The association between depressive symptoms and systemic inflammation in people with type 2 diabetes: findings from the South London Diabetes Study

Plasma biomarkers of endothelial function in people with depressive disorder: A systematic review and meta-analysis

The objective of this study is to conduct a literature review and summarize existing research comparing levels of blood markers of endothelial function in people with depression with controls. We searched major databases (Embase, PubMed, Web of Science, and PsycINFO) from inception to 23.07.2023, for studies comparing endothelial function blood markers in people with depression and controls including intercellular adhesion molecule-1 (sICAM-1), vascular cell adhesion molecule-1 (sVCAM-1), monocyte chemoattractant protein-1 (MCP-1), and sE-selectin. Comparative random effects meta-analysis, calculating standardized mean differences in levels of sICAM-1, sVCAM-1, MCP-1, and sE-selectin between depressed and controls were conducted. Study protocol was registered with PROSPERO (CRD42020222487). Nineteen studies including 10,566 participants [1322 depressed (mean age = 49.1 years, 63 % females) and 9239 controls (mean age = 52.3 years, 57.5 % females)] were included. People with depression had higher levels of sICAM-1 (SMD = 0.98, 95 % CI: 0.52; 1.44, P < 0.001) and MCP-1 (SMD = 0.37, 95 % CI: 0.01; 0.72, P = 0.04) than controls. There was a small difference on sVCAM-1 (k = 10, SMD = 0.215, 95%CI: 0.013; 0.417, p = 0.04), but no difference in levels of E-selectin between people with depression and controls (k = 5,SMD = 0.21, 95%CI:-0.09;0.52, P = 0.17). Subgroup analyzes demonstrated that people with depression and comorbid chronic illnesses, such as diabetes, have higher levels of sICAM-1 than people with depression without comorbid chronic illness. Mean age moderate the difference in sICAM-1 levels between depressed and controls (SMD = 0.01, 95%CI:-0.05;-0.02,P < 0.001, R2 = 0.61). Our findings suggest that people with depression exhibit increased levels of endothelial activation markers compared to controls, suggesting an endothelial dysfunction among this population.

Three-protein signature is associated with baseline and persistently elevated or recurrent depressive symptoms in individuals with recent-onset diabetes

Depression is associated with diabetes, but the underlying causes remain unclear. To better understand depression in diabetes, this study investigated associations between 135 inflammatory and neurological protein biomarkers and depressive symptoms in individuals with diabetes.This cross-sectional study included 430 adults with a known diabetes duration <1 year from the German Diabetes Study (GDS), in whom biomarkers were measured in serum and depressive symptoms were evaluated at baseline and annually over 5 years using the Center for Epidemiological Studies Depression Scale (CES-D). Based on the information on depressive symptoms from the baseline and follow-up visits (n=305, ≥3 time points), we subdivided the sample into individuals with persistent or recurrent and transient or never depressive symptoms. We assessed the associations of each biomarker with baseline CES-D score (continuous) and persistent/recurrent depressive symptoms using multiple linear and logistic regression models, respectively.After adjustment for covariates, we identified a three-protein signature associated with baseline CES-D score and persistent/recurrent depressive symptoms. CUB domain-containing protein 1 (CDCP1) and NAD-dependent protein deacetylase sirtuin-2 (SIRT2) were positively associated with baseline (β 1.24 (95% CI 0.19 to 2.29); β 0.89 (95% CI 0.06 to 1.72)), respectively) and persistent/recurrent depressive symptoms (OR 1.58 (95% CI 1.08 to 2.31); OR 1.32 (95% CI 1.03 to 1.71), respectively), whereas leptin receptor (LEPR) was inversely associated with baseline (β -0.99 (95% CI -1.87 to -0.11)) and persistent/recurrent depressive symptoms (OR 0.70 (95% CI 0.49 to 0.99)). However, results were not significant after adjustment for multiple testing.In conclusion, the three-protein signature identified may provide insights into mechanisms underlying depressive symptoms in diabetes and might open new therapeutic avenues.The trial registration number of the study is NCT01055093.

The interface of depression and diabetes: treatment considerations

This state-of-the-art review explores the relationship between depression and diabetes, highlighting the two-way influences that make treatment challenging and worsen the outcomes of both conditions. Depression and diabetes often co-occur and share genetic, lifestyle, and psychosocial risk factors. Lifestyle elements such as diet, physical activity, and sleep patterns play a role on the development and management of both conditions, highlighting the need for integrated treatment strategies. The evidence suggests that traditional management strategies focusing on either condition in isolation fall short of addressing the intertwined nature of diabetes and depression. Instead, integrated care models encompassing psychological support and medical management are recommended to improve treatment efficacy and patient adherence. Such models require collaboration across multiple healthcare disciplines, including endocrinology, psychiatry, and primary care, to offer a holistic approach to patient care. This review also identifies significant patient-related barriers to effective management, such as stigma, psychological resistance, and health literacy, which need to be addressed through patient-centered education and support systems. Future directions for research include longitudinal studies in diverse populations to further elucidate causal relationships and the exploration of novel therapeutic targets, as well as the effectiveness of healthcare models aimed at preventing the onset of one condition in individuals diagnosed with the other.

The risk factors for mental health disorders in patients with type 2 diabetes: An umbrella review of systematic reviews with and without meta-analysis

Background

Patients with type 2 diabetes have a nearly twofold higher rate of diagnosed mental disorders than those without diabetes. The association between type 2 diabetes and mental disorders is well established in the literature and recognized as a bidirectional relationship. This study aims to conduct an umbrella review of risk and protective factors for mental health disorders in patients with type 2 diabetes and assess the credibility of the evidence for the association between each factor and mental health disorders.

Methods

A comprehensive search was conducted of Medline via PubMed, Web of Science, EMBASE, CINHAL, and PsycINFO from inception to November 17, 2022, to identify systematic reviews with and without meta-analyses examining associations of factors with mental health disorders in patients with type 2 diabetes. For each association, we recalculated the summary effect size and 95% confidence intervals using random-effects models. We also reported the 95% prediction interval and between-group heterogeneity.

Results

The study included 11 systematic reviews that met the inclusion criteria, comprising eight meta-analyses and three without meta-analyses. This involved approximately 489,930 participants and encompassed 26 unique factors. Six factors were rated as having suggestive evidence at the Class III level. These factors were obesity (n = 18,456, OR 1.75 [1.2 to 2.59], I2 97.7%), neuropathy (n = 3898, OR 2.01 [1.60 to 2.54], I2 44.5%), diabetes complications (n = 1769, OR 1.90 [1.53 to 2.36], I2 39.3%), peripheral blood concentrations of CRP (n = 1742, SMD 0.31 [0.16 to 0.45], I2 84.1%), female sex (n = 35,162, OR 1.36 [1.19 to 1.54], I2 64.5%), and social support (n = 3151, OR 2.02 [1.51 to 2.70], I2 87.2%).

Conclusions

Several factors associated with mental health disorders in patients with type 2 diabetes were identified with varying degrees of supporting evidence. Significantly, obesity, neuropathy, complications, peripheral blood CRP concentrations, female sex, and social support emerged with suggestive evidence. An investigation of these factors should be conducted to target interventions accordingly. It may be helpful to prioritize patients who have these risk factors as high-risk groups and to implement plans and policies to enhance support before mental health disorders occur.

Does Emotional Distress Predict Worse Glycemic Control Over Time? Results From the Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE)

OBJECTIVE

To evaluate whether baseline levels of depressive symptoms and diabetes-specific distress are associated with glycemic control in Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE), a large randomized controlled trial comparing the metabolic effects of four common glucose-lowering medications when combined with metformin in individuals with type 2 diabetes mellitus (T2DM).

RESEARCH DESIGN AND METHODS

The primary and secondary outcomes were defined as an HbA1c value ≥7%, subsequently confirmed, and an HbA1c value >7.5%, subsequently confirmed, respectively. Separate Cox proportional hazards models assessed the association between baseline levels of each exposure of interest (depressive symptoms measured with the eight-item Patient Health Questionnaire and diabetes distress measured with the Diabetes Distress Scale) and the subsequent risk of metabolic outcomes.

RESULTS

This substudy included 1,739 participants (56% of whom were non-Hispanic White, 18% non-Hispanic Black, 17% Hispanic, and 68% male; mean [SD] age 58.0 [10.2] years, diabetes duration 4.2 [2.8] years, and HbA1c 7.5% [0.48%]). A total of 1,157 participants reached the primary outcome, with time to event of 2.1 years on average, while 738 participants reached the secondary outcome at 3 years on average. With adjustment for sex, race/ethnicity, treatment group, baseline age, duration of T2DM, BMI, and HbA1c, there were no significant associations between the depressive symptoms or diabetes distress and the subsequent risk of the primary or secondary outcomes.

CONCLUSIONS

The current findings suggest that, at least for individuals with diabetes of relatively short duration, baseline levels of emotional distress are not associated with glycemic control over time.

The dangerous "West Coast Swing" by hyperglycaemia and chronic stress in the mouse hippocampus: Role of kynurenine catabolism

Growing epidemiological studies highlight a bi-directional relationship between depressive symptoms and diabetes mellitus. However, the detrimental impact of their co-existence on mental health suggests the need to treat this comorbidity as a separate entity rather than the two different pathologies. Herein, we characterized the peculiar mechanisms activated in mouse hippocampus from the concurrent development of hyperglycaemia, characterizing the different diabetes subtypes, and chronic stress, recognized as a possible factor predisposing to major depression. Our work demonstrates that kynurenine overproduction, leading to apoptosis in the hippocampus, is triggered in a different way depending on hyperglycaemia or chronic stress. Indeed, in the former, kynurenine appears produced by infiltered macrophages whereas, in the latter, peripheral kynurenine preferentially promotes resident microglia activation. In this scenario, QA, derived from kynurenine catabolism, appears a key mediator causing glutamatergic synapse dysfunction and apoptosis, thus contributing to brain atrophy. We demonstrated that the coexistence of hyperglycaemia and chronic stress worsened hippocampal damage through alternative mechanisms, such as GLUT-4 and BDNF down-expression, denoting mitochondrial dysfunction and apoptosis on one hand and evoking the compromission of neurogenesis on the other. Overall, in the degeneration of neurovascular unit, hyperglycaemia and chronic stress interacted each other as the partners of a "West Coast Swing" in which the leading role can be assumed alternatively by each partner of the dance. The comprehension of these mechanisms can open novel perspectives in the management of diabetic/depressed patients, but also in the understanding the pathogenesis of other neurodegenerative disease characterized by the compromission of hippocampal function.

Exploring the role of inflammation in major depressive disorder: beyond the monoamine hypothesis

Major depressive disorder affects approximately 8.4% of the United States population. The World Health Organization estimates that 280 million adults worldwide are suffering from depression. They have estimated that by 2030 it will be the second most serious condition. Current treatment relies on the monoamine hypothesis, however, one-third of patients with MDD do not respond to monoamine-based antidepressants. For years, it was hypothesized that the primary pathway of MDD involved serotonin as the main neurotransmitter. The monoamine hypothesis, a widely accepted theory, sought to explain the biological basis of MDD as being caused by the depletion of monoamine neurotransmitters, namely norepinephrine and serotonin. This hypothesis regarding monoamines as the pathophysiological basis of MDD led to the design and widespread use of selective serotonin reuptake inhibitors. However, given that only one-third of patients improve with SSRI it is reasonable to infer that the pathway involved is more complex than once hypothesized and there are more neurotransmitters, receptors, and molecules involved. The monoamine hypothesis does not explain why there is a delay in the onset of effect and action of SSRIs. Several studies have demonstrated that chronic stress is a risk factor for the development of MDD. Thus the monoamine hypothesis alone is not enough to fully account for the pathophysiology of MDD highlighting the need for further research involving the pathways of MDD. In this paper, we review the role of inflammation and cytokines on MDD and discuss other pathways involved in the development and persistence of depressive symptoms.

Do glycaemic treatment targets affect the perinatal mental health status of women with gestational diabetes? - Data from the TARGET Trial

BACKGROUND

Gestational diabetes mellitus is associated with perinatal mental disorders. Effective management may reduce this risk, but there is little evidence on effects of different glycaemic treatment targets. We assessed whether tight glycaemic treatment targets compared with less-tight targets reduce the risk of poor mental health outcomes in women with gestational diabetes.

METHODS

This was a secondary analysis of data from women who consented to complete perinatal mental health questionnaires as participants in the TARGET Trial, a stepped-wedge cluster randomized trial in 10 hospitals in New Zealand. All hospitals initially used less tight glycaemic targets for management of gestational diabetes and were sequentially randomized, in clusters of two at 4-monthly intervals, to using tighter glycaemic targets. Data were collected from 414 participants on anxiety (6-item Spielberger State Anxiety scale), depression (Edinburgh Postnatal Depression Scale), and health-related quality of life (36-Item Short-Form General Health Survey) at the time of diagnosis (baseline), 36 weeks of gestation, and 6 months postpartum. The primary outcome was composite poor mental health (any of anxiety, vulnerability to depression, or poor mental health-related quality of life). Generalized linear mixed models were used to determine the main treatment effect with 95% confidence intervals using an intention-to-treat approach.

RESULTS

We found no differences between randomised glycaemic target groups in the primary outcome at 36 weeks' (relative risk (RR): 1.07; 95% confidence interval 0.58, 1.95) and 6 months postpartum (RR: 1.03; 0.58, 1.81). There were similarly no differences in the components of the primary outcome at 36 weeks' [anxiety (RR: 0.85; 0.44, 1.62), vulnerability to depression (RR: 1.10; 0.43, 2.83), or poor mental health-related quality of life (RR: 1.05; 0.50, 2.20)] or at 6 months postpartum [anxiety (RR:1.21; 0.59, 2.48), vulnerability to depression (RR:1.41; 0.53, 3.79), poor mental health-related quality of life (RR: 1.11; 0.59, 2.08)].

CONCLUSION

We found no evidence that adoption of tighter glycaemic treatment targets in women with gestational diabetes alters their mental health status at 36 weeks' gestation and at 6 months postpartum.

TRIAL REGISTRATION

The Australian New Zealand Clinical Trials Registry (ANZCTR). ACTRN12615000282583 (ANZCTR-Registration). Date of registration: 25 March 2015.

Itaconate: A promising precursor for treatment of neuroinflammation associated depression

Neuroinflammation triggers the production of inflammatory factors, influences neuron generation and synaptic plasticity, thus playing an important role in the pathogenesis of depression and becoming an important direction of depression prevention and treatment. Itaconate is a metabolite secreted by macrophages in immunomodulatory responses, that has potent immunomodulatory effects and has been proven to exert anti-inflammatory effects in a variety of diseases. Microglia are mononuclear macrophages that reside in the central nervous system (CNS), and may be the source of endogenous itaconate in the brain. Itaconate can directly inhibit succinate dehydrogenase (SDH), reduce the production of NOD-like receptor thermal protein domain associated protein 3 (NLRP3), activate nuclear factor erythroid-2 related factor 2 (Nrf2), and block glycolysis, and thereby improving the depressive symptoms associated with the above mechanisms. Notably, itaconate also indirectly ameliorates the depressive symptoms associated with some inflammatory diseases. With the optimization of the structure and the development of new delivery systems, the application value and therapeutic potential of itaconate have been significantly improved. Dimethyl itaconate (DI) and 4-octyl itaconate (4-OI), cell-permeable derivatives of itaconate, are more suitable for crossing the blood-brain barrier (BBB), exhibiting therapeutic effects in the research of multiple diseases. This article provides an overview of the immunomodulatory effects of itaconate and its potential therapeutic efficacy in inflammatory depression, focusing on the promising application of itaconate as a precursor of antidepressants.

Study Protocol Using Cohort Data and Latent Variable Modeling to Guide Sampling Women With Type 2 Diabetes and Depressive Symptoms

BACKGROUND

Depression affects one in three women with Type 2 diabetes, and this concurrence significantly increases the risks of diabetes complications, disability, and early mortality. Depression is underrecognized because of wide variation in presentation and the lack of diagnostic biomarkers. Converging evidence suggests inflammation is a shared biological pathway in diabetes and depression. Overlapping epigenetic associations and social determinants of diabetes and depression implicate inflammatory pathways as a common thread.

OBJECTIVES

This article describes the protocol and methods for a pilot study aimed to examine associations between depressive symptoms, inflammation, and social determinants of health among women with Type 2 diabetes.

METHODS

This is an observational correlational study that leverages existing longitudinal data from the Women's Interagency HIV Study (WIHS), a multicenter cohort of HIV seropositive (66%) and HIV seronegative (33%) women, to inform purposive sampling of members from latent subgroups emergent from a prior retrospective cohort-wide analysis. Local active cohort participants from the Bronx study site are then selected for the study. The WIHS recently merged with the Multicenter Aids Cohort Study (MACS) to form the MACS/WIHS Combined Cohort Study. Latent subgroups represent distinct symptom trajectories resultant from a growth mixture model analysis of biannually collected depressive symptom data. Participants complete surveys (symptom and social determinants) and provide blood samples to analyze plasma levels and DNA methylation of genes that encode for inflammatory markers (CRP, IL-6, TNF-α). Correlation and regression analysis will be used to estimate the effect sizes between depressive symptoms and inflammatory markers, clinical indices (body mass index, hemoglobin A1C, comorbidities), and social determinants of health.

RESULTS

The study began in January 2022, and completed data collection is estimated by early 2023. We hypothesize that depressive symptom severity will associate with higher levels of inflammation, clinical indices (e.g., higher hemoglobin A1C), and exposure to specific social determinants of health (e.g., lower income, nutritional insecurity).

DISCUSSION

Study findings will provide the basis for future studies aimed at improving outcomes for women with Type 2 diabetes by informing the development and testing of precision health strategies to address and prevent depression in populations most at risk.

Correlation analysis of monocyte chemoattractant protein-1 and clinical characteristics and cognitive impairment in type 2 diabetes mellitus comorbid major depressive disorder

Introduction

Type 2 diabetes mellitus (T2DM) and major depressive disorder (MDD) are both chronic diseases, and they are often co-morbid. Usually, T2DM and MDD are associated with cognitive impairment, and the comorbidity status of both may increase the risk of cognitive impairment, but the underlying pathogenesis is not clear. Studies have shown that inflammation, especially monocyte chemoattractant protein-1 (MCP-1), could be associated with the pathogenesis of type 2 diabetes mellitus comorbid major depressive disorder.

Aims

To investigate the correlations of MCP-1 with clinical characteristics and cognitive impairment in type 2 diabetes mellitus patients combined with major depressive disorder.

Methods

A total of 84 participants were recruited in this study, including 24 healthy controls (HC), 21 T2DM patients, 23 MDD patients, and 16 T2DM combined with MDD (TD) patients, to measure the serum MCP-1 levels using Enzyme-linked Immunosorbent Assay (ELISA). And the cognitive function, depression, and anxiety degree were assessed using Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), 17-item Hamilton Depression Scale (HAMD-17), and Hamilton Anxiety Scale (HAMA), respectively.

Results

(1) Serum MCP-1 expression levels in the TD group were higher than HC, T2DM, and MDD groups, respectively (p < 0.05). And compared with HC and MDD groups, serum MCP-1 levels in the T2DM group were higher (p < 0.05) statistically. Receiver Operating Characteristic (ROC) curve showed that MCP-1 could diagnose T2DM at cut-off values of 503.8 pg./mL (sensitivity 80.95%, specificity 79.17%, AUC = 0.7956) and of 718.1 pg./mL for TD (sensitivity 81.25%, specificity 91.67%, AUC = 0.9271). (2) Group differences in cognitive function were significant. Compared with the HC group, total RBANS scores, attention scores, and language scores in the TD group were lower, respectively (p < 0.05), and total RBANS scores, attention scores, and visuospatial/constructional scores in the MDD group were lower, respectively (p < 0.05). Compared with the T2DM group, immediate memory scores in HC, MDD, and TD groups were lower, respectively, and total RBANS scores in TD were lower (p < 0.05). (3) Correlation analysis showed that hip circumference was negatively correlated with MCP-1 levels in the T2DM group (R = -0.483, p = 0.027), but the correlation disappeared after adjusting age and gender (r = -0.372; p = 0.117), and there were no significant correlations between MCP-1 and other variables.

Conclusion

MCP-1 may be involved in the pathophysiology of type 2 diabetes mellitus patients combined with major depressive disorder. And MCP-1 may be significant for the early evaluation and diagnosis of TD in the future.

The potential antidepressant effect of antidiabetic agents: New insights from a pharmacovigilance study based on data from the reporting system databases FAERS and VigiBase

Background: Growing evidence supports a bidirectional association between diabetes and depression; promising but limited and conflicting data from human studies support the intriguing possibility that antidiabetic agents may be used to relieve effectively depressive symptoms in diabetic patients. We investigated the potential antidepressant effects of antidiabetic drugs in a high-scale population data from the two most important pharmacovigilance databases, i.e., the FDA Adverse Event Reporting System (FAERS) and the VigiBase. Material and methods: From the two primary cohorts of patients treated with antidepressants retrieved from FDA Adverse Event Reporting System and VigiBase we identified cases (depressed patients experiencing therapy failure) and non-cases (depressed patients experiencing any other adverse event). We then calculated the Reporting Odds Ratio (ROR), Proportional Reporting Ratio (PRR), Empirical Bayes Geometric Mean (EBGM), and Empirical Bayes Regression-Adjusted Mean (ERAM) for cases versus non-cases in relation with the concurrent exposure to at least one of the following antidiabetic agent: A10BA Biguanides; A10BB Sulfonylureas; A10BG Thiazolidinediones; A10BH DPP4-inhibitors; A10BJ GLP-1 analogues; A10BK SGLT2 inhibitors (i.e., those agents for which preliminary evidence from literature supports our pharmacological hypothesis). Results: For GLP-1 analogues, all the disproportionality scores showed values <1, i.e., statistically significant, in both analyses [from the FAERS: ROR confidence interval of 0.546 (0.450-0.662); PRR (p-value) of 0.596 (0.000); EBGM (CI) of 0.488 (0.407-0.582); ERAM (CI) of 0.480 (0.398-0.569) and VigiBase: ROR (CI) of 0.717 (0.559-0.921); PRR (p-value) of 0.745 (0.033); EBGM (CI) of 0.586 (0.464-0.733); ERAM of (CI): 0.515 (0.403-0.639)]. Alongside GLP-1 analogues, DPP-4 Inhibitors and Sulfonylureas showed the greatest potential protective effect. With regard to specific antidiabetic agents, liraglutide and gliclazide were associated with a statistically significant decrease in all disproportionality scores, in both analyses. Conclusion: The findings of this study provide encouraging results, albeit preliminary, supporting the need for further clinical research for investigating repurposing of antidiabetic drugs for neuropsychiatric disorders.

Depression in non-alcoholic fatty liver disease is associated with an increased risk of complications and mortality

Background and aims

The global prevalence of non-alcoholic fatty liver disease (NAFLD) is expected to rise continuously. Furthermore, emerging evidence has also shown the potential for concomitant depression in NAFLD. This study aims to examine the prevalence, risk factors, and adverse events of depression in NAFLD and evaluate whether treated depression can reverse the increased risks of adverse outcomes.

Materials and methods

This study analyses the 2000–2018 cycles of NHANES that examined liver steatosis with fatty liver index (FLI). The relationship between NAFLD and depression was assessed with a generalized linear mix model and a sensitivity analysis was conducted in the no depression, treated depression, and untreated depression groups. Survival analysis was conducted with cox regression and fine gray sub-distribution model.

Results

A total of 21,414 patients were included and 6,726 were diagnosed with NAFLD. The risk of depression in NAFLD was 12% higher compared to non-NAFLD individuals (RR: 1.12, CI: 1.00–1.26, p = 0.04). NAFLD individuals with depression were more likely to be older, females, Hispanics or Caucasians, diabetic, and have higher BMI. Individuals with depression have high risk for cardiovascular diseases (CVD) (RR: 1.40, CI: 1.25–1.58, p < 0.01), stroke (RR: 1.71, CI: 1.27–2.23, p < 0.01), all-cause mortality (HR: 1.50, CI: 1.25–1.81, p < 0.01), and cancer-related mortality (SHR: 1.43, CI: 1.14–1.80, p = 0.002) compared to NAFLD individuals without depression. The risk of CVD, stroke, all-cause mortality, and cancer-related mortality in NAFLD individuals with treated depression and depression with untreated treatment was higher compared to individuals without depression.

Conclusion

This study shows that concomitant depression in NAFLD patients can increase the risk of adverse outcomes. Early screening of depression in high-risk individuals should be encouraged to improve the wellbeing of NAFLD patients.

The Relationship between Stress, Inflammation, and Depression

A narrative review about the relationship between stress, inflammation, and depression is made as follows: Chronic stress leads to various stress-related diseases such as depression. Although most human diseases are related to stress exposure, the common pathways between stress and pathophysiological processes of different disorders are still debatable. Chronic inflammation is a crucial component of chronic diseases, including depression. Both experimental and clinical studies have demonstrated that an increase in the levels of pro-inflammatory cytokines and stress hormones, such as glucocorticoids, substantially contributes to the behavioral alterations associated with depression. Evidence suggests that inflammation plays a key role in the pathology of stress-related diseases; however, this link has not yet been completely explored. In this study, we aimed to determine the role of inflammation in stress-induced diseases and whether a common pathway for depression exists. Recent studies support pharmacological and non-pharmacological treatment approaches significantly associated with ameliorating depression-related inflammation. In addition, major depression can be associated with an activated immune system, whereas antidepressants can exert immunomodulatory effects. Moreover, non-pharmacological treatments for major depression (i.e., exercise) may be mediated by anti-inflammatory actions. This narrative review highlights the mechanisms underlying inflammation and provides new insights into the prevention and treatment of stress-related diseases, particularly depression.

Prospective study of the association between depressive symptoms at type 2 diabetes diagnosis and time to insulin initiation in the South London diabetes (SOUL-D) cohort

AIMS

Initiation of insulin is usually delayed even when required. We aim to estimate the association between depressive symptoms on time to become insulin requiring and time to insulin initiation.

METHODS

8-year follow-up of a cohort of newly diagnosed people with T2D recruited in south-east London, UK (2008-2012). Baseline depressive symptoms were assessed using the Patient Health Questionnaire-9. Time to insulin-requiring was defined when optimal glycaemic levels were not achieved (HbA1c >58 mmol/mol) at least three months after the 2nd oral antidiabetic was prescribed, and time to insulin initiation was defined as first insulin prescription.

RESULTS

Seventy percent (n = 1166) of the baseline cohort was followed up. Median time to insulin requiring was 84 months (IQR 63-100) and to insulin initiation 93 months (IQR 79-105). Participants with depressive symptoms at baseline required insulin earlier (mean [SD] 73.64 [32.16] vs. 79.05 [29.07] months, p = 0.007) and were prescribed insulin sooner (82.53 [30.19] vs. 89.72 [22.02] months, p < 0.001). In Cox regression, depressive symptoms at baseline were not associated with time to insulin requiring (HR [95 % CI]; 1.16 [0.86-1.57], p = 0.34) nor to insulin initiation (HR = 1.00 [0.99-1.00], p = 0.49).

CONCLUSIONS

Depressive symptoms were not associated with time to insulin requiring and initiation after adjusting for potential confounding.

Severe Mental Illness and the Risk of Diabetes Complications: A Nationwide, Register-based Cohort Study

CONTEXT

Individuals with severe mental illness (SMI) are at increased risk of developing type 2 diabetes.

OBJECTIVE

This work explores whether individuals with diabetes and SMI are also at increased risk of diabetes complications and the potential age-specific differences in development of these.

METHODS

Using nationwide registry data, we followed the entire Danish population with type 2 diabetes from January 1, 1996 to December 31, 2018. Exposure was SMI (schizophrenia, bipolar, or depression disorders). Outcome was diabetes complications (nephropathy, retinopathy, lower limp amputations, and cardiovascular disease). We applied Poisson regression models to estimate overall incidence rate ratios (IRRs) and age-specific incidence rates (IRs) and IRRs of the first event of each complication in individuals with SMI compared to individuals without SMI. The models were adjusted for sex, age, diabetes duration, calendar year, education, and migration status.

RESULTS

We followed 371 625 individuals with type 2 diabetes, of whom 30 102 had coexisting diagnosed SMI. Individuals with SMI had a higher IR of nephropathy (IRR: 1.15; 95% CI, 1.12-1.18), amputations (IRR: 1.15; 95% CI, 1.04-1.28), and cardiovascular disease (men: IRR: 1.10; 95% CI, 1.05-1.15, women: IRR: 1.18; 95% CI, 1.13-1.22) but a lower IR of retinopathy (IRR: 0.75; 95% CI, 0.70-0.81) when compared to individuals without SMI, after adjustment for confounders. For all complications except amputations, the difference in IR was highest in the younger age groups.

CONCLUSION

Individuals with type 2 diabetes and SMI had a higher risk and an earlier onset of several diabetes complications diagnoses, emphasizing focusing on improving diabetes management in younger age groups with SMI.

CD4+ T-cell activation of bone marrow causes bone fragility and insulin resistance in type 2 diabetes

Type 2 diabetes mellitus (T2DM) causes an increased risk of bone fractures. However, the pathophysiology of diabetic bone fragility is not completely understood. It has been proposed that an inflammatory microenvironment in bone could be a major mechanism by inducing uncontrolled bone resorption, inadequate bone formation and consequently more porous bones. We propose that activated T-cells in the bone marrow cause a pro-inflammatory microenvironment in bone, and cause bone fragility in T2DM. We induced T2DM in C57BL/6 male mice through a hypercaloric diet rich in carbohydrates and low doses of streptozocin. In T2DM mice we inhibited systemic activation of T-cells with a fusion protein between the extracellular domain of Cytotoxic T-Lymphocyte Antigen 4 and the Fc domain of human immunoglobulin G (CTLA4-Ig). We analysed the effects of T2DM or CTLA4-Ig in lymphocyte cell subsets and antigen-presenting cells in peripheral blood and femoral bone marrow; and their effect on the metabolic phenotype, blood and bone cytokine concentration, femoral bone microarchitecture and biomechanical properties, and the number of osteoblast-like cells in the femoral endosteum. We performed a Pearson multiple correlation analysis between all variables in order to understand the global mechanism. Results demonstrated that CTLA4-Ig decreased the number of activated CD4⁺ T-cells in the femoral bone marrow and consequently decreased TNF-α and RANK-L concentration in bone, notably improved femoral bone microarchitecture and biomechanical properties, increased the number of osteoblast-like cells, and reduces osteoclastic activity compared to T2DM mice that did not receive the inhibitor. Interestingly, we observed that blood glucose levels and insulin resistance may be related to the increase in activated CD4⁺ T-cells in the bone marrow. We conclude that bone marrow activated CD4⁺ T-cells cause poor bone quality and insulin resistance in T2DM.

Effect of depression on progression to end-stage renal disease or pre-end-stage renal disease death in advanced diabetic nephropathy: A prospective cohort study of the Diabetes Study from the Center of Tokyo Women's Medical University

AIMS/INTRODUCTION

This study aimed to determine the effect of depression on the progression to end-stage renal disease (ESRD) and pre-ESRD death in patients with advanced diabetic nephropathy.

MATERIALS AND METHODS

This single-center prospective cohort study enrolled Japanese patients with type 2 diabetes and advanced diabetic nephropathy. The total Patient Health Questionnaire-9 score was used to evaluate depression at baseline and classified patients into: no, mild and severe depression groups. The outcomes were ESRD, defined as initiation of renal replacement therapy, and pre-ESRD death. The relationship between the severity of depression and these outcomes was analyzed using a competing risks model, defining each outcome as the competing risk of the other outcome.

RESULTS

Of the 486 patients with a mean estimated glomerular filtration rate of 37.1 ± 21.1 mL/min/1.73 m2 , 345 were men. During the median follow up of 4.4 years, 164 patients progressed to ESRD and 50 died. The cumulative incidence function of ESRD was significantly higher in the severe depression group (Gray's test, P = 0.003). The ESRD risk increased by 12.4% and 45.1% in patients with mild and severe depression, respectively, compared with those without depression, although these differences did not reach statistical significance in the multivariate subdistribution hazard model (P = 0.450 and 0.161, respectively). The cumulative incidence of death was similar for the study groups.

CONCLUSION

Depression potentially has a weak impact on progression to ESRD, however, the presence of comorbidities might have the possibility to reduce the effect of depression on the renal outcome in patients with advanced diabetic nephropathy.

Genetic association between major depressive disorder and type 2 diabetes mellitus: Shared pathways and protein networks

BACKGROUND

Major depressive disorder (MDD) and type 2 diabetes mellitus (T2DM) are common public health disorders that often co-occur. This study aims to determine whether gene expression profiles from individuals with MDD or T2DM overlap and if there are any functional interconnectivity between identified genes using protein-protein interaction (PPI).

METHODS

The DNA microarray datasets were extracted from the Gene Expression Omnibus. Gene expression dataset GSE98793 from a case-control study of MDD (64 healthy control subjects, 128 patients) and dataset GSE15653 from a case-control study of T2DM (nine controls, nine individuals with T2DM) were used for this secondary and post-hoc analysis. GO enrichment analyses and Reactome pathway enrichment analysis were performed for functional enrichment analyses with the shared genes. PPI networks, PPI clusters and hub genes were performed to detect the potential relationships among differentially expressed genes (DEG) -encoding proteins in both MDD and T2DM.

RESULTS

A total of 3640 DEGs were identified in the MDD group when compared to the control group, whereas 3700 DEGs were identified in the T2DM group when compared to the control groups, among which 244 DEGs were overlap genes. The identified DEGs were enriched for Interleukin-4 and Interleukin-13 signaling, neutrophil degranulation, as well as other select species of the innate immune system. The biological processes of neurofibrillary tangle assembly regulation, tau-protein kinase activity regulation, amyloid-beta clearance regulation, amyloid-beta formation regulation and neuron apoptotic processes were also identified. Molecular function analysis indicated that identified genes were mainly enriched for amyloid-beta binding. 925 out of 1006 protein-protein interactions and six sub-networks were identified reflecting the disparate biological domains of overlapping genes. Ten hub genes further highlight the putative importance of tau-protein kinase activity, inflammatory response and neuron apoptotic regulatory processes across MDD and T2DM.

CONCLUSIONS

Our results indicate that an overlapping genetic architecture subserves MDD and T2DM. Genes relevant to the innate immune system, tau protein formation, and cellular aging were identified. Results indicate that the common, often comorbid, conditions of MDD and T2DM have a pathoetiologic nexus.

Depression in type 2 diabetes: A systematic review and meta-analysis of blood inflammatory markers

The prevalence of depression is higher among people with type 2 diabetes (T2DM). Individually, both conditions are associated with systemic inflammation. This study aimed to summarize the clinical data comparing peripheral inflammatory markers in blood between people with T2DM, with and without comorbid depression. From 2187 records, we identified 20 original peer-reviewed articles from which blood inflammatory marker concentrations could be combined and compared between people with T2DM and comorbid depression (D) vs. no depression (ND) as standardized mean differences (SMD) in random effects meta-analysis. Concentrations of C-reactive protein (CRP; ND/NND = 1742/15244, SMD = 0.31 95% confidence interval [0.16, 0.45], Z16 = 4.03, p < 0.01; I2 = 84.0%) and interleukin-6 (IL-6; ND/NND = 677/4349, SMD = 0.17 [0.04, 0.30], Z4 = 2.58, p = 0.01; I2 = 48.1%), were higher, and concentrations of brain derived neurotrophic factor (BDNF; ND/NND = 358/1512, SMD = -0.37 95% confidence interval [-0.64,-0.10], Z2 = -2.68, p = 0.01; I2 = 61.2%) were lower, among those with depression. Depression in T2DM was associated with systemic inflammation and lower peripheral blood BDNF concentrations. Inconsistency between studies suggests the need to explore further population heterogeneity and pathophysiological elements. PROSPERO (CRD42020188509).

SITAgliptin for Depressive Symptoms in Type 2 Diabetes: A Feasibility Randomized Controlled Trial

OBJECTIVE

We tested the feasibility of using sitagliptin-a dipeptidyl peptidase-IV inhibitor-for depressive symptoms in type 2 diabetes (T2D).

METHODS

In a feasibility, double-blind, randomized controlled trial, we recruited people aged 18 to 75 years with T2D (glycated hemoglobin A1c levels ≥53 and ≤86 mmol/mol prescribed oral hypoglycemic therapy) and comorbid depressive symptoms (Patient Health Questionnaire-9 score ≥10) from family practices in South London. Eligible patients were randomized to sitagliptin 100 mg per day or matched placebo for 12 weeks. The primary feasibility outcomes were participation rates, attrition rates, and adverse events. The primary clinical outcomes were depressive symptoms (Patient Health Questionnaire-9 and 16-item Quick Inventory of Depressive Symptomatology scores) at 12 weeks as assessed using analyses of covariance. Ranges of treatment effects were estimated using Cohen d and associated 95% confidence intervals, where negative values favored sitagliptin over placebo.

RESULTS

Of 153 people screened across 32 practices, 44 were randomized (22 to each arm). The mean (standard deviation) age was 58.8 (8.3) years, 46% were female, and 52% were of non-white ethnicity. Of those treated, 1 patient (4.5%) in each arm withdrew, and there were no group differences in adverse events. Despite improving 12-week glycated hemoglobin A1c (d = -1.19 [95% confidence interval = -1.90 to -0.48), improvement in 12-week Quick Inventory of Depressive Symptomatology score with sitagliptin was inferior to placebo across the range of estimated treatment effects (d = 0.71 [0.13 to 1.30]). Effects of sitagliptin on inflammation were inconsistent (d = -0.32 [-0.81 to 0.17] for high-sensitivity C-reactive protein).

CONCLUSIONS

Repositioning of oral hypoglycemic therapy for depressive symptoms in T2D is feasible. However, in this unpowered feasibility study, we did not detect evidence of superiority of sitagliptin over placebo. The results are cautioned by the small sample size and limited treatment duration.Trial Registration: EudraCT: 2015-004527-32.

P2X7R antagonists in chronic stress-based depression models: a review

Depression affects around 320 million people worldwide. Growing evidence proposes the immune system to be the core interface between psychosocial stress and the neurobiological and behavioural features of depression. Many studies have identified purinergic signalling via the P2X7 receptor (P2X7R) to be of great importance in depression genesis yet only a few have evaluated P2X7R antagonists in chronic stress-based depression models. This review summarizes their findings and analyses their methodology. The four available studies used three to nine weeks of unpredictable, chronic mild stress or unpredictable, chronic stress in male mice or rats. Stress paradigm composition varied moderately, with stimuli being primarily psychophysical rather than psychosocial. Behavioural testing was performed during or after the last week of stress application and resulted in depressive-like behaviours, immune changes (NLRP3 assembly, interleukin-1β level increase, microglia activation) and neuroplasticity impairment. During the second half of each stress paradigm, a P2X7R antagonist (Brilliant Blue G, A-438079, A-804598) was applied. Studies differed with regard to antagonist dosage and application timing. Nonetheless, all treatments attenuated the stress-induced neurobiological changes and depressive-like behaviours. The evidence at hand underpins the importance of P2X7R signalling in chronic stress and depression. However, improvements in study planning and reporting are necessary to minimize experimental bias and increase data purview. To achieve this, we propose adherence to the Research Domain Criteria and the STRANGE framework.

Study of emotional distress in a comparative effectiveness trial of diabetes treatments: Rationale and design

Emotional distress, including depression and diabetes-specific distress (e.g., feeling overwhelmed by living with diabetes, feelings of failure related to diabetes self-care), is a significant and prevalent problem for patients with type 2 diabetes. Both depression and diabetes distress have been associated with metabolic/glycemic control, diabetes complications, mortality, and quality of life. Recent findings further suggest that risk for emotional distress is influenced by diabetes treatment. The GRADE Study (Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study) is generating prospective data that will provide a unique opportunity to examine the relationships between emotional distress, diabetes treatment, and outcomes in an experimental design. The GRADE study is a randomized clinical trial that will compare the metabolic effects of four common anti-hyperglycemic drugs when combined with metformin. This sub-study recruited a subset (n = 1739) of GRADE participants and will examine patient-level variation in baseline emotional distress as a predictor of glycemic control and other health outcomes, independent of treatment effects. The study will also provide an experimental examination of treatment regimen effects on emotional distress over time as part of the overall evaluation of comparative effectiveness. Evaluation of emotional distress using validated measures will allow us to disentangle the roles of depressive symptoms and diabetes distress, factors that share significant overlap but require distinct approaches to screening and treatment. Study findings may directly influence practice decisions regarding screening and treatment for emotional distress as part of diabetes care. ClinicalTrials.gov Identifier: NCT01794143.

Relationships between depression and anxiety symptoms and adipocyte-derived proteins in postmenopausal women

INTRODUCTION

Studies on the association between adiponectin and leptin and anxiety and depression among postmenopausal women are limited. Therefore, the present study specifically evaluates the mutual relationships between adiponectin and leptin and anxiety and depression in postmenopausal women.

PARTICIPANTS AND DESIGN

In this cross-sectional study, a total of 190 women aged 40-65 years were enrolled. Depression symptoms were assessed using the Center for Epidemiologic Studies Depression Scale (CES-D), and anxiety symptoms were evaluated using the Hamilton Anxiety Rating Scale (HAM-A). Fasting specimens were collected to measure sex hormone, glucose, insulin, and adipokine levels. Multiple linear regression analysis was performed to evaluate the associations between depression and anxiety and adipocyte-derived hormones.

SETTINGS

The study was performed in a hospital medical center.

RESULTS

Among 190 enrolled postmenopausal women, Spearman's rank correlation analysis revealed significant correlations between CES-D and HAM-A (r = 0.715, P < 0.0001), between CES-D and adiponectin (p = 0.009) and leptin (p = 0.015), and between HAM-A and adiponectin (p = 0.01) and leptin (p = 0.001). The subjects with CES-D ≥ 16 and with HAM-A ≥ 18 had higher adiponectin levels than those with CES-D < 16 and HAM-A < 18, respectively. After adjusting for age, body mass index, exercise, alanine amino transferase and parameters of lipid profiles, Log adiponectin levels were found to be significantly associated with both CES-D and HAM-A, and Log leptin levels were only significantly associated with HAM-A.

CONCLUSIONS

The data show that adiponectin and leptin levels are significantly associated with depression and anxiety symptoms. These results suggest that higher adiponectin and lower leptin levels may serve as potential markers related to anxiety and mood in postmenopausal women. More future research that is designed to deal with the important confounders (e.g., population heterogeneity) is needed to investigate comprehensively on these associations.

Association Between Genetic Risk for Type 2 Diabetes and Structural Brain Connectivity in Major Depressive Disorder

BACKGROUND

Major depressive disorder (MDD) and type 2 diabetes mellitus (T2D) are known to share clinical comorbidity and to have genetic overlap. Besides their shared genetics, both diseases seem to be associated with alterations in brain structural connectivity and impaired cognitive performance, but little is known about the mechanisms by which genetic risk of T2D might affect brain structure and function and if they do, how these effects could contribute to the disease course of MDD.

METHODS

This study explores the association of polygenic risk for T2D with structural brain connectome topology and cognitive performance in 434 nondiabetic patients with MDD and 539 healthy control subjects.

RESULTS

Polygenic risk score for T2D across MDD patients and healthy control subjects was found to be associated with reduced global fractional anisotropy, a marker of white matter microstructure, an effect found to be predominantly present in MDD-related fronto-temporo-parietal connections. A mediation analysis further suggests that this fractional anisotropy variation may mediate the association between polygenic risk score and cognitive performance.

CONCLUSIONS

Our findings provide preliminary evidence of a polygenic risk for T2D to be linked to brain structural connectivity and cognition in patients with MDD and healthy control subjects, even in the absence of a direct T2D diagnosis. This suggests an effect of T2D genetic risk on white matter integrity, which may mediate an association of genetic risk for diabetes and cognitive impairments.

Depression as a risk factor for dementia in older people with type 2 diabetes and the mediating effect of inflammation

AIMS/HYPOTHESIS

We aimed to determine the association of depression with dementia risk in people with type 2 diabetes, and to explore the possible mediating role of inflammation in this relationship.

METHODS

The Edinburgh Type 2 Diabetes Study is a prospective cohort of 1066 men and women with type 2 diabetes aged 60-75 years. Cox proportional hazards regression analysis was used to investigate the association between depression, assessed at baseline, and subsequent risk of dementia over 10 years. Depression was defined using the Hospital Anxiety and Depression Scale, while incident dementia was defined using medical records, prescription data and death certificates. The potential mediating effect of systemic inflammation was assessed by adjusting models for a generalised inflammation factor, derived from four inflammatory markers measured at baseline (C-reactive protein, IL-6, TNF-α and fibrinogen), and carrying out an exploratory mediation analysis.

RESULTS

Dementia developed in 105 participants over a median follow-up of 10.6 years. After adjusting for age and sex, depression was associated with over a 2.5-fold increase in risk of dementia (HR 2.59 [95% CI 1.62, 4.15]). Additional adjustment for the generalised inflammation factor and other covariates did not attenuate the size of association between depression and incident dementia and mediation analysis showed that it was not a mediator. Adjusted logistic regression models showed cross-sectional associations of C-reactive protein and IL-6 with depression.

CONCLUSIONS/INTERPRETATION

Depression is an important risk factor for dementia in people with type 2 diabetes. Some inflammatory markers were associated with depression, but systemic inflammation does not appear to mediate the relationship between depression and dementia. Graphical abstract.

Treatment for comorbid depressive disorder or subthreshold depression in diabetes mellitus: Systematic review and meta-analysis

OBJECTIVE

To provide an estimate of the effect of interventions on comorbid depressive disorder (MDD) or subthreshold depression in type 1 and type 2 diabetes.

METHODS

Systematic review and meta-analysis. We searched PubMed, PsycINFO, Embase, and the Cochrane Library for randomized controlled trials evaluating the outcome of depression treatments in diabetes and comorbid MDD or subthreshold symptoms published before August 2019 compared to care as usual (CAU), placebo, waiting list (WL), or active comparator treatment as in a comparative effectiveness trial (CET). Primary outcomes were depressive symptom severity and glycemic control. Cohen's d is reported.

RESULTS

Forty-three randomized controlled trials (RCTs) were selected, and 32 RCTs comprising 3,543 patients were included in the meta-analysis. Our meta-analysis showed that, compared to CAU, placebo or WL, all interventions showed a significant effect on combined outcome 0,485 (95% CI 0.360; 0.609). All interventions showed a significant effect on depression. Pharmacological treatment, group therapy, psychotherapy, and collaborative care had a significant effect on glycemic control. High baseline depression score was associated with a greater reduction in HbA1 c and depressive outcome. High baseline HbA1 c was associated with a greater reduction in HbA1 c.

CONCLUSION

All treatments are effective for comorbid depression in type 1 diabetes and type 2 diabetes. Over the last decade, new interventions with large effect sizes have been introduced, such as group-based therapy, online treatment, and exercise. Although all interventions were effective for depression, not all treatments were effective for glycemic control. Effective interventions in comorbid depressive disorder may not be as effective in comorbid subthreshold depression. Baseline depression and HbA1 c scores modify the treatment effect. Based on the findings, we provide guidance for treatment depending on patient profile and desired outcome, and discuss possible avenues for further research.

Association Between Anxiety and Depression and Nonalcoholic Fatty Liver Disease

Backgrounds: Depression and anxiety disorder are frequently seen in patients with nonalcoholic fatty liver disease (NAFLD). However, the associations between mood disorders and NAFLD have not been fully evaluated. In this study, we investigated the relationship between NAFLD and depression or anxiety in a Korean population.

Methods: We conducted a retrospective cross-sectional study that included subjects who underwent abdominal ultrasonography and completed a symptom questionnaire for a routine health check-up. NAFLD was diagnosed and graded according to the ultrasonography findings. Depression and anxiety were assessed using the Beck Depression Inventory and State-Trait Anxiety Inventory, respectively.

Results: Among the total of 25,333 subjects, the mean age was 47 years (men, 56.2%), and the prevalence rate of NAFLD was 30.9%. In the multivariate analysis, NAFLD showed a significant association with depression [adjusted odds ratio (OR) 1.43 and 95% confidence interval (CI) 1.14–1.80, p = 0.002] in women. Severe NAFLD significantly correlated with state anxiety and trait anxiety (adjusted OR 1.84 and 95% CI 1.01–3.37, p = 0.047 and adjusted OR 2.45 and 95% CI 1.08–4.85, p = 0.018, respectively) in women.

Conclusions: There was a higher tendency of women with NAFLD to suffer from depression with increase in steatosis, and severe stage of steatosis was significantly associated with anxiety in the female compared to non-NAFLD. Understanding the association between NAFLD and mood disorders may have clinical implications for reducing the prevalence of comorbidities.

The relationship between diabetes and depressive symptoms in men with or at risk of HIV infection

OBJECTIVES

The aim of the study was to compare the prevalence of comorbid diabetes and depressive symptoms in men living with HIV (MLWH) with that in men without HIV infection and to determine associations between glycaemic control and depressive symptoms.

METHODS

Participants included 920 MLWH and 840 men without HIV infection from the Multicenter AIDS Cohort Study (MACS) with available data regarding glycaemic status [categorized as normal for fasting blood glucose (FBG) < 100 mg/dL, prediabetes for FBG 100-125 mg/dL, and diabetes, defined by self-report, diabetes medication use or FBG ≥ 126 mg/dL on at least two consecutive visits, with diabetes classified as controlled if Hemoglobin A1c (HbA1C) < 7.5% and uncontrolled if HbA1C ≥ 7.5%]. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression (CES-D) score, with CES-D ≥ 16 scores classified as elevated depressive symptoms. A modified Poisson regression model with robust variance was used and adjusted for covariates including HIV serostatus.

RESULTS

Compared to men without HIV infection, MLWH had a higher mean CES-D score, but a similar prevalence of diabetes (11.3% versus 12.8%, respectively; P = 0.33). The concomitant prevalence of diabetes and elevated depressive symptoms did not differ by HIV serostatus (P = 0.215). In an adjusted analysis, men with uncontrolled diabetes had a greater prevalence of depressive symptoms compared to men with normoglycaemia (prevalence ratio = 1.43; 95% confidence interval 1.11, 1.84). The association between glycaemic status and depressive symptoms did not differ by HIV serostatus (P = 0.22 for interaction).

CONCLUSIONS

Both controlled and uncontrolled diabetes were independently associated with a greater prevalence of depressive symptoms, regardless of HIV serostatus. These results highlight the importance of identifying depression in people with diabetes.

The joint association of diabetes distress and depressive symptoms with all-cause mortality in Japanese individuals with type 2 diabetes: a prospective cohort study (Diabetes Distress and Care Registry in Tenri [DDCRT 20])

AIMS/HYPOTHESIS

The independent association of depressive symptoms and diabetes distress with mortality risk in individuals with diabetes has not been evaluated. We examined the temporal joint association of diabetes distress and depressive symptoms at baseline and the subsequent risk of all-cause mortality.

METHODS

The longitudinal data of 3118 individuals with type 2 diabetes were obtained from a large Japanese diabetes registry. To assess the joint association of diabetes distress and depressive symptoms at baseline with the subsequent risk of all-cause mortality, the Cox proportional hazards model was used with adjustment for potential confounders.

RESULTS

The mean age, BMI and HbA_1c levels were 64.7 years, 24.6 kg/m² and 58.6 mmol/mol (7.5%), respectively, and 38.1% of the participants were women. In the multivariable-adjusted models evaluating the diabetes distress and depressive symptoms separately, the HRs for all-cause mortality were 1.67 (95% CI 1.14, 2.43; p = 0.008) and 1.40 (95% CI 1.05, 1.85; p = 0.020), respectively. In such models evaluating the joint association of diabetes distress and depressive symptoms, compared with individuals without diabetes distress or depressive symptoms (DD^-/DS^-), the HRs for all-cause mortality for the group without diabetes distress but with depressive symptoms (DD^-/DS⁺), with diabetes distress but without depressive symptoms (DD⁺/DS^-), and with diabetes distress and depressive symptoms (DD⁺/DS⁺) were 1.34 (95% CI 0.99, 1.86; p = 0.056), 1.96 (95% CI 1.10, 3.50; p = 0.023) and 1.71 (95% CI 1.06, 2.77; p = 0.029), respectively. We did not observe a significant interaction between diabetes distress and depressive symptoms with all-cause mortality risk (p = 0.2636). In the stratified analysis by sex, a significant joint association of diabetes distress and depressive symptoms with the risk of all-cause mortality was observed only in men.

CONCLUSIONS/INTERPRETATION

Diabetes distress and depressive symptoms were independently associated with all-cause mortality risk in male participants with type 2 diabetes, but we did not observe a significant interaction between diabetes distress and depressive symptoms in relation to all-cause mortality. Graphical abstract.

Comorbid depression in medical diseases

Depression is one of the most common comorbidities of many chronic medical diseases including cancer and cardiovascular, metabolic, inflammatory and neurological disorders. Indeed, the prevalence of depression in these patient groups is often substantially higher than in the general population, and depression accounts for a substantial part of the psychosocial burden of these disorders. Many factors can contribute to the occurrence of comorbid depression, such as shared genetic factors, converging biological pathways, social factors, health behaviours and psychological factors. Diagnosis of depression in patients with a medical disorder can be particularly challenging owing to symptomatic overlap. Although pharmacological and psychological treatments can be effective, adjustments may need to be made for patients with a comorbid medical disorder. In addition, symptoms or treatments of medical disorders may interfere with the treatment of depression. Conversely, symptoms of depression may decrease adherence to treatment of both disorders. Thus, comprehensive treatment plans are necessary to optimize care.

Ginseng Extracts, GS-KG9 and GS-E3D, Prevent Blood-Brain Barrier Disruption and Thereby Inhibit Apoptotic Cell Death of Hippocampal Neurons in Streptozotocin-Induced Diabetic Rats

Type 1 diabetes mellitus is known to be linked to the impairment of blood–brain barrier (BBB) integrity following neuronal cell death. Here, we investigated whether GS-KG9 and GS-E3D, bioactive ginseng extracts from Korean ginseng (Panax ginseng Meyer), inhibit BBB disruption following neuronal death in the hippocampus in streptozotocin-induced diabetic rats showing type 1-like diabetes mellitus. GS-KG9 and GS-E3D (50, 150, or 300 mg/kg, twice a day for 4 weeks) administered orally showed antihyperglycemic activity in a dose-dependent manner and significantly attenuated the increase in BBB permeability and loss of tight junction proteins. GS-KG9 and GS-E3D also inhibited the expression and activation of matrix metalloproteinase-9 and the infiltration of macrophages into the brain parenchyma, especially into the hippocampal region. In addition, microglia and astrocyte activation in the hippocampus and the expression of proinflammatory mediators such as tnf-α, Il-1β, IL-6, cox-2, and inos were markedly alleviated in GS-KG9 and GS-E3D-treated group. Furthermore, apoptotic cell death of hippocampal neurons, especially in CA1 region, was significantly reduced in GS-KG9 and GS-E3D-treated groups as compared to vehicle control. These results suggest that GS-KG9 and GS-E3D effectively prevent apoptotic cell death of hippocampal neurons by inhibiting BBB disruption and may be a potential therapy for the treatment of diabetic patients.

Increased serum interleukin-9 and interleukin-1β are associated with depression in type 2 diabetes patients

BACKGROUND

Co-morbid diabetes and depression are prevalent chronic conditions negatively affecting quality of life (QoL). Inflammation has been considered as an integral mechanism in patients with both diabetes and depression.

OBJECTIVE

The aim of the present study was to investigate depression and its association with interleukins (IL)-1β and IL-9 in type 2 diabetic patients (T2DM) and controls. The QoL in diabetic patient was also assessed.

METHODS

Eighty subjects were included, distributed among three groups: Group 1 - Healthy controls; Group 2 - T2DM patients without depression; Group 3 - T2DM patients with depression. Depression and QoL were assessed using Patient Health Questionnaire (PHQ-9) and The Audit of Diabetes-Dependent QoL (ADDQoL), respectively. IL-1β and IL-9 were measured in serum samples of all the patients using ELISA kit.

RESULTS

The PHQ score in the Group 3 was significantly higher as compared to Group 1. The ADDQoL scores in the Group 3 were significantly higher as compared to Group 2. Levels of IL-9 and IL-1β were elevated in Group 3, as compared to the other groups.

CONCLUSION

This study showed positive association between depression and IL-1β, IL-9 in T2DM patients. Additionally, the diabetic patients have poorer quality of life, which is further worsened by the presence of depression. Thus, routine assessment for the presence of depression is suggested in T2DM patients.

Is there an increased risk of perinatal mental disorder in women with gestational diabetes? A systematic review and meta-analysis

AIM

Gestational diabetes (GDM) and mental disorder are common perinatal morbidities and are associated with adverse maternal and child outcomes. While there is a relationship between type 2 diabetes and mental disorder, the relationship between GDM and mental disorder has been less studied. We conducted a systematic review and meta-analysis of the prevalence of mental disorders in women with GDM and their risk for mental disorders compared with women without GDM.

METHODS

Published, peer-reviewed literature measuring prevalence and/or odds of GDM and perinatal mental disorders was reviewed systematically. Risk of bias was assessed using a checklist. Two independent reviewers were involved. Analyses were grouped by stage of peripartum, i.e. antepartum at the time of GDM diagnosis and after diagnosis, and in the postpartum.

RESULTS

Sixty-two studies were included. There was an increased risk of depressive symptoms in the antenatal period around the time of diagnosis of GDM [odds ratio (OR) 2.08; 95% confidence interval (CI) 1.42, 3.05] and in the postnatal period (OR 1.59; 95% CI 1.26, 2.00).

CONCLUSIONS

Given the potential relationship between GDM and perinatal mental disorders, integration of physical and mental healthcare in women experiencing GDM and mental disorders could improve short- and long-term outcomes for women and their children.

Depression among Peruvian adults with hypertension and diabetes: Analysis of a national survey

BACKGROUND AND AIMS

Hypertension and diabetes are global health problems with an incidence that is rapidly increasing worldwide. Depression is the most frequent mental health co-morbidity and is considered an important risk factor for the development of both diseases. This study aimed to determine the prevalence and factors associated with depression among Peruvian adults with hypertension and diabetes.

METHODS

We performed a secondary analysis of the 2017 Peru Demographic and Family Health Survey, using data from 10,566 adults aged 40 and older. The main outcome was depression assessed with the Patient Health Questionnaire-9 (PHQ-9). Other important variables were the diagnosis of hypertension or diabetes, sex, age, level of education, geographical region, wealth index, daily smoking, harmful alcohol consumption and physical disability.

RESULTS

The overall prevalence of depression was 23.15% (CI 95%: 21.42%-24.88%) and among adults with hypertension and diabetes it was 34.96% (CI 95%: 29.33%-40.59%) and 35.56% (CI 95%: 24.49%-46.63%), respectively. Whereas the prevalence of depression among adults with type 2 diabetes mellitus (T2DM) was higher in the physical disability group (PRa: 1.28; CI 95%: 1.12-1.45), the prevalence of depression among adults with hypertension was higher in the female group (PRa: 1.36; CI 95%: 1.20-1.54) and among those with harmful alcohol consumption (PRa: 1.50; CI 95%: 1.01-2.24).

CONCLUSION

Peru has a considerable burden of depression in the hypertensive and diabetic populations. While the variables positively associated with depression in hypertensive adults were female gender and harmful alcohol consumption, in adults with diabetes it was the presence of physical disability.

Prevalence and Associated Factors of Anxiety and Depression Among Patients with Type 2 Diabetes in Kerman, Southern Iran

PURPOSE

Depression and anxiety are common disorders in patients suffering from type 2 diabetes. These disorders can lead to premature morbidity, exacerbate disease complications, make patients suffer more, and increase health-care costs. As diabetes has increased worldwide recently, it is necessary to reduce the prevalence of factors that are associated with depression and anxiety in diabetes patients. This study aimed to assess the prevalence of anxiety and depression and to identify their associated factors, including metabolic components among people with type 2 diabetes.

PATIENTS AND METHODS

We performed a cross-sectional study in 1500 patients with type 2 diabetes in Kerman, in the southern part of Iran. The prevalence of depression and anxiety was estimated using the Beck Depression Inventory and the Hamilton Anxiety questionnaires, respectively. After calculating the proportions of depression and anxiety, univariate logistic regression was performed. Factors whose P-values were smaller than 0.2 in univariate logistic regression were included in multiple logistic regression for confounder adjustments. The analysis was performed using SPSS version 20.

RESULTS

The rates of depression and anxiety were 59% (95% CI: 54.48-63.12) and 62% (95% CI: 59.51-66.27), respectively. Factors found to be independently associated with anxiety were high FBS, high LDL-C, high TG, hypertension, complications, low physical activity. Factors found to be independently associated with depression were female gender, older age, high BMI, high FBS, high LDL-C, low HDL-C, high TG, high HbA1c, hypertension, and low physical activity. Complications were independently associated with anxiety but not with depression. Female gender, older age, high BMI, low HDL-C, and high HbA1c were independently associated with depression but not with anxiety.

CONCLUSION

Current findings demonstrated that a large proportion of patients with type 2 diabetes suffer from depression and anxiety. This study also identified factors associated with these disorders. Controlling some metabolic variables will decrease the prevalence of these disorders and improves clinical remedy and quality of life in patients with type 2 diabetes.

Genetic Overlap Between Type 2 Diabetes and Depression in a Sri Lankan Population Twin Sample

OBJECTIVE

Results from twin studies examining the genetic overlap between type 2 diabetes and depression are currently inconclusive. This question has not been addressed in non-Western populations. We aimed to examine whether there are common genetic factors between type 2 diabetes and depression in a Sri Lankan population using genetic model-fitting analysis.

METHOD

The Colombo Twin and Singleton Study-Phase 2 consists of 2019 singletons, and 842 monozygotic and 578 dizygotic twin pairs. The primary outcomes were self-reported type 2 diabetes diagnosis and Beck Depression Inventory scores. Standard bivariate twin models were fitted to estimate the genetic and environmental (co)variance of type 2 diabetes and depression.

RESULTS

In the best-fitting model, the phenotypic correlation between type 2 diabetes and depression was significant in female individuals only (r = 0.15 [0.08-0.21]). This association was primarily attributed to a significant genetic correlation between the traits (rA = 0.53 [0.19-0.98]).

CONCLUSIONS

In female individuals, but not male individuals, we found a significant genetic overlap between type 2 diabetes and depression in the context of a modest phenotypic correlation.

Metformin ameliorates stress-induced depression-like behaviors via enhancing the expression of BDNF by activating AMPK/CREB-mediated histone acetylation

BACKGROUND

Metformin, a first-line antiglycemic drug, has been reported to have anti-depressant effects in patients with type 2 diabetes; however, its exact role and underlying mechanism still need to be investigated.

METHOD

C57BL/6J mice were subjected to the Chronic social defeat stress (SDS) and drug administration (Control + Vehicle, SDS + Vehicle, SDS + MET (200 mg kg^-1), SDS + FLUOX (3 mg kg^-1), SDS + MET + FLUOX). And the depression phenotypes were evaluated by the sucrose preference test, social interaction, tail suspension test and forced swimming test. The potential mechanisms underlying the effects of metformin on depression was discussed by using Chromatin immunoprecipitation, Quantitative real-time PCR mRNA expression analysis and Western blot in vivo and in primary cultured hippocampal neurons.

RESULT

The metformin treatment counteracted the development of depression-like behaviors in mice suffering SDS when administered alone and enhanced the anti-depressant effect of fluoxetine when combined with fluoxetine. Further RNA sequencing analysis revealed that metformin treatment prevented the transcriptional changes in the medial prefrontal cortex (mPFC) of the animals and Golgi staining indicated favorable morphological changes in the neurite plasticity of CA1 pyramidal neurons, which approximated to those found in unstressed mice. At a molecular level, metformin significantly upregulated the expression of the brain-derived neurotrophic factor (BDNF) by increasing the histone acetylation along with the BDNF promoter, which was attributed to the activation of AMP-activated protein kinase (AMPK) and cAMP-response element binding protein (CREB).

CONCLUSION

Our findings suggest that metformin can produce antidepressant effects, which provides empirical insights into the clinical value of metformin in the prevention and therapy of depression.

Longitudinal associations between depression and diabetes complications: a systematic review and meta-analysis

To conduct a systematic review and meta-analysis of longitudinal studies assessing the bi-directional association between depression and diabetes macrovascular and microvascular complications. Embase, Medline and PsycINFO databases were searched from inception through 27 November 2017. A total of 4592 abstracts were screened for eligibility. Meta-analyses used multilevel random/mixed-effects models. Quality was assessed using the Newcastle-Ottawa scale. Twenty-two studies were included in the systematic review. Sixteen studies examined the relationship between baseline depression and incident diabetes complications, of which nine studies involving over one million participants were suitable for meta-analysis. Depression was associated with an increased risk of incident macrovascular (HR = 1.38; 95% CI: 1.30-1.47) and microvascular disease (HR = 1.33; 95% CI: 1.25-1.41). Six studies examined the association between baseline diabetes complications and subsequent depression, of which two studies involving over 230 000 participants were suitable for meta-analysis. The results showed that diabetes complications increased the risk of incident depressive disorder (HR = 1.14; 95% CI: 1.07-1.21). The quality analysis showed increased risk of bias notably in the representativeness of selected cohorts and ascertainment of exposure and outcome. Depression in people with diabetes is associated with an increased risk of incident macrovascular and microvascular complications. The relationship between depression and diabetes complications appears bi-directional. However, the risk of developing diabetes complications in depressed people is higher than the risk of developing depression in people with diabetes complications. The underlying mechanisms warrant further research.

Self-Reported Depressive Symptoms Might be Associated with Sudomotor Dysfunction in Chinese T2DM Patients

AIMS

To determine the relationships of sudomotor functions, nerve conductions and self-reported depressive symptoms in Chinese type 2 diabetes (T2DM) patients.

METHODS

T2DM patients in a single community health center were included in this study. Demographic, medical and laboratory data were collected. Michigan Neuropathy Screening Instrument (MNSI) examination was conducted in all patients. SUDOSCAN test and Point-of-care Nerve Conduction Device (DPN-check) were conducted and all the patients finished the Patient Health Questionnaire-9 (PHQ-9).

RESULTS

A total of 162 T2DM patients (74 males and 88 females) were included. The mean age was 69.0±7.2 years and the mean course of diabetes was 10.5±8.0 years with a mean HbA1c level of 7.3±1.4%. Thirty of them (18.5%) had self-reported depressive symptoms (PHQ-9 scores≥5). Diabetic peripheral neuropathy (DPN) was diagnosed according to the MSNI examination in 74 patients. Electrochemical skin conductance (ESC) values of both hands and feet were significantly lower in patients with depressive symptoms (Hands ESC: 60.63±18.92 vs. 67.64±16.02 μS, p<0.05; Feet ESC: 59.60 ± 15.19 vs. 66.19±14.99 μS, p<0.05). The proportion of patients with moderate to severe depressive symptoms were significantly higher in those with ESC values<60 μS (13.33% vs. 3.846%, p<0.05). Hands ESC values were negatively related to PHQ-9 scores (r =- 0.168, p<0.05). After adjusting for variables, hands and feet ESC values remained negatively related with depressive symptoms (β =- 0.036 and-0.038, p<0.05). Female were positively related to depressive symptoms with odds ratio 3.4 (95%CI 1.1-10.5, p<0.05).

CONCLUSION

Self-reported depressive symptoms might be associated with sudomotor dysfunction in Chinese T2DM patients.

Diabetes, depressive symptoms, and mortality risk in old age: The role of inflammation

BACKGROUND

Both diabetes and depression increase the mortality risk in the elderly. In this study, we evaluated mortality risk associated with the comorbidity between depression and diabetes. We also assessed the moderating role of inflammation in the mortality risk in this population.

METHODS

We included a total of 1,183 community-dwelling older adults, divided into four groups: "neither diabetes nor depression"; "diabetes only"; "depression only," and "both diabetes and depression," and followed-up for a median of 13.5 years. We evaluated the inflammatory status by the high-sensitivity C-reactive protein (hs-CRP) levels. Date of death was computed by reviewing death certificates. We used Cox's proportional hazards models and additive interactions to evaluate the risk of mortality in the subject groups and the moderating effect of hs-CRP.

RESULTS

Participants with both diabetes and depression had higher death risk (hazard ratio [HR]: 2.33; 95% confidence interval [CI]: 1.59-3.42) than those with each condition alone (HR diabetes: 2.08 95% CI: 1.56-2.76 HR depression: 1.26; 95% CI: 1.03-1.54). High level of hs-CRP, indicative of high inflammatory status, significantly moderated the risk of mortality in subjects with both diabetes and depression (Bonferroni-adjusted p = 0.0116).

CONCLUSIONS

The coexistence of diabetes and depression symptoms is associated with the highest death risk in this population. This risk is moderated by inflammatory status.

The Prospective Association Between Inflammation and Depressive Symptoms in Type 2 Diabetes Stratified by Sex

OBJECTIVE

We tested whether inflammation is associated with worsening depressive symptoms in type 2 diabetes and examined whether sex moderated this association.

RESEARCH DESIGN AND METHODS

In a prospective cohort study of people with newly diagnosed type 2 diabetes, we measured depressive symptoms over a 2-year follow-up using the Patient Health Questionnaire-9 (PHQ-9). The independent variable was a composite inflammation burden score at diagnosis of diabetes, derived from hs-CRP, white cell count, interleukin (IL)-1β, IL-1 receptor antagonist, monocyte chemotactic protein-1, and vascular endothelial growth factor concentrations. General linear models assessed 1) the association between overall inflammation burden and estimated marginal mean PHQ-9 score (ln transformed) at 2 years and 2) whether sex interacted with elevated inflammation burden (above-median score) in predicting change in PHQ-9 score. Models were adjusted for age, ethnicity, BMI, blood pressure, cholesterol, HbA_1c, antidepressants, anti-inflammatory medications, and baseline ln PHQ-9 score.

RESULTS

Of 1,174 people with complete inflammation data, mean (SD) age was 56.7 (11.0) years and 46.1% were of nonwhite ethnicity and 44.1% female. After full adjustment, inflammation burden was not associated with worsening ln PHQ-9 score (P = 0.65). However, female sex interacted with elevated inflammation in predicting higher 2-year ln PHQ-9 score (β = 0.32, P = 0.005), showing that the difference by inflammation burden in females was 0.32 larger than in males. In post hoc comparisons, ln PHQ-9 score was higher in females than males with elevated inflammation (P = 0.003) but not with low inflammation (P = 0.34) burden.

CONCLUSIONS

In type 2 diabetes, female sex confers specific vulnerability to the effects of inflammation on depressive symptoms.

Anxiety and depression in patients with peripheral arterial disease admitted to a tertiary hospital

Background

Anxiety and depression are highly prevalent neuropsychiatric conditions and are associated with chronic diseases, pain, loss of autonomy, dependence on others to perform routine activities, and loneliness. Depression often has a cause-and-effect relationship with other diseases, such as: acute myocardial infarction (AMI), systemic arterial hypertension (SAH), diabetes mellitus (DM) and peripheral arterial disease (PAD).

Objectives

To estimate the frequency of anxiety and depression in patients of both sexes with PAD admitted to a tertiary hospital.

Methods

This is a descriptive, cross-sectional study, with a non-random sample selected consecutively. The Hospital Anxiety and Depression Scale (HADS) was used to assess anxiety and depression, and the ankle-brachial index (ABI) was used to assess PAD.

Results

The prevalence of anxiety in these patients was 24.4%, with associations between anxiety and monthly family income, smoking, and SAH. The prevalence of depression was 27.6%, with associations between depression and the female gender, being married or in a stable relationship, living on a family income of one minimum wage or less, not being an alcoholic, and having hypertension.

Conclusions

There are high prevalence rates of anxiety and depressive disorders among patients with PAD, which are underdiagnosed and, hence, not properly treated.

Depression and change in occupational functioning in type 2 diabetes

BACKGROUND

The effect of depression on both employment and productivity in type 2 diabetes (T2D) is poorly understood.

AIMS

We tested whether depressive symptoms at diagnosis of T2D are associated with change in employment status and productivity over 2-year follow-up.

METHODS

In a prospective analysis of working-age (18-63 years) people with newly diagnosed T2D recruited from primary care, we tested the association between depressive symptoms at diagnosis of T2D (baseline) and employment rates over 2 years. Using the Patient Health Questionnaire-9, depressive symptoms were measured categorically (depression caseness score ≥10) and continuously. In those employed, we measured changes in presenteeism and absenteeism using the World Health Organization (WHO) Health and Work Performance Questionnaire in univariate and multivariate models, respectively, including and excluding part-time workers.

RESULTS

Of 1202 people aged 18-63 at baseline, 982 (82%) provided employment information; the mean age was 50.3 (SD 8.1) years, 44% were female, 59% of non-white ethnicity and 16% had depression. After adjustment for age, sex, ethnicity, socio-economic status, diabetes control and depression treatment, depression caseness was associated with worsening unemployment over 2 years only in full-time workers (odds ratio 0.43 (95% CI 0.20, 0.96), P < 0.05). In those employed full-time or part-time, total depressive symptoms were associated with worsening presenteeism over 2 years after full adjustment (β = -2.63 (95% CI -4.81, -0.45), P < 0.05), despite no association with worsening absenteeism.

CONCLUSIONS

In newly diagnosed T2D, depressive symptoms demonstrate an association with worsening employment rate and decline in work productivity over 2-year follow-up.

The Role of Inflammation in Depression and Fatigue

Depression and fatigue are conditions responsible for heavy global societal burden, especially in patients already suffering from chronic diseases. These symptoms have been identified by those affected as some of the most disabling symptoms which affect the quality of life and productivity of the individual. While many factors play a role in the development of depression and fatigue, both have been associated with increased inflammatory activation of the immune system affecting both the periphery and the central nervous system (CNS). This is further supported by the well-described association between diseases that involve immune activation and these symptoms in autoimmune disorders, such as multiple sclerosis and immune system activation in response to infections, like sepsis. Treatments for depression also support this immunopsychiatric link. Antidepressants have been shown to decrease inflammation, while higher levels of baseline inflammation predict lower treatment efficacy for most treatments. Those patients with higher initial immune activation may on the other hand be more responsive to treatments targeting immune pathways, which have been found to be effective in treating depression and fatigue in some cases. These results show strong support for the hypothesis that depression and fatigue are associated with an increased activation of the immune system which may serve as a valid target for treatment. Further studies should focus on the pathways involved in these symptoms and the development of treatments that target those pathways will help us to better understand these conditions and devise more targeted treatments.

Increasing Adiponergic System Activity as a Potential Treatment for Depressive Disorders

Depression is the most devastating mental disorder and one of the leading contributors to the global medical burden. Current antidepressant prescriptions present drawbacks, including treatment resistance, delayed onset of treatment response, and side effects. The rapid and long-lasting antidepressant effect of ketamine has brought hope to treatment-resistant major depressive disorder patients. However, ketamine has undesirable addictive properties and is a drug of abuse. There is an urgent need, therefore, to develop novel pharmacological interventions that could be as effective as ketamine, but without its side effects. Adiponectin, a pleiotropic adipocyte-secreted hormone, has insulin-sensitizing and neurotrophic properties. It can cross the blood-brain barrier and target multiple brain regions where the adiponectin receptors are detected. Emerging evidence has suggested that adiponectin and the adiponectin receptor agonist, AdipoRon, could promote adult neurogenesis, dendritic and spine remodeling, and synaptic plasticity in the hippocampus, resulting in antidepressant effects in adult mice. By summarizing the most recent clinical and animal studies, this review provides a timely insight on how modulating the adiponergic system in the hippocampus could be a potential therapeutic target for an effective and fast-acting antidepressant response.

Prospective Study of Glycated Hemoglobin and Trajectories of Depressive Symptoms: The China Health and Retirement Longitudinal Study

The longitudinal association between glycated hemoglobin (HbA_1c) and different courses of depressive symptoms is understudied. This study aimed to identify different trajectories of depressive symptoms and investigate the relation of HbA_1c with the risk of increasing and high-stable depressive symptoms. In the China Health and Retirement Longitudinal Study, depressive symptoms were measured using the 10-item Center for Epidemiological Studies-Depression scale in three visits (years: 2011, 2013 and 2015) among 9804 participants (mean age 60.0 ± 9.0 years). Group-based trajectory modeling was used to identify trajectories of depressive symptoms. HbA_1c was measured at baseline and categorized five groups according to the respective quintile. Multinomial logistic regression was fitted to examine this relationship. Four distinct trajectories of depressive symptoms were identified: low symptoms (n=6401, 65.29%); decreasing symptoms (n=1362, 13.89%); increasing symptoms (n=1452, 14.81%); and high symptoms (n=1452, 14.81%). Adjusting for demographic, health-related, and cognitive factors, the risk ratio (95% confidence interval) pertaining to the highest HbA_1c (Quintile 5) for decreasing, increasing, and high symptoms of depression versus low symptoms was 1.01 (0.82-1.25), 1.12 (0.92-1.36), and 1.39 (1.04-1.86) compared with the lowest HbA_1c (Quintile 1), respectively. We observed a J-shaped relationship between HbA_1c and high depressive symptoms, with the lowest risk at a HbA_1c concentration of 5.0%. In summary, in this large population-based cohort, high levels of glycated hemoglobin concentrations were associated with a higher risk of increasing and high-stable symptoms of depression.

Subclinical inflammation and depressive symptoms in patients with type 1 and type 2 diabetes

Depression is a frequent comorbidity of type 1 diabetes (T1D) and type 2 diabetes (T2D). Depression and diabetes are linked by a bidirectional relationship, but the underlying mechanisms are still incompletely understood. Experimental, observational and intervention studies showed that inflammatory processes contribute to the development of depression in animal models and humans. Given the high risk of morbidity and mortality in patients with the double burden of diabetes and depression, this review provides an overview of epidemiological studies that addressed the relationship between biomarkers of inflammation and depressive symptoms or depression in diabetes patients. In patients with T1D, there is some evidence that higher levels of high-sensitivity C-reactive protein (hsCRP), IL-6, IL-1 receptor antagonist (IL-1RA) and sICAM-1 may be related to depressive symptoms or (for hsCRP) lower treatment response. For T2D, hsCRP, IL-1RA, CCL2 and adiponectin or its isoforms were associated with depressive symptoms in at least two studies, whereas positive associations of IL-1β, IL-6 and IL-18 with depressive symptoms or depression were reported from single cohorts. However, the number of studies is too low for any meaningful meta-analysis. Prospective life course studies including both patients with T1D and T2D, a comprehensive assessment of systemic inflammation and repeated assessment of depressive symptoms should represent a future research priority to clarify to what extent subclinical inflammation affects the risk of depression in patients with diabetes. A better understanding of the role of inflammatory processes may help to identify subtypes of depression with partly different pathogenesis, which could have consequences with respect to therapeutic options including immunomodulation.