism and healthy controls with largest total adrenal gland volume in T2DM (healthy controls: 10.0 ± 3.9 ml, prediabetes: 12.5 ± 3.8 ml, T2DM: 13.9 ± 4.6 ml; p < 0.001). In the multivariate analysis, association of T2DM and increased adrenal gland volume was independent of age, sex, hypertension, triglycerides and body mass index (BMI), but was attenuated in subjects with prediabetes after adjustment for BMI.

CONCLUSIONS

T2DM is significantly associated with increased adrenal gland volume by MRI in an asymptomatic cohort, independent of age, sex, dyslipidaemia, hypertension and BMI. Adrenal gland volume may represent an indirect marker of impaired glucose metabolism and HPA axis dysfunction.

Association between visceral adipose tissue and major depressive disorder across the lifespan: A scoping review

OBJECTIVES

Increasing evidence supports a bidirectional relationship between major depressive disorder (MDD) and obesity, but the role of visceral adipose tissue (VAT) as a measure of obesity in relation to MDD is not well understood. Here we review literature investigating the link between MDD and VAT in terms of biomarkers, sex differences, and aging.

METHODS

PubMed, EMBASE, PsycINFO, and CINAHL searches were conducted on December 11, 2020. No date or language limits were imposed. Major concepts searched were Depressive Disorder linked with Adipose Tissue, White, Hypothalmo-Hypophyseal System, and Pituitary-Adrenal System in addition to keywords. A final set of 32 items meeting criteria for inclusion.

RESULTS

Converging biological evidence suggests a significant bidirectional relationship between VAT and MDD across the lifespan. In adulthood, greater VAT was associated with increased risk for depression, especially in vulnerable groups such as individuals who are overweight/obese, postmenopausal women, and individuals with comorbid medical or psychiatric illness. In older adults, sarcopenia had an impact on the relationship between abnormal VAT and risk of depression. Additionally, sex differences emerged as a potential factor affecting the strength of the association between VAT and depression.

CONCLUSIONS

Elucidating the pathophysiological mechanisms associated with increased rates of depression in obese individuals will be crucial for developing specific treatment strategies that seek to improve outcomes in individuals with comorbid depression and obesity. Moreover, identifying age- and sex-specific risk factors may contribute to a more personalized medicine approach, thereby improving the quality of clinical care.

Adipose Tissue Compartments, Inflammation, and Cardiovascular Risk in the Context of Depression

The neurobiological and behavioral underpinnings linking mental disorders, in particular, major depressive disorder (MDD), with cardiovascular disorders are a matter of debate. Recent research focuses on visceral (intra-abdominal and epicardial) adipose tissue and inflammation and their impact on the development of cardiometabolic disorders. Intra-abdominal adipose tissue is defined as an endocrine active fat compartment surrounding inner organs and is associated with type 2 diabetes mellitus, a risk factor for the later development of cardiovascular disorders. Epicardial (pericardial) adipose tissue is a fat compartment surrounding the heart with close proximity to the arteries supporting the heart. Visceral adipose tissue (VAT) is an important source of inflammatory mediators that, in concert with other risk factors, plays a leading role in cardiovascular diseases. In conjunction with the behavioral (physical inactivity, sedentary lifestyle), psychological (adherence problems), and hormonal (dysfunction of the hypothalamus-pituitary-adrenal axis with subsequent hypercortisolism) alterations frequently accompanying MDD, an enhanced risk for cardiovascular disorders results.

Behavioral pathway to a broken heart: The link between adverse childhood experiences, depression, physical exercise and cardiovascular health

BACKGROUND AND AIM

Adverse childhood experiences (ACEs) are a major risk factor for unfavorable behavioral, mental and health outcomes later in life. However, the precise pathway via which ACEs convey these risks, in particular regarding health outcomes such as cardiovascular disease, remains unknown. Here, we combined psychiatric and cardiac methods to investigate the pathway via which childhood adversities may lead to adult adverse cardiovascular health, with a focus on epicardial adipose tissue (EAT) as a risk marker.

METHODS

210 adult congenital heart disease outpatients (mean age 35.5 y, 43% female) completed a thorough cardiac and psychiatric evaluation. Psychiatric measurements included an expert interview, the childhood trauma questionnaire (CTQ), Beck's depression inventory II (BDI-II), quality of life and the global scale of functioning, amongst others. All patients completed a full cardiac workup including EAT assessment using echocardiography. We then computed bootstrapping mediation models using ACEs as a predictor, depression and physical activity as mediators and EAT as dependent variable in PROCESS.

RESULTS

CTQ scores had a significant indirect effect on EAT via a serial mediation of BDI and physical activity [a^*b2^*d = 0.0260, 95% BCa CI [0.0047, 0.0619]].

CONCLUSION

Using mediation analyses, we show that adverse childhood events are linked to increased depressive symptoms, which are linked to decreased physical activity, which in turn are linked to a higher amount of epicardial adipose tissue. While other pathways most certainly exist and replication is needed, this suggests a meaningful pathway via which ACEs lead to adverse cardiovascular health, with several potential targets for health interventions across time.

Impact of COVID-19 on Medical Supply in Adults With Congenital Heart Disease

INTRODUCTION

In March 2020, the World Health organization declared COVID-19 a global pandemic. One year later, the direct and indirect burden of the COVID-19 pandemic become more visible. In this context, there is concern about the allocation of medical resources and medical treatment of other diseases than COVID-19. Particularly, patients with chronic diseases need constant medical and pharmacological treatment. Therefore, we evaluated a large cohort of patients with adult congenital heart disease (ACHD) regarding postponed medical appointments and their possibilities to receive medical treatment during the COVID-19 pandemic.

METHODS

This cross-sectional study included 559 patients with ACHD (mean age 37.32 ± 11.98; 47% female). Clinical characteristics, answers to questionnaires concerning lifestyle, psychological well-being, addictive behavior and adherence were related to postponed medical appointments and limited access to medical care.

RESULTS

One hundred and nine patients (19.5%) reported problems getting necessary medical treatment or visiting a physician. Higher anxiety levels (p = 0.004) emerged as the main factor associated with medical undertreatment. The main risk factors for postponement of least one medical appointment (n = 91) were higher depression (p = 0.013) and anxiety (p = 0.05) symptoms as well as female sex (p ≤ 0.0001) and documented arrhythmias (p = 0.007) indicating a particular risk group of cardiovascular complications. In contrast, frequent physical activity identified patients at lower risk.

CONCLUSION

In ACHD anxiety and depressive symptoms handicap patients to receive medical care. Postponement of medical appointments additionally relates to female sex and documented arrhythmias. The latter indicates that patients at high risk of adverse cardiac outcome avoid routine medical care. Our data may lead policy makers to develop strategies for the provision of medical services to particular vulnerable patient groups, and to optimize management of both future pandemics and daily routine.

Epicardial adipose tissue and adrenal gland volume in patients with borderline personality disorder

Borderline personality disorder (BPD) is associated with an elevated mortality risk that is partially attributed to suicide, but few studies examined other possible causes of premature death. The present study compared epicardial adipose tissue (EAT) volume as a known early predictor of premature cardiovascular morbidity, cardiovascular risk indices, and adrenal gland volume (AGV) as an indicator for chronic hypothalamus-pituitary-adrenal (HPA) axis activation in females with borderline personality disorder (BPD), major depressive disorder (MDD) and in healthy individuals. Twenty-eight patients with BPD comorbid with MDD (BPD/MDD), 22 MDD patients and 26 healthy females (CTRL) of comparable age were included. EAT and AGV were assessed by magnetic resonance tomography; 10-year cardiovascular risk and diabetes risk were determined by PROCAM and FINDRISK score; metabolic syndrome was defined following National Cholesterol Education Adult Treatment Panel III R (NCEP/ATP III) criteria. MADRS was used to assess depression severity. After adjustment for age, body mass index (BMI), and physical activity, EAT and AGV were significantly increased in BPD/MDD compared to MDD and CTRL. EAT and AGV displayed a positive correlation. Finally, diabetes risk in BPD/MDD was elevated compared to CTRL and MDD. The present study highlights the increased cardiometabolic risk of BPD patients. We identify EAT accumulation as an early predictor and potential mediator of cardiovascular disease in BPD that appears to be driven at least in part by HPA axis dysregulation. Therefore, interventions that reduce EAT volume (i.e. exercise and diet) should be considered in the clinical management of BPD.

Glibenclamide treatment prevents depressive-like behavior and memory impairment induced by chronic unpredictable stress in female mice

Glibenclamide is a second-generation sulfonylurea used in the treatment of Type 2 Diabetes Mellitus. The primary target of glibenclamide is ATP-sensitive potassium channels inhibition; however, other possible targets include the control of inflammation and blood-brain barrier permeability, which makes this compound potentially interesting for the management of brain-related disorders. Here, we showed that systemic treatment with glibenclamide (5 mg/kg, p.o., for 21 days) could prevent the behavioral despair and the cognitive dysfunction induced by chronic unpredictable stress (CUS) in mice. In nonhypoglycemic doses, glibenclamide attenuated the stress-induced weight loss, decreased adrenal weight, and prevented the increase in glucocorticoid receptors in the prefrontal cortex, suggesting an impact in hypothalamic-pituitary-adrenal (HPA) axis function. Additionally, we did not observe changes in Iba-1, NLRP3 and caspase-1 levels in the prefrontal cortex or hippocampus after CUS or glibenclamide treatment. Thus, this study suggests that chronic treatment with glibenclamide prevents the emotional and cognitive effects of chronic stress in female mice. On the other hand, the control of neuroinflammation and NLRP3 inflammasome pathway is not the major mechanism mediating these effects. The behavioral effects might be mediated, in part, by the normalization of glucocorticoid receptors and HPA axis.

Inflammatory markers in depression: A meta-analysis of mean differences and variability in 5,166 patients and 5,083 controls

IMPORTANCE

The magnitude and variability of cytokine alterations in depression are not clear.

OBJECTIVE

To perform an up to date meta-analysis of mean differences of immune markers in depression, and to quantify and test for evidence of heterogeneity in immune markers in depression by conducting a meta-analysis of variability to ascertain whether only a sub-group of patients with depression show evidence of inflammation.

DATA SOURCES

Studies that reported immune marker levels in peripheral blood in patients with depression and matched healthy controls in the MEDLINE database from inception to August 29th 2018 were examined.

STUDY SELECTION

Case-control studies that reported immune marker levels in peripheral blood in patients with depression and healthy controls were selected.

DATA EXTRACTION AND SYNTHESIS

Means and variances (SDs) were extracted for each measure to calculate effect sizes, which were combined using multivariate meta-analysis.

MAIN OUTCOMES AND MEASURES

Hedges g was used to quantify mean differences. Relative variability of immune marker measurements in patients compared with control groups as indexed by the coefficient of variation ratio (CVR).

RESULTS

A total of 107 studies that reported measurements from 5,166 patients with depression and 5,083 controls were included in the analyses. Levels of CRP (g = 0.71; 95%CI: 0.50-0.92; p < 0.0001); IL-3 (g = 0.60; 95%CI: 0.31-0.89; p < 0.0001); IL-6 (g = 0.61; 95%CI: 0.39-0.82; p < 0.0001); IL-12 (g = 1.18; 95%CI: 0.74-1.62; p < 0.0001); IL-18 (g = 1.97; 95%CI: 1.00-2.95; p < 0.0001); sIL-2R (g = 0.71; 95%CI: 0.44-0.98; p < 0.0001); and TNFα (g = 0.54; 95%CI: 0.32-0.76; p < 0.0001) were significantly higher in patients with depression. These findings were robust to a range of potential confounds and moderators. Mean-scaled variability, measured as CVR, was significantly lower in patients with depression for CRP (CVR = 0.85; 95%CI: 0.75-0.98; p = 0.02); IL-12 (CVR = 0.61; 95%CI: 0.46-0.80; p < 0.01); and sIL-2R (CVR = 0.85; 95%CI: 0.73-0.99; p = 0.04), while it was unchanged for IL-3, IL-6, IL-18, and TNF α.

CONCLUSIONS AND RELEVANCE

Depression is confirmed as a pro-inflammatory state. Some of the inflammatory markers elevated in depression, including CRP and IL-12, show reduced variability in patients with depression, therefore supporting greater homogeneity in terms of an inflammatory phenotype in depression. Some inflammatory marker elevations in depression do not appear due to an inflamed sub-group, but rather to a right shift of the immune marker distribution.

Obesity Might Persistently Increase Adrenal Gland Volume: a Preliminary Study

OBJECTIVES

This study aimed to investigate the association of obesity with adrenal gland volume (AGV) and the effects of weight loss on AGV.

METHODS

This study included obese patients (N = 25) who underwent sleeve gastrectomy and age- and sex-matched healthy volunteers (HVs) (N = 25) and overweight healthy volunteers (overweight-HVs) (N = 21). Thin-slice computed tomography was used to evaluate adrenal morphological changes. AGV was measured semiautomatically based on the digital imaging and communications in medicine (DICOM) image. The effects of weight loss on AGV and adrenal gland density were evaluated in patients for 1 year or more after sleeve gastrectomy.

RESULTS

Left, right, and total AGV were 6.77 ± 0.36, 5.76 ± 0.31, and 12.53 ± 0.64 cm³ in obese patients, which were significantly higher than those in the overweight-HVs (3.88 ± 0.14, 3.09 ± 0.13, and 6.97 ± 0.24 cm³) and HVs (3.38 ± 0.23, 2.67 ± 0.15, and 6.04 ± 0.36 cm³). AGV was larger in overweight-HVs than in HVs, but no statistically significant difference was identified. Sleeve gastrectomy significantly reduced body weight (- 27.1 ± 2.5 kg), left AGV (- 0.80 ± 0.26 cm³), and right AGV (- 0.88 ± 0.20 cm²). The adrenal volume in five patients was not reduced, despite significant weight loss postsurgery. The mean density of adrenal glands was lower in obese patients (P = 0.025) but were not significantly increased postsurgery.

CONCLUSIONS

Obesity leads to increased AGV, and in some cases, this effect seems to be irreversible. The clinical implication of obesity-induced adrenal morphological changes needs to be studied further.

Enlargement of the human adrenal zona fasciculata and chronic psychiatric illness - an autopsy-based study

Severe mental illness (SMI) is associated with a reduced life expectancy of up to 20 years. One possible contributor to this fact is dysregulation of the hypothalamus-pituitary-adrenal (HPA)-axis. Looking at the morphology of effector organs, such as the adrenal glands themselves, could reveal insights into organ function and response to possible HPA-dysregulation. This forensic autopsy-based study investigated if there were any morphological changes in adrenal glands between decedents who had previously been submitted to a psychiatric hospital with a diagnosis of schizophrenia (n = 34), bipolar (n = 5), or depressive disorder (n = 20), any other psychiatric diagnosis (n = 36) compared with decedents who had no previous psychiatric admission (n = 40). Length of admissions to psychiatric wards and admission in the 180 days preceding death was included in regression as proxy variables for severity of illness. On the macroscopic level, we found no difference in gland weight or volume. On the microscopic level, we found a 25% increase in cross-sectional area of the zona fasciculata (ZF) in decedents who had a diagnosis of schizophrenia compared with controls (p = 0.033). Other diagnosis groups did not differ from controls. Total admission length was positively correlated with area of the ZF.Lay SummaryPeople with a severe mental disorder may be in a constant state of increased stress, which is harmful. This study looked at the adrenal gland, which produces stress hormones, to see if they were different in deceased persons who had suffered from a severe mental illness. We found that the part of the adrenal gland that produces stress hormones is larger in deceased patients who suffered from schizophrenia, but not other types of psychiatric illnesses, compared to deceased persons with no history of psychiatric illness.

An enlarged left adrenal gland is an indirect sign of infection on 18F-FDG PET/CT

OBJECTIVES

To determine whether hypermetabolisms of the spleen and bone marrow and an enlarged adrenal gland are significant indirect signs of infection on fluorine-18-fluorodeoxyglucose (F-FDG) PET/CT performed in patients with known or suspected infectious disease.

PATIENTS AND METHODS

Potential indirect signs of infection were as follows: (i) investigated in a retrospectively selected group of patients referred to F-FDG PET/CT for a known or suspected infectious disease and among whom the presence or absence of infectious foci was ascertained in 43 and 12 cases, respectively, and (ii) further validated in groups prospectively constituted of 12 patients with severe sepsis and of 39 control patients with no sign of any infectious disease. Standardised uptake values were determined on left adrenal gland, spleen and bone marrow, whereas the size of left adrenal gland was assessed by its maximal surface on unenhanced axial computed tomography (CT) slices.

RESULTS

Only the maximal surface of the left adrenal gland was a predictor in the initial study group (infection: 2.72±0.99 cm vs. no infection: 1.85±0.76 cm, P=0.004) and further validation groups (sepsis: 2.79±0.83 cm vs. controls: 1.91±0.67 cm, P=0.001). Patients with a greater than 1.8 cm maximal surface had more than two-fold higher infection rate than the other patients in the initial study group [88 (36/41) vs. 36% (4/11), P=0.001], even when only considering the subgroup with no evident infectious focus on F-FDG PET/CT [76 (16/21) vs. 30% (3/10), P=0.02].

CONCLUSION

An enlarged left adrenal gland is a significant sign of infection on F-FDG PET/CT, even in the absence of any evident infectious focus on F-FDG PET/CT images.

Increased epicardial adipose tissue in young adults with congenital heart disease comorbid with major depressive disorder

OBJECTIVE

Congenital heart disease is the most common congenital malformation. In adult congenital heart disease (ACHD), the prevalence of major depressive disorder (MDD) is increased. Beyond its immanent health risks, increased epi‑ and paracardial adipose tissue has been described in MDD. Epicardial adipose tissue (EAT) is a fat depot surrounding the heart, and it is hypothesized to be associated with coronary artery disease, left-ventricular dysfunction and atrial fibrillation, being frequent problems in ACHD long-term management. We here examined whether EAT is increased in depressed patients with ACHD.

METHODS

Two-hundred and ten ACHD outpatients (mean age 35.5y, 43% female) were included. MDD was diagnosed according to DSM-IV criteria using expert interviews. EAT was measured using echocardiography. Further assessments comprised NT-proBNP, left and right ventricular end-diastolic diameter, left-ventricular ejection fraction, smoking behavior and physical activity.

RESULTS

Of 210 patients, 53 (25.2%) were diagnosed with MDD. EAT was increased in depressed ACHD (F = 5.04; df = 1; p = 0.026). Depressed male patients were less physically active (p < 0.05) and smoked more cigarettes (p < 0.05). EAT was positively predicted by depression severity (p = 0.039), body mass index (p < 0.001), and negatively predicted by physical activity (p = 0.019).

CONCLUSIONS

The presence of MDD is associated with an increased amount of EAT in ACHD, and is dependent on depression severity. Further, the amount of EAT is at least in part mediated by a more sedentary lifestyle. Given the long-term health risks associated with increased EAT, interventions aiming at increased physical activity, smoking cessation and early identification of comorbid MDD may be recommended in ACHD.

Glucocorticoid Resistance: Is It a Requisite for Increased Cytokine Production in Depression? A Systematic Review and Meta-Analysis

Background: Glucocorticoid resistance-reduced function of the glucocorticoid receptor (GR)-is seen in many depressed patients. It is argued that this resistance to glucocorticoids leads to failure of normal feedback regulation on the immune system. High levels of pro-inflammatory cytokines result. Purpose: We sought to identify evidence supporting or refuting a link between glucocorticoid resistance and immune dysregulation in depression and to summarize retrieved evidence in aggregate form. Methods: We systematically reviewed and meta-analyzed studies that examined cytokine levels in depressed patients compared with controls and that also reported a measure of glucocorticoid resistance. These measures included plasma cortisol, the dexamethasone suppression test (DST), GR expression levels, and the results of in vitro assays of GR function. We conducted four separate meta-analyses to test for moderating effects of glucocorticoid resistance on cytokine production in depression. Results: After sub-grouping 32 studies by the ratio of cortisol levels in patients compared with controls, we observed a trend for increasing glucocorticoid resistance (i.e., the most hypercortisolemic patients) to be associated with increased production of interleukin (IL)-6 [d = 0.94; 95% CI (0.29, 1.59)] and tumour necrosis factor (TNF)-α [d = 0.46; 95% CI (0.12, 0.79)]. We stratified nine studies that reported DST results by relative glucocorticoid resistance between patients and controls, identifying a trend for higher glucocorticoid resistance in patients, compared with controls, to be associated with higher cytokine production in patients (170 patients and 187 controls). This was particularly evident when studies were sub-grouped by source of cytokine-plasma (d = 1.04; 95% CI, 0.57-1.50) versus in vitro (d = 0.24; 95% CI, -0.20 to 0.67). Stratifying the four studies (147 patients and 118 controls) that used in vitro assays of GR function or GR expression to quantify glucocorticoid resistance revealed variable contributions to cytokine production in patients compared with controls (overall effect size: d = 1.35; 95% CI 0.53-2.18). Combining our analyses of studies that reported DST results with those that used in vitro assays of GR function or GR expression to quantify glucocorticoid resistance (302 patients and 277 controls), we noted that although depressed patients produced more cytokines than controls (d = 1.02; 95% CI, 0.55-1.49), there was no evident positive correlation between glucocorticoid resistance and inflammation. Conclusions: Our work provides some support for a model conceptualizing glucocorticoid resistance as a requisite for increased inflammation in depression. The limited number of studies identified highlights the need for purpose-designed investigations that directly examine the relationship between glucocorticoid resistance and cytokine production in depression.

Hypothalamus enlargement in mood disorders

OBJECTIVE

The purpose of this study was to determine, in vivo, whether the hypothalamus volume is reduced in patients with mood disorders.

METHODS

The cross-sectional study included 20 unmedicated (MDDu) and 20 medicated patients with major depressive disorder, 21 patients with bipolar disorder, and 23 controls. Twenty of the controls were matched to the MDDu. Seven Tesla, T1-weighted magnetic resonance images were acquired and processed using methods specifically developed for high-precision volumetry of the hypothalamus.

RESULTS

An overall group difference was observed for the left hypothalamus volume corrected for intracranial volume. Planned contrasts identified that the left hypothalamus was approximately 5% larger in each patient group compared with the control group. A paired t-test with the 20 matched pairs of MDDu and controls and without correction for covariates confirmed the larger left hypothalamus volume in MDDu.

CONCLUSIONS

Contrary to our expectations, the hypothalamus volume was increased in patients with uni- and bipolar affective disorders. The effect was left-sided and independent of medication status or statistical correction for covariates. Supported by emerging evidence that the stress response may be related to structural and functional asymmetry in the brain, our finding suggests a crucial role of the hypothalamus in mood disorders.

Visceral adipose tissue in patients with severe mental illness

Background Severe mental illnesses (SMIs), i.e. major depression, schizophrenia and bipolar disorder, are associated with an elevated risk for the development of type-2 diabetes mellitus and cardiovascular disorders. Several factors have been associated with increased cardiometabolic morbidity and mortality in SMI, including lifestyle factors (smoking, inactivity, unhealthy diet), endocrine and immunologic alterations; however, the underlying mechanisms remain to be fully uncovered. It is now well accepted that visceral adipose tissue (VAT) promotes the development of cardiometabolic disorders, at least in part by inflammatory and metabolic functions. Methods This paper reviews studies concerning VAT, with special focus on intra-abdominal and pericardial adipose tissue, in SMI. Results In patients with SMI, several studies have been performed concerning VAT. Most of these studies reported alterations of VAT particularly in patients with major depression and schizophrenia, independent of body weight and body mass index. Some of the studies also reported an increased cardiometabolic risk. Conclusion Patients with SMI are at increased risk of developing cardiometabolic disorders, and display increased amounts of VAT. As studies so far were mainly performed on patients before the onset of cardiometabolic disorders, VAT may serve as a biomarker for patients with SMI to assess cardiometabolic risks beyond established risk scores. Further, interventions aiming at reducing VAT in SMI are highly recommended in long-term multimodal treatment plans.

Reduced muscle mass in middle-aged depressed patients is associated with male gender and chronicity

OBJECTIVE

Reduced muscle mass is a characteristic finding in sarcopenia, the central element of physical frailty syndrome, and a major cause of physical function decay, morbidity and mortality in the elderly. Studies so far demonstrated reduced muscle mass in depressed patients with an average age over 60years. An open question is whether muscle mass reduction is already observed earlier. Therefore, muscle mass was assessed in middle-aged male and female depressive patients, and the findings were related to indicators of hypothalamus-pituitary adrenal axis activation, lifestyle factors, endocrine and immune measures.

METHODS

Sixty-seven depressed patients (mean age 38.6y; 58.2% female) and 26 healthy volunteers (mean age 40.5y; 61.5% female) were included. Muscle mass, adrenal gland volume, and intra-abdominal adipose tissue were assessed by magnetic resonance tomography. Laboratory parameters included fasting cortisol, pro-inflammatory cytokines, factors constituting the metabolic syndrome, and relative insulin resistance according to the homeostasis model assessment (HOMA-IR).

RESULTS

We found significant effects of depression (F=4.2; P=0.043) and gender (F=182; P<0.001) on muscle mass. Muscle mass was reduced in depressed men compared to healthy men (F=3.4; P=0.044), particularly in those with chronic depression. In contrast, no such association was observed in depressed females. Adrenal gland volume and intra-abdominal fat was increased in depressed men and women, although not significantly. Correlations were observed for muscle mass with the amount of self-reported exercise and depression severity, and for depression severity with self-reported exercise. Further findings comprised lower self-reported activity and higher cortisol concentrations in depressed male and female compared to healthy probands.

CONCLUSIONS

Muscle mass is reduced in middle-aged depressed men, particularly those with chronic disease course. This association is not observed in depressed females, possibly pointing to the role of female sex steroids in maintaining muscle mass. The increase of adrenal gland volume in depressed patients may point to the role of a dysregulated hypothalamus-pituitary-adrenal system. The inverse association of exercise with muscle mass demonstrates the importance of physical activity. Looking at the long term consequences of reduced muscle mass, interventions to preserve and rebuild muscle mass in depression - such as structured exercise interventions - should be recommended.

SIGNIFICANT OUTCOMES

Muscle mass is decreased in male patients with major depressive disorder, particular those with chronic disease course. This difference was not observed in female depressed patients. The extent of muscle mass reduction is correlated to depression severity and inversely to physical activity, pointing to the role of depression associated inactivity. Low muscle mass is a risk factor for physical frailty, therefore interventions aiming at improving physical fitness may be recommended.

LIMITATIONS

Sex steroids were not assessed in the study groups.

Pericardial adipose tissue and the metabolic syndrome is increased in patients with chronic major depressive disorder compared to acute depression and controls

OBJECTIVE

Major depressive disorder (MDD) is associated with an estimated fourfold risk for premature death, largely attributed to cardiovascular disorders. Pericardial adipose tissue (PAT), a fat compartment surrounding the heart, has been implicated in the development of coronary artery disease. An unanswered question is whether people with chronic MDD are more likely to have elevated PAT volumes versus acute MDD and controls (CTRL).

METHODS

The study group consists of sixteen patients with chronic MDD, thirty-four patients with acute MDD, and twenty-five CTRL. PAT and adrenal gland volume were measured by magnetic resonance tomography. Additional measures comprised factors of the metabolic syndrome, cortisol, relative insulin resistance, and pro-inflammatory cytokines (interleukin-6; IL-6 and tumor necrosis factor-α, TNF-α).

RESULTS

PAT volumes were significantly increased in patients with chronic MDD>patients with acute MDD>CTRL. Adrenal gland volume was slightly enlarged in patients with chronic MDD>acute MDD>CTRL, although this difference failed to reach significance. The PAT volume was correlated with adrenal gland volume, and cortisol concentrations were correlated with depression severity, measured by BDI-2 and MADRS. Group differences were found concerning the rate of the metabolic syndrome, being most frequent in chronic MDD>acute MDD>CTRL. Further findings comprised increased fasting cortisol, increased TNF-α concentration, and decreased physical activity level in MDD compared to CTRL.

CONCLUSION

Our results extend the existing literature in demonstrating that patients with chronic MDD have the highest risk for developing cardiovascular disorders, indicated by the highest PAT volume and prevalence of metabolic syndrome. The correlation of PAT with adrenal gland volume underscores the role of the hypothalamus-pituitary-adrenal system as mediator for body-composition changes. Metabolic monitoring, health advices and motivation for the improvement of physical fitness may be recommended in depressed patients, in particular in chronic depression.

Altered DNA methylation of glucose transporter 1 and glucose transporter 4 in patients with major depressive disorder

Alterations in brain glucose metabolism and in peripheral glucose metabolism have frequently been observed in major depressive disorder (MDD). The insulin independent glucose transporter 1 (GLUT1) plays a key role in brain metabolism while the insulin-dependent GLUT4 is the major glucose transporter for skeletal and cardiac muscle. We therefore examined methylation of GLUT1 and GLUT4 in fifty-two depressed inpatients and compared data to eighteen healthy comparison subjects. DNA methylation of the core promoter regions of GLUT1 and GLUT4 was assessed by bisulfite sequencing. Further factors determined were fasting glucose, cortisol, insulin, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). We found significantly increased methylation of the GLUT1 in depressed inpatients compared to healthy comparison subjects (CG). Further findings comprise increased concentrations of fasting cortisol, glucose, insulin, and increased IL-6 and TNF-α. After six weeks of inpatient treatment, significantly lower GLUT1 methylation was observed in remitted patients compared to non-remitters. GLUT4 methylation was not different between depressed patients and CG, and did not differ between remitted and non-remitted patients. Although preliminary we conclude from our results that the acute phase of major depressive disorder is associated with increased GLUT1 methylation and mild insulin resistance. The successful treatment of depression is associated with normalization of GLUT1 methylation in remitters, indicating that this condition may be reversible. Failure of normalization of GLUT1 methylation in non-remitters may point to a possible role of impeded brain glucose metabolism in the maintenance of MDD.

The Adrenal Gland Volume Measurements in Manifestation of the Metabolic Status in Type-2 Diabetes Mellitus Patients

Objectives. The aim of our study was to investigate the differences in adrenal gland volume between nondiabetic controls and Type-2 diabetic patients and to examine the influence of glycemic control in diabetes mellitus on adrenal gland volume. Methods. From March 2 to November 25, 2015, 62 consecutive patients with Type-2 DM along with 62 nondiabetics matched by age, gender, and BMI were enrolled in this prospective study. Our diabetes patients were categorized into two groups, well-controlled and poorly controlled diabetes groups. Adrenal volumetric measurements were performed by two radiologists, prospectively and independently, with semiautomatic software. Interobserver reliability was studied using the interobserver correlation coefficient (ICC). Results. The total adrenal volume (TAV) was significantly higher in Type-2 diabetic patients when compared with nondiabetic patients (p < 0.05). When we investigated diabetic patients according to glycemic controls, the TAVs in controlled diabetic patients were significantly higher than in those of the poorly controlled or uncontrolled diabetic patients (p < 0.05). Nondiabetic control patients have significantly smaller TAVs when compared to controlled and poorly or noncontrolled diabetic patients (p < 0.05). Conclusion. Our study suggests that adrenal gland volume measurement may be used as an indirect marker of glycemic control in patients with diabetes.