Pathophysiology linking depression and type 2 diabetes: Psychotherapy, physical exercise, and fecal microbiome transplantation as damage control

Scientometric analysis and historical review of diabetic encephalopathy research: Trends and hotspots (2004-2023)

BACKGROUND

Diabetic encephalopathy (DE) is a common and serious complication of diabetes that can cause death in many patients and significantly affects the lives of individuals and society. Multiple studies investigating the pathogenesis of DE have been reported. However, few studies have focused on scientometric analysis of DE.

AIM

To analyze literature on DE using scientometrics to provide a comprehensive picture of research directions and progress in this field.

METHODS

We reviewed studies on DE or cognitive impairment published between 2004 and 2023. The latter were used to identify the most frequent keywords in the keyword analysis and explore the hotspots and trends of DE.

RESULTS

Scientometric analysis revealed 1308 research papers on DE, a number that increased annually over the past 20 years, and that the primary topics explored were domain distribution, knowledge structure, evolution, and emergence of research topics related to DE. The inducing factors, comorbidities, pathogenesis, treatment, and animal models of DE help clarify its occurrence, development, and treatment. An increasing number of studies on DE may be a result of the recent increase in patients with diabetes, unhealthy lifestyles, and unhealthy eating habits, which have aggravated the incidence of this disease.

CONCLUSION

We identified the main inducing factors and comorbidities of DE, though other complex factors undoubtedly increase social and economic burdens. These findings provide vital references for future studies.

Clinical research progress on β-cell dysfunction in T2DM development in the Chinese population

The prevalence of type-2 diabetes mellitus (T2DM) has increased over 10-fold in the past 40 years in China, which now has the largest T2DM population in the world. Insulin resistance and β-cell dysfunction are the typical features of T2DM. Although both factors play a role, decreased β-cell function and β-cell mass are the predominant factors for progression to T2DM. Considering the differences between Chinese T2DM patients and those of other ethnicities, it is important to characterize β-cell dysfunction in Chinese patients during T2DM progression. Herein, we reviewed the studies on the relationships between β-cell function and T2DM progression in the Chinese population and discussed the differences among individuals of varying ethnicities. Meanwhile, we summarized the risk factors and current treatments of T2DM in Chinese individuals and discussed their impacts on β-cell function with the hope of identifying a better T2DM therapy.

Type 2 diabetes mellitus modifies and mediates the association between the visceral adiposity index and depression: A cross-sectional study using NHANES 2005-2018 data

BACKGROUND

The objective of this investigation was to explore the correlation between the visceral adiposity index (VAI) and depression, and to analyze how type 2 diabetes mellitus (T2DM) may influence this relationship.

METHODS

This study included data of 12,378 participants sourced from the National Health and Nutrition Examination Survey (NHANES) 2005-2018. Utilizing multivariate logistic regression and restricted cubic spline (RCS) regression, we examined the correlation between VAI and depression. Additionally, we investigated the interactive and mediating effects of T2DM on the association between VAI and depression.

RESULTS

Controlling for all potential confounders, the Ln logarithmic transformation of VAI showed a significant positive correlation with depression [odds ratio (OR) = 1.16, 95 % confidence interval (CI): 1.01-1.35, P = 0.041]. T2DM exhibited a notable interaction effect on the relationship connecting lnVAI and depression (P for interaction = 0.013). Specifically, the T2DM group exhibited a notable positive correlation between lnVAI and depression (OR = 1.46, 95 % CI: 1.17-1.82, P < 0.001), whereas such correlation didn't reach statistical significance within the non-T2DM group. The RCS model revealed a J-shaped nonlinear link between lnVAI and depression, with an inflection point value of 0.052. Mediation analysis indicated that diabetes accounted for 8.0 % of the correlation between lnVAI and depression. Furthermore, sensitivity analysis confirmed the consistency of these findings.

CONCLUSIONS

A J-shaped nonlinear dose-response relationship was observed between lnVAI and depression among American adults, with a threshold of 0.052. T2DM not only served as a mediator between the two variables but also modified their association.

Aerobic Exercise Improves the Overall Outcome of Type 2 Diabetes Mellitus Among People With Mental Disorders

The escalating global prevalence of type 2 diabetes mellitus (T2DM) and mental disorder (MD) including schizophrenia, bipolar disorder, major depressive disorder, and anxiety highlights the urgency for comprehensive therapeutic strategies. Aerobic exercise (AE) is a viable adjunct therapy, providing significant benefits for individuals dealing with both T2DM and MD. This review consolidates evidence on AE's role in alleviating the physiological and psychological effects of these comorbid conditions. It delves into the pathophysiological connections between T2DM and various MD, including depression, schizophrenia, anxiety, and bipolar disorder-emphasizing their reciprocal exacerbation. Key neurophysiological mechanisms through which AE confers benefits are explored, including neuroinflammation modulation, brain structure and neuroplasticity enhancement, growth factor expression regulation, and hypothalamic-pituitary-adrenal (HPA)/microbiota-gut-brain (MGB) axis normalization. Clinical results indicate that AE significantly improves both metabolic and psychological parameters in patients with T2DM and MD, providing a substantial argument for integrating AE into comprehensive treatment plans. Future research should aim to establish detailed, personalized exercise prescriptions and explore the long-term benefits of AE in this population. This review underscores the potential of AE to complement existing therapeutic modalities and enhance the management of patients with T2DM and MD.

Immune-related gene characterization and biological mechanisms in major depressive disorder revealed based on transcriptomics and network pharmacology

Background

Major depressive disorder (MDD) is a severe psychiatric disorder characterized by complex etiology, with genetic determinants that are not fully understood. The objective of this study was to investigate the pathogenesis of MDD and to explore its association with the immune system by identifying hub biomarkers using bioinformatics analyses and examining immune infiltrates in human autopsy samples.

Methods

Gene microarray data were obtained from the Gene Expression Omnibus (GEO) datasets GSE32280, GSE76826, GSE98793, and GSE39653. Our approach included differential expression analysis, weighted gene co-expression network analysis (WGCNA), and protein-protein interaction (PPI) network analysis to identify hub genes associated with MDD. Subsequently, gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), Cytoscape plugin CluGO, and Gene Set Enrichment Analysis (GSEA) were utilized to identify immune-related genes. The final selection of immune-related hub genes was determined through the least absolute shrinkage and selection operator (Lasso) regression analysis and PPI analysis. Immune cell infiltration in MDD patients was analyzed using CIBERSORT, and correlation analysis was performed between key immune cells and genes. The diagnostic accuracy of the identified hub genes was evaluated using receiver operating characteristic (ROC) curve analysis. Furthermore, we conducted a study involving 10 MDD patients and 10 healthy controls (HCs) meeting specific criteria to assess the expression levels of these hub genes in their peripheral blood mononuclear cells (PBMCs). The Herbal Ingredient Target Database (HIT) was employed to screen for herbal components that target these genes, potentially identifying novel therapeutic agents.

Results

A total of 159 down-regulated and 51 up-regulated genes were identified for further analysis. WGCNA revealed 12 co-expression modules, with modules "darked", "darkurquoise" and "light yellow" showing significant positive associations with MDD. Functional enrichment pathway analysis indicated that these differential genes were associated with immune functions. Integration of differential and immune-related gene analysis identified 21 common genes. The Lasso algorithm confirmed 4 hub genes as potential biomarkers for MDD. GSEA analysis suggested that these genes may be involved in biological processes such as protein export, RNA degradation, and fc gamma r mediated cytotoxis. Pathway enrichment analysis identified three highly enriched immune-related pathways associated with the 4 hub genes. ROC curve analysis indicated that these hub genes possess good diagnostic value. Quantitative reverse transcription-polymerase chain reaction (RT-qPCR) demonstrated significant expression differences of these hub genes in PBMCs between MDD patients and HCs. Immune infiltration analysis revealed significant correlations between immune cells, including Mast cells resting, T cells CD8, NK cells resting, and Neutrophils, which were significantly correlated with the hub genes expression. HIT identified one herb target related to IL7R and 14 targets related to TLR2.

Conclusions

The study identified four immune-related hub genes (TLR2, RETN, HP, and IL7R) in MDD that may impact the diagnosis and treatment of the disorder. By leveraging the GEO database, our findings contribute to the understanding of the relationship between MDD and immunity, presenting potential therapeutic targets.

Exploring the link between SIRT1 gene variants and depression comorbidity in type 2 diabetes

This study aims to (1) analyze the clinical characteristics and risk factors of patients with type 2 diabetes and comorbid depression and (2) explore the association between SIRT1 gene single-nucleotide polymorphism sites and this comorbidity. A total of 450 type 2 diabetes patients hospitalized in the General Medicine Department at The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology from July 2022 to September 2023, and 300 healthy individuals from the physical examination department were selected as study subjects. Both groups were assessed using general information surveys and questionnaires. Statistical analyses were performed to compare clinical indicators across 3 groups: individuals with only type 2 diabetes, those with comorbid depression, and healthy controls. The age, gender, disease duration, marital status, income and drug expenditure, employment status, fasting blood glucose level, fasting insulin level difference, insulin resistance index difference, glycated hemoglobin, high-density lipoprotein level, and HCY difference among the 3 groups of patients were risk factors for type 2 diabetes comorbid depression patients. The SIRT1 mRNA level was significantly reduced in type 2 diabetes comorbid depression patients. The SIRT1 gene had 3 sites: rs12415800, rs3758391, and rs932658, which were related to the patient's type 2 diabetes comorbid depression. They were the additive model and dominant model of rs12415800 and rs3758391, respectively. In addition, the GTGGT haplotype composed of rs12415800-rs932658-rs7895833-rs2273773-rs1467568 and the AGACT haplotype composed of rs3758391-rs932658-rs33957861-rs3818292-rs1467568 were significantly associated with type 2 diabetes comorbid depression. Numerous factors influence the presence of depression in patients with type 2 diabetes, with the SIRT1 gene playing a significant role, serving as a potential biomarker for this comorbidity.

Short-physical performance battery: complete mediator of cognitive depressive symptoms and diabetes mellitus in hemodialysis patients

OBJECTIVE

This study aimed to examine the relationship between different dimensions of depressive symptoms and the presence of diabetes mellitus in hemodialysis patients. Additionally, the study sought to elucidate the mediating effect of physical performance on this association.

METHODS

This was a cross-sectional multicenter study conducted between July 2020 and March 2023, involving 1024 patients from eight hemodialysis centers in Shanghai. Diabetes mellitus was based on a documented physician diagnosis and blood glucose tests. Physical performance and depressive symptoms were assessed using short-physical performance battery (SPPB) and the patient health questionnaire-9, respectively. Regression and mediation analysis were applied to statistical analysis.

RESULTS

Among the 1024 participants, 39.26% (n = 402) were found to have coexisting diabetes mellitus. Diminished SPPB scores (OR = 0.843, 95% CI = 0.792-0.897) and cognitive depressive symptoms (OR = 1.068, 95% CI = 1.011-1.129) exhibited significant associations with diabetes mellitus, while somatic depressive symptoms did not show a significant correlation. Notably, SPPB emerged as a complete mediator in the relationship between cognitive depressive symptoms and diabetes mellitus. The observed indirect effect of SPPB on this relationship was estimated at 0.038 (95% CI: 0.021-0.057).

CONCLUSION

This study showed an association between diabetes mellitus and cognitive depressive symptoms in patients undergoing hemodialysis, with physical performance appearing to mediate the relationship between diabetes mellitus and depressive symptoms.

Targeting self-care adherence for glycaemic control in multimorbid type 2 diabetes mellitus with depression using bupropion: a protocol for cross-over randomised controlled trial

INTRODUCTION

Diabetes and depression are among the 10 biggest health burdens globally. They often coexist and exhibit a strong bidirectional relationship. Depression leads to decreased adherence to self-care activities. This impacts glycaemic control and worsens type 2 diabetes mellitus (T2D). Both conditions have a synergistic effect and lead to greater complications, hospitalisations, healthcare expenditure and a worse quality of life. There is no consensus on managing people with comorbid T2D and depression. Bupropion is an efficacious antidepressant with many properties suitable for T2D with depression, including a favourable metabolic profile, persistent weight loss and improvement in sexual dysfunction. We will assess the efficacy and safety of add-on bupropion compared with standard care in people with T2D and mild depression. This study can give valuable insights into managing the multimorbidity of T2D and depression. This can help mitigate the health, social and economic burden of both these diseases.

RESEARCH DESIGN AND METHODS

This cross-over randomised controlled trial will recruit people with T2D (for 5 years or more) with mild depression. They will be randomised to add-on bupropion and standard care. After 3 months of treatment, there will be a washout period of 1 month (without add-on bupropion while standard treatment will continue). Following this, the two arms will be swapped. Participants will be assessed for glycosylated haemoglobin, adherence to diabetes self-care activities, lipid profile, urine albumin-to-creatinine ratio, autonomic function, sexual function, quality of life and adverse events.

ETHICS AND DISSEMINATION

The Institutional Ethics Committee at All India Institute of Medical Sciences, Jodhpur has approved this study (AIIMS/IEC/2022/4172, 19 September 2022). We plan to disseminate the research findings via closed group discussions at the site of study, scientific conferences, peer-reviewed published manuscripts and social media.

TRIAL REGISTRATION NUMBER

CTRI/2022/10/046411.

Dangers of the chronic stress response in the context of the microbiota-gut-immune-brain axis and mental health: a narrative review

More than 20% of American adults live with a mental disorder, many of whom are treatment resistant or continue to experience symptoms. Other approaches are needed to improve mental health care, including prevention. The role of the microbiome has emerged as a central tenet in mental and physical health and their interconnectedness (well-being). Under normal conditions, a healthy microbiome promotes homeostasis within the host by maintaining intestinal and brain barrier integrity, thereby facilitating host well-being. Owing to the multidirectional crosstalk between the microbiome and neuro-endocrine-immune systems, dysbiosis within the microbiome is a main driver of immune-mediated systemic and neural inflammation that can promote disease progression and is detrimental to well-being broadly and mental health in particular. In predisposed individuals, immune dysregulation can shift to autoimmunity, especially in the presence of physical or psychological triggers. The chronic stress response involves the immune system, which is intimately involved with the gut microbiome, particularly in the process of immune education. This interconnection forms the microbiota-gut-immune-brain axis and promotes mental health or disorders. In this brief review, we aim to highlight the relationships between stress, mental health, and the gut microbiome, along with the ways in which dysbiosis and a dysregulated immune system can shift to an autoimmune response with concomitant neuropsychological consequences in the context of the microbiota-gut-immune-brain axis. Finally, we aim to review evidenced-based prevention strategies and potential therapeutic targets.

Empagliflozin alleviates diabetes-induced cognitive impairments by lowering nicotinamide adenine dinucleotide phosphate oxidase-4 expression and potentiating the antioxidant defense system in brain tissue of diabetic rats

BACKGROUND

Diabetes-induced cognitive impairment is a major challenge in patients with uncontrolled diabetes mellitus. It has a complicated pathophysiology, but the role of oxidative stress is central. Therefore, the use of antidiabetic drugs with extra-glycemic effects that reduce oxidative damage may be a promising treatment option.

METHODS

Male Wistar rats were randomly divided into four groups as normal, normal treated, diabetic and diabetic treated (n = 8 per group). Type 1 diabetes was induced by a single intraperitoneal dose of streptozotocin (STZ) (40 mg/kg). Two treatment groups received empagliflozin for 5 weeks (20 mg/kg/po). Cognitive ability was evaluated using open field, Elevated Plus Maze (EPM) and the Morris Water Maze (MWM) tests at study completion. Blood and brain tissue samples were collected - and analysis for malondialdehyde (MDA) and glutathione (GLT) content and catalase (CAT) and superoxide dismutase (SOD) enzyme activity were performed. Additionally, expression of nicotinamide adenine dinucleotide phosphate oxidase-4 (Nox-4) enzyme in brain tissue was analyzed using RT-PCR.

RESULTS

STZ increased blood glucose and induced diabetes with oxidative stress by lowering the antioxidant system potency and increasing Nox-4 expression after 5-weeks in brain tissue accompanied by reduction in cognitive performance. Also, diabetes induced anxiety-like behavior and impaired spatial memory in MWM, EPM and open field tests. However, empagliflozin reversed these changes, improving SOD and CAT activity, GLT content and reducing Nox-4 expression and MDA concentration in brain tissue while improving cognitive ability. It reduced anxiety and depression-related activities. It also improved spatial memory in MWM test.

CONCLUSION

Uncontrolled diabetes negatively impacts mental function and impairs learning and cognitive performance via oxidative stress induction, the Nox-4 enzyme playing a central role. Empagliflozin reverses these effects, improving cognitive ability via promoting the anti-oxidative system and damping Nox-4 free radical generator enzyme expression. Therefore, empagliflozin is a promising treatment, providing both antidiabetic and extra-glycemic benefits for improving brain function in the diabetic milieu.

Thromboxane-induced cerebral microvascular rarefaction predicts depressive symptom emergence in metabolic disease

Previous studies have suggested that the loss of microvessel density in the peripheral circulation with evolving metabolic disease severity represents a significant contributor to impaired skeletal muscle oxygenation and fatigue-resistance. Based on this and our recent work, we hypothesized that cerebral microvascular rarefaction was initiated from the increased prooxidant and proinflammatory environment with metabolic disease and is predictive of the severity of the emergence of depressive symptoms in obese Zucker rats (OZRs). In male OZR, cerebrovascular rarefaction followed the emergence of elevated oxidant and inflammatory environments characterized by increased vascular production of thromboxane A2 (TxA2). The subsequent emergence of depressive symptoms in OZR was associated with the timing and severity of the rarefaction. Chronic intervention with antioxidant (TEMPOL) or anti-inflammation (pentoxifylline) therapy blunted the severity of rarefaction and depressive symptoms, although the effectiveness was limited. Blockade of TxA2 production (dazmegrel) or action (SQ-29548) resulted in a stronger therapeutic effect, suggesting that vascular production and action represent a significant contributor to rarefaction and the emergence of depressive symptoms with chronic metabolic disease (although other pathways clearly contribute as well). A de novo biosimulation of cerebrovascular oxygenation in the face of progressive rarefaction demonstrates the increased probability of generating hypoxic regions within the microvascular networks, which could contribute to impaired neuronal metabolism and the emergence of depressive symptoms. The results of the present study also implicate the potential importance of aggressive prodromic intervention in reducing the severity of chronic complications arising from metabolic disease.NEW & NOTEWORTHY With clinical studies linking vascular disease risk to depressive symptom emergence, we used obese Zucker rats, a model of chronic metabolic disease, to identify potential mechanistic links between these two negative outcomes. Depressive symptom severity correlated with the extent of cerebrovascular rarefaction, after increased vascular oxidant stress/inflammation and TxA2 production. Anti-TxA2 interventions prevasculopathy blunted rarefaction and depressive symptoms, while biosimulation indicated that cerebrovascular rarefaction increased hypoxia within capillary networks as a potential contributing mechanism.

Exploring the Impact of Combined Thai Yoga and Elastic Band Exercise on Physical Fitness and Exercise Capacity in Older Patients with Type 2 Diabetes

Study purpose. Although it is acknowledged that exercise can positively affect both physical and biochemical markers in older individuals with type 2 diabetes (T2DM), there are still uncertainties about the specific impacts of combining Thai yoga with an elastic band exercise in this population. The objective of the study was to assess the impact of a 12-week program involving Thai yoga combined with an elastic band exercise on the physical fitness and functional exercise capacity among older individuals with T2DM. Materials and methods. A total of 42 participants, consisting of 20 men and 22 women with T2DM and a mean age of 64.6±3.6 years, were randomly assigned to two groups: the control group and the exercise group. The exercise group engaged in a daily regimen of Thai yoga combined with an elastic band exercise for 40 minutes, 5 days a week, over a 12-week period. In contrast, the control group maintained their regular routines. Physical fitness and functional exercise capacity were assessed both before and after the 12-week intervention. Results. The exercise group showed significant reductions in body weight (58.7±11.9 vs. 58.0±12.0 kg), body mass index (24.2±3.0 vs. 23.9±3.0 kg/m2), waist circumference (33.6±3.6 vs. 33.1±3.6 in), and waist-hip ratio (0.90±0.06 vs. 0.89±0.06) (p < 0.001). Additionally, there were notable improvements in physical fitness parameters, including hand grips, back strength, leg strength (p < 0.01), and trunk flexibility (p < 0.001). Functional exercise capacity, indicated by the 6-minute walk test and estimated peak oxygen consumption (p < 0.01), also improved significantly. Conclusions. Thai yoga combined with an elastic band exercise enhances physical fitness and functional exercise capacity in older individuals with T2DM. This improvement has the potential to enhance their cardiopulmonary performance. Consequently, this exercise regimen is considered a health alternative for older individuals with T2DM.

Association of the APOE gene variants with depression in type 2 diabetes

Background

The risk of depression among patients with diabetes is higher than the general population. The exact mechanisms linking these two diseases are mostly unknown. Energy metabolism disorders seem to be a shared pathway. One of the key genes playing important roles in energy metabolism-related pathways is the APOE gene. We aimed to investigate the association of the APOE gene variants with depression among Iranian patients with type 2 diabetes (T2DM).

Methods

Three APOE gene alleles and genotypes frequencies (E2, E3, E4) were determined in 244 patients with T2DM (114 with depression and 130 without depression) using the high-resolution melting (HRM) method on the genomic DNA extracted from the patient's peripheral blood.

Results

Apoe4 allele frequency was significantly higher in T2DM patients without depression compared with those with depression (11.9 vs. 2.2%, p-value < 0.0001 and p-value = 0.001, respectively). Conversely, the wild allele apoe3 frequency was significantly higher in T2DM patients with depression (86% vs., 69%, p-value < 0.0001). Apoe4 carrier status was associated with decreased risk of depression in patients with T2DM [OR: 0.19 (0.07-0.53)].

Conclusion

Our results showed that the apoe4 allele and apoe4 carrier status significantly reduced the risk of depression among patients with T2DM. Further studies are needed to unravel the complex role of the APOE gene in depression among patients with diabetes.

Sex- and age-specific prevalence and risk factors of depressive symptoms in Parkinson's disease

Although depressive symptoms are common in PD, few studies investigated sex and age differences in depressive symptoms. Our study aimed to explore the sex and age differences in the clinical correlates of depressive symptoms in patients with PD. 210 PD patients aged 50-80 were recruited. Levels of glucose and lipid profiles were measured. The Hamilton Depression Rating Scale-17 (HAMD-17), the Montreal Cognitive Assessment (MoCA) and the Movement Disorder Society Unified Parkinson's Disease Rating Scale Part III (MDS-UPDRS-III) assessed depressive symptom, cognition and motor function, respectively. Male depressive PD participants had higher fasting plasma glucose (FPG) levels. Regarding the 50-59 years group, depressive patients had higher TG levels. Moreover, there were sex and age differences in the factors associated with severity of depressive symptoms. In male PD patients, FPG was an independent contributor to HAMD-17 (Beta = 0.412, t = 4.118, p < 0.001), and UPDRS-III score was still associated with HAMD-17 in female patients after controlling for confounding factors (Beta = 0.304, t = 2.961, p = 0.004). Regarding the different age groups, UPDRS-III (Beta = 0.426, t = 2.986, p = 0.005) and TG (Beta = 0.366, t = 2.561, p = 0.015) were independent contributors to HAMD-17 in PD patients aged 50-59. Furthermore, non-depressive PD patients demonstrated better performance with respect to visuospatial/executive function among the 70-80 years group. These findings suggest that sex and age are crucial non-specific factors to consider when assessing the relationship between glycolipid metabolism, PD-specific factors and depression.

Higher metabolic variability increases the risk of depressive disorder in type 2 diabetes mellitus: a longitudinal nationwide cohort study

BACKGROUND AND OBJECTIVES

While variabilities in metabolic parameters (METv) have been linked to adverse health outcomes in type 2 DM, their association with depression is yet to be studied. This research aimed to investigate the association between METv and depressive disorder in patients with type 2 DM.

METHODS

The study involved a nationwide cohort of 1,119,631 type 2 DM patients who had undergone three or more serial health examinations between 2005 and 2012. At each visit, body mass index (BMI), fasting glucose (FG), systolic blood pressure (BP), and total cholesterol (TC) were measured and stratified into quartiles, with Q4 being the highest and Q1 the lowest. The risk of depressive disorder was evaluated using Cox proportional hazard regression models, which accounted for METs in the indexes, after adjusting for sex, income status, lifestyle habits, medical comorbidities, DM severity, and baseline levels of BMI, FG, BP, and TC.

RESULTS

During a mean follow-up period of 6.00 ± 2.42 years, 239,477 (21.4%) cases of type 2 DM patients developed depressive disorder. The risk of developing depressive disorder was gradually increased as the number of METv increased (HR 1.18; 95% CI 1.13, 1.23 for the group with the highest METv in all parameters compared to those with the lowest METv in all parameters). In the subgroup analysis, the risk of developing depressive disorder was 43% higher in men (HR 1.43; 95% CI 1.34, 1.51), and 31% higher in those younger than 65 years of age (HR 1.31; 95% CI 1.23, 1.39) in the group with the highest number of METv compared to the group with the lowest number of METv.

CONCLUSION

In type 2 DM, higher METv was an independent risk factor for depressive disorder. This risk is notably elevated in men and individuals under the age of 65 years.

Generalization of contextual fear is sex-specifically affected by high salt intake

A hallmark symptom of many anxiety disorders, and multiple neuropsychiatric disorders more broadly, is generalization of fearful responses to non-fearful stimuli. Anxiety disorders are often comorbid with cardiovascular diseases. One established, and modifiable, risk factor for cardiovascular diseases is salt intake. Yet, investigations into how excess salt consumption affects anxiety-relevant behaviors remains little explored. Moreover, no studies have yet assessed how high salt intake influences generalization of fear. Here, we used adult C57BL/6J mice of both sexes to evaluate the influence of two or six weeks of high salt consumption (4.0% NaCl), compared to controls (0.4% NaCl), on contextual fear acquisition, expression, and generalization. Further, we measured osmotic and physiological stress by quantifying serum osmolality and corticosterone levels, respectively. Consuming excess salt did not influence contextual fear acquisition nor discrimination between the context used for training and a novel, neutral context when training occurred 48 prior to testing. However, when a four week delay between training and testing was employed to induce natural fear generalization processes, we found that high salt intake selectively increases contextual fear generalization in females, but the same diet reduces contextual fear generalization in males. These sex-specific effects were independent of any changes in serum osmolality nor corticosterone levels, suggesting the behavioral shifts are a consequence of more subtle, neurophysiologic changes. This is the first evidence of salt consumption influencing contextual fear generalization, and adds information about sex-specific effects of salt that are largely missing from current literature.

Association between Serum Irisin and Leptin Levels and Risk of Depressive Symptoms in the Diabetic Elderly Population

BACKGROUND

Adipokines are considered to be involved in the pathogenesis of diabetes and depression. The associations of serum levels of leptin and irisin with depressive symptoms were investigated in elderly patients with type 2 diabetes (T2DM).

METHODS

189 elderly diabetics were assessed with the 30-item Geriatric Depression Scale (GDS-30), and 57 patients with depressive symptoms and 132 controls were selected. Blood biochemical parameters, including serum irisin and leptin, were measured.

RESULTS

Serum irisin levels were decreased and leptin concentrations were significantly higher in T2DM patients with depressive symptoms compared to controls. In all subjects, the irisin level was inversely correlated with the leptin level and the GDS-30 score, whereas the leptin level was highly correlated with BMI and the GDS-30 score. Higher levels of leptin and lower concentrations of irisin are, among other factors, variables indicative of predictive capacity for depressive symptoms in elderly patients with T2DM.

CONCLUSIONS

The results indicated that irisin and leptin levels may be used as diagnostic markers of depressive symptoms in diabetic, elderly patients and as potential therapeutic targets for the treatment. Further prospective and more extensive studies are needed to clarify the role of these adipokines in the common pathogenesis of depression and diabetes.

Prevalence and influencing factors of suicide in first-episode and drug-naive young major depressive disorder patients with impaired fasting glucose: a cross-sectional study

Background

An association exists between major depression disorder (MDD), suicide attempts, and glucose metabolism, but suicide attempts in young MDD patients with comorbid impaired fasting glucose (IFG) have been less well studied. The purpose of this study was to examine the prevalence and risk factors for suicide attempts in young, first-episode, drug-naive (FEDN) MDD patients with comorbid IFG.

Methods

We recruited 917 young patients with FEDN MDD, 116 of whom were judged to have combined IFG because their blood glucose was >6.0. We collected anthropological and clinical data on all of them. The Hamilton Depression Scale (HAMD) score, the Hamilton Anxiety Scale (HAMA) score and the Positive and Negative Syndrome Scale (PANSS) positive subscale score were used to assess their clinical symptoms. Blood glucose, plasma thyroid function and lipid indicators were measured.

Results

The prevalence of suicide attempts in young MDD patients with IFG was 32.8% (38/116). Furthermore, among young MDD patients with comorbid IFG, suicide attempters had more severe depression and anxiety symptoms, more comorbid psychotic symptom, higher levels of antibody of thyroid stimulating hormone and thyroid peroxidases (TPOAb), and more severe lipid metabolism disorders than those without suicide attempts. In addition, HAMA scores and TPOAb were independently associated with suicide attempts in young patients with FEDN MDD.

Conclusion

Our study suggests that young MDD patients with IFG have a high rate of suicide attempts. Some clinical symptoms and thyroid function parameters may be the risk factor for suicide attempts in young MDD patients with impaired glucose metabolism.

Glucagon-like peptide 1 (GLP-1) receptor agonists as a protective factor for incident depression in patients with diabetes mellitus: A systematic review

Glucagon-like peptide 1 (GLP-1) receptor agonists are widely used for glycemic control in patients with diabetes mellitus (DM) and are primarily indicated for type 2 diabetes mellitus (T2DM). GLP-1 receptor agonists have also been shown to have neuroprotective and antidepressant properties. Replicated evidence suggests that individuals with DM are significantly more likely to develop depression. Herein, we aim to investigate whether GLP-1 receptor agonists can be used prophylactically on patients with DM to lower the risk of incident depression. We conducted a systematic search for English-language articles published on the PubMed/MEDLINE, Scopus, Embase, APA, PsycInfo, Ovid and Google Scholar databases from inception to June 6, 2022. Four retrospective observational studies were identified that evaluated the neuroprotective effects of GLP-1 receptor agonists on incident depression in patients with DM. We found mixed results with regards to lowering the risk of incident depression, with two studies demonstrating a significant reduction in risk and two studies showing no such effect. A single study found that dulaglutide may lower susceptibility to depression. Our results were limited by high interstudy heterogeneity, paucity of literature, and lack of controlled trials. While we did not find evidence of GLP-1 receptor agonists significantly lowering risk of incident depression in patients with DM, promising neuroprotective data presented in two of the included papers, specifically on dulaglutide where information is scarce, provide the impetus for further investigation. Future research should focus on better elucidating the neuroprotective potential of different classes and doses of GLP-1 receptor agonists using controlled trials.

The importance of exercise for glycemic control in type 2 diabetes

Exercise is a first-line therapy recommended for patients with type 2 diabetes (T2D). Although moderate to vigorous exercise (e.g. 150 min/wk) is often advised alongside diet and/or behavior modification, exercise is an independent treatment that can prevent, delay or reverse T2D. Habitual exercise, consisting of aerobic, resistance or their combination, fosters improved short- and long-term glycemic control. Recent work also shows high-intensity interval training is successful at lowering blood glucose, as is breaking up sedentary behavior with short-bouts of light to vigorous movement (e.g. up to 3min). Interestingly, performing afternoon compared with morning as well as post-meal versus pre-meal exercise may yield slightly better glycemic benefit. Despite these efficacious benefits of exercise for T2D care, optimal exercise recommendations remain unclear when considering, dietary, medication, and/or other behaviors.

A network perspective on the ecology of gut microbiota and progression of type 2 diabetes: Linkages to keystone taxa in a Mexican cohort

Introduction

The human gut microbiota (GM) is a dynamic system which ecological interactions among the community members affect the host metabolism. Understanding the principles that rule the bidirectional communication between GM and its host, is one of the most valuable enterprise for uncovering how bacterial ecology influences the clinical variables in the host.

Methods

Here, we used SparCC to infer association networks in 16S rRNA gene amplicon data from the GM of a cohort of Mexican patients with type 2 diabetes (T2D) in different stages: NG (normoglycemic), IFG (impaired fasting glucose), IGT (impaired glucose tolerance), IFG + IGT (impaired fasting glucose plus impaired glucose tolerance), T2D and T2D treated (T2D with a 5-year ongoing treatment).

Results

By exploring the network topology from the different stages of T2D, we observed that, as the disease progress, the networks lose the association between bacteria. It suggests that the microbial community becomes highly sensitive to perturbations in individuals with T2D. With the purpose to identify those genera that guide this transition, we computationally found keystone taxa (driver nodes) and core genera for a Mexican T2D cohort. Altogether, we suggest a set of genera driving the progress of the T2D in a Mexican cohort, among them Ruminococcaceae NK4A214 group, Ruminococcaceae UCG-010, Ruminococcaceae UCG-002, Ruminococcaceae UCG-005, Alistipes, Anaerostipes, and Terrisporobacter.

Discussion

Based on a network approach, this study suggests a set of genera that can serve as a potential biomarker to distinguish the distinct degree of advances in T2D for a Mexican cohort of patients. Beyond limiting our conclusion to one population, we present a computational pipeline to link ecological networks and clinical stages in T2D, and desirable aim to advance in the field of precision medicine.

The mediating effect of depression on new-onset stroke in diabetic population: Evidence from the China health and retirement longitudinal study

BACKGROUND

Diabetes has a high incidence in China, which may cause stroke and depression. However, the relationship between diabetes and the incidence of new-onset stroke and depression has not been fully studied.

METHODS

The data from the China Longitudinal Study on Health and Retirement (CHARLS) from 2013 to 2018 were used. A total of 8530 respondents aged ≥45 years old were included in the follow-up study. Logistic regression model, Cox regression, and Mediation analyses were used to explore the association between diabetes, depression, and new-onset stroke.

RESULTS

The depression score of patients with diabetes history was higher (HR,95%CI = 1.02, 1.01-1.04) and were more likely to experience new-onset stroke events (HR, 95%CI = 1.046, 1.02-1.07). With a history of hypertension (HR,95%CI = 1.747, 1.381-2.208), older (HR,95%CI = 1.033, 1.020-1.046) with high BMI (HR,95%CI = 1.056, 1.027-1.086) have a high risk of new-onset stroke. In the combined subgroup analysis, the incidence of new-onset stroke in the subgroup with diabetes depression was higher than in others. The mediating effect of depression on new-onset stroke events in diabetic patients is more pronounced in the medium to long term (>3 years) after adjusting covariates.

LIMITATIONS

We defined new-onset stroke by patient self-report, there might be some memory bias. In addition, new-onset stroke was not classified in the CHARLS questionnaire, which would hinder us to evaluate the mediating effect of depression on different types of new-onset stroke.

CONCLUSION

Our results showed that depression has a partial mediating effect between diabetes and new-onset stroke in the middle-aged and elderly population in China.

Bidirectional association between depression and diabetic nephropathy by meta-analysis

BACKGROUND

Studies suggested that the association between depression and diabetic nephropathy may be bi-directional, but this hypothesis remains investigating. In this meta-analysis, the bi-directional relationship between depression and diabetic nephropathy was investigated.

METHODS

A search for the publications on depression and diabetic nephropathy in the databases of PubMed, Web of science, and Embase from the earliest available to August 2022 was conducted. Two sets of pooled risk estimates were calculated using random effects models: diabetic nephropathy predicting depression and depression predicting diabetic nephropathy. Cross-sectional studies were assessed using Agency for Healthcare Research and Quality (AHRQ), cohort and case-control studies were assessed using Newcastle-Ottawa Scale (NOS).

RESULT

Of the 974,121 patients in 30 clinical studies, 24 studies met eligibility for diabetic nephropathy predicting onset of depression, representing 28,438 incident cases. The other 6 studies met criteria for depression predicting onset of diabetic nephropathy, representing 945,683 incident cases. The pooled odds ratio (OR) of diabetic nephropathy predicting depression was 1.46 (95% CI 1.27-1.67). The OR of depression predicting diabetic nephropathy was 1.22 (95% CI 1.13-1.31).

CONCLUSION

This meta-analysis shows that the relationship between depression and diabetic nephropathy may be bidirectional. Diabetic nephropathy may be a predictor of depression, and depression may also be an indicator of diabetic nephropathy. The mechanisms underlying the bidirectional relationship need to be further investigated and interventions of the comorbidity of depression and diabetic nephropathy need be studied in clinical practice.

Effect of aerobic exercise as a treatment on type 2 diabetes mellitus with depression-like behavior zebrafish

BACKGROUND

Depression is the most known complication of type 2 diabetes mellitus (T2DM). Aerobic exercise improves glycemic control in T2DM, although the underlying mechanisms of comorbid depression-like behaviors in T2DM have not yet been fully elucidated.

METHODS

120 zebrafish were randomly assigned to four groups: Control, T2DM, T2DM + metformin, and T2DM + aerobic exercise. Then, all animals except the control group were fed with high glucose fairy shrimp (~40 g/kg/day) and exposed reserpine (40 μg/ml for 20 min) for 10 days. Here, behavioral tests were used for model verification. Following the verification, all groups were treated as before. Additionally, the T2DM + metformin group received metformin (~10.6 mg/kg/day) at the same time, while the T2DM + aerobic exercise group received aerobic exercise 30 min/day. Finally, blood glucose and behavioral tests, as well as protein and molecular levels were determined at Day 11 and 12.

RESULTS

Aerobic exercise alleviated depressive-like behavior and enhanced the levels of antidepressant biomarkers (NE, 5-HIAA) in zebrafish after 10 consecutive days of exercise. Additionally, 10 consecutive days of aerobic exercise decreased the levels of inflammatory biomarkers (IFN-γ, IL-1, IL-4) and depressive biomarkers (cortisol). Meanwhile, it also aided in the reduction of CD11b, IL-6, IL-6R, and caspase-3 expression to combat the neuroinflammation induced by T2DM, mediated the BDNF-TrkB pathway, and increased Bcl-2/Bax levels.

CONCLUSION

Given the remarkable similarity in neurochemistry between humans and zebrafish, this study supports the effectiveness of aerobic exercise as clinical guidance in preventing and treating T2DM complicated with depression.

Prevalence and Clinical Significance of Occult Pulmonary Infection in Elderly Patients with Type 2 Diabetes Mellitus

The occult pulmonary infection is the most common complications in elderly patients with type 2 diabetes mellitus (T2DM). Since its etiological characteristics has not been clarified, infection control remains a serious problem for public health. To investigate the prevalence and clinical significance of occult pulmonary infection in elderly T2DM patients, in this study, 573 elderly patients cochallenged with T2DM and community-acquired pulmonary infection from January 2018 to December 2020 were selected in the hospitals and divided into occult pneumonia group (OP, n = 249) and nonoccult pneumonia group (NOP, n = 324) according to the nature of infection. Clinical medical records were analyzed retrospectively to summarize the infection characteristics of elderly diabetics with occult pneumonia. The prevalence of the cases (278/324, 85.8%) in NOP group was not higher than that in OP group (206/249, 82.7%; P > 0.05). Also, there was not significant difference in the distribution of isolated pathogens among the positive patients. The length of hospitalization and mortality of OP patients were significantly higher than those NOP patients. Multivariate logistic regression showed that advanced age, comorbidities, hypothyroidism, senile dementia, and prolonged bed rest were independent risk factors for occult pneumonia in elderly diabetic patients. Therefore, the results demonstrated that the pulmonary infection in elderly patients with diabetes mellitus is often occult. Gram-negative bacteria are the predominant pathogens and cause poor prognosis. Advanced age, comorbidities (senile dementia, hypothyroidism), and prolonged bed rest are the independent risk factors for occult pneumonia.

Neuropeptides as the Shared Genetic Crosstalks Linking Periodontitis and Major Depression Disorder

Background

The aim of this study was at investigating the association between major depressive disorder (MDD) and periodontitis based on crosstalk genes and neuropeptides.

Methods

Datasets for periodontitis (GSE10334, GSE16134, and GSE23586) and MDD (GSE38206 and GSE39653) were downloaded from GEO. Following batch correction, a differential expression analysis was applied (MDD: ∣log2FC | >0 and periodontitis ∣log2FC | ≥0.5, p < 0.05). The neuropeptide data were downloaded from NeuroPep and NeuroPedia. Intersected genes were potential crosstalk genes. The correlation between neuropeptides and crosstalk genes in MDD and periodontitis was analyzed with Pearson correlation coefficient. Subsequently, regression analysis was performed to calculate the differentially regulated link. Cytoscape was used to map the pathways of crosstalk genes and neuropeptides and to construct the protein-protein interaction network. Lasso regression was applied to screen neuropeptides, whereby boxplots were created, and receiver operating curve (ROC) analysis was conducted.

Results

The MDD dataset contained 30 case and 33 control samples, and the periodontitis dataset contained 430 case and 139 control samples. 35 crosstalk genes were obtained. A total of 102 neuropeptides were extracted from the database, which were not differentially expressed in MDD and periodontitis and had no intersection with crosstalk genes. Through lasso regression, 9 neuropeptides in MDD and 43 neuropeptides in periodontitis were obtained. Four intersected neuropeptide genes were obtained, i.e., ADM, IGF2, PDYN, and RETN. The results of ROC analysis showed that IGF2 was highly predictive in MDD and periodontitis. ADM was better than the other three genes in predicting MDD disease. A total of 13 crosstalk genes were differentially coexpressed with four neuropeptides, whereby FOSB was highly expressed in MDD and periodontitis.

Conclusion

The neuropeptide genes ADM, IGF2, PDYN, and RETN were intersected between periodontitis and MDD, and FOSB was a crosstalk gene related to these neuropeptides on the transcriptomic level. These results are a basis for future research in the field, needing further validation.