Serum adiponectin and resistin levels in major depressive disorder

Evaluation of Orexin-A, Adiponectin and Apelin-13 Serum Levels in Children Diagnosed With Attention Deficit Hyperactivity Disorder

OBJECTIVE

This study investigates the role of orexin-a, adiponectin (HMWA) and apelin-13 serum levels in the etiopathogenesis of attention deficit hyperactivity disorder (ADHD), a neurodevelopmental disorder with unclear aetiology involving neuropathological, genetic and environmental factors.

METHODS

The study involved 37 children with ADHD and 35 healthy controls, aged 6-18 years, with no history of other physical or psychiatric illnesses and no psychotropic medication use in the last 6 months. Serum levels of orexin-a, adiponectin (HMWA) and apelin-13 were measured using enzyme-linked immunosorbent assay (ELISA). ADHD symptoms were assessed through Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5)-based clinical interviews, Conners Parent and Teacher Rating Scales and Wisconsin Card Sorting Test.

RESULTS

No significant differences in serum orexin-a, adiponectin (HMWA) and apelin-13 levels were found between the ADHD and control groups. Additionally, there was no relationship between orexin-a, apelin-13 and adinopectin levels and ADHD symptoms and Wisconsin Card Sorting Test results. Analysis of adiponectin levels in preadolescent children aged 6-11, adjusting for age and BMI, revealed a statistically significant reduction in the ADHD group (p = 0.002).

CONCLUSION

The results did not demonstrate any correlation between ADHD and the levels of orexin-a and apelin-13. However, the study revealed that children with ADHD, aged 6-11, exhibited decreased adiponectin concentrations. These results suggest that a decrease in serum adinopectin levels may be associated with ADHD in children.

Adiponectin blood levels and autism spectrum disorders: a systematic review

OBJECTIVE

To review the relationship between adiponectin levels and autism spectrum disorders (ASDs) in children.

BACKGROUND

ASDs are associated with pervasive social interaction and communication abnormalities. Researchers have studied various pathophysiological mechanisms underlying ASDs to identify predictors for an early diagnosis to optimize treatment outcomes. Immune dysfunction, perhaps mediated by a decrease in anti-inflammatory adipokine, adiponectin, along with changes in other adipokines, may play a central role in increasing the risk for ASDs. However, other factors, such as low maternal vitamin D levels, atherosclerosis, diabetes, obesity, cardio-metabolic diseases, preterm delivery, and oxytocin gene polymorphism may also contribute to increased risk for ASDs.

METHODS

Searches on the database; PubMed, Google Scholar, and Cochrane using keywords; adiponectin, adipokines, ASD, autism, autistic disorder, included English-language studies published till September 2022. Data were extracted on mean differences between adiponectin levels in children with and without ASDs.

RESULTS

The search yielded six studies providing data on adiponectin levels in young patients with ASDs. As can be seen from Table 1, four of the six studies were positive for an inverse correlation between ASD and adiponectin levels. In addition, two of the four positive and one negative studies found low adiponectin levels associated with and the severity of autistic symptoms. However, results from one reviewed study were insignificant.

CONCLUSION

Most studies reviewed yielded lower adiponectin levels in children with ASDs as well as the severity of autistic symptoms.

Prevalence and risk factors for psychotic symptoms in young, first-episode and drug-naïve patients with major depressive disorder

BACKGROUND

Major depressive disorder (MDD) is a common psychiatric disorder worldwide. Psychotic depression has been reported to be frequently under-diagnosed due to poor recognition of psychotic features. Therefore, the purpose of this study was to reveal the rate and risk factors of psychotic symptoms in young, drug-naïve patients with major depressive disorder at the time of their first episode.

METHODS

A total of 917 patients were recruited and divided into psychotic and non-psychotic subgroups based on the Positive and Negative Syndrome Scale (PANSS) positive subscale score. Anxiety symptoms and depressive symptoms were measured by the Hamilton Anxiety Rating Scale (HAMA) and the 17-item Hamilton Depression Rating Scale (HAMD-17), respectively. Several biochemical indicators such as total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), fasting blood glucose (FBG), thyroid stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) were also measured.

RESULTS

The rate of psychotic symptoms among young adult MDD patients was 9.1%. There were significant differences in TSH (p<0.001), FBG (p<0.001), TC (p<0.0001), TG (p = 0.001), HDL-C (p = 0.049), LDL-C (p = 0.010), diastolic blood pressure (DP) (p<0.001), systolic blood pressure (SP) (p<0.001), and HAMD total score (p<0.001) between young MDD patients with and without psychotic depression. HAMD, TSH, TC, and severe anxiety were independently associated with psychotic symptoms in young adult MDD patients. In addition, among young MDD patients, the rate of suicide attempts in the psychotic subgroup was much higher than in the non-psychotic subgroup (45.8% vs. 16.9%).

CONCLUSIONS

Our findings suggest that psychotic symptoms are common in young MDD patients. Several clinical variables and biochemical indicators are associated with the occurrence of psychotic symptoms in young MDD patients.

Correlation analysis between per-fluoroalkyl and poly-fluoroalkyl substances exposure and depressive symptoms in adults: NHANES 2005-2018

BACKGROUND

Excessive exposure to per and poly-fluoroalkyl compounds (PFAS) can lead to various negative health effects. However, there's a lack of research studying the link between PFAS exposure and depression in adults, and the existing findings are inconsistent.

OBJECTIVES

Utilizing data collected from the National Health and Nutrition Examination Survey (NHANES) database spanning 2005 to 2018, this study aimed to examine the potential connection between PFAS exposure and depressive symptoms in adults.

METHODS

The correlation between individual PFAS exposure and depressive symptoms was examined through the establishment of weighted logistic regression models (crude model, model 1, model 2) and restricted cubic spline models. To verify the stability of the model, receiver operating characteristic (ROC) curves of the logistic regression model were generated, and a ten-fold cross-validation model was employed. Additionally, the relationship between adult depressive symptoms and mixed PFAS exposure was tested through the utilization of quantile g-computation (qgcomp).

RESULTS

The findings revealed that heightened exposure levels to PFOA, PFHxS, and PFUnDA, were connected with a diminished risk of depressive symptoms in adults (ORPFOA: 0.67, 95 % confidence interval (CI): 0.47, 0.95; ORPFHxS: 0.66, 95 %CI: 0.49, 0.89; ORPFUnDA: 0.65, 95 %CI: 0.45, 0.96). PFOS, PFHxS, and PFDA demonstrated a dose-response relationship with the risk of depressive symptoms. The ROC curve indicated model stability, with recognition accuracy exceeding 90 % in the cross-validation model. The outcomes of qgcomp demonstrated that an increase in serum PFAS concentration was linked to a decreased risk of depressive symptoms in adults (OR: 0.85, 95 %CI: 0.75, 0.96).

DISCUSSION

Due to the cross-sectional design of this study, it's important to acknowledge the potential for reverse causality between PFAS exposure and depressive symptoms. As a result, the outcomes should not be oversimplified to interpret PFAS exposure as a protective factor against adult depressive symptoms.

Changes in Adipokine, Resitin, and BDNF Concentrations in Treatment-Resistant Depression after Electroconvulsive Therapy

OBJECTIVES

One of the current challenges in psychiatry is the search for answers on how to effectively manage drug-resistant depression. The occurrence of drug resistance in patients is an indication for the use of electroconvulsive therapy (ECT). This method is highly effective and usually results in relatively quick health improvement. Despite the knowledge of how ECT works, not all of the biological pathways activated during its use have been identified. Hence, based on the neuroinflammatory hypothesis of depression, we investigated the concentration of two opposite-acting adipokines (anti-inflammatory adiponectin and proinflammatory resistin) and BDNF in antidepressant-resistant patients undergoing ECT.

METHODS

The study group comprised 52 patients hospitalized due to episodes of depression in the course of unipolar and bipolar affective disorder. The serum concentration of adipokines and BDNF was determined before and after the therapeutic intervention using an ELISA method. In the analyses, we also included comparisons considering the type of depression, sex, and achieving remission.

RESULTS

Adiponectin, resistin, and BDNF concentrations change after ECT treatment. These changes are correlated with an improvement in the severity of depressive symptoms and are more or less pronounced depending on the type of depression.

CONCLUSIONS

Although not all observed changes reach statistical significance, adipokines in particular remain exciting candidates for biomarkers in assessing the course of the disease and response to ECT treatment.

RETN gene polymorphisms interact with alcohol dependence in association with depression

BACKGROUND

Previous studies suggest that alcohol dependence is associated with increased risk of depression. The occurrence of depressive symptoms is related to polymorphisms in various genetic regions. This study aimed to investigate the interaction of RETN gene polymorphisms (rs1477341, rs3745368) with alcohol dependence on depressive symptoms in adult male during acute alcohol withdrawal.

METHODS

A total of 429 male adults were recruited in this study. Alcohol dependence was assessed using the Michigan alcoholism screening test (MAST). Depression was assessed using the 20-item self-rating depression scale (SDS). Hierarchical regression analysis was used to evaluate the interaction between genes and alcohol dependence on depression. Region of significance (ROS) test was used to explain the interaction effect. The strong and weak forms of the differential susceptibility and diathesis models were used to determine which fits the data better.

RESULTS

Our results showed that MAST scores were significantly positively associated with SDS scores (r = 0.23, p < 0.01) in alcohol-dependent patients during alcohol withdrawal. The interaction between genotype and alcohol dependence was significant (β = -0.14, p < 0.05) in a strong diathesis-stress model. Susceptibility for depression symptoms was associated with alcohol dependence in RETN rs1477341 A carriers. Specifically, those that showed more alcohol dependence and the A allele of RETN rs1477341 exhibited more depression symptoms. However, RETN rs3745368 had no significant interaction with alcohol dependence.

CONCLUSIONS

The A allele of RETN rs1477341 may correlate with susceptibility to depression symptoms in alcohol-dependent individuals during acute alcohol withdrawal.

Peripheral Inflammatory Markers in Subtypes and Core Features of Depression: A Systematized Review

INTRODUCTION

The aim of this work was to summarize relationships between two subtypes of major depressive disorder (melancholic and atypical) and four core features of depression that reflect the domains identified consistently in previous studies of major depressive disorder endophenotypes (exaggerated reactivity to negative information, altered reward processing, cognitive control deficits, and somatic symptoms) on the one hand and selected peripheral inflammatory markers (C-reactive protein [CRP], cytokines, and adipokines) on the other.

METHODS

A systematized review was conducted. The database used for searching articles was PubMed (MEDLINE).

RESULTS

According to our search, most peripheral immunological markers associated with major depressive disorder are not specific to a single depressive symptom group. The most evident examples are CRP, IL-6, and TNF-α. The strongest evidence supports the connection of peripheral inflammatory markers with somatic symptoms; weaker evidence indicates a role of immune changes in altered reward processing. The least amount of evidence was found for the role of peripheral inflammatory markers in exaggerated reactivity to negative information and cognitive control deficits. Regarding the depression subtypes, a tendency for higher CRP and adipokines was observed in atypical depression; increased IL-6 was found in melancholic depression.

CONCLUSION

Somatic symptoms of depression could be a manifestation of a specific immunological endophenotype of depressive disorder. Melancholic and atypical depression may be characterized by different profiles of immunological markers.

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.

Altered serum adiponectin and interleukin-8 levels are associated in the pathophysiology of major depressive disorder: A case-control study

BACKGROUND

Major depressive disorder (MDD) is a complex mental health condition that results in several obstacles including disabilities, loss of productivity, and economic burdens on both patients and society. Etiopathogenesis of MDD involves several factors such as sociodemographic, genetic, and biological determinants. However, any suitable biomarkers for risk assessment of depression have not been established yet. Alterations of cytokine are assumed to be involved in the pathophysiology and severity of the depressive disorder. Therefore, we aimed to evaluate serum adiponectin and interleukin-8 (IL-8) among MDD patients in Bangladesh.

METHODS

We recruited a total of 63 MDD patients and 94 age-sex matched healthy controls (HCs) in the present study. MDD patients were enrolled from a tertiary care teaching hospital, Dhaka, Bangladesh, and HCs from surrounding parts of Dhaka city. A psychiatrist assessed all the study participants following the criteria mentioned in the DSM-5. We applied the Hamilton depression (Ham-D) rating scale to assess the depression severity. Serum adiponectin and IL-8 levels were determined using ELISA kits (BosterBio, USA).

RESULTS

The mean serum concentration of adiponectin was decreased (30.67±4.43 μg/mL vs. 53.81±5.37 μg/mL), and the IL-8 level was increased (160.93±14.84 pg/mL vs. 88.68±6.33 pg/mL) in MDD patients compared to HCs. Sex-specific scatters plot graphs showed the distribution of adiponectin and IL-8 levels with Ham-D scores in MDD patients. Also, ROC curve analysis demonstrated good predictive performances of serum adiponectin and IL-8 for MDD with the area under the curve (AUC) as 0.895 and 0.806, respectively.

CONCLUSION

The present study findings suggest that alterations of serum adiponectin and IL-8 levels in MDD patients might be involved in the disease process. Therefore, we can use these changes of cytokines in serum levels as early risk assessment tools for depression. The present study findings should be considered preliminary. We propose further interventional studies to evaluate the exact role of adiponectin and IL-8 in depression.

Mechanisms of Xiong-Pi-Fang in treating coronary heart disease associated with depression: A systematic pharmacology strategy and in vivo pharmacological validation

BACKGROUND

Coronary heart disease (CHD) and depression are very common and often co-existing disorders. Xiong-Pi-Fang (XPF), a therapeutic classical traditional Chinese medicine (TCM) formula, has shown satisfactory efficacy in treating CHD associated with depression. However, its mechanism of action is still unknown.

PURPOSE

To employ a systematic pharmacology approach for identifying the action mechanisms of XPF in treating CHD associated with depression.

METHODS

We used a systematic pharmacology approach to identify the potential active mechanisms of XPF in treating CHD with depression. Potential active compounds in XPF and the diseases targets were screened using relevant databases to build corresponding pathways, following the experiments that were conducted to confirm whether the presumptive results of systemic pharmacology were correct.

RESULTS

Network pharmacology predicted 42 key targets and 20 signaling pathways involved in XPF-mediated treatment, with IL-6/JAK2/STAT3/HIF-1α/VEGF-A pathway significantly affected. The common influences were hypothalamic-pituitary-adrenal axis (HPA axis) and glucocorticoid signaling, validated through chronic unexpected mild stress (CUMS) with isoprenaline (ISO) for inducing CHD within the depression model in rats. In addition, XPF intake reduced depressive-like behaviors and improved ECG ischemic changes. Furthermore, XPF exerted some anti-inflammatory effects by inhibiting the interleukin-6 (IL-6) induced phosphorylation of janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3), ultimately downregulating hypoxia-inducible factor 1-α (HIF-1α) and vascular endothelial growth factor-A (VEGF-A) activation. The dysfunctional HPA axis feedback loop was also regulated, which enhanced the glucocorticoid receptor (GR) expression. In contrast, it improved glucocorticoid resistance by reducing the mineralocorticoid receptor expression.

CONCLUSIONS

Suppressing IL-6 release and maintaining the HPA feedback loop balance could be the primary mechanism of XPF against CHD with depression. The significance of the IL-6 and HPA axis identified indicates their potential as essential targets for CHD therapy with depression.

Prospective Association of Circulating Adipokines with Cardiometabolic Risk Profile Among Women: The Rape Impact Cohort Evaluation Study

BACKGROUND

Sexual violence is associated with poor cardiometabolic outcomes, yet the etiopathogenic pathways remain unclear. Adipokines may contribute to pathways in the development of cardiometabolic disease (CMD), including in vulnerable populations. Further investigation of adipokines among sexually traumatized individuals may inform cardiometabolic screening. This study aimed to investigate the association between circulating adipokines, metabolic syndrome (MetS), and longitudinal change in MetS components (namely abdominal obesity, blood pressure, lipid profile, and glycemic status) over a 1-year period in a cohort of rape exposed (RE) and rape unexposed (RUE) females.

MATERIALS AND METHODS

Seven hundred seventy-eight RE and 617 RUE black South African women aged 18-40 years were recruited for the Rape Impact Cohort Evaluation study. Nonfasting blood samples were analyzed for cardiometabolic variables and adipokine levels using enzyme-linked immunosorbent assay. Serum adiponectin was measured in both RE and RUE and resistin, leptin, and leptin/adiponectin (L/A) ratio in RE only. Associations between baseline serum adipokines, MetS, and its components were assessed at baseline and follow-up using adjusted linear and logistic regressions.

RESULTS

In the RE group, adiponectin, leptin, and L/A ratio were significantly associated with MetS prevalence cross-sectionally (all p ≤ 0.001). No adipokine marker was related to incident MetS at 12-month follow-up. In the RE group, significant longitudinal associations with high-density lipoprotein cholesterol were shown for adiponectin (β = 0.146 [0.064], p = 0.022) and leptin (β = 0.001 [0.002], p = 0.012).

CONCLUSIONS

Findings suggest that adipokines may have a potential role as biomarkers to identify RE individuals at high risk for CMD.

Changes in adipokine concentrations in antidepressant-resistant bipolar depression after ketamine infusion and electroconvulsive therapy

OBJECTIVES

This study attempts to assess the concentration of two opposite-acting adipokines (anti-inflammatory adiponectin and pro-inflammatory resistin) in antidepressant-resistant patients undergoing ketamine infusion (KI) and electroconvulsive therapy (ECT).

METHODS

The study group comprised 52 patients hospitalised due to episodes of depression in the course of bipolar disorders. The Hamilton depression scale was used to assess the intensity of the depression symptoms before starting therapy and one day after its completion. The serum concentration of adipokines was determined before and after the therapeutic intervention using an ELISA method.

RESULTS

Baseline adipokine levels differed between patients receiving KI and ECT therapy. Regardless of the procedure used, these levels changed after treatment, with the nature of these changes being different. In the case of KI, the adiponectin levels increased, and resistin levels decreased. In contrast, after ECT, the concentrations of both adipokines decreased. Changes in adipokine concentrations correlated with improvement in mental status, as assessed by the Hamilton Rating Scale, type of bipolar disorder, and gender.

CONCLUSIONS

Adipokines remain interesting candidate biomarkers in assessing the state and course of the disease depending on the therapeutic procedure applied. However, the relatively small study group and limited original research available for discussion justify further investigation.

Increased serum resistin but not G-CSF levels are associated in the pathophysiology of major depressive disorder: Findings from a case-control study

Background

Many studies have predicted major depressive disorder (MDD) as the leading cause of global health by 2030 due to its high prevalence, disability, and illness. However, the actual pathophysiological mechanism behind depression is unknown. Scientists consider alterations in cytokines might be tools for understanding the pathogenesis and treatment of MDD. Several past studies on several inflammatory cytokine expressions in MDD reveal that an inflammatory process is activated, although the precise causes of that changes in cytokine levels are unclear. Therefore, we aimed to investigate resistin and G-CSF in MDD patients and controls to explore their role in the pathogenesis and development of depression.

Methods

We included 220 participants in this study. Among them, 108 MDD patients and 112 age-sex matched healthy control (HCs). We used DSM-5 to evaluate study participants. Also, we applied the Ham-D rating scale to assess the severity of patients. Serum resistin and G-CSF levels were measured using ELISA kits (BosterBio, USA).

Results

The present study observed increased serum resistin levels in MDD patients compared to HCs (13.82 ± 1.24ng/mL and 6.35 ± 0.51ng/mL, p <0.001). However, we did not find such changes for serum G-CSF levels between the groups. Ham-D scores showed a significant correlation with serum resistin levels but not G-CSF levels in the patient group. Furthermore, ROC analysis showed a fairly predictive performance of serum resistin levels in major depression (AUC = 0.746).

Conclusion

The present study findings suggest higher serum resistin levels are associated with the pathophysiology of MDD. This elevated serum resistin level may serve as an early risk assessment indicator for MDD. However, the role of serum G-CSF in the development of MDD is still unclear despite its neuroprotective and anti-inflammatory effects.

The Associations of Body Image Perception with Serum Resistin Levels in Highly Trained Adolescent Estonian Rhythmic Gymnasts

Rhythmic gymnasts (RGs) are more likely to be dissatisfied with their body mass and shape compared to untrained controls (UCs). However, due to the lack of information, the aim of this study was to investigate the associations of body image perception (BIP) with body composition, daily energy consumption and different blood biochemical markers in adolescent RGs compared to UCs. Thirty-three highly trained RG girls and 20 UC girls aged 14–18 years participated in this cross-sectional study. Height, body mass, body composition, energy intake, resting energy expenditure, training volume and different blood biochemical markers were measured. The body attitude test (BAT) was used to evaluate the BIP of the participants. There were no differences in the total BAT scores between the groups. In RGs, the BAT score correlated positively with the serum resistin level (r = 0.35; p = 0.047). A stepwise multiple regression analysis showed that 40.8% of the variability in the BAT score was determined by resistin and BMI. The association of BIP with resistin values was observed only in RGs. In conclusion, our findings add to the increasing evidence that resistin may be a link between BIP and body composition, most likely through fat mass, in adolescent female RGs.

Inflammatory Markers Profile in Older Adolescents During Treatment with Selective Serotonin Reuptake Inhibitors

Objective: This study aimed to investigate the serum levels of inflammatory markers in adolescents with major depressive disorder (MDD) using selective serotonin reuptake inhibitors. Methods: This was an 8-month observational study, involving 30 adolescents with and 38 without (control) MDD diagnosis. Demographic (age and gender) and anthropometric data (weight, height, and calculated body mass index [BMI] z score) were collected. Body composition was assessed with whole-body DXA scan. Depressive and anxiety symptoms were assessed using the Beck Depression and Anxiety Inventories (BDI-II and BAI), respectively. Serum levels of interleukin (IL)-6, IL-8, IL-1β, tumor necrosis factor, monocyte chemoattractant protein-1 (MCP-1), leptin, resistin, and adiponectin were measured using Bio-Plex Multiplex Immunoassays at baseline and after 8 months. Results: At baseline, patients with MDD and controls did not differ in age, gender, BMI z score, and fat mass index (FMI) z score. At follow-up, 58.3% (21/36) of patients with MDD were in full remission. Patients with MDD had higher levels of resistin at baseline (26274.16 pg/mL [16162.68-54252.72]) than controls (21678.53 pg/mL [11221.17-37343.27]; p < 0.01). This difference remained statistically significant after adjustment for sex, age, and FMI z score. No differences in other inflammatory markers were observed between the groups. By follow up, depressive and anxiety symptom severity had decreased significantly in patients with MDD in parallel with a decrease in the serum levels of TNF (p = 0.02), IL-8 (p < 0.01) and MCP-1 (p = 0.04). Among these markers, BDI-II score was positively correlated with serum levels of MCP-1. Conclusion: These results corroborate the view of involvement of peripheral inflammatory mechanisms in the pathophysiology of MDD in adolescents. This trial is registered at ClinicalTrials.gov: NCT02147184.

Carnosic acid alleviates depression-like behaviors on chronic mild stressed mice via PPAR-γ-dependent regulation of ADPN/FGF9 pathway

RATIONALE

The pathway of adiponectin (ADPN)/fibroblast growth factor 9 (FGF9) was recently thought as a key role in the development of depression. ADPN is crucially regulated by peroxisome proliferator-activated receptor-gamma (PPAR-γ). Natural material carnosic acid (CA) has been applied for therapeutics of mental disorders.

OBJECTIVES

To evaluate the antidepressive effect of CA in stress-treated mice and define whether its effects is involved in the regulation of ADPN/FGF9 pathway.

METHODS

In vivo study, the levels of ADPN and FGF9 in both serum and hippocampus tissues, the expressions of ADPN receptor 2 (AdipoR2) in hippocampus and PPAR-γ in abdominal adipose, as well as the pathological changes of hippocampus were determined in 28-day period of chronic unpredictable mild stress (CUMS)-induced depression model of male ICR (Institute of Cancer Research) mice or adipo^-/- mice. In vitro study, the level of ADPN and the mRNA expressions of both ADPN and PPAR-γ were determined in mouse 3T3-L1 preadipocytes.

RESULTS

In vivo study, treatment with CA (50 or 100 mg/kg per day) for 21 days markedly suppressed depressive-like behaviors, the elevating levels of FGF9 and decreasing levels of ADPN in both serum and hippocampus tissues, the downregulating protein and mRNA expressions of AdipoR2 in hippocampus and PPAR-γ in abdominal adipose, as well as the pathological injury of hippocampus induced by CUMS in male ICR mice. The antidepressive effects of CA were markedly attenuated in male CUMS-treated adipo^-/- mice. In vitro study, incubation with CA (3-30 μmol/L) for 24 h could concentration-dependently upregulate the mRNA expressions of both PPAR-γ and ADPN as well as increase the level of ADPN. The experiments using PPAR-γ-specific inhibitor GW9662 and transient transfection with mutated PPAR-γ-binding site promotor constructs showed that the activation of PPAR-γ mediated CA-induced ADPN expression in adipocytes.

CONCLUSIONS

CA could significantly improve stress-induced depressive disorder, which may be related to regulating the dysfunction of ADPN-FGF9 pathway via activating PPAR-γ in adipocytes.

Modulation of depression-related behaviors by adiponectin AdipoR1 receptors in 5-HT neurons

The adipocyte-derived hormone adiponectin has a broad spectrum of functions beyond metabolic control. We previously reported that adiponectin acts in the brain to regulate depression-related behaviors. However, its underlying neural substrates have not been identified. Here we show that adiponectin receptor 1 (AdipoR1) is expressed in the dorsal raphe nucleus (DRN) and colocalized with tryptophan hydroxylase 2 (TPH2), a marker of serotonin (5-HT) neurons. Selective deletion of AdipoR1 in 5-HT neurons induced anhedonia in male mice, as indicated by reduced female urine sniffing time and saccharin preference, and behavioral despair in female mice and enhanced stress-induced decrease in sucrose preference in both sexes. The expression levels of TPH2 were downregulated with a concurrent reduction of 5-HT-immunoreactivity in the DRN and its two major projection regions, the hippocampus and medial prefrontal cortex (mPFC), in male but not female mice lacking AdipoR1 in 5-HT neurons. In addition, serotonin transporter (SERT) expression was upregulated in both DRN projection fields of male mice but only in the mPFC of female mice. These changes presumably lead to decreased 5-HT synthesis and/or increased 5-HT reuptake, thereby reducing 5-HT transmission. The augmented behavioral responses to the selective serotonin reuptake inhibitor fluoxetine but not desipramine, a selective norepinephrine reuptake inhibitor, observed in conditional knockout male mice supports deficient 5-HT transmission underlying depression-related phenotypes. Our results indicate that adiponectin acts on 5-HT neurons through AdipoR1 receptors to regulate depression-related behaviors in a sex-dependent manner.

Evaluation of Stress and Associated Biochemical Changes in Patients with Type 2 Diabetes Mellitus and Obesity

PURPOSE

Type 2 diabetes mellitus (T2DM), a metabolic disorder, remains associated with a physiological impairment affecting large populations worldwide. Onset of T2DM is multifactorial where obesity and abnormal basal metabolic rate are considered most critical. Of people diagnosed with T2DM, about 80% are also obese. It is also reported that obese individuals have an increased odds of developing depression, whereas T2DM is estimated to increase the incidence by two-fold. The preponderance of research data demonstrates that T2DM alters the serum level of cortisol and adiponectin which are known to be associated with neuronal physiology. The study explored, how a metabolic disorder like T2DM is linked with the altered plasma level of cortisol and adiponectin, the risk factors for stress and depression.

PATIENTS AND METHODS

A cross-sectional population study was conducted in T2DM patients using a bimodal approach. First approach used questionnaires, (1) Patient Health Questionnaire (PHQ-9) and (2) Stress Coping Inventory Questionnaire (SCQ) to assess signs and symptoms of depression and stress, respectively, in T2DM patients. In the second approach, robust biochemical analysis was conducted for serum adiponectin and cortisol levels.

RESULTS

An association of T2DM in stress and depression was evaluated in 158 subjects (105 T2DM obese patients and 53 healthy controls). A lower PHQ-9 score and adiponectin levels were seen in T2DM obese patients compared to healthy controls (p<0.05). Further, results also depicted a lower adiponectin levels in T2DM obese patients with depression compared to T2DM obese patients without depression (p<0.05). The study did not find a significant difference in cortisol serum levels among the T2DM and control groups. However, a higher level of serum cortisol was reported in T2DM obese patients with depression over those T2DM obese patients who lacked depression (p<0.05).

CONCLUSION

The findings suggest that T2DM obese patients might have a higher risk of developing stress and depression. Further, biochemical parameters, adiponectin and cortisol, might be the potential biomarkers for T2DM and may help in early diagnosis of these comorbid conditions.

Depression and Cardiovascular Disease: The Viewpoint of Platelets

Depression is a major cause of morbidity and low quality of life among patients with cardiovascular disease (CVD), and it is now considered as an independent risk factor for major adverse cardiovascular events. Increasing evidence indicates not only that depression worsens the prognosis of cardiac events, but also that a cross-vulnerability between the two conditions occurs. Among the several mechanisms proposed to explain this interplay, platelet activation is the more attractive, seeing platelets as potential mirror of the brain function. In this review, we dissected the mechanisms linking depression and CVD highlighting the critical role of platelet behavior during depression as trigger of cardiovascular complication. In particular, we will discuss the relationship between depression and molecules involved in the CVD (e.g., catecholamines, adipokines, lipids, reactive oxygen species, and chemokines), emphasizing their impact on platelet activation and related mechanisms.

Protein and gene markers of metabolic dysfunction and inflammation together associate with functional connectivity in reward and motor circuits in depression

Bidirectional relationships between inflammation and metabolic dysfunction may contribute to the pathophysiology of psychiatric illnesses like depression. Metabolic disturbances drive inflammation, which in turn exacerbate metabolic outcomes including insulin resistance. Both inflammatory (e.g. endotoxin, vaccination) and metabolic challenges (e.g. glucose ingestion) have been shown to affect activity and functional connectivity (FC) in brain regions that subserve reward and motor processing. We previously reported relationships between elevated concentrations of endogenous inflammatory markers including C-reactive protein (CRP) and low corticostriatal FC, which correlated with symptoms of anhedonia and motor slowing in major depression (MD). Herein, we examined whether similar relationships were observed between plasma markers related to glucose metabolism (non-fasting concentrations of glucose, insulin, leptin, adiponectin and resistin) in 42 medically-stable, unmedicated MD outpatients who underwent fMRI. A targeted, hypothesis-driven approach was used to assess FC between seeds in subdivisions of the ventral and dorsal striatum and a region in ventromedial prefrontal cortex (VS-vmPFC), which was previously found to correlate with both inflammation and symptoms of anhedonia and motor slowing. Associations between FC and gene expression signatures were also explored. A composite score of all 5 glucose-related markers (with increasing values reflecting higher concentrations) was negatively correlated with both ventral striatum (VS)-vmPFC (r = -0.33, p < 0.05) and dorsal caudal putamen (dcP)-vmPFC (r = -0.51, p < 0.01) FC, and remained significant after adjusting for covariates including body mass index (p < 0.05). Moreover, an interaction between the glucose-related composite score and CRP was observed for these relationships (F[2,33] = 4.3, p < 0.05) whereby significant correlations between the glucose-related metabolic markers and FC was found only in patients with high plasma CRP (>3 mg/L; r = -0.61 to -0.81, p < 0.05). Insulin and resistin were the individual markers most predictive of VS-vmPFC and dcP-mPFC FC, respectively, and insulin, resistin and CRP clustered together and in association with both LV-vmPFC and dcP-vmPFC in principal component analyses. Exploratory whole blood gene expression analyses also confirmed that gene probes negatively associated with FC were enriched for both inflammatory and metabolic pathways (FDR p < 0.05). These results provide preliminary evidence that inflammation and metabolic dysfunction contribute jointly to deficits in reward and motor circuits in MD. Future studies using fasting samples and longitudinal and interventional approaches are required to further elucidate the respective contributions of inflammation and metabolic dysfunction to circuits and symptoms relevant to motivation and motor activity, which may have treatment implications for patients with psychiatric illnesses like depression.

Seasonal affective disorder and seasonal changes in weight and sleep duration are inversely associated with plasma adiponectin levels

Overlapping pathways between mood and metabolic regulation have increasingly been reported. Although impaired regulation of adiponectin, a major metabolism-regulating hormone, has been implicated in major depressive disorder, its role in seasonal changes in mood and seasonal affective disorder-winter type (SAD), a disorder characterized by onset of mood impairment and metabolic dysregulation (e.g., carbohydrate craving and weight gain) in fall/winter and spontaneous alleviation in spring/summer, has not been previously studied. We studied a convenience sample of 636 Old Order Amish (mean (± SD), 53.6 (±14.8) years; 50.1% males), a population with self-imposed restriction on network electric light at home, and low prevalence of total SAD (t-SAD = syndromal + subsyndromal). We calculated the global seasonality score (GSS), estimated SAD and subsyndromal-SAD after obtaining Seasonal Pattern Assessment Questionnaires (SPAQs), and measured overnight fasting plasma adiponectin levels. We then tested associations between plasma adiponectin levels and GSS, t-SAD, winter-summer difference in self-reported sleep duration, and self-reported seasonal weight change, by using analysis of co-variance (ANCOVA) and linear regression analysis after adjusting for age, gender, and BMI. Participants with t-SAD (N = 14; 2.2%) had significantly lower plasma adiponectin levels (mean ± SEM, 8.76 ± 1.56 μg/mL) than those without t-SAD (mean ± SEM, 11.93 ± 0.22 μg/mL) (p = 0.035). In addition, there was significant negative association between adiponectin levels and winter-summer difference in self-reported sleep duration (p = 0.025) and between adiponectin levels and self-reported seasonal change in weight (p = 0.006). There was no significant association between GSS and adiponectin levels (p = 0.88). To our knowledge, this is the first study testing the association of SAD with adiponectin levels. Replication and extension of our findings longitudinally and, then, interventionally, may implicate low adiponectin as a novel target for therapeutic intervention in SAD.

Serum Levels of Chemerin, Apelin, and Adiponectin in Relation to Clinical Symptoms, Quality of Life, and Psychological Factors in Irritable Bowel Syndrome

BACKGROUND

Adipokines have endocrine roles in metabolism and immunity. Dysregulation of adipokine levels is associated with several diseases with chronic inflammation. We aimed to assess the serum concentrations of chemerin, apelin, and adiponectin in irritable bowel syndrome (IBS). Furthermore, we evaluated the possible association of these adipokines with clinical symptoms, quality of life (QoL), and psychological factors.

MATERIALS AND METHODS

In this case-control study, 114 male and female IBS patients were recruited from outpatient clinics. Along with the IBS patients, 114 sex and age-matched healthy volunteers were recruited. Patients filled in the questionnaires of the IBS severity scoring system (IBSSS), gastrointestinal (GI) and somatic symptoms, IBS specific QoL (IBS-QoL), and psychological disorders, and went to the lab for blood sampling.

RESULTS

Serum levels of both adiponectin and apelin were significantly (P=0.04, 0.03, respectively) lower, whereas chemerin was significantly (P=0.01) higher in IBS patients. Chemerin was higher in IBS-D compared with both IBS-C and IBS-A, while apelin and adiponectin were not different between subtypes. After adjustments for confounders only, chemerin had a positive association with IB severity scoring system and GI symptoms. Furthermore, chemerin had positive associations, whereas apelin and adiponectin had inverse associations with somatic symptoms and psychological factors. There were no significant associations between adipokines including chemerin, apelin, and adiponectin, and IBS-QoL.

CONCLUSIONS

Chemerin had significant associations with both the severity of clinical symptoms and psychological factors in IBS; thus, it could be considered as a potential therapeutic target in these patients; however, further studies are needed.

Peripheral adiponectin levels in anxiety, mood, trauma- and stressor-related disorders: A systematic review and meta-analysis

BACKGROUND

Anxiety, mood, trauma- and stressor-related disorders confer increased risk for metabolic disease. Adiponectin, a cytokine released by adipose tissue is associated with these disorders and obesity via inflammatory processes. Available data describing associations with mental disorders remain limited and conflicted.

METHODS

A systematic search was conducted for English, peer-reviewed articles from inception until February 2019 that assessed for serum or plasma adiponectin levels in adults with an anxiety, mood or trauma-related disorder. Diagnoses were determined by psychiatric interview, based on DSM-IV, DSM-5 or ICD-10 criteria. Analyses were performed using STATA 15 and Standardized mean difference (SMD) with 95% confidence interval was applied to pool the effect size of meta-analysis studies.

RESULTS

In total 65 eligible studies were included in the systematic review and 30 studies in this meta-analysis. 19,178 participants (11,262 females and 7916 males), comprising healthy adults and adults with anxiety, mood and trauma-related disorders, were included. Overall results indicated an inverse association between adiponectin levels and examined mental disorders. Specifically, patients with an anxiety disorder (SMD  = -1.18 µg/mL, 95% CI, -2.34; -0.01, p  = 0.047); trauma or stressor-related disorder (SMD  =  -0.34 µg/mL, 95% CI, -0.52; -0.17, p  = 0.0000) or bipolar disorder (SMD  =  -0.638 µg/mL, 95% CI, -1.16, -0.12, p  = 0.017) had significant lower adiponectin levels compared to healthy adults.

LIMITATIONS

Heterogeneity, potential publication bias, and lack of control for important potential confounders were significant limitations.

CONCLUSION

Peripheral adiponectin levels appear to be inversely associated with anxiety, mood, trauma- and stressor related disorders and may be a promising biomarker for diagnosis and disease monitoring.

The correlation between adiponectin and FGF9 in depression disorder

Adiponectin (ADPN) and fibroblast growth factor 9 (FGF9) has been reported as anti-depressive and pro-depressive factor, respectively. However, it is unknown whether there is directly interaction between ADPN and FGF9 in depression. The present study aims to investigate the correlation between ADPN and FGF9 in depression disorder. Firstly, the decreased level of ADPN and the increased level of FGF9 in plasma of depressive patients compared with non-depressive subjects were observed. Furthermore, these is a significant negative correlation between the ratio of ADPN to FGF9 and the total score of Hamilton Depression Scale in total investigated subjects. The similar changes of ADPN and FGF9 were also observed in elder adiponectin gene knockout (Adipo^-/-) mice with an increasing trend to depressive-like behaviors. Secondly, the decreasing level of ADPN and increasing level of FGF9 in plasma and hippocampus tissues were observed in chronic unpredictable mild stress (CUMS)-induced depression in ICR mice with significant depressive-like behaviors and hippocampus damage, which attenuated by injection of recombinant ADPN or FGF9 antibody into lateral ventricle. In Adipo^-/- mice, injection of FGF9 antibody into lateral ventricle also attenuated CUMS-induced depressivelike behaviors. The protein expression of FGF receptor 3 (FGFR3), the main receptor of FGF9, was significantly down-regulated in hippocampus tissues of CUMS-treated mice, which could be attenuated by treatment with either recombinant ADPN or anti-FGF9. In summary, the present results suggest that ADPN maybe a key negative regulator of FGF9/FGFR3 in depressive disorder and the dysfunction of ADPN-FGF9 pathway plays a key role in stress-induced depression.

Adiponectin and resistin in acutely ill and weight-recovered adolescent anorexia nervosa: Association with psychiatric symptoms

Objectives: Anorexia nervosa (AN) is a chronic illness where restriction of food intake results in decreased adipose tissue. The aim of this study was to measure the concentration of adiponectin and resistin in acute and partially weight-recovered anorectic inpatients. The associations of their levels with eating disorder symptoms were also assessed.Methods: A longitudinal study was conducted on 76 adolescent patients (ANG) and 30 age-matched healthy girls (CG). Selected adipokines serum levels, as well as the severity of depressive, obsessive-compulsive and disturbed eating behaviours, were analysed in the group of anorectic patients before (accAN) and after weight gain (recAN) and compared with the CG.Results: The concentration of adiponectin in the accAN was higher than in the CG (P = 0.05) and increased in recAN (P = 0.01). Resistin concentrations were lower in accAN and recAN than in the CG (P = 0.00). A negative correlation between adiponectin and the scores in Yale-Brown Obsessive Compulsive Scale as well as positive between resistin and Beck Depression Inventory were found.Conclusions: In the acute AN, adiponectin and resistin levels are impaired and partial weight recovery fails to normalise them thus we suggest that they can be involved in the chronicity of certain symptoms. The level of adiponectin is associated with obsessive and compulsive symptoms and resistin with depressive symptoms, which indicates their potential contribution to the regulation of emotions and behaviours in AN.

Cord and Early Childhood Plasma Adiponectin Levels and Autism Risk: A Prospective Birth Cohort Study

Emerging research suggests that adiponectin, a cytokine produced by adipose tissue, may be implicated in ASD. In this prospective birth cohort study (n = 847), we assessed the association between cord, early childhood plasma adiponectin and the risk of developing ASD. ASD was defined based on ICD codes of physician diagnosis. Cord adiponectin levels were inversely associated with ASD risk (aOR 0.50; 95% CI 0.33, 0.77), independent of preterm birth, early childhood adiponectin and other known ASD risk factors. Early childhood adiponectin, assessed prior to ASD diagnosis, was associated with lower risk of ASD, which attenuated after adjusting for cord adiponectin, indicating the relative importance of cord adiponectin in ASD risk. Further research is warranted to confirm our findings and elucidate biological mechanisms.

Plasma levels of leptin and adiponectin and depressive symptoms in young adults

Circulating levels of adipokines are known to be associated with depression. This study aimed to investigate a possible association between leptin, adiponectin and dimensional measures of depressive symptoms in young adults with and without psychiatric illness. Total plasma adiponectin and leptin levels were measured in 194 young adults seeking psychiatric ambulatory care and 57 healthy controls. Depressive symptoms were assessed using the Montgomery-Åsberg Depression Self-Rating Scale (MADRS-S). Analysis was performed on men and women separately. P-leptin levels were significantly elevated in patients compared with controls and correlated with total MADRS-S scores in the women. Women with P-leptin in the highest quartile reached a significantly higher MADRS-S score than women in the lowest quartile, but this difference disappeared after adjusting for body mass index (BMI) and antidepressant use. MADRS-S score was associated with P-leptin in female patients without antidepressant use, independently of BMI. There was no association between P-leptin levels and current major depression. P-adiponectin levels were not associated with depressive symptoms or current major depression. The findings indicate that P-leptin levels are associated with depressive symptom severity in young women; however, the association is linked to other factors, which challenges its usefulness as a biomarker for depression in clinical psychiatry.

Proteomic Studies of Psychiatric Disorders

Many diseases result from programming effects in utero. This chapter describes recent advances in proteomic studies which have improved our understanding of the underlying pathophysiological pathways in the major psychiatric disorders, resulting in the development of potential novel biomarker tests. Such tests should be based on measurement of blood-based proteins given the ease of accessibility of this medium and the known connections between the periphery and the central nervous system. Most importantly, emerging biomarker tests should be developed on lab-on-a-chip and other handheld devices to enable point-of-care use. This should help to identify individuals with psychiatric disorders much sooner than ever before, which will allow more rapid treatment options for the best possible patient outcomes.

Early-Life Home Environment and Obesity in a Mexican American Birth Cohort: The CHAMACOS Study

OBJECTIVE

Little is known about the impact of the home environment on biomarkers of obesity, such as adipokines, in children. In this study, we examined the relationship of maternal depressive symptoms and potentially protective social factors, including maternal support and the home learning environment, with body mass index and adipokines.

METHODS

Data were obtained from 326 Mexican American participants from the Center for the Health Assessment of Mothers and Children of Salinas cohort. Plasma adipokine levels were assessed in 326 children by enzyme-linked immunoassay at birth or ages 5, 9, or 14 years. Maternal depressive symptoms were evaluated using the Center for Epidemiological Studies Depression Scale when children were 1, 3.5, 7, and 9 years old; social support was assessed by the Duke-University of North Carolina Questionnaire at ages 1 and 5 years; and home learning environment by the Home Observation for the Measurement of the Environment (HOME) at ages of 6 months and 1, 2, 3.5, 7, 9, and 10.5 years.

RESULTS

Age was significantly associated with adiponectin (B = -5.0, SE = 0.2) and leptin (B = 0.01, SE = 0.003) levels. Individual time point analyses identified significant positive associations of HOME scores in childhood with adiponectin at ages 9 years (HOME score; age 3.5 years: B = 0.9, p = .04) and 14 years (HOME score; age 7 years: B = 0.6, p = .02, age 9 years: B = 0.6, p = .05, age 10.5 years: B = 0.5, p = .04). We observed significant relationships of maternal depressive symptoms at age 9 years with adiponectin and body mass index z-score at age 14 years (B = -0.2, p = .003 and B = 0.02, p = .002, resp.), which were confirmed in longitudinal models.

CONCLUSIONS

This study adds new evidence that adverse and protective aspects of the home environment could lead to altered obesity status in children.

Morus alba L. Diminishes visceral adiposity, insulin resistance, behavioral alterations via regulation of gene expression of leptin, resistin and adiponectin in rats fed a high-cholesterol diet

Ethanolic extract of leaves of Morus alba L. (M. alba), known as white mulberry, was orally administered (100 mg/kg b.wt) for 8 weeks to female Wistar rats that were fed a high-cholesterol diet (HCD), to investigate the potential of M. alba leaves in attenuation of obesity, dyslipidemia, insulin resistance, and deficits in mood, cognitive as well as motor activity that are linked to the adipokines secretions of visceral adipose tissue. Results showed that M. alba diminished body weight gain, hypercholesterolemia, hypertriglyceridemia, atherogenic (AI) & coronary artery indices (CRI), and ameliorated glucose level and insulin resistance index in rats on HCD, compared with untreated HCD rats. Moreover, M. alba administration significantly decreased serum leptin and resistin contents as well as their mRNA expression in visceral adipose tissue, but significantly increased serum adiponectin level, and its mRNA expression in visceral adipose tissue in rats fed on HCD, compared to those in untreated HCD group. Regarding behavioral alterations, M. alba attenuated motor deficit, declined memory, depression and anxiety-like behavior, as well in rats on HCD, compared to that noticed in untreated HCD rats. The current data showed that serum leptin and resistin showed a positive correlation with and body weight gain, triglycerides (TG), AI as well as CRI, but showed a negative correlation with exploration, declined memory, depression- and anxiety-like behavior. Conversely, serum adiponectin showed a negative correlation with and body weight gain, TG, AI as well as CRI, but showed a positive correlation with locomotor activity, exploration, declined memory, and depression- and anxiety-like behavior. In conclusion, M. alba leaves supplementation could attenuate adiposity, insulin resistance behavioral deficits via down-regulation of regulation of gene expression of leptin, resistin, but up-regulation of adiponectin gene expression in the visceral adipose tissue of rats fed a high-cholesterol diet.

Glucose and lipid-related biomarkers and the antidepressant response to infliximab in patients with treatment-resistant depression

The tumor necrosis factor (TNF) antagonist infliximab was previously found to reduce depressive symptoms in patients with treatment-resistant major depression (TRD) who exhibited high baseline inflammation, as reflected by plasma C-reactive protein (CRP) >5 mg/L. Further predictors of antidepressant response to infliximab included differential expression of peripheral blood gene transcripts that were related not only to inflammation but also to glucose and lipid metabolism. To determine whether plasma biomarkers of glucose and lipid metabolism were similarly associated with antidepressant response to infliximab and with relevant gene transcripts, we measured concentrations of glucose, insulin, and protein hormones that regulate glucose homeostasis and metabolism (leptin, resistin, and adiponectin), as well as cholesterols, triglycerides, and non-esterified fatty acids (NEFA), in medically-stable TRD outpatients at baseline and 2 weeks after the first infusion of infliximab (n = 26) or placebo (n = 26). Treatment response was defined as 50% reduction in depressive symptoms at any point during the 12-week trial. We found that baseline cholesterol (total, low-density lipoprotein [LDL], and non-high-density lipoprotein [non-HDL]), triglycerides and NEFA were elevated in patients who exhibited an antidepressant response to infliximab (all p < 0.05) but not placebo (all p > 0.299). HDL and non-HDL cholesterol concentrations also correlated with two lipid-related gene transcripts that were predictive of antidepressant response (r = 0.33 to 0.39, p < 0.05). Although not associated with response to infliximab, resistin correlated with numerous glucose-related transcripts (r = -0.32 to 0.37, p < 0.05) and was higher at 2 weeks post-infusion in patients treated with infliximab compared to placebo (p = 0.028). Concentrations of cholesterol (total, LDL, HDL, non-HDL) were also lower at 2 weeks in patients treated with infliximab compared to placebo, but only in those patients with CRP >5 mg/L at baseline (all p < 0.05). These results are consistent with previous work showing that high inflammation in patients with depression is associated with metabolic alterations, which together predict response to both traditional and experimental antidepressant therapies. Additionally, our findings suggest a causal relationship between increased inflammation and high cholesterol in depression, as a single infusion of infliximab reduced cholesterol in TRD patients with high CRP compared to placebo.

Inflammatory gene expression in adipose tissue according to diagnosis of anxiety and mood disorders in obese and non-obese subjects

Psychiatric disorders have been widely reported to be associated with systemic inflammation upregulation and adiposity. However, there are no data that link adipose tissue inflammation to these mental disorders. The analysis of adipokines and inflammation-related markers in adipose tissue could help to elucidate the potential association between obesity and mental health. An observational study was conducted in samples of patients consisting of non-obese and obese subjects, who were diagnosed with anxiety or mood disorders. Gene expression of adiponectin (ADIPOQ), leptin (LEP) and inflammatory markers (IL6, IL1B, TNF, CCL2, CSF3, ITGAM, and PLAUR) were determined in visceral (VAT) and subcutaneous (SAT) adipose tissues. Our results showed that the gene expression of adipokines and inflammation-related markers was higher in the VAT and SAT of obese subjects compared with non-obese subjects. Regarding mental disorders, all the inflammatory genes in the VAT were significantly higher in non-obese subjects with anxiety or mood disorders than in subjects without mental disorders, except for TNF and ITGAM. Additionally, IL6 expression was significantly lower in SAT. In contrast, obese patients diagnosed with anxiety or mood disorders only showed significantly lower expression levels of IL1B in VAT and ADIPOQ in SAT when compared with obese subjects without mental disorders. These data suggest the potential involvement of VAT inflammation in anxiety and mood disorders, involving complex mechanisms which are strongly affected by obesity.

Leptin and adiponectin levels in major depressive disorder: A systematic review and meta-analysis

OBJECTIVES

To explore differences in adipokine levels (i.e., leptin and adiponectin levels) between adults with Major Depressive Disorder (MDD) and healthy controls (HC), and to discuss the possible role of adipokine regulation in the development and progression of MDD.

METHODS

A systematic review and meta-analysis were conducted based on the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. A systematic search was conducted for all English and Chinese peer-reviewed articles from inception to November 2017. A random effects model was used to calculate the standardized mean difference (SMD) of leptin and/or adiponectin levels in subjects diagnosed with MDD versus HC within a 95% confidence interval (CI).

RESULTS

Thirty-three studies were included in this meta-analysis. In total, 4,372 (52.3%) subjects with MDD and 3,984 (47.7%) HC were compared. We identified significant lower adiponectin levels in MDD compared to HC with a small effect size (ES) (SMD = -0.25; 95% CI: -0.48, -0.02; P < 0.001). However, no significant difference was observed in leptin levels between MDD subjects and HC (SMD = 0.13; 95% CI: -0.06, 0.31; P = 0.170). The heterogeneity in the results of our meta-analysis could not be completely explained by dividing subjects into subgroups. Results from subgroup analyses suggested that studies involving samples with BMI ≥ 25 had lower adiponectin levels in subjects with MDD compared to HC, and older age samples (i.e., age ≥ 40) with BMI ≥ 25 had both higher leptin levels and lower adiponectin levels in MDD subjects as compared to HC.

LIMITATIONS

The heterogeneity of included studies, small sample sizes, and potential publication bias were significant limitations.

CONCLUSIONS

The current systematic review and meta-analysis indicated that lower adiponectin levels may be associated with MDD. Moreover, the results suggest that males expressing lower adiponectin and leptin levels have an increased likelihood of developing MDD. Future studies should aim to investigate the manifestation of depressive phenotypes in older, obese populations with altered metabolic profiles resulting from adipokine dysregulation. The review has been registered with PROSPERO (registration number CRD42018082733).

Adiponectin Moderates Antidepressant Treatment Outcome in the Combining Medications to Enhance Depression Outcomes Randomized Clinical Trial

Background

Major depressive disorder (MDD) is often comorbid with metabolic diseases such as obesity, cardiovascular disease, and type 2 diabetes. A potential link between these disorders is adiponectin, an adipocyte-derived circulating hormone with insulin-sensitizing, anti-inflammatory, and neuroplasticity effects. Reductions in plasma levels of adiponectin have been reported in both humans with depression and in the chronic-defeat mouse model of depression. However, the predictive value of adiponectin for treatment response to depression has not been determined.

Methods

We investigated the potential predictive effect of baseline adiponectin levels in patients who provided plasma and were undergoing one of three pharmacological treatments (escitalopram monotherapy; escitalopram plus bupropion; and venlafaxine plus mirtazapine) in the Combining Medications to Enhance Depression Outcomes clinical trial (n=160). Specifically, we assessed whether adiponectin moderates-that is, differentially predicts-treatment response among the treatment arms. Improvements with treatment were assessed using change in the clinician-rated 30-item Inventory of Depressive Symptomatology (IDS-C) from baseline through week 12. Moderator effects were tested using separate pairwise repeated measures mixed-effects models with a treatment-arm-by-adiponectin interaction.

Results

Baseline adiponectin levels moderated treatment outcome between two combination therapies. Specifically, low adiponectin predicted better response to escitalopram plus bupropion compared to venlafaxine plus mirtazapine, whereas high adiponectin predicted better response to venlafaxine plus mirtazapine compared to escitalopram plus bupropion (F=4.84, p=0.03). Adiponectin levels did not correlate with baseline depression severity (r=-0.03, p=.59).

Conclusions

Antidepressant selection for patients with MDD can be personalized using pre-treatment blood-based biomarkers, such as adiponectin, thereby improving treatment outcomes.

The effects of adiposity and alcohol use disorder on adipokines and biomarkers of inflammation in depressed patients

Patients with depression and alcohol use disorder frequently present with elevated markers of inflammation. Adipose tissue may function as a source for inflammation, yet the interplay between adiposity, alcohol use and depression has remained unknown. We examined 242 patients, referred to treatment for depressive symptoms, and followed for a period of 6 months. The assessments included screening for alcohol use and measurements of body mass index, serum adiponectin, leptin, resistin, progranulin, hs-CRP, IL-6 and MCP-1 at baseline and after 6 months of treatment. During follow-up, mean MADRS and AUDIT scores decreased significantly, whereas BMI increased. The changes in the levels of cytokines and adipokines were influenced by alcohol consumption and adiposity in a gender-dependent manner. The presence of AUD seemed to particularly influence the levels of cytokines. The levels of IL-6, hs-CRP, progranulin, and leptin differed between AUD and non-AUD groups at baseline, but no longer at 6 months. Baseline levels of leptin and resistin were higher in women and changes occurring in leptin, progranulin, and adiponectin were more notable in women. The data indicates significant gender-dependent interactions between depression, alcohol and mediators of inflammation, which should be considered in studies on the pathogenesis of depression and its comorbidities.

Decreased level of irisin, a skeletal muscle cell-derived myokine, is associated with post-stroke depression in the ischemic stroke population

BACKGROUND

Depression is a frequent mood disorder in stroke patient. Our aim was to determine irisin levels in serum and investigate their associations with post-stroke depression (PSD) in a 6-month follow-up study in Chinese patients with first-ever acute ischemic stroke (AIS).

METHODS

The subjects were first-ever AIS patients who were hospitalized at three stroke centers during the period from January 2015 to December 2016. Neurological and neuropsychological evaluations were conducted at the 6-month follow-up. Serum irisin concentrations were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

During the study period, 1205 patients were included in the analysis. There were 370 patients (30.7%) classified as depression. The depression distribution across the irisin quartiles ranged between 49.8% (first quartile) and 9.9% (fourth quartile). In the patients with depression, serum irisin levels were lower compared with those in patients without depression (P < 0.001). In a multivariate model using the first (Q1) quartile of irisin vs. Q2-4 together with the clinical variables, the marker displayed predictive information and increased risk of PSD by 75% (odds ratio [OR] for Q1, 1.75 [95% confidence interval [CI], 1.15-2.65]). In addition, a model containing known risk factors plus irisin compared with a model containing known risk factors without irisin showed a greater discriminatory ability; the area under the curve (AUC) increased from 0.77 to 0.81 (95% CI, 0.76-0.86).

CONCLUSIONS

The data suggested that reduced serum levels of irisin were powerful biological markers of risk of developing PSD even after adjustment by variables. Further studies are necessary to confirm this association, which may open the way to the proposal of new therapeutic options.

TRIAL REGISTRATION

ChiCTR-OPC-17013501 . Retrospectively registered 23 September 2017.

Depressive symptoms, impaired glucose metabolism, high visceral fat, and high systolic blood pressure in a subgroup of women with recent gestational diabetes

Women with gestational diabetes (GDM) are a high risk group for early type 2 diabetes (T2D). Depression is a risk factor for T2D in the general population. We investigated in women after a recent pregnancy with GDM and without a clinical diagnosis of depression, whether mild to moderate depressive symptoms associate with pathologic glucose metabolism. In a cross-sectional analysis, we examined 173 women, 9 ± 3 months after delivery with several psychopathological assessments, 5-point oral glucose tolerance test with insulin, anthropometrics, and laboratory chemistry. In a subgroup of 101 women, abdominal visceral fat was quantified by magnetic resonance imaging (MRI). A total of 22 women (13%) showed mild to moderate depressive symptoms, and the proportion of women with pathologic glucose metabolism (impaired fasting glucose, impaired glucose tolerance, or T2D) was higher in this group than in the women without depressive symptoms (59.1% vs. 33.1%, p = 0.018). Women with depressive symptoms also had higher body mass index (BMI), systolic blood pressure, plasma leptin, plasma resistin, and abdominal visceral fat volume. Pathologic glucose metabolism (OR = 2.594, 95% CI: 1.021-6.592), systolic blood pressure (OR = 1.076, 95% CI: 1.027-1.128), and abdominal visceral fat volume (OR = 2.491, 95% CI: 1.142-5.433) remained, even after adjustment for BMI, associated with the presence of depressive symptoms. Taken together, we found depressive symptoms at a level not generally diagnosed in clinical practice in a subgroup of women with recent GDM. This subgroup also showed an unfavorable metabolic profile. Mild to moderate depressive symptoms may therefore help to identify this special subgroup.

Roles of Inflammation and Depression in the Development of Gestational Diabetes

Inflammation, the body's response to harmful external agents, has long been found to be associated with depressive symptoms. The relationship between inflammation and depression is well established in the general population of people with depression, but is less so among perinatal women. Depression in the perinatal period is a common disorder, however available data do not indicate that there is a specific inflammatory picture associated with perinatal depression. We suggest that perinatal depression may be a heterogeneous construct, and that inflammation may be relevant to it in the context of other inflammatory morbidities of pregnancy. In this review we explore the available support for the hypothesis that inflammation associated with depression can represent a precipitating insult for the development of gestational diabetes, a known inflammatory morbidity of pregnancy.

Decreased plasma adiponectin among male firefighters with symptoms of post-traumatic stress disorder

BACKGROUND

Recent studies have reported that adiponectin-mediated neuromolecular pathways are involved in fear extinction, implying that adiponectin may be an important biological marker for posttraumatic stress disorder (PTSD). However, no study has investigated the association between adiponectin and patients with PTSD.

METHODS

We examined plasma adiponectin levels, high-sensitivity C-reactive protein (hs-CRP), and psychopathological factors using the Korean version of the Impact Event Scale-Revised (IES-R-K) and the Center for Epidemiologic Studies Depression Scale in 507 male firefighters. The PTSD symptom group was defined as those with a score of 25 or higher on the IES-R-K. Multiple logistic regression analysis was conducted to examine the covariates for the PTSD symptom group.

RESULTS

Out of 507 male firefighters, 139 (27.4%) had a score of 25 or more on the IES-R-K. The PTSD symptom group had lower plasma adiponectin levels than the controls. There was an inverse correlation between plasma adiponectin levels and PTSD severity. There was no correlation between adiponectin levels and depression. The adiponectin level was associated with the presence of PTSD symptom (odds ratio = 0.955, 95% CI = 0.920-0.991).

LIMITATIONS

A cross-sectional design and using self-rated instruments.

CONCLUSIONS

To the best of our knowledge, the results showed that decreased adiponectin-mediated activity is associated with PTSD. Future studies are necessary to identify the causative role of adiponectin for PTSD as well as any possible covariates.

CNS Targets of Adipokines

Our understanding of adipose tissue as an endocrine organ has been transformed over the last 20 years. During this time, a number of adipocyte-derived factors or adipokines have been identified. This article will review evidence for how adipokines acting via the central nervous system (CNS) regulate normal physiology and disease pathology. The reported CNS-mediated effects of adipokines are varied and include the regulation of energy homeostasis, autonomic nervous system activity, the reproductive axis, neurodevelopment, cardiovascular function, and cognition. Due to the wealth of information available and the diversity of their known functions, the archetypal adipokines leptin and adiponectin will be focused on extensively. Other adipokines with established CNS actions will also be discussed. Due to the difficulties associated with studying CNS function on a molecular level in humans, the majority of our knowledge, and as such the studies described in this paper, comes from work in experimental animal models; however, where possible the relevant data from human studies are also highlighted. © 2017 American Physiological Society. Compr Physiol 7:1359-1406, 2017.

Pathway-wide association study identifies five shared pathways associated with schizophrenia in three ancestral distinct populations

Genome-wide association studies have confirmed the polygenic nature of schizophrenia and suggest that there are hundreds or thousands of alleles associated with increased liability for the disorder. However, the generalizability of any one allelic marker of liability is remarkably low and has bred the notion that schizophrenia may be better conceptualized as a pathway(s) disorder. Here, we empirically tested this notion by conducting a pathway-wide association study (PWAS) encompassing 255 experimentally validated Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways among 5033 individuals diagnosed with schizophrenia and 5332 unrelated healthy controls across three distinct ethnic populations; European-American (EA), African-American (AA) and Han Chinese (CH). We identified 103, 74 and 87 pathways associated with schizophrenia liability in the EA, CH and AA populations, respectively. About half of these pathways were uniquely associated with schizophrenia liability in each of the three populations. Five pathways (serotonergic synapse, ubiquitin mediated proteolysis, hedgehog signaling, adipocytokine signaling and renin secretion) were shared across all three populations and the single-nucleotide polymorphism sets representing these five pathways were enriched for single-nucleotide polymorphisms with regulatory function. Our findings provide empirical support for schizophrenia as a pathway disorder and suggest schizophrenia is not only a polygenic but likely also a poly-pathway disorder characterized by both genetic and pathway heterogeneity.

The role of adipokines in the rapid antidepressant effects of ketamine

We previously found that body mass index (BMI) strongly predicted response to ketamine. Adipokines have a key role in metabolism (including BMI). They directly regulate inflammation and neuroplasticity pathways and also influence insulin sensitivity, bone metabolism and sympathetic outflow; all of these have been implicated in mood disorders. Here, we sought to examine the role of three key adipokines-adiponectin, resistin and leptin-as potential predictors of response to ketamine or as possible transducers of its therapeutic effects. Eighty treatment-resistant subjects who met DSM-IV criteria for either major depressive disorder (MDD) or bipolar disorder I/II and who were currently experiencing a major depressive episode received a single ketamine infusion (0.5 mg kg-1 for 40 min). Plasma adipokine levels were measured at three time points (pre-infusion baseline, 230 min post infusion and day 1 post infusion). Overall improvement and response were assessed using percent change from baseline on the Montgomery-Asberg Depression Rating Scale and the Hamilton Depression Rating Scale. Lower baseline levels of adiponectin significantly predicted ketamine's antidepressant efficacy, suggesting an adverse metabolic state. Because adiponectin significantly improves insulin sensitivity and has potent anti-inflammatory effects, this finding suggests that specific systemic abnormalities might predict positive response to ketamine. A ketamine-induced decrease in resistin was also observed; because resistin is a potent pro-inflammatory compound, this decrease suggests that ketamine's anti-inflammatory effects may be transduced, in part, by its impact on resistin. Overall, the findings suggest that adipokines may either predict response to ketamine or have a role in its possible therapeutic effects.

Increased Ghrelin Levels and Unchanged Adipocytokine Levels in Major Depressive Disorder

OBJECTIVE

One of the hypotheses of the pathophysiology of major depressive disorder (MDD) proposes that there is a relationship between adipocytokine and ghrelin levels and depression.

METHODS

Patients with major depression with a BMI ≤25 kg/m² between the ages of 11 and 18 years (n = 30) were compared with a healthy control group (n = 30). Both groups were evaluated across a pretreatment period (MD-PT) and an improved period (MD-I). We measured serum leptin, adiponectin, resistin, and ghrelin levels and other parameters related to metabolic syndrome, such as glucose, insulin, insulin resistance (homeostasis model assessment [HOMA]), triglycerides (TG), and total cholesterol (TCHOL).

RESULTS

Leptin, adiponectin, and resistin levels did not differ across groups; however, ghrelin levels were increased in the MD-I group compared with the control and MD-PT groups (p < 0.05). HOMA levels were also higher in the MD-PT group than in the control group (p < 0.05). After treatment, there was no difference in this measurement.

CONCLUSIONS

The relationship between adipocytokines and major depression may be dependent on ghrelin levels as a result of antidepressant treatment and subsequent obesity.

Seeking an objective diagnosis of depression

Major depressive disorder (MDD: unipolar depression) is widely distributed in the USA and world-wide populations and it is one of the leading causes of disability in both adolescents and adults. Traditional diagnostic approaches for MDD are based on patient interviews, which provide a subjective assessment of clinical symptoms which are frequently shared with other maladies. Reliance upon clinical assessments and patient interviews for diagnosing MDD is frequently associated with misdiagnosis and suboptimal treatment outcomes. As such, there is increasing interest in the identification of objective methods for the diagnosis of depression. Newer technologies from genomics, transcriptomics, proteomics, metabolomics and imaging are technically sophisticated and objective but their application to diagnostic tests in psychiatry is still emerging. This brief overview evaluates the technical basis for these technologies and discusses how the extension of their clinical performance can lead to an objective diagnosis of MDD.

Serum proteomic profiles of depressive subtypes

Depression is a highly heterogeneous disorder. Accumulating evidence suggests biological and genetic differences between subtypes of depression that are homogeneous in symptom presentation. We aimed to evaluate differences in serum protein profiles between persons with atypical and melancholic depressive subtypes, and compare these profiles with serum protein levels of healthy controls. We used the baseline data from the Netherlands Study of Depression and Anxiety on 414 controls, 231 persons with a melancholic depressive subtype and 128 persons with an atypical depressive subtype for whom the proteomic data were available. Depressive subtypes were previously established using a data-driven analysis, and 171 serum proteins were measured on a multi-analyte profiling platform. Linear regression models were adjusted for several covariates and corrected for multiple testing using false discovery rate q-values. We observed differences in analytes between the atypical and melancholic subtypes (9 analytes, q<0.05) and between atypical depression and controls (23 analytes, q<0.05). Eight of the nine markers differing between the atypical and melancholic subtype overlapped with markers from the comparison between atypical subtype and controls (mesothelin, leptin, IGFBP1, IGFBP2, FABPa, insulin, C3 and B2M), and were mainly involved in cellular communication and signal transduction, and immune response. No markers differed significantly between the melancholic subtype and controls. To conclude, although some uncertainties exist in our results as a result of missing data imputation and lack of proteomic replication samples, many of the identified analytes are inflammatory or metabolic markers, which supports the notion of atypical depression as a syndrome characterized by metabolic disturbances and inflammation, and underline the importance and relevance of subtypes of depression in biological and genetic research, and potentially in the treatment of depression.

Mood and metabolism: Anhedonia as a clinical target in Type 2 diabetes

Epidemiological evidence suggests a bidirectional relationship between depression and Type 2 diabetes mellitus. In Type 2 diabetes, depression affects behavioural factors such as diet and physical activity that promote positive energy balance and influence diabetes outcomes. Examinations of depressive symptoms by dimension have suggested that anhedonia, the inability to anticipate, seek, choose and enjoy reward, may be of particular clinical importance. Structural and functional brain changes in Type 2 diabetes distributed throughout the principally dopaminergic reward circuitry suggest a neurobiological basis for motivational and decisional aspects of anhedonia. Interrelated neuroendocrine, bio-energetic, oxidative and inflammatory changes suggest mechanisms underlying neuronal damage and dopaminergic deficits. A consequential shift in effort-related reward choices and their effects on energy expenditure, self-care and eating behaviours is suggested to affect Type 2 diabetes outcomes. The clinical implications for screening and psychopharmacology of depressive symptoms in people with Type 2 diabetes are discussed.

Plasma adiponectin and depressive symptoms during pregnancy and the postpartum period: A prospective cohort study

BACKGROUND

Some authors have described an inverse association between adiponectin and depression, but this association has not yet been investigated during the perinatal period.

OBJECTIVE

To evaluate the association between the plasma adiponectin levels and symptoms of depression in women from early pregnancy to 30-45 days postpartum.

METHODS

A prospective cohort of 235 women was analyzed, with four waves of follow-up: 5-13th, 22-26th, and 30-36th gestational weeks and 30-45 days postpartum. Depressive symptoms were measured using the Edinburgh Postnatal Depression Scale (EPDS; cutoff ≥ 11). The plasma adiponectin concentrations were measured using an enzyme-linked immunosorbent assay. The statistical analyses included linear mixed effects regressions to model the association between these time-dependent variables.

RESULTS

The prevalence of depressive symptoms was 35.5%, 22.8%, 21.8%, and 16.9% and the median (µg/mL) adiponectin levels were 4.8, 4.7, 4.4, and 7.5 in the 1st, 2nd, and 3rd trimesters and the postpartum period, respectively. Women who remained non-depressed throughout the study tended to have higher values of adiponectin throughout pregnancy and the postpartum period compared to those who had depressive symptoms at least once, but this difference was not statistically significant (β=-0.14; p=0.071). There was no statistically significant association between the plasma adiponectin levels and the EPDS scores in the multiple model (β=-0.07; p=0.320).

LIMITATIONS

Losses to follow-up, different procedures for the blood draws at the prenatal and postpartum visits, and the presence of a nested clinical trial with omega-3 supplementation.

CONCLUSION

The plasma adiponectin levels were not associated with depressive symptoms during the perinatal period.

Bright versus dim ambient light affects subjective well-being but not serotonin-related biological factors

Light falling on the retina is converted into an electrical signal which stimulates serotonin synthesis. Previous studies described an increase of plasma and CNS serotonin levels after bright light exposure. Ghrelin and leptin are peptide hormones which are involved in the regulation of hunger/satiety and are related to serotonin. Neopterin and kynurenine are immunological markers which are also linked to serotonin biosynthesis. In this study, 29 healthy male volunteers were exposed to bright (5000lx) and dim (50lx) light conditions for 120min in a cross-over manner. Subjective well-being and hunger as well as various serotonin associated plasma factors were assessed before and after light exposure. Subjective well-being showed a small increase under bright light and a small decrease under dim light, resulting in a significant interaction between light condition and time. Ghrelin concentrations increased significantly under both light conditions, but there was no interaction between light and time. Correspondingly, leptin decreased significantly under both light conditions. Hunger increased significantly with no light-time interaction. We also found a significant decrease of neopterin, tryptophan and tyrosine levels, but no interaction between light and time. In conclusion, ambient light was affecting subjective well-being rather than serotonin associated biological factors.