Depression and insulin resistance: cross-sectional associations in young adults

The association of the Prime Diet Quality Score (PDQS) with depression and anxiety symptoms: the Isfahan functional disorders (ISFUN) cohort study

BACKGROUND

Due to scarce epidemiologic data regarding the Prime Diet Quality Score (PDQS) and mental health disorders, this study aimed to investigate the association of PDQS with depression and anxiety symptoms in Iranian adults.

METHODS

This cross-sectional analysis was performed using the baseline data collected for the Isfahan functional disorders (ISFUN) cohort study. ISFUN was established in 2017 and enrolled apparently healthy adults, aged 18-65 years in Isfahan, Iran. Information on usual dietary intakes was collected using a validated Dish-based, 106-item food frequency questionnaire. The severity of depression and anxiety was assessed using a validated Iranian version of the Hospital Anxiety and Depression Scale.

RESULTS

A total number of1892 participants were enrolled in the present study. In total, 54.50% of subjects were female. In the fully adjusted model, participants with PDQS lower than median compared with those with PDQS higher than median had higher risk of depression (OR =   1.62; 95% CI: 1.11, 2.37) and anxiety (OR: 1.57; 95% CI: 1.08, 2.27). In stratified analysis by sex, males with PDQS lower than median compared with those with PDQS higher than median had greater risk for depressive (OR: 1.57) and anxiety symptoms (OR =   1.52). However, in females, no significant association was found between PDQS and odds of depression, and anxiety in the fully adjusted model.

CONCLUSION

We found evidence indicating a significant inverse association between PDQS and depression and anxiety symptoms among Iranian adults. Further studies, in particular with prospective design, are required to confirm these findings.

Neuron-derived extracellular vesicles as a liquid biopsy for brain insulin dysregulation in Alzheimer's disease and related disorders

Extracellular vesicles (EVs) have emerged as novel blood-based biomarkers for various pathologies. The development of methods to enrich cell-specific EVs from biofluids has enabled us to monitor difficult-to-access organs, such as the brain, in real time without disrupting their function, thus serving as liquid biopsy. Burgeoning evidence indicates that the contents of neuron-derived EVs (NDEs) in blood reveal dynamic alterations that occur during neurodegenerative pathogenesis, including Alzheimer's disease (AD), reflecting a disease-specific molecular signature. Among these AD-specific molecular changes is brain insulin-signaling dysregulation, which cannot be assessed clinically in a living patient and remains an unexplained co-occurrence during AD pathogenesis. This review is focused on delineating how NDEs in the blood may begin to close the gap between identifying molecular changes associated with brain insulin dysregulation reliably in living patients and its connection to AD. This approach could lead to the identification of novel early and less-invasive diagnostic molecular biomarkers for AD. HIGHLIGHTS: Neuron-derived extracellular vesicles (NDEs) could be isolated from peripheral blood. NDEs in blood reflect the molecular signature of Alzheimer's disease (AD). Brain insulin-signaling dysregulation plays a critical role in AD. NDEs in blood could predict brain insulin-signaling dysregulation. NDEs offer novel early and less-invasive diagnostic biomarkers for AD.

Association between fasting blood glucose and psychotic symptoms in Chinese patients with first-episode drug-naïve major depressive disorder

INTRODUCTION

Psychotic depression (PD) is a highly debilitating disorder characterized by hallucinations and/or delusions accompanied by depression. A variety of neurotransmitters, hormones and corresponding receptors in the endocrine system are involved in the onset and progression of depression, and fasting blood glucose (FBG) can be an important indicator for monitoring the stability of the endocrine system. The aim of this study was to investigate the relationship between FBG and PD in a Chinese population with first-episode drug-naïve (FEDN) major depressive disorder (MDD).

METHODS

In this study, 1718 outpatient individuals diagnosed with first-episode drug-naïve major depressive disorder (FEDN MDD) were included. The association between PD and FBG levels was identified through multivariable binary logistic regression analysis. To investigate potential non-linear relationships, a two-piecewise linear regression model was utilized. Additionally, interaction and stratified analyses were performed based on gender, educational background, marital status, presence of comorbid anxiety, and history of suicide attempt.

RESULTS

Multivariate logistic regression analysis showed that FBG was positively associated with the risk of PD in FEDN MDD patients (OR = 1.68, 95% CI: 1.31 to 2.13; P < 0.05). Smoothed plots showed a non-linear relationship between FBG and PD, while the inflection point of FBG was calculated using a two-segmented logistic regression model to be 6.23 mmol/L. On the right side of the inflection point, the probability of PD increased substantially by 278% (OR = 3.78, 95% CI: 1.75 to 8.18, p < 0.001), while no significant association was observed on the left side of the inflection point (OR = 1.06, 95% CI: 0.73 to 1.52, p = 0.772).

CONCLUSIONS

Our investigation revealed a nonlinear relationship between FBG and PD in patients with FEDN MDD, thereby informing more effective intervention strategies for managing psychotic symptoms in individuals with depression.

The relationship between depression and insulin resistance in the population without diabetes: Results from the 2005-2016 NHANES

BACKGROUND

Insulin resistance (IR), a precursor of type 2 diabetes and other metabolic disorders, is becoming more common owing to rising obesity rates. Depression, which affects 4.4 % of the global population, has been linked to IR; however, the findings are inconsistent. The roles of moderating factors in the depression-IR relationship remain underexplored, creating a gap in the current understanding.

METHODS

Data from six cycles of the National Health and Nutrition Examination Survey (NHANES, 2005-2016), including 6636 participants without diabetes, were analyzed. Depression was assessed using the Patient Health Questionnaire-9 (PHQ-9), with scores of 5-9 and 10-27 defined as mild and moderate-to-severe depression, respectively. IR was measured using the HOMA2-IR model, with IR defined as a value of ≥ 2.3. Weighted generalized linear models (GLMs) were used to investigate the relationship between depression and IR. Stratified analyses were used to evaluate the potential moderators.

RESULTS

After adjusting for demographic factors and metabolic indicators, the results of GLMs analysis showed that moderate-to-severe depression significantly increased the odds of IR (OR = 1.65, 95 % CI: 1.04-2.61, p = 0.035), especially in non-Hispanic White individuals (OR = 2.64, 95 % CI: 1.39-5.00, p = 0.004). Antidepressant use also reduced this association.

CONCLUSION

Moderate-to-severe depression was significantly associated with IR, and race/ethnicity and antidepressant use were important moderators. These findings underscore the need for targeted interventions to address both mental and metabolic health risks in high-risk populations.

Association of TyG Index and TG/HDL-C Ratio with Trajectories of Depressive Symptoms: Evidence from China Health and Retirement Longitudinal Study

OBJECTIVES

To explore whether the triglyceride-glucose (TyG) index and the triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio are associated with the trajectories of depressive symptoms.

METHODS

In this longitudinal study, 4215 participants aged 45 years and older were recruited from the China Health and Retirement Longitudinal Study from 2011 to 2018. The trajectories of depressive symptoms, measured by the 10-item Center for Epidemiologic Studies Depression Scale (CESD-10), were identified using group-based trajectory modeling. Multinomial logistic models and restricted cubic spline analysis were used to investigate the relationships between the TyG index and the TG/HDL-C ratio and the trajectories of depressive symptoms. Stratified analyses were conducted based on sex, age, place of residence, and body mass index (BMI).

RESULTS

Five distinct trajectories of depressive symptoms characterized by stable low, stable moderate, decreasing, increasing, and stable high were identified during a follow-up of 7 years. The associations of the TyG index and the TG/HDL-C ratio with trajectories of depressive symptoms are not entirely consistent. After adjusting for covariates, a higher TyG index at baseline was associated with lower odds of being on the decreasing trajectory of depressive symptoms (ORad = 0.61, 95% CI: 0.40-0.92) compared to the stable low trajectory, and restricted cubic spline analysis revealed a negative linear relationship between the TyG index and the likelihood of a decreasing trajectory of depressive symptoms. However, the relationship between the TG/HDL-C ratio and the decreasing trajectory of depressive symptoms was no longer statistically significant when all confounders were controlled (ORad = 0.72, 95% CI: 0.50-1.04). Additionally, this negative association between the TyG index and decreasing trajectory of depressive symptoms was observed among 45-64-year-old individuals, female participants, those living in rural areas, and those with a normal BMI.

LIMITATIONS

This study was conducted in a middle-aged and elderly population in China, and extrapolation to other regions and populations requires further confirmation.

CONCLUSIONS

Compared to the TG/HDL-C ratio, the TyG index may be a better predictor for trajectories of depressive symptoms in middle-aged and older adults. Considering that the pathology of depression progresses long term, our findings may have utility for identifying available and reliable markers for the development of depression.

Gender differences in the relationship between depressive symptoms and diabetes associated with cognitive-affective symptoms

BACKGROUND

Despite the frequent co-occurrence of depression and diabetes, gender differences in their relationship remain unclear.

AIMS

This exploratory study examined if gender modifies the association between depressive symptoms, prediabetes and diabetes with cognitive-affective and somatic depressive symptom clusters.

METHOD

Cross-sectional analyses were conducted on 29 619 participants from the 2007-2018 National Health and Nutrition Examination Survey. Depressive symptoms were measured by the nine-item Patient Health Questionnaire. Multiple logistic regression was used to analyse the relationship between depressive symptoms and diabetes. Multiple linear regression was used to analyse the relationship between depressive symptom clusters and diabetes.

RESULTS

The odds of having depressive symptoms were greater in those with diabetes compared to those without. Similarly, total symptom cluster scores were higher in participants with diabetes. Statistically significant diabetes-gender interactions were found in the cognitive-affective symptom cluster model. Mean cognitive-affective symptom scores were higher for females with diabetes (coefficient = 0.23, CI: 0.10, 0.36, P = 0.001) than males with diabetes (coefficient = -0.05, CI: -0.16, 0.07, P = 0.434) when compared to the non-diabetic groups.

CONCLUSIONS

Diabetes was associated with higher cognitive-affective symptom scores in females than in males. Future studies should examine gender differences in causal pathways and how diabetic states interact with gender and influence symptom profiles.

Role of Peripheral and Central Insulin Resistance in Neuropsychiatric Disorders

Insulin acts on different organs, including the brain, which helps it regulate energy metabolism. Insulin signaling plays an important role in the function of different cell types. In this review, we have summarized the key roles of insulin and insulin receptors in healthy brains and in different brain disorders. Insulin signaling, as well as insulin resistance (IR), is a major contributor in the regulation of mood, behavior, and cognition. Recent evidence showed that both peripheral and central insulin resistance play a role in the pathophysiology, clinical presentation, and management of neuropsychiatric disorders like Cognitive Impairment/Dementia, Depression, and Schizophrenia. Many human studies point out Insulin Resistance/Metabolic Syndrome can increase the risk of dementia especially Alzheimer's dementia (AD). IR has been shown to play a role in AD development but also in its progression. This review article discusses the pathophysiological pathways and mechanisms of insulin resistance in major neuropsychiatric disorders. The extent of insulin resistance can be quantified using IR biomarkers like insulin levels, HOMA-IR index, and Triglyceride glucose-body mass index (TyG-BMI) levels. IR has been shown to precede neurodegeneration. Human trials showed current treatment with certain antidiabetic drugs, as well as life style management, like weight loss and exercise for IR, have shown promise in the management of cognitive/neuropsychiatric disorders. This may pave the pathway to the development of new therapeutic approaches to these challenging disorders of dementia and psychiatric diseases. Recent clinical trials are showing some encouraging evidence for these pharmacological and nonpharmacological approaches for IR in psychiatric and cognitive disorders, even though more research is needed to apply this evidence into clinical practice. Early identification and management of IR may help as a strategy to potentially alter neuropsychiatric disorders onset as well as its progression.

The association between lipid accumulation products and depression in U.S. adults: A cross-sectional study from NHANES 2005-2018

OBJECTIVE

The purpose of this study was to investigate the correlation between lipid accumulation products (LAP) and depression among adults in the United States.

METHODS

We analyzed data from 13,051 persons participating in the NHANES 2005-2018 cycle. The LAP index was calculated using the waist circumference (WC) and serum triglyceride (TG) levels, which reflect lipid toxicity. Participants who scored ≥10 on the Patient Health Questionnaire-9 (PHQ-9) were considered depressed. Multivariate logistic regression analyses were conducted to explore the association between the LAP index and depression. Subgroup analysis was also conducted to identify sensitive populations. Smoothed curve fitting and generalized additive model (GAM) regression were performed to verify the association between the LAP index and depression.

RESULTS

After adjusting for all potential confounders, the risk of depression increased with increasing LAP index (odds ratio [OR]=1.0011, 95% confidence interval [CI]= 1.0001-1.0021). Compared to participants in LAP quartile 1, participants in LAP quartile 3 exhibited the highest risk for depression (OR=1.43, 95% CI: 1.03-1.99). Subgroup analysis demonstrated a stronger association between the LAP index and depression in men (OR= 1.002, 95% CI= 1.001-1.004) and in those with hypertension (OR=1.002, 95% CI=1.000-1.003). Additionally, smoothed curve fitting and GAM regression demonstrated a positive linear correlation between the LAP index and depression.

CONCLUSIONS

These findings suggest that individuals with a higher LAP index may be at greater risk for depression, particularly among men and those with hypertension. Further studies are required to confirm these findings.

The relationship between depression and lipid accumulation product: a population-based study

Background

Lipid Accumulation Product (LAP) is a new type of obesity index. The relationship between LAP and depression is unclear, and this cross-sectional study was conducted to explore the relationship between LAP and depression using the National Health and Nutrition Examination Survey (NHANES) database from 2005-2018.

Methods

In our study, logistic regression analysis was used to calculate the odds ratio between depression and LAP, and subgroup analysis and sensitivity analysis were also performed to verify the robustness of the results.

Results

The analysis included 13,240 participants aged 20 years or older. After adjusting for multiple variables, LAP was positively associated with depression, OR 1. 50 (95% CI, 1. 05-2. 12). In subgroup analysis, LAP was significantly positively, associated with depression among male (2. 52, OR; 95% CI, 1. 39,4. 57), non-Hispanic Black (2. 55, OR; 95% CI, 1. 49,4. 36), those without diabetes (1. 67, OR; 95% CI, (1. 06,2. 61) or in the overweight (2. 09, OR; 95% CI, (1. 23,3. 54) subgroups. After inverse probability of treatment weighting (IPTW), the OR for the highest versus lowest quartile was 1. 55 (95% CI: 1. 24 - 1. 95).

Conclusion

There are positive results between LAP and depression after adjusting for multiple potential variables, and prospective studies are needed to verify the results.

Insulin Resistance/Hyperinsulinemia as an Independent Risk Factor That Has Been Overlooked for Too Long

Unfortunately, cardiovascular diseases and cancers are still the leading causes of death in developed and developing countries despite the considerable progress made in the prevention and treatment of diseases. Maybe we missed something? Insulin resistance (IR) with associated hyperinsulinemia (Hypein) is a silent pandemic whose prevalence is continually growing in developed and developing countries, now exceeding 51% of the general population. IR/Hypein, despite the vast scientific literature supporting its adverse action on the development of type 2 diabetes, cardiovascular alterations, tumors, neurological disorders, and cellular senescence, is not yet considered an independent risk factor and, therefore, is not screened in the general population and adequately treated. There are now numerous substances, drugs, and natural substances that, in association with the correction of a wrong lifestyle, can help to reduce IR/Hypein. We are convinced that the time has come to implement a prevention plan against this critical risk factor. Therefore, this manuscript aims to highlight IR/Hypein as an independent risk factor for type 2 diabetes, cardiovascular diseases, cancers, cellular senescence, and neuropsychiatric disorders, supporting our conviction with the available scientific literature on the topic.

Insulinemic potential of lifestyle is associated with depression and anxiety in adults: A large community-based study

BACKGROUND

We aimed to investigate the association between an empirical lifestyle index for hyperinsulinemia (ELIH), empirical lifestyle index for insulin resistance (ELIR), and depression and anxiety in an adult Iranian population.

METHODS

In this cross-sectional study, a total of 6450 participants, aged 35-65 years were recruited as part of the MASHAD cohort study. Dietary intakes were assessed using a validated food frequency questionnaire (FFQ). Depression and anxiety were screened using Beck Depression Inventory (BDI) and Beck Anxiety Inventory (BAI). ELIH and ELIR were calculated using dietary intake, body mass index, and physical activity information. Multivariable ordinal logistic regression models were applied to determine the association between ELIH, ELIR, and depression and anxiety severity.

RESULTS

In a fully adjusted model, participants with the highest ELIH quartile had a higher odds of more severe depression and anxiety compared to those in the lowest category (OR = 1.44; 95 % CI = 1.22-1.71 and OR = 1.62; 95 % CI = 1.37-1.25, respectively). Participants with the highest ELIR had higher odds of more severe depression and anxiety compared to those in the lowest category (OR = 1.22; 95 % CI = 1.04-1.43 and OR = 1.21; 95 % CI = 1.03-1.42, respectively).

LIMITATIONS

The assessment of dietary intake and mental health by questionnaires may increases the rate of misclassification. Due to the study's cross-sectional nature, causal relationships cannot be established.

CONCLUSION

There was a significant positive association between the hyperinsulinemia and insulin resistance potential of lifestyle and severity of depression and anxiety among Iranian adults.

Metabolic underpinnings of cancer-related fatigue

Cancer-related fatigue (CRF) is one of the most prevalent and detrimental complications of cancer. Emerging evidence suggests that obesity and insulin resistance are associated with CRF occurrence and severity in cancer patients and survivors. In this narrative review, we analyzed recent studies including both preclinical and clinical research on the relationship between obesity and/or insulin resistance and CRF. We also describe potential mechanisms for these relationships, though with the caveat that because the mechanisms underlying CRF are incompletely understood, the mechanisms mediating the association between obesity/insulin resistance and CRF are similarly incompletely delineated. The data suggest that, in addition to their effects to worsen CRF by directly promoting tumor growth and metastasis, obesity and insulin resistance may also contribute to CRF by inducing chronic inflammation, neuroendocrinological disturbance, and metabolic alterations. Furthermore, studies suggest that patients with obesity and insulin resistance experience more cancer-induced pain and are at more risk of emotional and behavioral disruptions correlated with CRF. However, other studies implied a potentially paradoxical impact of obesity and insulin resistance to reduce CRF symptoms. Despite the need for further investigation utilizing interventions to directly elucidate the mechanisms of cancer-related fatigue, current evidence demonstrates a correlation between obesity and/or insulin resistance and CRF, and suggests potential therapeutics for CRF by targeting obesity and/or obesity-related mediators.

Understanding Mental Health Challenges in Cardiovascular Care

There is a profound link between cardiovascular health and mental well-being. This narrative review shows that heart and mental health are not isolated domains but deeply interconnected, influencing each other. It describes how cardiovascular diseases (CVDs) can cause mental health issues such as stress, anxiety, and depression. It also explains how these mental conditions can, in turn, worsen or raise the risk of CVDs. In addition, it emphasizes the necessity of a holistic approach to healthcare that integrates the treatment of physical symptoms of CVDs with interventions aimed at addressing mental health issues. This approach advocates for comprehensive care strategies that include psychotherapy, pharmacological treatments, lifestyle modifications, and digital health technologies. It also highlights the significant role of family and social support in recovery and discusses barriers to integrating mental health care in cardiovascular treatment. The article argues for a paradigm shift in healthcare towards more inclusive and integrated care models. The authors hope to foster a healthcare environment that prioritizes holistic care by increasing awareness about the connection between heart and mind. The call to action includes policy changes and healthcare system reforms aimed at facilitating the integration of mental health services into cardiovascular care, ultimately leading to improved outcomes for patients with CVDs and associated mental health issues.

A review on linking stress, depression, and insulin resistance via low-grade chronic inflammation

Stress is a disturbance in homeostasis caused by psychological, physiological, or environmental factors. Prolonged reactions to chronic stress can be detrimental, resulting in various metabolic abnormalities, referred to as metabolic syndrome (MS). There is a reciprocal increased risk between MS and major depressive disorder. Recent studies established an association between inflammation and insulin signaling in type 2 diabetes mellitus with depression. In the present review, we discuss chronic low-grade inflammation, pathways of insulin resistance, and brain glucose metabolism in the context of neuroinflammation and depression. Specific attention is given to psychotropic drugs such as bupropion, mirtazapine, and nefazodone, anti-inflammatory drugs like Celecoxib (COX-2 inhibitor), Etanercept, adalimumab, IL-4Ra antagonist, Anti-IL- 17A antibody (Ixekizumab) and lifestyle modifications including exercise, dietary changes, and sleep hygiene. These therapeutic solutions offer potential in treating depression by targeting metabolic conditions like insulin resistance and inflammatory pathways. The article further explains the significance of a nutrition and antioxidants-rich diet, emphasizing the role of omega-3 fatty acids, vitamin D, zinc, and polyphenols, to improve immunity and activate anti-inflammatory signaling pathways.

Assessment of depression and anxiety in young and old with a question-based computational language approach

Middle aged adults experience depression and anxiety differently than younger adults. Age may affect life circumstances, depending on accessibility of social connections, jobs, physical health, etc, as these factors influence the prevalence and symptomatology. Depression and anxiety are typically measured using rating scales; however, recent research suggests that such symptoms can be assessed by open-ended questions that are analysed by question-based computational language assessments (QCLA). Here, we study middle aged and younger adults' responses about their mental health using open-ended questions and rating scales about their mental health. We then analyse their responses with computational methods based on natural language processing (NLP). The results demonstrate that: (1) middle aged adults describe their mental health differently compared to younger adults; (2) where, for example, middle aged adults emphasise depression and loneliness whereas young adults list anxiety and financial concerns; (3) different semantic models are warranted for younger and middle aged adults; (4) compared to young participants, the middle aged participants described their mental health more accurately with words; (5) middle-aged adults have better mental health than younger adults as measured by semantic measures. In conclusion, NLP combined with machine learning methods may provide new opportunities to identify, model, and describe mental health in middle aged and younger adults and could possibly be applied to the older adults in future research. These semantic measures may provide ecological validity and aid the assessment of mental health.

Resveratrol, Endocrine Disrupting Chemicals, Neurodegenerative Diseases and Depression: Genes, Transcription Factors, microRNAs, and Sponges Involved

We aimed to examine the molecular basis of the positive effect of resveratrol against amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD), cognitive impairment (CI), and depression induced by a mixture of bisphenol A (BPA), BPS, and BPF. The CTD, GeneMania, Metascape, SwissADME, Cytoscape, MIENTURNET, miRNAsong, and Autodock Vina were the fundamental tools for analysis. Resveratrol exerts its protective effects on selected diseases induced by a mixture of BPA, BPS, and BPF through the following genes: PTGS2 and GSR for ALS; INS, IL6, BDNF, and SOD1 for PD; BDNF, CASP3, TNF, INS, IGF1, IL1B for CI; and BDNF, PTGS2, and IL6 for depression. Detoxification was noted as the most important for ALS, dopamine metabolism for PD, apoptosis for CI, and the selenium micronutrient network for depression. hsa-miR-377-3p, hsa-miR-1-3p, hsa-miR-128-3p, and hsa-miR-204-5p were highlighted. We created and tested in silico sponges that inhibited these miRNAs. NFE2L2, BACH1, PPARG, and NR4A3 were listed as the key transcription factors implicated in resveratrol's protective effect against harmful studied chemicals. Furthermore, resveratrol's physicochemical properties and pharmacokinetics are consistent with its therapeutic benefits in ALS, PD, CI, and depression, owing to its high gastrointestinal absorption, drug-likeness, non-P-glycoprotein substrate, and capacity to penetrate the blood-brain barrier.

The role of exercise in the treatment of depression: biological underpinnings and clinical outcomes

Globally, depression is a leading cause of disability and has remained so for decades. Antidepressant medications have suboptimal outcomes and are too frequently associated with side effects, highlighting the need for alternative treatment options. Although primarily known for its robust physical health benefits, exercise is increasingly recognized for its mental health and antidepressant benefits. Empirical evidence indicates that exercise is effective in treating individuals with depression; however, the mechanisms by which exercise exerts anti-depressant effects are not fully understood. Acute bouts of exercise have been shown to transiently modulate circulating levels of serotonin and norepinephrine, brain-derived neurotrophic factor, and a variety of immuno-inflammatory mechanisms in clinical cohorts with depression. However, exercise training has not been demonstrated to consistently modulate such mechanisms, and evidence linking these putative mechanisms and reductions in depression is lacking. The complexity of the biological underpinnings of depression coupled with the intricate molecular cascade induced by exercise are significant obstacles in the attempt to disentangle exercise's effects on depression. Notwithstanding our limited understanding of these effects, clinical evidence uniformly argues for the use of exercise to treat depression. Regrettably, exercise remains underutilized despite being an accessible, low-cost alternative/adjunctive intervention that can simultaneously reduce depression and improve overall health. To address the gaps in our understanding of the clinical and molecular effects of exercise on depression, we propose a model that leverages systems biology and multidisciplinary team science with a large-scale public health investment. Until the science matches the scale of complexity and burden posed by depression, our ability to advance knowledge and treatment will continue to be plagued by fragmented, irreproducible mechanistic findings and no guidelines for standards of care.

The metabolic regulator USF-1 is involved in the control of affective behaviour in mice

Epidemiological studies indicate a bidirectional association between metabolic disturbances, including obesity and related pathological states, and mood disorders, most prominently major depression. However, the biological mechanisms mediating the comorbid relationship between the deranged metabolic and mood states remain incompletely understood. Here, we tested the hypothesis that the enhanced activation of brown fat tissue (BAT), known to beneficially regulate obesity and accompanying dysfunctional metabolic states, is also paralleled by an alteration of affective behaviour. We used upstream stimulatory factor 1 (USF-1) knock-out (KO) mice as a genetic model of constitutively activated BAT and positive cardiometabolic traits and found a reduction of depression-like and anxiety-like behaviours associated with USF-1 deficiency. Surgical removal of interscapular BAT did not impact the behavioural phenotype of USF-1 KO mice. Further, the absence of USF-1 did not lead to alterations of adult hippocampal neural progenitor cell proliferation, differentiation, or survival. RNA-seq analysis characterised the molecular signature of USF-1 deficiency in the hippocampus and revealed a significant increase in the expression of several members of the X-linked lymphocyte-regulated (xlr) genes, including xlr3b and xlr4b. Xlr genes are the mouse orthologues of the human FAM9 gene family and are implicated in the regulation of dendritic branching, dendritic spine number and morphology. The transcriptional changes were associated with morphological alterations in hippocampal neurons, manifested in reduced dendritic length and complexity in USF-1 KO mice. Collectively these data suggest that the metabolic regulator USF-1 is involved in the control of affective behaviour in mice and that this modulation of mood states is unrelated to USF-1-dependent BAT activation, but reflected in structural changes in the brain.

Depression status and insulin resistance in adults with obesity: A cross-sectional study

OBJECTIVE

Insulin resistance (IR) frequently co-occurs with depression, but inconsistent associations between IR and depression have been reported, and less is known about the association in obesity, a major risk factor for both IR and depression. Thus the association between depression status and IR in a nationally representative sample of the US adults with obesity was evaluated.

METHODS

This cross-sectional study involved 3507 adults with obesity from National Health and Nutrition Examination Survey from 2005 to 2016. The homeostasis model assessment of insulin resistance (HOMA-IR) was used, where IR was defined as a HOMA-IR value greater than its 75^th percentile. The Patient Health Questionnaire 9 was used to assess the depression status. Multivariate logistic regression model was applied to evaluate the association between depression status and IR.

RESULTS

The cut-off value of HOMA-IR in adults with obesity was 5.5, and the prevalence of IR was 26.3% in men, 19.8% in women. The association of depression status with IR depended upon gender (P for depression status by gender interaction = 0.04). Depression status was positively associated with IR in women (P = 0.01), where the ORs (95% CIs) for the risk of IR in the mild, moderate, severe depression status were 1.79 (1.21-2.64), 1.95 (1.10-3.45), and 2.21 (1.04-4.71), respectively (P for trend = 0.002). No association was found in men (P = 0.91).

CONCLUSION

Positive association between IR and depression status was identified in women with obesity, where the risk of IR increased with the level of depression status, while no association was found in men with obesity.

Hyperinsulinemia Associated Depression

Hyperinsulinemia promotes fat accumulation, causing obesity. Being an inflammatory state, obesity can induce further inflammation and is a risk factor for HPA (hypothalamic pituitary axis) dysregulation through hypercortisolism-related hyperglycemia. In another hypothesis, the sympathetic nervous system (SNS) plays a significant role in the regulation of hormone secretion from the pancreas such as an increase in catecholamines and glucagon as well as a decrease in plasma insulin levels, a disruption on SNS activity increases insulin levels, and induces glycogenolysis in the liver and lipolysis in adipose tissue during hypoglycemia. Hyperglycemia-hyperinsulinemia exacerbates inflammation and increases the oxidative stress along with regulating the levels of norepinephrine in the brain sympathetic system. Increased inflammatory cytokines have also been shown to disrupt neurotransmitter metabolism and synaptic plasticity which play a role in the development of depression via inhibiting serotonin, dopamine, melatonin, and glutamate signaling. An increased level of plasma insulin over time in the absence of exercising causes accumulation of lipid droplets in hepatocytes and striated muscles thus preventing the movement of glucose transporters shown to result in an increase in insulin resistance due to obesity and further culminates into depression. Further hyperinsulinemia-hyperglycemia condition arising due to exogenous insulin supplementation for diabetes management may also lead to physiological hyperinsulinemia associated depression. Triple therapy with SSRI, bupropion, and cognitive behavioral therapy aids in improving glycemic control, lowering fasting blood glucose, decreasing the chances of relapse, as well as decreasing cortisol levels to improve cognition and the underlying depression. Restoring the gut microbiota has also been shown to restore insulin sensitivity and reduce anxiety and depression symptoms in patients.

Mental health and quality of life in different obesity phenotypes: a systematic review

Objectives

It has been suggested that obesity phenotypes are related to mental health problems and health-related quality of life (HRQoL). However, there is no certain consensus. This systematic review aimed to evaluate the association between different obesity phenotypes with common psychiatric symptoms and HRQoL.

Methods

Electronic databases i.e. PubMed, Scopus, EMBASE, and google scholar were searched until September 2021, to identify studies that investigated associations between the obesity phenotypes with psychiatric symptoms and/or mental and physical HRQoL. Two researchers independently checked titles and abstracts, evaluated full-text studies, extracted data, and appraised their quality using the Newcastle–Ottawa Scale.

Results

Eighteen studies, with a total of 3,929,203 participants, were included. Of the studies included in this systematic review, 10 articles evaluated the association between obesity phenotypes and psychiatric symptoms, while six papers investigated the association between HRQoL and obesity phenotypes, and two studies assessed both. As a whole, the findings of these studies suggest that obese individuals with a favorable metabolic profile have a slightly higher risk of mental health problems and poor quality of life, however, the risk becomes larger when obesity is combined with an adverse metabolic profile. So, metabolically healthy obesity may not be a completely benign condition in relation to mental disorders and poor quality of life.

Conclusion

According to published research, obesity is likely to increase the risk of mental health problems and poor quality of life when metabolic disturbances are present.

SNP and Haplotype Regional Heritability Mapping (SNHap-RHM): Joint Mapping of Common and Rare Variation Affecting Complex Traits

We describe a genome-wide analytical approach, SNP and Haplotype Regional Heritability Mapping (SNHap-RHM), that provides regional estimates of the heritability across locally defined regions in the genome. This approach utilises relationship matrices that are based on sharing of SNP and haplotype alleles at local haplotype blocks delimited by recombination boundaries in the genome. We implemented the approach on simulated data and show that the haplotype-based regional GRMs capture variation that is complementary to that captured by SNP-based regional GRMs, and thus justifying the fitting of the two GRMs jointly in a single analysis (SNHap-RHM). SNHap-RHM captures regions in the genome contributing to the phenotypic variation that existing genome-wide analysis methods may fail to capture. We further demonstrate that there are real benefits to be gained from this approach by applying it to real data from about 20,000 individuals from the Generation Scotland: Scottish Family Health Study. We analysed height and major depressive disorder (MDD). We identified seven genomic regions that are genome-wide significant for height, and three regions significant at a suggestive threshold (p-value < 1 × 10-5) for MDD. These significant regions have genes mapped to within 400 kb of them. The genes mapped for height have been reported to be associated with height in humans. Similarly, those mapped for MDD have been reported to be associated with major depressive disorder and other psychiatry phenotypes. The results show that SNHap-RHM presents an exciting new opportunity to analyse complex traits by allowing the joint mapping of novel genomic regions tagged by either SNPs or haplotypes, potentially leading to the recovery of some of the "missing" heritability.

The Association of Metabolic Dysfunction and Mood Across Lifespan Interacts With the Default Mode Network Functional Connectivity

Background: Numerous studies suggest a relationship between depression and metabolic syndrome, which is likely influenced by age. Interestingly, functional imaging analysis has shown an association between functional connectivity in the default mode network (DMN-FC) and components of metabolic syndrome, which is explored in this study.

Methods: From a larger longitudinal cohort study on healthy aging, 943 individuals were extensively characterized for mood and cognition. Among these, 120 individuals who were selected for displaying extreme cognitive performance within the normal range (good and poor performers) were further studied. Here, in a cross-sectional design, using confirmatory factor analysis (CFA), the association between metabolic dysfunction and depressive mood as a function of age and its relationship with DMN-FC was studied.

Results: Metabolic dysfunction was modeled as a second-order latent variable using CFA. First-order latent variables were obesity, glucose dysmetabolism, lipids imbalance, and blood pressure. Using multiple linear regression models, this study observed that metabolic dysfunction, glucose dysmetabolism, and lipids imbalance were linearly associated with depressive mood, and the association with obesity was U-shaped. The association of metabolic dysfunction, obesity, and glucose dysmetabolism with depressive mood is positive for the younger individuals in our sample and vanishes with aging. The FC of the right superior temporal gyrus with the DMN correlated with both obesity and depressive mood. In participants with higher obesity scores, FC increased with higher GDS scores, while in those with lower GDS scores, FC decreased. Age and blood pressure were associated with a more complex pattern of association between FC of the right supramarginal gyrus and GDS score.

Conclusion: The association of metabolic dysfunction with depressive mood is influenced by age and relates with differential patterns of DMN-FC. The combination of the effects of age, mood, and metabolic dysfunction is likely to explain the heterogeneity of DMN-FC, which deserves further investigation with larger and longitudinal studies.

Depressive symptoms in Chinese adults with risk factors for diabetes: the Shanghai High-Risk Diabetic Screen (SHiDS) study

AIMS

To evaluate the relationship between newly diagnosed diabetes or prediabetes and depressive symptoms among individuals with risk factors for diabetes in China. We also investigated the associations of depressive symptoms with pancreatic β-cell function and insulin resistance.

METHODS

We used cross-sectional data from the Shanghai High-Risk Diabetic Screen (SHiDS) project. Between 2014 and 2017, a total of 1728 participants were enrolled in this study and underwent an oral glucose tolerance test to screen for diabetes and prediabetes. Insulin resistance was evaluated using the homeostatic model assessment of insulin resistance and the modified Matsuda index. Pancreatic β-cell function was calculated using the homeostatic model assessment of β-cell function, Stumvoll first- and second-phase indexes. Elevated depressive symptoms were determined using the Patient Health Questionnaire-9 (PHQ-9 score ≥ 10).

RESULTS

The prevalence of elevated depressive symptoms in the total study population was 4.8% (83 of 1728). Compared with the normal glucose tolerance group, individuals with newly diagnosed diabetes were less likely to have elevated depressive symptoms even after controlling for potential confounders [adjusted odds ratio (OR) 0.35, 95% confidence interval (CI) 0.18-0.68; P = 0.002]. However, prediabetes was not associated with depressive symptoms. The odds for elevated depressive symptoms were increased in individuals with higher levels of the Stumvoll first-phase index. No association was observed between depressive symptoms and insulin resistance.

CONCLUSION

Elevated depressive symptoms were less prevalent in Chinese individuals with newly diagnosed diabetes among a high-risk population for diabetes.

Linking atypical depression and insulin resistance-related disorders via low-grade chronic inflammation: Integrating the phenotypic, molecular and neuroanatomical dimensions

Insulin resistance (IR) and related disorders, such as T2DM, increase the risk of major depressive disorder (MDD) and vice versa. Current evidence indicates that psychological stress and overeating can induce chronic low-grade inflammation that can interfere with glutamate metabolism in MDD as well as insulin signaling, particularly in the atypical subtype. Here we first review the interactive role of inflammatory processes in the development of MDD, IR and related metabolic disorders. Next, we describe the role of the anterior cingulate cortex in the pathophysiology of MDD and IR-related disorders. Furthermore, we outline how specific clinical features of atypical depression, such as hyperphagia, are more associated with inflammation and IR-related disorders. Finally, we examine the regional specificity of the effects of inflammation on the brain that show an overlap with the functional and morphometric brain patterns activated in MDD and IR-related disorders.

Insulin resistance is associated with deficits in hedonic, self-reported cognitive, and psychosocial functional response to antidepressant treatment in individuals with major depressive disorder

BACKGROUND

To assess the effect of insulin resistance (IR) on treatment response to the antidepressant, vortioxetine, in patients with Major Depressive Disorder (MDD).

METHODS

This is a secondary analysis of an 8-week, open-label clinical trial. Ninety-five adults in a primary care setting experiencing a major depressive episode were included. Response to vortioxetine was measured using the THINC-integrated tool, Montgomery Åsberg Depression Rating Scale (MADRS), the Snaith-Hamilton Pleasure Scale (SHAPS), the Perceived Deficits Questionnaire (PDQ-5), and the Sheehan Disability Scale (SDS). Generalized estimating equation models were utilized for data analysis.

RESULTS

When adjusted for age, gender, dose, and BMI, there was a significant baseline IR by time interaction for SHAPS (p = 0.022), PDQ-5 (p = 0.037), and SDS (p = 0.013). Higher baseline IR predicted decreased early improvements in anhedonia. It also predicted poorer subjective assessments of cognition and increased functional impairment at the endpoint of treatment. For functional capacity (i.e. SDS) other covariates including severity of symptoms, illness course, other metabolic factors (e.g. cholesterol), and physical activity were included with no changes to the moderating effect of baseline IR.

LIMITATIONS

This was a post-hoc analysis of a primarily non-diabetic sample. Also, only one agent was assessed.

CONCLUSIONS

IR was a predictor of response to vortioxetine. This persisted after controlling for other factors including, but not limited to, BMI. These findings strengthen the link between depression and IR and may point to another novel metabolic predictor of response. These findings should be replicated using other antidepressants.

Why are Women With Polycystic Ovary Syndrome at Increased Risk of Depression? Exploring the Etiological Maze

Polycystic ovary syndrome (PCOS) is a complex and common multisystemic disorder. Women with PCOS have up to eight times higher prevalence of depression than control groups. This paper aims to explore the underlying risk factors for developing depression in this high-risk group. Studies indicate an interplay of multiple mechanisms that place women with PCOS at an increased risk for depression. The pathophysiology thought to play a role includes disturbances in the endocrine axes and changes to the metabolic pathway. The risk of depression is independently linked to insulin resistance and obesity in this population. However, rates of depression were still higher than control groups when accounting for these variables, demonstrating that they are not the only mechanism causing depression. The clinical manifestations of hyperandrogenism and menstrual abnormalities may compound negative views and lower self-esteem and negatively impact mood. Many of these women also struggle with infertility, and due to the added external pressures like societal beliefs and culture, they may be further negatively impacted and worsen their depressive symptoms. The prevalence of depression in women with PCOS is high; thus, this paper highlights the essential understanding of the underlying mechanisms at play. This is to better aid in addressing the fundamental cause of depression in this high-risk group effectively.

Association Between Pittsburgh Sleep Quality Index and Depressive Symptoms in Chinese Resident Physicians

Background: Previous studies have suggested that sleep quality is associated with depressive symptoms. However, associations between overall sleep quality and depressive symptoms in Chinese resident physicians remain unclear. Therefore, we aimed to determine whether overall sleep quality is associated with depressive symptoms in Chinese resident physicians. Methods: This cross-sectional study included 1,230 resident physicians. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Depressive symptoms were assessed using the Patient Health Questionnaire-9 (PHQ-9). Logistic regression analysis was applied to estimate the associations between the PSQI and PHQ-9. Results: Among all participants, the prevalence of mild (PHQ-9 ≥ 5) and moderate or severe (PHQ-9 ≥ 10) depressive symptoms were 48.28 and 12.93%, respectively. PSQI score was positively associated with PHQ-9 score before and after adjustments of socio-demographic, behavioral, and psychologic confounding factors (all P < 0.0001). After adjustments, the regression coefficients (standard error) between PSQI scores and PHQ-9 scores were 0.95 (0.04), 0.88 (0.09), and 0.96 (0.05) in all participants, men, and women, respectively. Compared to physicians with good sleep quality (PSQI scores ≤ 5), the adjusted odds ratios (ORs) [95% confidence intervals (CIs)] for mild (PHQ-9 ≥ 5) and moderate or severe (PHQ-9 ≥ 10) depressive symptoms in physicians with poor sleep quality were 7.15 (5.44, 9.46) and 6.17 (4.03, 9.71) in all participants, respectively. Conclusions: Our findings suggest that poor sleep quality was associated with a higher prevalence of depressive symptoms in Chinese resident physicians.

Association between depression and nonalcoholic fatty liver disease: Contributions of insulin resistance and inflammation

BACKGROUND

It is unclear whether depression is linked to nonalcoholic fatty liver disease (NAFLD). The purpose of this study was to examine the association between depression and NAFLD and whether the association is partly explained by insulin resistance or inflammation.

METHODS

Subjects consisted of 4,688 adults who participated in the 2016 Korea National Health and Nutrition Examination Survey. Depression was defined by Patient Health Questionnaire-9 score ≥ 10 or a previous diagnosis of depression. NAFLD was defined by hepatic steatosis index >36. Insulin resistance was assessed by triglycerides and glucose (TyG) index. Inflammation was measured with C-reactive protein (CRP).

RESULTS

Depression had a significant association with TyG index (p = 0.005), but not with CRP. Depression was a significant predictor of NAFLD (OR = 1.63; 95% CI, 1.26-2.10; p < 0.001). Adjustment for sociodemographic features and waist circumference did not substantially affect the results. Further adjustment for comorbidities reduced the estimate for depression by 23% (OR = 1.56; 95% CI, 1.18-2.06; p = 0.002). Inclusion of CRP in a fully adjusted model did not affect the results. Addition of the TyG index decreased the estimate for depression by 28% (OR = 1.39; 95% CI, 0.88-2.19; p = 0.161), and the resulting estimate became no longer significant. The TyG index remained the independent predictor of outcome.

LIMITATIONS

The absence of a structured diagnostic interview for depression and histological diagnosis of NAFLD.

CONCLUSIONS

These data support an association of depression with NAFLD. Insulin resistance seems to play a major role in modulating the association between depression and NAFLD risk.

Age and leptinemia association with anxiety and depression symptoms in overweight middle-aged women

OBJECTIVE

The aim of the study was to investigate the effect of menopause and of postmenopausal stages on depression and anxiety symptoms, and whether these symptoms associate with anthropometric, metabolic, and hormonal parameters in midlife women.

METHODS

Postmenopausal women (age 50-65), either at early (EPM, n=33) or late (LPM, n = 23) postmenopause, and 23 premenopausal controls (PreM, age 40-50), matched for BMI with the PM groups, were studied. Blood biochemical and hormonal determinations, bioimpedance anthropometry, and depression and anxiety symptoms (Beck's depression [BDI] and anxiety [BAI] inventories) were conducted.

RESULTS

The BAI score was higher in both PM groups than in the PreM group. In contrast, only the LPM group showed a significantly elevated BDI score. All groups presented overweight and abdominal obesity, having similar BMI and waist/hip ratio values. Both PM groups showed insulin resistance, whereas only the LPM group presented decreased skeletal muscle mass and basal metabolic rate. Correlation analysis, including all 79 middle-aged women, showed age, percentage body fat, waist/hip ratio, and leptinemia to correlate positively with the anxiety and depression scores. Multivariate regression showed leptin and age to associate positively with depressive- and anxious-like symptoms.

CONCLUSIONS

Postmenopausal women presented impaired body composition, energy expenditure, insulin sensitivity, and mental symptoms, in comparison to similarly overweight premenopausal women. Among all the overweight midlife women, these symptoms were more strongly associated with age and leptin levels than with reproductive aging itself. The data indicate that, among overweight middle-aged women with abdominal obesity, the aging process and the development of leptin resistance are associated with impairment of mental health.

Impact of Brain Insulin Signaling on Dopamine Function, Food Intake, Reward, and Emotional Behavior

PURPOSE OF REVIEW

Dietary obesity is primarily attributed to an imbalance between food intake and energy expenditure. Adherence to lifestyle interventions reducing weight is typically low. As a result, obesity becomes a chronic state with increased co-morbidities such as insulin resistance and diabetes. We review the effects of brain insulin action and dopaminergic signal transmission on food intake, reward, and mood as well as potential modulations of these systems to counteract the obesity epidemic.

RECENT FINDINGS

Central insulin and dopamine action are interlinked and impact on food intake, reward, and mood. Brain insulin resistance causes hyperphagia, anxiety, and depressive-like behavior and compromises the dopaminergic system. Such effects can induce reduced compliance to medical treatment. Insulin receptor sensitization and dopamine receptor agonists show attenuation of obesity and improvement of mental health in rodents and humans. Modulating brain insulin and dopamine signaling in obese patients can potentially improve therapeutic outcomes.

Genome-wide profiling of DNA methylome and transcriptome in peripheral blood monocytes for major depression: A Monozygotic Discordant Twin Study

DNA methylation plays an important role in major depressive disorder (MDD), but the specific genes and genomic regions associated with MDD remain largely unknown. Here we conducted genome-wide profiling of DNA methylation (Infinium MethylationEPIC BeadChip) and gene expression (RNA-seq) in peripheral blood monocytes from 79 monozygotic twin pairs (mean age 38.2 ± 15.6 years) discordant on lifetime history of MDD to identify differentially methylated regions (DMRs) and differentially expressed genes (DEGs) associated with MDD, followed by replication in brain tissue samples. Integrative DNA methylome and transcriptome analysis and network analysis was performed to identify potential functional epigenetic determinants for MDD. We identified 39 DMRs and 30 DEGs associated with lifetime history of MDD. Some genes were replicated in postmortem brain tissue. Integrative DNA methylome and transcriptome analysis revealed both negative and positive correlations between DNA methylation and gene expression, but the correlation pattern varies greatly by genomic locations. Network analysis revealed distinct gene modules enriched in signaling pathways related to stress responses, neuron apoptosis, insulin receptor signaling, mTOR signaling, and nerve growth factor receptor signaling, suggesting potential functional relevance to MDD. These results demonstrated that altered DNA methylation and gene expression in peripheral blood monocytes are associated with MDD. Our results highlight the utility of using peripheral blood epigenetic markers and demonstrate that a monozygotic discordant co-twin control design can aid in the discovery of novel genes associated with MDD. If validated, the newly identified genes may serve as novel biomarkers or druggable targets for MDD and related disorders.

Acyloxyacyl hydrolase modulates depressive-like behaviors through aryl hydrocarbon receptor

Corticotropin-releasing factor (CRF) regulates stress responses, and aberrant CRF signals are associated with depressive disorders. Crf expression is responsive to arachidonic acid (AA), where CRF is released from the hypothalamic paraventricular nucleus (PVN) to initiate the hypothalamic-pituitary-adrenal axis, culminating in glucocorticoid stress hormone release. Despite this biological and clinical significance, Crf regulation is unclear. Here, we report that acyloxyacyl hydrolase, encoded by Aoah, is expressed in the PVN, and Aoah regulates Crf through the aryl hydrocarbon receptor (AhR). We previously showed that AOAH-deficient mice mimicked interstitial cystitis/bladder pain syndrome, a condition frequently associated with comorbid anxiety and depression. With the use of novelty-suppressed feeding and sucrose preference assays to quantify rodent correlates of anxiety/depression, AOAH-deficient mice exhibited depressive behaviors. AOAH-deficient mice also had increased CNS AA, increased Crf expression in the PVN, and elevated serum corticosterone, consistent with dysfunction of the hypothalamic-pituitary-adrenal axis. The human Crf promoter has putative binding sites for AhR and peroxisome proliferator-activated receptor (PPARγ). PPARγ did not affect AA-dependent Crf expression in vitro, and conditional Pparγ knockout did not alter the AOAH-deficient depressive phenotype, despite previous studies implicating PPARγ as a therapeutic target for depression. In contrast, Crf induction was mediated by AhR binding sites in vitro and increased by AhR overexpression. Furthermore, conditional Ahr knockout rescued the depressive phenotype of AOAH-deficient mice. Finally, an AhR antagonist rescued the AOAH-deficient depressive phenotype. Together, our results demonstrate that Aoah is a novel genetic regulator of Crf mediated through AhR, and AhR is a therapeutic target for depression.

A structural equation modeling approach for the association of a healthy eating index with metabolic syndrome and cardio-metabolic risk factors among obese individuals

Background

Numerous studies have evaluated the association between dietary factors and cardiovascular risk among patients with chronic disease. It is worthwhile to assess these associations in a combination model rather than in an isolated form. In the current study, we aimed to use structural equation modeling (SEM) to assess the association of adherence to a healthy eating index (HEI)-2015 with socio-demographic factors, psychological characteristics, metabolic syndrome (MetS) and other cardio-metabolic risk factors among obese individuals.

Methods

This cross-sectional study was conducted among 188 healthy obese adults (96 males and 92 females) aged 20–50 years in Tabriz. A validated semi-quantitative food frequency questionnaire (FFQ) was used to record dietary intake and to estimate HEI-2015. Anthropometric parameters, blood pressure and biochemical measurements were evaluated according to standard protocols. Interrelationships among socio-demographic parameters and HEI with cardio-metabolic risk factors were analyzed using SEM.

Results

The results of SEM analysis revealed that HEI mediated the association between age and several cardio-metabolic risk factors including fat mass (FM), fat free mass (FFM), systolic blood pressure (SBP) and high-density lipoprotein (HDL) (p < 0.05). Moreover, adherence to Dietary Guidelines for Americans (DGA) appears to mediate association between gender and waist circumference (B = -9.78), SBP (B = -4.83), triglyceride (B = -13.01) and HDL (B = 4.31). HEI also mediated indirect negative effects of socioeconomic status on FM (B = -0.56), FFM (B = -0.25), SBP (B = -0.55) and diastolic blood pressure (DBP) (B = -0.3). Additionally, depression and age had indirect unfavorable effects on some insulin resistance indices such as homeostasis model assessment of insulin resistance (B = 0.07; p<0.05, for age) and quantitative insulin sensitivity check index (p<0.05, for age and depression) via HEI. High adherence to HEI was found to be inversely associated with MetS risk (p<0.05).

Conclusion

Adherence to HEI-2015 seems to mediate the effect of socio-demographic parameters and mental health on cardio-metabolic risk factors as well as MetS risk. Further studies are needed to confirm these findings.

Brain and behavioral correlates of insulin resistance in youth with depression and obesity

Depression, together with insulin resistance, is increasingly prevalent among youth. These conditions have traditionally been compartmentalized, but recent evidence suggests that a shared brain motivational network underlies their co-occurrence. We posit that, in the context of depressive symptoms, insulin resistance is associated with aberrant structure and functional connectivity in the Anterior Cingulate Cortex (ACC) and hippocampus. This motivational neural circuit underlies dysfunctional behavioral responses and increased sensitivity to rewarding aspects of ingesting high calorie food that lead to disinhibition of eating even when satiated. To investigate this shared mechanism, we evaluated a sample of forty-two depressed and overweight (BMI > 85th%) youth aged 9 to 17. Using ACC and hippocampus structural and seed-based regions of interest, we investigated associations between insulin resistance, depression, structure (ACC thickness, and ACC and hippocampal area), and resting-state functional connectivity (RSFC). We predicted that aberrant associations among these neural and behavioral characteristics would be stronger in insulin resistant compared to insulin sensitive youth. We found that youth with greater insulin resistance had higher levels of anhedonia and more food seeking behaviors, reduced hippocampal and ACC volumes, and greater levels of ACC and hippocampal dysconnectivity to fronto-limbic reward networks at rest. For youth with high levels of insulin resistance, thinner ACC and smaller hippocampal volumes were associated with more severe depressive symptoms, whereas the opposite was true for youth with low levels of insulin resistance. The ACC-hippocampal motivational network that subserves depression and insulin resistance separately, may represent a critical neural interaction that link these syndromes together.

Melatonin receptor 1B gene rs10830963 polymorphism, depressive symptoms and glycaemic traits

BACKGROUND

The association between depression and type 2 diabetes is bidirectional. Underlying biological determinants remain elusive. We examined whether a common melatonin receptor 1B gene diabetes risk variant rs10830963 influenced the associations between depressive symptoms and glycaemic traits.

MATERIALS

The Prevalence, Prediction and Prevention of Diabetes-Botnia Study participants (n = 4,455) with no diabetes who underwent an oral glucose tolerance test were genotyped for rs10830963 and completed the Mental Health Inventory on depressive symptoms.

RESULTS

The rs10830963 did not influence significantly the associations between depressive symptoms and glycaemic traits. Yet, the addition of each copy of the minor G allele of the rs1080963 and higher depressive symptoms were both, independent of each other, associated significantly with higher glucose response (glucose area under the curve), higher insulin resistance (Insulin Sensitivity Index) and lower insulin secretion (Disposition Index). Depressive symptoms, but not rs1080963, were also significantly associated with higher fasting insulin, insulin area under the curve and insulin resistance (Homeostasis Model Assessment, Homeostasis Model Assessment-2); rs1080963, but not depressive symptoms, was significantly associated with higher fasting glucose and lower Corrected Insulin Response.

CONCLUSIONS

Our study shows that the diabetes risk variant rs10830963 does not contribute to the known comorbidity between depression and type 2 diabetes. Key messages The association between depression and type 2 diabetes is bidirectional. We tested whether a common variant rs10830963 in the gene encoding Melatonin Receptor 1B influences the known association between depressive symptoms and glycaemic traits in a population-based sample from Western Finland. The MTNR1B genetic diabetes risk variant rs10830963 does not contribute to the known comorbidity between depression and type 2 diabetes. Depressive symptoms and rs10830963 are associated with a worse glycaemic profile independently of each other.

Insulin resistance is associated with depression risk in polycystic ovary syndrome

OBJECTIVE

To test the hypothesis that insulin resistance is associated with depression risk in polycystic ovary syndrome (PCOS).

DESIGN

Secondary analysis of data from a multicenter randomized trial.

SETTING

Multicenter university-based clinical practices.

PATIENT(S)

Seven hundred thirty-eight women with PCOS by modified Rotterdam criteria seeking pregnancy enrolled in a randomized clinical trial comparing clomiphene citrate versus letrozole.

INTERVENTION(S)

The Primary Care Evaluation of Mental Disorders Patient Health Questionnaire was self-administered to identify depression using a validated algorithm at enrollment. Demographic and anthropometric data were collected, and serum assays were performed. Insulin resistance was estimated using the homeostatic model of insulin resistance (HOMA-IR), with a cutoff of >2.2 considered abnormal.

MAIN OUTCOME MEASURE(S)

Demographic, endocrine, and metabolic parameters associated with depression.

RESULT(S)

In a univariate logistic regression analysis, elevated HOMA-IR was associated with 2.3-fold increased odds of depression (odds ratio [OR] = 2.32; 95% confidence interval [CI], 1.28-4.21). This association remained significant after controlling for age and body mass index (adjusted OR [aOR] = 2.23; 95% CI, 1.11-4.46) and in a model including additional potential confounders (aOR = 2.03; 95% CI, 1.00-4.16).

CONCLUSION(S)

Insulin resistance has a strong and independent association with depression in PCOS and may serve as a physiologic mediator. Our findings corroborate a growing body of evidence linking insulin resistance to depressed mood. The association between insulin resistance and depressed mood warrants further investigation to elucidate mechanisms and identify potential therapeutic targets.

Neural and Endocrine Correlates of Early Life Abuse in Youth With Depression and Obesity

Depression and insulin resistance are becoming increasingly prevalent in younger populations. The origin and consequence of insulin resistance in depressed youth may, in part, be rooted in exposure to environmental stressors, such as early life abuse, that may lead to aberrant brain motivational networks mediating maladaptive food-seeking behaviors and insipient insulin resistance. In this paper, we aimed to investigate the impact of early life abuse on the development of insulin resistance in depressed and overweight youth aged 9 to 17 years. We hypothesized that youth with the greatest burden of early life abuse would have the highest levels of insulin resistance and corresponding aberrant reward network connectivities. To test this hypothesis, we evaluated sixty-nine depressed and overweight youth aged 9 to 17, using multimodal assessments of early life abuse, food-seeking behavior, and insulin resistance. Based on results of the Childhood Trauma Questionnaire (CTQ), we separated our study participants into two groups: 35 youth who reported high levels of the sum of emotional, physical, or sexual abuse and 34 youth who reported insignificant or no levels of any abuse. Results of an oral glucose tolerance test (OGTT) and resting state functional connectivity (RSFC), using the amygdala, insula, and nucleus accumbens (NAcc) as seed-based reward network regions of interest, were analyzed for group differences between high abuse and low abuse groups. High abuse youth exhibited differences from low abuse youth in amygdala-precuneus, NAcc-paracingulate gyrus, and NAcc-prefrontal cortex connectivities, that correlated with levels of abuse experienced. The more different their connectivity from of that of low abuse youth, the higher were their fasting glucose and glucose at OGTT endpoint. Importantly, level of abuse moderated the relation between reward network connectivity and OGTT glucose response. In contrast, low abuse youth showed hyperinsulinemia and more insulin resistance than high abuse youth, and their higher OGTT insulin areas under the curve correlated with more negative insula-precuneus connectivity. Our findings suggest distinct neural and endocrine profiles of youth with depression and obesity based on their histories of early life abuse.

The association between depressive symptoms and insulin resistance, inflammation and adiposity in men and women

INTRODUCTION

Depression has been shown to be associated with elevated leptin levels, low-grade inflammation and insulin resistance. These derangements are often measured in mixed gender cohorts despite the different body compositions and hormonal environments of men and women and gender-specific prevalence and responses to depression.

METHODS

A cross-sectional analysis was carried out on a cohort of 639 participants from the ADDITION-Leicester dataset to assess differences in markers of diabetes risk, cardiovascular risk and inflammation in depressed and non-depressed individuals. Depressive symptoms were determined using the WHO (Five) well-being index. Multivariate linear and logistic regression analyses were adjusted for age, sex, ethnicity, body mass index, smoking, social deprivation and activity levels for continuous and binary variables respectively. Further analysis included stratifying the data by gender as well as assessing the interaction between depression and gender by including an interaction term in the model.

RESULTS

Women with depressive symptoms had a 5.3% larger waist circumference (p = 0.003), 28.7% higher HOMA IR levels (p = 0.026), 6.6% higher log-leptin levels (p = 0.01) and 22.37% higher TNF-α levels (p = 0.015) compared with women without. Conversely, depressive symptoms in men were associated with 7.8% lower body fat % (p = 0.015) but 48.7% higher CRP levels (p = 0.031) compared to men without. However, interaction analysis failed to show a significant difference between men and women.

CONCLUSIONS

Depressive symptoms are associated with metabolic derangements. Whilst women tended to show elevations in biomarkers related to an increased risk of type 2 diabetes (HOMA IR, leptin and TNF-α), men showed a marked increase in the cardiovascular disease risk biomarker CRP. However, perhaps due to the cohort size, interaction analysis did not show a significant gender difference.

Linking Stress and Infertility: A Novel Role for Ghrelin

Infertility affects a remarkable one in four couples in developing countries. Psychological stress is a ubiquitous facet of life, and although stress affects us all at some point, prolonged or unmanageable stress may become harmful for some individuals, negatively impacting on their health, including fertility. For instance, women who struggle to conceive are twice as likely to suffer from emotional distress than fertile women. Assisted reproductive technology treatments place an additional physical, emotional, and financial burden of stress, particularly on women, who are often exposed to invasive techniques associated with treatment. Stress-reduction interventions can reduce negative affect and in some cases to improve in vitro fertilization outcomes. Although it has been well-established that stress negatively affects fertility in animal models, human research remains inconsistent due to individual differences and methodological flaws. Attempts to isolate single causal links between stress and infertility have not yet been successful due to their multifaceted etiologies. In this review, we will discuss the current literature in the field of stress-induced reproductive dysfunction based on animal and human models, and introduce a recently unexplored link between stress and infertility, the gut-derived hormone, ghrelin. We also present evidence from recent seminal studies demonstrating that ghrelin has a principal role in the stress response and reward processing, as well as in regulating reproductive function, and that these roles are tightly interlinked. Collectively, these data support the hypothesis that stress may negatively impact upon fertility at least in part by stimulating a dysregulation in ghrelin signaling.

Fasting Glucose and the Risk of Depressive Symptoms: Instrumental-Variable Regression in the Cardiovascular Risk in Young Finns Study

PURPOSE

Type 2 diabetes (T2D) has been associated with depressive symptoms, but the causal direction of this association and the underlying mechanisms, such as increased glucose levels, remain unclear. We used instrumental-variable regression with a genetic instrument (Mendelian randomization) to examine a causal role of increased glucose concentrations in the development of depressive symptoms.

METHOD

Data were from the population-based Cardiovascular Risk in Young Finns Study (n = 1217). Depressive symptoms were assessed in 2012 using a modified Beck Depression Inventory (BDI-I). Fasting glucose was measured concurrently with depressive symptoms. A genetic risk score for fasting glucose (with 35 single nucleotide polymorphisms) was used as an instrumental variable for glucose.

RESULTS

Glucose was not associated with depressive symptoms in the standard linear regression (B = -0.04, 95% CI [-0.12, 0.04], p = .34), but the instrumental-variable regression showed an inverse association between glucose and depressive symptoms (B = -0.43, 95% CI [-0.79, -0.07], p = .020). The difference between the estimates of standard linear regression and instrumental-variable regression was significant (p = .026) CONCLUSION: Our results suggest that the association between T2D and depressive symptoms is unlikely to be caused by increased glucose concentrations. It seems possible that T2D might be linked to depressive symptoms due to low glucose levels.

Novel 5-HT3 receptor antagonist QCM-4 attenuates depressive-like phenotype associated with obesity in high-fat-diet-fed mice

RATIONALE

Depression associated with obesity remains an interesting area to study the biological mechanisms and novel therapeutic intervention.

OBJECTIVES

The present study investigates the effect of a novel 5-HT₃ receptor antagonist 3-methoxy-N-p-tolylquinoxalin-2-carboxamide (QCM-4) on several pathogenic markers of depression associated with obesity such as plasma insulin resistance, hippocampal cyclic adenosine monophosphate (cAMP), brain-derived neurotrophic factor (BDNF), serotonin (5-HT) concentrations, hippocampal neuronal damage, and p53 protein expression in high-fat-diet (HFD)-fed mice.

METHODS

Obesity was experimentally induced in mice by feeding with HFD for 14 weeks followed by administration of QCM-4 (1 and 2 mg/kg, p.o.)/standard escitalopram (ESC) (10 mg/kg, p.o.)/vehicle (10 ml/kg, p.o.) for 28 days. Behavioral assays such as sucrose preference test (SPT); forced swim test (FST); elevated plus maze (EPM); biochemical assays including oral glucose tolerance tests (OGTT), insulin, cAMP, BDNF, and 5-HT concentrations; and molecular assays mainly histology and immunohistochemistry (IHC) of p53 protein in the dentate gyrus (DG), CA1, and CA3 regions of hippocampus in HFD fed mice were performed.

RESULTS

Chronic treatment with QCM-4 in HFD-fed mice reversed the behavioral alterations in SPT, FST, and EPM. QCM-4 showed poor sensitivity for plasma glucose, improved insulin sensitivity, increased hippocampal cAMP, BDNF, and 5-HT concentrations. In the hippocampal DG, CA1, and CA3 regions, QCM-4 treatment improved the neuronal morphology in the histopathology and inhibited p53 protein expression in IHC assay in HFD-fed mice.

CONCLUSION

QCM-4 attenuated the depressive-like phenotype in HFD-fed mice by improving behavioral, biochemical, and molecular alterations through serotonergic neuromodulation.

Regulation of insulin receptor phosphorylation in the brains of prenatally stressed rats: New insight into the benefits of antidepressant drug treatment

A growing body of evidence supports the involvement of disturbances in the brain insulin pathway in the pathogenesis of depression. On the other hand, data concerning the impact of antidepressant drug therapy on brain insulin signaling remain scare and insufficient. We determinated the influence of chronic treatment with antidepressant drugs (imipramine, fluoxetine and tianeptine) on the insulin signaling pathway of the brain of adult prenatally stressed rats. 3-month-old prenatally stressed and control rats were treated for 21 days with imipramine, fluoxetine or tianeptine (10mg/kg/day i.p.).The impact of chronic antidepressant administration was examined in forced swim test. In the frontal cortex and hippocampus, the mRNA and protein expression of insulin, insulin receptor, insulin receptor substrates (IRS-1,IRS-2) and adaptor proteins (Shc1, Grb2) before and after drugs administration were measured.Rats exposed prenatally to stressful stimuli displayed depressive-like disturbances, which were attenuated by antidepressant drug administration. We did not reveal the impact of prenatal stress or antidepressant treatment on insulin and the insulin receptor expression in the examined structures. We revealed that diminished insulin receptor phosphorylation evoked by the prenatal stress procedure was attenuated by drugs treatment. We demonstrated that the favorable effect of antidepressans on insulin receptor phosphorylation in the frontal cortex was mainly related with the normalization of serine312 and tyrosine IRS-1 phosphorylation, while in the hippocampus, it was related with the adaptor proteins Shc1/Grb2. It can be suggested that the behavioral effectiveness of antidepressant drug therapy may be related with the beneficial impact of antidepressant on insulin receptor phosphorylation pathways.

The association between insulin resistance and depression in the Korean general population

BACKGROUND

Previous studies showed that the insulin resistance (IR) could be related to depression. However, this association is still equivocal in the general population. Herein, we aimed to investigate the association between IR and depressive symptoms in a large sample in South Korea.

METHODS

A cross-sectional study was carried out for 165,443 Korean men and women who received a health checkup including various clinical parameters and the Center for Epidemiologic Studies Depression scales (CES-D). Subjects were stratified into subgroups by CES-D score, sex, age, and presence of diabetes. The odd ratios (ORs) for homeostasis model assessment of insulin resistance (HOMA-IR) were compared between groups using multivariable logistic regression analyses.

RESULTS

After adjusting covariates (e.g. smoking, family income, marriage state, unemployment status, average alcohol use, BMI, physical activity, systolic blood pressure, diabetes), increased IR was weakly associated with greater depressive symptoms (adjusted OR=1.01 [95% CI 1.0001-1.03]). Subgroup analysis revealed this association was statistically significant in females (adjusted OR=1.03, [95% CI 1.001-1.06]), non-diabetic group (adjusted OR=1.04, [95% CI 1.02-1.06]), and young participants under the age of thirty (adjusted OR=1.17, [95% CI 1.07-1.27]). But we couldn't find significant association in diabetic and middle to elderly participants.

CONCLUSIONS

This study demonstrates that there is a relationship between IR and depressive symptoms in the Korean general population. Results from this epidemiological study revealed that young adults and non-diabetic individuals with increased IR may be related with depressive symptoms.

CLOCK and BMAL1 Regulate Muscle Insulin Sensitivity via SIRT1 in Male Mice

Circadian misalignment induces insulin resistance in both human and animal models, and skeletal muscle is the largest organ response to insulin. However, how circadian clock regulates muscle insulin sensitivity and the underlying molecular mechanisms are still largely unknown. Here we show circadian locomotor output cycles kaput (CLOCK) and brain and muscle aryl hydrocarbon receptor nuclear translocator-like protein (BMAL)-1, two core circadian transcription factors, are down-regulated in insulin-resistant C2C12 myotubes and mouse skeletal muscle. Furthermore, insulin signaling is attenuated in the skeletal muscle of Clock(Δ19/Δ19) mice, and knockdown of CLOCK or BMAL1 by small interfering RNAs induces insulin resistance in C2C12 myotubes. Consistently, ectopic expression of CLOCK and BMAL1 improves insulin sensitivity in C2C12 myotubes. Moreover, CLOCK and BMAL1 regulate the expression of sirtuin 1 (SIRT1), an important regulator of insulin sensitivity, in C2C12 myotubes and mouse skeletal muscle, and two E-box elements in Sirt1 promoter are responsible for its CLOCK- and BMAL1-dependent transcription in muscle cells. Further studies show that CLOCK and BMAL1 regulate muscle insulin sensitivity through SIRT1. In addition, we find that BMAL1 and SIRT1 are decreased in the muscle of mice maintained in constant darkness, and resveratrol supplementation activates SIRT1 and improves insulin sensitivity. All these data demonstrate that CLOCK and BMAL1 regulate muscle insulin sensitivity via SIRT1, and activation of SIRT1 might be a potential valuable strategy to attenuate muscle insulin resistance related to circadian misalignment.

Visceral Fat Accumulation, Insulin Resistance, and Elevated Depressive Symptoms in Middle-Aged Japanese Men

Objective

To investigate visceral fat accumulation and markers of insulin resistance in relation to elevated depressive symptoms (EDS).

Methods

Participants were 4,333 male employees (mean age, 49.3 years) who underwent abdominal computed tomography scanning, measured fasting insulin, and did not self-report diabetes and mental disorders under treatment and history of cancer, myocardial infarction, and stroke. Multivariable logistic regression was used to assess the association of EDS with abdominal fat deposition and markers of insulin resistance.

Results

Visceral fat area (VFA) and fasting insulin were significantly, positively associated with EDS. Multivariable-adjusted odds ratios (95% confidence interval) of high VFA for the lowest through highest quartile of depression score were 1 (reference), 1.18 (0.97–1.42), 1.25 (1.02–1.54), 1.23 (1.01–1.51), respectively, and corresponding figures for high fasting insulin were 1 (reference), 0.98 (0.80–1.19), 1.12 (0.91–1.38), and 1.29 (1.06–1.57), respectively. Subcutaneous fat area was not associated with EDS.

Conclusions

Results suggest that EDS is related to visceral, but not subcutaneous, fat accumulation and insulin resistance in middle-aged Japanese men.

Exploring the Link between the Components of Metabolic Syndrome and the Risk of Depression

BACKGROUND

Metabolic syndrome (MetS) has been reported with an increased risk of depression. MetS was also associated with insulin resistance. This study aimed to evaluate whether MetS components might contribute to depression in participants with insulin resistance (IR) or not.

METHODS

This study included 3,331 participants ≥18 years in the NHANES 2009-2010. Depressive symptoms were assessed using the Patient Health Questionnaire-9 (PHQ-9). MetS components were measured using blood chemistry and body measurements. IR was identified using the homeostasis model assessment method.

RESULTS

Predicted PHQ-9 scores significantly increased as the number of MetS components increased in patients with IR. The adjusted β coefficients of the predicted PHQ-9 score with 2, 4, and 5 MetS components were 1.803, 2.081, and 3.048, respectively (P for trend < 0.05). Low HDL-C levels were significantly associated with higher predicted total PHQ-9 scores in fully adjusted models in the IR group (P < 0.05).

CONCLUSION

The results indicated that the presence of a greater number of components of MetS was significantly associated with higher predicted total PHQ-9 scores in participants with IR. Among the components of MetS, the most apparent association was observed between low HDL and higher predicted total PHQ-9 scores.

Depressive symptoms, anxiety and well-being among metabolic health obese subtypes

BACKGROUND

The metabolically healthy obese (MHO) phenotype is characterized by favorable lipid and inflammatory profiles, preserved insulin sensitivity and normal blood pressure. Limited data regards whether metabolically healthy obesity also confers beneficial effects on mental health and well-being exists.

METHODS

We investigated depressive symptoms, anxiety and well-being among metabolically healthy and unhealthy obese and non-obese adults from a cross-sectional sample of 2047 middle-aged Irish men and women. Subjects were classified as obese (BMI ≥30kg/m(2)) and non-obese (BMI <30kg/m(2)). Metabolic health status was defined using three metabolic health definitions based on a range of cardiometabolic abnormalities including metabolic syndrome criteria, insulin resistance and inflammation. Depressive symptoms, anxiety and well-being were assessed using the Center for Epidemiologic Studies Depression Scale (CES-D), the Hospital Anxiety and Depression Scale (HADS) and the World Health Organization (WHO)-5 Well Being Index.

RESULTS

Relative to the metabolically healthy non-obese individuals the risk of anxiety and depressive symptoms was greater among the metabolically unhealthy obese subjects (odds ratios (ORs) 1.63-1.66 and ORs 1.82-1.83 for anxiety and depressive symptoms, respectively depending on metabolic health definition). Increased risk of these conditions was not observed among the MHO subjects.

CONCLUSIONS

Our data suggest that a favorable metabolic profile is positively associated with mental health among obese middle-aged adults, although findings were dependent on metabolic health definition. Improved understanding of the relationship between obesity associated metabolic health subtypes, anxiety and depressive symptoms may inform future targeted screening and interventions for those at greatest risk of adverse mental and cardiometabolic health outcomes.