Bidirectional association between depression and metabolic syndrome: a systematic review and meta-analysis of epidemiological studies

A conserved BDNF, glutamate- and GABA-enriched gene module related to human depression identified by coexpression meta-analysis and DNA variant genome-wide association studies

Large scale gene expression (transcriptome) analysis and genome-wide association studies (GWAS) for single nucleotide polymorphisms have generated a considerable amount of gene- and disease-related information, but heterogeneity and various sources of noise have limited the discovery of disease mechanisms. As systematic dataset integration is becoming essential, we developed methods and performed meta-clustering of gene coexpression links in 11 transcriptome studies from postmortem brains of human subjects with major depressive disorder (MDD) and non-psychiatric control subjects. We next sought enrichment in the top 50 meta-analyzed coexpression modules for genes otherwise identified by GWAS for various sets of disorders. One coexpression module of 88 genes was consistently and significantly associated with GWAS for MDD, other neuropsychiatric disorders and brain functions, and for medical illnesses with elevated clinical risk of depression, but not for other diseases. In support of the superior discriminative power of this novel approach, we observed no significant enrichment for GWAS-related genes in coexpression modules extracted from single studies or in meta-modules using gene expression data from non-psychiatric control subjects. Genes in the identified module encode proteins implicated in neuronal signaling and structure, including glutamate metabotropic receptors (GRM1, GRM7), GABA receptors (GABRA2, GABRA4), and neurotrophic and development-related proteins [BDNF, reelin (RELN), Ephrin receptors (EPHA3, EPHA5)]. These results are consistent with the current understanding of molecular mechanisms of MDD and provide a set of putative interacting molecular partners, potentially reflecting components of a functional module across cells and biological pathways that are synchronously recruited in MDD, other brain disorders and MDD-related illnesses. Collectively, this study demonstrates the importance of integrating transcriptome data, gene coexpression modules and GWAS results for providing novel and complementary approaches to investigate the molecular pathology of MDD and other complex brain disorders.

Castelli risk indexes 1 and 2 are higher in major depression but other characteristics of the metabolic syndrome are not specific to mood disorders

AIMS

This study examined whether Castelli risk indexes 1 (total/high-density lipoprotein (HDL) cholesterol) and 2 (low density lipoprotein (LDL)/HDL cholesterol) and other shared metabolic disorders might underpin the pathophysiology of the metabolic syndrome, major depression or bipolar disorder.

MAIN METHODS

This cross-sectional study examined 92 major depressed, 49 bipolar depressed and 201 normal controls in whom the Castelli risk indexes 1 and 2 and key characteristics of the metabolic syndrome, i.e. waist/hip circumference, body mass index (BMI), systolic/diastolic blood pressure, total cholesterol, low-density lipoprotein (LDL) and HDL cholesterol, triglycerides, insulin, glucose, hemoglobin A1c (HbA1c) and homocysteine were assessed.

KEY FINDINGS

Castelli risk indexes 1 and 2 were significantly higher in major depressed patients than in bipolar disorder patients and controls. There were no significant differences in waist or hip circumference, total and LDL cholesterol, triglycerides, plasma glucose, insulin, homocysteine and HbA1c between depression and bipolar patients and controls. Bipolar patients had a significantly higher BMI than major depressed patients and normal controls.

SIGNIFICANCE

Major depression is accompanied by increased Castelli risk indexes 1 and 2, which may be risk factors for cardiovascular disease. Other key characteristics of the metabolic syndrome, either metabolic biomarkers or central obesity, are not necessarily specific to major depression or bipolar disorder.

Depression and type 2 diabetes: a causal association?

There is a controversy regarding whether depression and type 2 diabetes are causally linked. To assess this issue, we review key findings for the association between depression and diabetes, and its underlying mechanisms. Findings from meta-analyses of cohort studies show a modestly sized bidirectional association between depression and type 2 diabetes (ie, depression predicts diabetes onset and diabetes predicts future depression). However, depression-related biological alterations in the hypothalamic-pituitary-adrenal cortex axis and the sympathetic nervous system, and subclinical inflammation, are not consistently linked with increased diabetes risk. The evidence for an association between depression and glycaemic traits (eg, glucose, insulin, insulin sensitivity, and insulin secretion) is also mixed. Diabetes increases the risk of depression to the same extent as do other chronic disorders (eg, cardiac diseases, osteoarthritis, lung disease, and poor hearing). At present, the available evidence suggests that pathophysiological changes preceding the onset of type 2 diabetes might not cause depression, nor might depression directly increase the risk of developing type 2 diabetes. Despite insufficient robust causal evidence, treating physicians should be aware of the co-occurrence of depression and type 2 diabetes.

Interactions between diabetes and anxiety and depression: implications for treatment

Anxiety or depression may be a risk factor for the development of diabetes. This relationship may occur through a combination of genetic predispositions; epigenetic contingencies; exacerbating conditions such as metabolic syndrome (a precursor to diabetes); and other serious medical conditions. Medications used to treat anxiety and depression have significant side effects, such as weight gain, further increasing the possibility of developing diabetes. These components combine, interact, and reassemble to create a precarious system for persons with, or predisposed to, diabetes. Clinicians must be aware of these interrelationships to adequately treat the disease.

Somatic comorbidity, metabolic syndrome, cardiovascular risk, and CRP in patients with recurrent depressive disorders

Aim

To investigate the association between depression, metabolic syndrome (MBS), somatic, particularly cardiovascular comorbidity, and low-grade chronic inflammation assessed using C-reactive protein (CRP).

Methods

This cross-sectional study included 76 patients with recurrent depressive disorder (RDD) and 72 non-depressed medical staff controls from the Department of Psychiatry, University Hospital Center Zagreb between January 2011 and June 2012.

Results

Seventy-five percent of patients had somatic comorbidity. The most common comorbid conditions were cardiovascular disorders (46.1%), locomotor system diseases (35.5%), carcinoma (15.8%), thyroid diseases (9.2%), and diabetes (9.2%). MTB was more common in RDD patients (31.6%) than in controls (23.6%), but the difference was not significant. Elevated CRP was found to be significantly more frequent in patients with recurrent depressive disorders (RDD) (35.5%; χ² test, P = 0.001, Cramer V = 0.29) than in controls (12.5%) and was associated with lowered high-density lipoprotein and overweight/obesity.

Conclusion

We found some intriguing links between stress, depression, metabolic syndrome, and low grade inflammation, which may be relevant for the prevalence of somatic comorbidity in patients with RDD, but further studies are needed to confirm our results.

Chronic high-fat diet increases acute neuroendocrine stress response independently of prenatal dexamethasone treatment in male rats

OBJECTIVE

Intrauterine growth restriction (IUGR) has been associated with metabolic disorders later in life such as obesity and diabetes as well as psychiatric disorders such as depression and schizophrenia. Therefore, we wanted to investigate whether behavioural, metabolic or neuroendocrine abnormalities could be provoked or exacerbated by a high-fat diet (HFD) in an experimental model of IUGR.

METHODS

Pregnant dams were exposed to dexamethasone (DEX) in the third gestational week to induce IUGR. Late adolescent male offspring of DEX- and vehicle-treated dams were then fed a HFD or standard chow for 8 weeks and subjected to a variety of assessments.

RESULTS

Only diet affected the hypothalamus-pituitary-adrenal (HPA) axis stress response, as HFD doubled the observed corticosterone levels following acute restraint. HFD and prenatal DEX exposure concomitantly exacerbated depressive-like behaviour in the forced swim test, even though no interaction was seen. Prenatal DEX treatment tended to increase the basal acoustic startle response (ASR), while an interaction between HFD and DEX was present in the ASR pre-pulse inhibition suggestive of fundamental changes in neuronal gating mechanisms. Metabolic parameters were only affected by diet, as HFD increased fasting glucose and insulin levels.

CONCLUSION

We conclude that chronic HFD may be more important in programming of the HPA axis stress responsiveness than an adverse foetal environment and therefore potentially implies an increased risk for developing psychiatric and metabolic disease.

Depression but not anxiety is associated with metabolic syndrome in primary care based community sample

INTRODUCTION

Metabolic syndrome (MetS) and depression are considered important risk factors for diabetes and cardiovascular disease. Recent evidence suggests that depression can be an important predictor of MetS. Data on the association between anxiety and MetS remain mixed. In a large primary care based community sample we investigated an association of depressive and anxiety disorders and symptoms with MetS.

METHODS

A total of 1115 (51% men, mean age 62.0 ± 9.6 years) randomly selected individuals of 45 years and older were evaluated for: (i) MetS using the World Health Organization (WHO), National Cholesterol Education Program Adult Treatment Panel III (NCEP/ATP III) and International Diabetes Federation (IDF) criteria; (ii) current major depressive episode (MDE) and current generalized anxiety disorder (GAD), the Mini International Neuropsychiatric interview; (iii) lifetime MDE; and (iv) symptoms of depression and anxiety, the Hospital Anxiety and Depression scale (HADS). Socio-demographic characteristics (education, residence, marital status and social status) and medical histories (physical activity, smoking status, alcohol consumption and histories of myocardial infarction and stroke) were also evaluated.

RESULTS

After adjusting for socio-demographic status, medical histories and current GAD, current MDE and lifetime MDE were associated with greater prevalence of MetS according to the WHO criteria (OR=1.7, 95%CI [1.1-2.7] and OR=3.7, 95%CI [2.4-5.7], respectively, p ≤ 0.001). Lifetime MDE was also associated with MetS according to the IDF and NCEP/ATP III criteria. On the other hand, current GAD was not associated with MetS in multivariate regression models when adjusted for current MDE. Similar results were obtained when evaluating an association between depression/anxiety symptoms and MetS, since elevated depressive, but not anxiety, symptoms were independently associated with MetS.

CONCLUSIONS

Depressive, but not anxiety, disorders and symptoms are associated with greater prevalence rate of MetS. Assessment and management of MetS risk factors should be considered in depressed individuals.

Is there a practical way of predicting therapeutic success in type 2 diabetes on the basis of psychological features? Development and validation of the Psychological Predictors of Therapeutic success in Diabetes (PPTD) questionnaire

Many psychiatric disorders and symptoms have been associated with impaired metabolic control in type 2 diabetes; several studies focused on non-pathological psychological features. Aims of this observational, longitudinal study are: the assessment of the impact of a wide range of psychological factors on metabolic control in type 2 diabetes; and the development and validation of a simple questionnaire to assess the impact of psychological factors on therapeutic success. To identify psychological factors interfering with attainment of glycemic targets, a prospective 1-year study was performed on a sample of 250 patients with type 2 diabetes. The impact of identified factors on therapeutic outcome was then subsequently verified on a further, independent sample of 200 patients. The first phase of the study allowed the development of a 19-items questionnaire, the Psychological Predictors of Therapeutic success in Diabetes (PPTD) questionnaire. Validation analyses showed that the questionnaire was able to predict therapeutic success. Patients with HbA1c ≤7% (53 mmol/mol) at follow-up showed higher test scores than those with HbA1c >7% [31.0 (26.2; 35.0) vs 28.0 (23.0; 32.0); p = 0.016]. The attainment and maintenance of therapeutic goals in patients with type 2 diabetes depend on a wide range of factors. The PPTD is an attempt at condensing the complexity of psychological factors affecting glycemic control in a simple and easy-to-use self-reported questionnaire, which can be used in wide-scale research.

Childhood trauma and metabolic syndrome in men and women

The long-term effects of childhood trauma on health are well-documented, but few population-based studies have explored how childhood trauma affects the risk of developing metabolic syndrome (MetS) in adulthood. Using data from 1234 adults in the second wave of Midlife in the United States (MIDUS), we investigate (1) the extent to which childhood abuse affects the risk of developing MetS in adulthood; (2) how the severity of different types of abuse (emotional, physical, sexual, or cumulative abuse) affects this risk; and (3) the extent to which adult socioeconomic status (SES), maladaptive stress responses, and unhealthy behaviors mediate the association. We also test whether these associations differ significantly by sex. We find that emotional and physical abuse increase the risk of developing MetS for both sexes, whereas sexual abuse is a predictor for women only. For both sexes, individuals who experienced more cumulative abuse have a greater risk of developing MetS. Adult SES partially explains the association between childhood abuse and MetS. Maladaptive stress responses and unhealthy behaviors further explain the association. Among the potential mediators, poor sleep quality was a significant pathway for men and women, while stress-induced eating was a significant pathway for women only. Our findings suggest that the well-documented health consequences of early life trauma may vary by the nature of the trauma, the victim's sex, and the coping mechanisms that he or she employs.

Disruptions in ovarian function are related to depression and cardiometabolic risk during premenopause

OBJECTIVE

The aim of this study was to evaluate the extent to which mild disruptions in ovarian function, indexed by changes in menstrual cycle length, may relate to cardiometabolic and psychological health in premenopausal women.

METHODS

Among 804 healthy, regularly cycling women (aged 25-45 y; mean [SD] age, 35.5 [5.5] y), patterns of any change (shortening, lengthening, or increased variability) versus no change in menstrual cycle length were examined in relation to a composite of cardiometabolic risk and individual risk factors (high-density lipoprotein, triglycerides, waist circumference, glucose, and hypertensive status), as well as in relation to depression indicators (Center for Epidemiological Studies Depression Scale score ≥16 [yes/no], lifetime depression diagnosis [yes/no], and lifetime antidepressant medication use [yes/no]). Models were also explored to test whether changes in menstrual cycle length mediated relations between depression history and cardiometabolic risk.

RESULTS

In covariate-adjusted models compared with no change, any change in menstrual cycle length was associated with higher cardiometabolic risk composite scores and lower high-density lipoprotein (P < 0.05). In addition, compared with no change, any change in menstrual cycle length was associated with a Center for Epidemiological Studies Depression Scale score of 16 or higher, having received a depression diagnosis, and having used antidepressant medications (P < 0.05). In exploratory analyses, any change in menstrual cycle length partially mediated the relation between depression history and cardiometabolic risk (b = 0.152, P = 0.040), which attenuated (b = 0.129, P = 0.083) when any change in menstrual cycle length was covaried.

CONCLUSIONS

Findings suggest that disruptions in ovarian function, marked by subtle changes in menstrual cycle length, may relate to aspects of cardiometabolic and psychological health among healthy, premenopausal women.

Body composition and depressive/anxiety symptoms in overweight and obese individuals with metabolic syndrome

BACKGROUND

Several studies point to a correlation between obesity and the severity of depressive and anxiety symptoms in children and adults, but there are still some controversial points about this association. The aim of this study is to investigate the relationship between body composition and the severity of anxiety/depressive symptoms in overweight and obese individuals with Metabolic Syndrome (MS).

METHODS

Fifty patients, 18-50 years old, overweight or obese and with the diagnosis of MS based on the International Diabetes Federation (IDF) criteria were selected for this study. Body composition was evaluated using Dual Energy X-ray Absorptiometry (DXA). Depressive symptoms were evaluated using the Hospital Anxiety and Depression Scale (HADS-Depression) and the Beck Depression Inventory (BDI). Anxiety symptoms were evaluated using HADS-Anxiety.

RESULTS

No correlation was found between depressive symptoms (HADS-Depression or BDI) and Body Mass Index (BMI) (r = 0.01; p = 0.94 and r = -0.12, p = 0.38; respectively), Waist Circumference (WC) (r = -0.06, p = 0.67 and r = -0.22, p = 0.12; respectively), and Waist-to-Hip Ratio (WHR) (r = -0.12, p = 0.40 and r = -0.17, p = 0.23; respectively). Additionally, no correlation was found among anxiety symptoms (HADS-Anxiety) and BMI (r = -0.15, p = 0.27), and WHR (r = -0.17, p = 0.24). In contrast, a significant correlation was found between percentage of total fat (DXA) and HADS-Depression (r = 0.34, p = 0.019) and HADS-Anxiety (r = 0.30, p = 0.039). Additionally, an inverse and strong correlation was found between lean mass (in grams) and HADS-Depression (r = -0.42, p = 0.004), HADS anxiety (r = -0.57, p < 0.0001), and BDI (r = -0.44, p = 0.026).

CONCLUSIONS

In individuals with MS, the percentage of body fat, and not central fat, BMI, WC, or WHR, was associated with an increased severity of anxiety and depressive symptoms. In contrast, total lean mass was strongly associated with fewer anxiety/depressive symptoms, suggesting that body composition might be related to psychiatric comorbidity in overweight individuals with MS.

Clinical biomarkers in metabolic syndrome

A biomarker can be defined as a measurable variable that may be used as an indicator of a given biological state or condition. Biomarkers have been used in health and disease for diagnostic purposes, as tools to assess effectiveness of nutritional or drug intervention, or as risk markers to predict the development of certain diseases. In nutrition studies, selecting appropriate biomarkers is important to assess compliance, or incidence of a particular dietary component in the biochemistry of the organism, and in the diagnosis and prognosis of nutrition-related diseases. Metabolic syndrome is a cluster of cardiovascular risk factors that occur simultaneously in the same individual, and it is associated with systemic alterations that may involve several organs and tissues. Given its close association with obesity and the increasing prevalence of obesity worldwide, identifying obese individuals at risk for metabolic syndrome is a major clinical priority. Biomarkers for metabolic syndrome are therefore potential important tools to maximize the effectiveness of treatment in subjects who would likely benefit the most. Choice of biomarkers may be challenging due to the complexity of the syndrome, and this article will mainly focus on nutrition biomarkers related to the diagnosis and prognosis of the metabolic syndrome.

Nutritional strategies for dealing with depression

Depression is a highly recurrent and debilitating psychiatric disorder associated with multicausal origins. Impairments in the monoaminergic transmission, increased glutamatergic excitotoxicity, neuroinflammation, oxidative stress and deficits in neurotrophic factors are the main hypothesis raised in order to explain the etiological basis of depression. Although the current antidepressant therapy usually alleviates symptoms and prevents recurrence of episodes, the delay in the onset of the therapeutic effect and the refractory or intolerant responses exhibited by a large number of patients are the main drawbacks of the current therapy. For these reasons, several studies have dealt with the investigation of alternative therapeutic approaches or adjunctive strategies which could improve clinical outcomes. One potential adjunctive treatment with conventional antidepressants involves the use of nutraceuticals (a food, a part of a food, a vitamin, a mineral, or a herb that provides health benefits). In this review, we will focus on the main nutrients, phytochemicals and food that have been shown to have beneficial effects against depression.

Metabolic syndrome: differences between psychiatric and internal medicine patients

OBJECTIVES

The existence of specific features of Metabolic Syndrome (MetS) in psychiatric population in comparison to not psychiatric patients has not been systematically investigated. The purpose of this study is to evaluate the differences of MetS among a group of psychiatric patients and a group of internal medicine patients in terms of anthropometric measurements, biochemical variables, and cardiovascular risk.

METHODS

We enrolled 83 psychiatric inpatients under pharmacological treatment (schizophrenia n = 24, bipolar disorder n = 27, major depression n = 14, other n = 18) and 77 internal medicine patients visited for supposed MetS as affected by overweight or arterial hypertension.

RESULTS

Psychiatric patients differed from control subjects by age (yrs) (47 +/- 9 vs. 52 +/- 8.6, p = 0.001), waist circumference (cm) (111.9 +/- 10.9 vs. 106 +/- 12.6, p = 0.02), HDL cholesterol (mg/dl) (36.8 +/- 7 vs. 48 +/- 11.3, p = 0.001), serum insulin (microU/ml) (26 +/- 12.5 vs. 16.4 +/- 8.8, p = 0.001), triglyceride/HDL cholesterol ratio (4.8 +/- 2.7 vs. 3.3 +/- 2.2, p = 0.01). Female psychiatric patients had higher levels of triglycerides (mg) (178 + 86 vs. 115 + 53, p = 0.002) and of HOMA index (7.8 + 5 vs. 3.8 + 3.3, p = 0.005). Triglycerides and triglycerides/HDL ratio levels were higher in Unipolar Depression. A positive association was found between antidepressant drug treatment with triglycerides and triglycerides/HDL ratio levels, neuroleptic treatment with the HOMA index, and antipsychotics drugs with the Framingham index.

LIMITATIONS

Psychiatric study population numerosity and duration of psychiatric illness and drug treatment.

CONCLUSIONS

Specific features of MetS in psychiatric population are mainly represented by young age of onset, hyperinsulinemia, increased abdominal adiposity, and low HDL cholesterol whose common denominator may be insulin-resistance.

Association of metabolic syndrome with atypical features of depression in Japanese people

AIM

It has been controversial whether metabolic syndrome (MetS) is associated with depression. We aimed to clarify the correlation between MetS and depression, considering atypical features of depression.

METHODS

Participants were 1011 Japanese men aged 20-59 years. MetS was diagnosed according to criteria set by the International Diabetes Federation. Clinical interviews for major depressive disorder (MDD) employed the DSM-IV; MDD was classified into atypical and non-atypical types. The prevalence of MetS was compared between the groups with no MDD, atypical depression, and non-atypical depression via trend analyses. Multiple logistic regression analyses examined the association of MetS with atypical depression and the features thereof.

RESULTS

In total, 141 (14.0%) participants were diagnosed with MetS and 57 (5.6%) were diagnosed with MDD (14 had atypical and 43 had non-atypicalMDD). The prevalence of MetS was the highest in the group with atypical depression, followed by the non-atypical depression and no MDD groups, respectively, with a marginally significant trend (P = 0.07). The adjusted odds ratios of MetS associated with depression were 3.8 (95% confidence interval [CI] 1.1-13.2) for atypical depression and 1.6 (95% CI 0.7-3.6) for non-atypical depression. Among the five features of atypical depression, only hyperphagia was significantly related to MetS (odds ratio 2.7, 95% CI 1.8-4.1).

CONCLUSION

There was a positive association between MetS and atypical depression, but not between MetS and non-atypical depression. Specifically, hyperphagia seems to be an important factor affecting the correlation between MetS and atypical depression.

Validity of meta-analysis in diabetes: meta-analysis is an indispensable tool in evidence synthesis

To deliver high-quality clinical care to patients with diabetes and other chronic conditions, clinicians must understand the evidence available from studies that have been performed to address important clinical management questions. In an evidence-based approach to clinical care, the evidence from clinical research should be integrated with clinical expertise, pathophysiological knowledge, and an understanding of patient values. As such, in an effort to provide information from many studies, the publication of diabetes meta-analyses has increased markedly in the recent past, using either observational or clinical trial data. In this regard, guidelines have been developed to direct the performance of meta-analysis to provide consistency among contributions. Thus, when done appropriately, meta-analysis can provide estimates from clinically and statistically homogeneous but underpowered studies and is useful in supporting clinical decisions, guidelines, and cost-effectiveness analysis. However, often these conditions are not met, the data considered are unreliable, and the results should not be assumed to be any more valid than the data underlying the included studies. To provide an understanding of both sides of the argument, we provide a discussion of this topic as part of this two-part point-counterpoint narrative. In the point narrative preceding the counterpoint narrative below, Dr. Home provides his opinion and review of the data to date showing that we need to carefully evaluate meta-analysis, and we need to learn what results are reliable. In the counterpoint narrative here, Drs. Golden and Bass emphasize that an effective system exists to guide meta-analysis and that rigorously conducted, high-quality systematic reviews and meta-analyses using established guidelines are an indispensable tool in evidence synthesis despite their limitations. —William T. Cefalu, MD Editor in Chief, Diabetes Care

Mediterranean dietary pattern and depression: the PREDIMED randomized trial

BACKGROUND

A few observational studies have found an inverse association between adherence to a Mediterranean diet and the risk of depression. Randomized trials with an intervention based on this dietary pattern could provide the most definitive answer to the findings reported by observational studies. The aim of this study was to compare in a randomized trial the effects of two Mediterranean diets versus a low-fat diet on depression risk after at least 3 years of intervention.

METHODS

This was a multicenter, randomized, primary prevention field trial of cardiovascular disease (Prevención con Dieta Mediterránea (PREDIMED Study)) based on community-dwelling men aged 55 to 80 years and women aged 60 to 80 years at high risk of cardiovascular disease (51% of them had type 2 diabetes; DM2) attending primary care centers affiliated with 11 Spanish teaching hospitals. Primary analyses were performed on an intention-to-treat basis. Cox regression models were used to assess the relationship between the nutritional intervention groups and the incidence of depression.

RESULTS

We identified 224 new cases of depression during follow-up. There was an inverse association with depression for participants assigned to a Mediterranean diet supplemented with nuts (multivariate hazard ratio (HR) 0.78; 95% confidence interval (CI) 0.55 to 1.10) compared with participants assigned to the control group, although this was not significant. However, when the analysis was restricted to participants with DM2, the magnitude of the effect of the intervention with the Mediterranean diet supplemented with nuts did reach statistical significance (multivariate HR = 0.59; 95% CI 0.36 to 0.98).

CONCLUSIONS

The result suggest that a Mediterranean diet supplemented with nuts could exert a beneficial effect on the risk of depression in patients with DM2.

TRIAL REGISTRATION

This trial has been registered in the Current Controlled Trials with the number ISRCTN 35739639.

Elevated depressive symptoms in metabolic syndrome in a general population of Japanese men: a cross-sectional study

BACKGROUND

Uncertainty still surrounds the association between metabolic syndrome (MetS) and depression. We aimed to evaluate the association between MetS and elevated depressive symptoms in a general Japanese population.

METHODS

This is a cross-sectional survey of 3,113 community-dwelling individuals aged 40 years or over. MetS was defined according to the joint interim statement. MetS was diagnosed when a subject had three or more of the following components: 1) central obesity (waist circumference ≥ 90 cm for men, ≥ 80 cm in for women); 2) elevated blood pressure (≥ 130/85 mmHg or current use of antihypertensive medication); 3) hypertriglyceridemia (≥ 1.7 mmol/L); 4) low HDL cholesterol (< 1.0 mmol/L for men, < 1.3 mmol/L for women); and 5) elevated fasting plasma glucose (≥ 5.55 mmol/L or current use of antidiabetic medication). Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale (CES-D). The age- and multivariable-adjusted odds ratio (OR) and 95% confidence interval (CI) were estimated using a logistic regression model.

RESULTS

Elevated depressive symptoms were observed in 4.3% of male and 6.3% of female participants. In men, the age-adjusted prevalence of elevated depressive symptoms was significantly higher in subjects with MetS than in those without (7.1% versus 3.6%, p = 0.04). The prevalence of elevated depressive symptoms rose progressively as the number of MetS components increased (3.5%, 3.6%, 5.8%, and 9.2% in male subjects with 0-1, 2, 3, and ≥ 4 components, respectively; p = 0.02 for trend). This association remained significant even after adjustment for age, marital status, history of cardiovascular disease, smoking habit, alcohol intake, and regular exercise. In women, on the other hand, there was no clear association between MetS and depressive symptoms.

CONCLUSIONS

MetS was associated with elevated depressive symptoms in a general population of Japanese men.

Sex Differences in Associations of Depressive Symptoms with Cardiovascular Risk Factors and Metabolic Syndrome among African Americans

Young to middle-aged women usually have notably lower rates of cardiovascular disease (CVD) than their male counterparts, but African American women lack this advantage. Their elevated CVD may be influenced by sex differences in associations between depressed mood and CVD risk factors. This cross-sectional study examined whether relations between scores on the Center for Epidemiologic Studies-Depression (CES-D) scale and a spectrum of CVD risk factors varied by sex among African Americans (n = 1076; ages 30-64) from the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study. Sex-stratified multiple regressions and logistic regressions were conducted. Among women, CES-D scores correlated positively with systolic blood pressure and waist-to-hip ratio (P's < .05), but inversely with high-density lipoprotein cholesterol (HDL-C) (P < .01). Women had twice the odds for metabolic syndrome if CES-D scores ≥16 and had a ≥14% increase in odds of hypertension, abdominal obesity, and low HDL-C with each 5-unit increase in CES-D scores. Among men, CES-D scores correlated positively with high-sensitivity C-reactive protein (P < .05), and odds of hypertension increased by 21% with each 5-unit increase in CES-D scores. Depressive symptoms may promote premature CVD risk in African Americans, at least in part, via CVD risk factors and prevalent metabolic syndrome, particularly in African American women.

The change of insulin levels after six weeks antidepressant use in drug-naïve major depressive patients

BACKGROUND

A reciprocal relationship between diabetes risk and depression has been reported. There are few studies investigating glucose-insulin homeostasis before and after short-term antidepressant treatment in drug-naïve major depressive disorder (MDD) patients.

METHODS

This study included 104 healthy controls and 50 drug-naïve MDD patients diagnosed according to the DSM-IV criteria. These MDD patients were randomly assigned to receive fluoxetine or venlafaxine for six weeks. Depressive symptoms, body mass index, fasting plasma levels of glucose and insulin were measured.

RESULTS

Compared to the healthy controls, the fasting plasma insulin and the homeostasis model of assessment for pancreatic β-cell secretory function (HOMA-β) was significantly lower in the MDD patients before antidepressant treatment (7.7±4.8 μIU/mL vs. 5.1±4.2 μIU/mL, p=0.006; 114.2±72.3% vs. 74.8±52.0%, p=0.005, respectively). However, these indices were not correlated with depression severity. After 6 weeks of fluoxetine or venlafaxine treatment, the level of HOMA-β borderline significantly increased (108.1±75.5%, p=0.059).

LIMITATIONS

The study was limited by the follow-up duration and lack of a placebo group.

CONCLUSIONS

Antidepressants might affect insulin secretion independently of the therapeutic effects on MDD. Further studies are needed to investigate the long-term effects of antidepressants on insulin regulation in MDD patients.

The comorbidity between depression and diabetes

Comorbidity of depression and diabetes is common, and each disorder has a negative impact on the outcome of the other. The direction of causality is not certain as each disorder seems to act as both a risk factor and consequence for the other in longitudinal studies. This bidirectional association is possibly mediated by shared environmental and genetic risk factors. Comorbid depression is associated with reduced adherence to medication and self-care management, poor glycaemic control, increased health care utilization, increased costs and elevated risk of complications, as well as mortality in patients with diabetes. Psychological and pharmacological interventions are shown to be effective in improving depression symptoms; however, collaborative care programs that simultaneously manage both disorders seem to be most effective in improving diabetes-related outcomes.

The long-term psychiatric and medical prognosis of perinatal mental illness

The perinatal period provides an important window into a woman's long-term health. Perinatal mental illness is a common condition conferring potential serious long-term psychiatric and medical consequences for the mother and family. It is known that childbirth acts as a powerful trigger for depressive episodes in some women, and that women with histories of a mood disorder are particularly vulnerable. Some evidence links perinatal mental illness with obstetrical complications and reduced lactation initiation and duration. Therefore, perinatal mental illness may be a marker for long-term risk, and may contribute directly to subsequent cardiometabolic disease through both neuroendocrine mechanisms and the effects of mental illness on health behaviours. In clinical practice, these associations underscore the importance of screening and treating women with perinatal mental illness to ensure best possible long-term outcomes. Early screening and treatment may both mitigate the primary disease process and reduce the risk of comorbid medical conditions.

How might circadian rhythms control mood? Let me count the ways

Mood disorders are serious diseases that affect a large portion of the population. There have been many hypotheses put forth over the years to explain the development of major depression, bipolar disorder, and other mood disorders. These hypotheses include disruptions in monoamine transmission, hypothalamus-pituitary-adrenal axis function, immune function, neurogenesis, mitochondrial dysfunction, and neuropeptide signaling (to name a few). Nearly all people suffering from mood disorders have significant disruptions in circadian rhythms and the sleep/wake cycle. In fact, altered sleep patterns are one of the major diagnostic criteria for these disorders. Moreover, environmental disruptions to circadian rhythms, including shift work, travel across time zones, and irregular social schedules, tend to precipitate or exacerbate mood-related episodes. Recent studies have found that molecular clocks are found throughout the brain and body where they participate in the regulation of most physiological processes, including those thought to be involved in mood regulation. This review will summarize recent data that implicate the circadian system as a vital regulator of a variety of systems that are thought to play a role in the development of mood disorders.

Hypothalamic orexin prevents hepatic insulin resistance induced by social defeat stress in mice

Depression is associated with insulin resistance and type 2 diabetes, although the molecular mechanism behind the pathological link remains unclear. Orexin, a hypothalamic neuropeptide regulating energy and glucose homeostasis, has been implicated in the endogenous antidepressant mechanism. To clarify whether orexin is involved in the coordination between mental and metabolic functions, we investigated the influence of orexin deficiency on social interaction behavior and glucose metabolism in mice subjected to chronic social defeat stress. Chronic stress-induced glucose intolerance and systemic insulin resistance as well as social avoidance were ameliorated by calorie restriction in an orexin-dependent manner. Moreover, orexin-deficient mice maintained under ad libitum-fed conditions after defeat stress exhibited hyperinsulinemia and elevated HOMA-IR (homeostasis model assessment for insulin resistance), despite normal fasting blood glucose levels. In a pyruvate tolerance test to evaluate hepatic insulin sensitivity, chronic stress-induced abnormal glucose elevation was observed in orexin-deficient but not wild-type mice, although both types of mice were susceptible to chronic stress. In addition, insulin-induced phosphorylation of Akt in the liver was impaired in orexin-deficient but not wild-type mice after chronic stress. These results demonstrate that the central physiological actions of orexin under ad libitum-fed conditions are required for the adaptive response to chronic defeat stress, which can prevent the development of hepatic insulin resistance but not social avoidance behavior. Moreover, calorie restriction, a paradigm to strongly activate orexin neurons, appears to prevent the persistence of depression-like behavior per se, leading to the amelioration of impaired glucose metabolism after chronic stress; therefore, we suggest that hypothalamic orexin system is the key for inhibiting the exacerbating link between depression and type 2 diabetes.

Understanding the somatic consequences of depression: biological mechanisms and the role of depression symptom profile

Depression is the most common psychiatric disorder worldwide. The burden of disease for depression goes beyond functioning and quality of life and extends to somatic health. Depression has been shown to subsequently increase the risk of, for example, cardiovascular, stroke, diabetes and obesity morbidity. These somatic consequences could partly be due to metabolic, immuno-inflammatory, autonomic and hypothalamic-pituitary-adrenal (HPA)-axis dysregulations which have been suggested to be more often present among depressed patients. Evidence linking depression to metabolic syndrome abnormalities indicates that depression is especially associated with its obesity-related components (for example, abdominal obesity and dyslipidemia). In addition, systemic inflammation and hyperactivity of the HPA-axis have been consistently observed among depressed patients. Slightly less consistent observations are for autonomic dysregulation among depressed patients. The heterogeneity of the depression concept seems to play a differentiating role: metabolic syndrome and inflammation up-regulations appear more specific to the atypical depression subtype, whereas hypercortisolemia appears more specific for melancholic depression. This review finishes with potential treatment implications for the downward spiral in which different depressive symptom profiles and biological dysregulations may impact on each other and interact with somatic health decline.

Sleep duration and metabolic syndrome in adult populations: a meta-analysis of observational studies

OBJECTIVE

Epidemiological studies have repeatedly investigated the association between sleep duration and metabolic syndrome. However, the results have been inconsistent. This meta-analysis aimed to summarize the current evidence from cross-sectional and prospective cohort studies that evaluated this.

DATA SOURCES

Relevant studies were identified by systematically searching the PubMed, Cochrane CENTRAL, EMBASE and PsycINFO databases through November 2012 without language restriction.

STUDY SELECTION

We identified 12 cross-sectional studies with 76 027 participants including 14 404 cases of metabolic syndrome, and 3 cohort studies with 2055 participants and 283 incident cases of metabolic syndrome.

RESULTS

For short sleep durations (<5 to 6 h), the odds ratios (OR) was 1.27 (95% confidence interval (CI)=1.10-1.48, I(2)=75.5%) in the 12 cross-sectional studies and 1.62 (95% CI=0.74-3.55, I(2)=71.4%) in the 3 cohort studies; for long sleep durations (>8 to 10 h), the OR was 1.23 (95% CI=1.02-1.49, I(2)=75.8%) in the 11 cross-sectional studies and 1.62 (95% CI=0.86-3.04, I(2)=0.0%) in the 2 cohort studies.

CONCLUSIONS

Short and long sleep durations are risky behaviors for increasing the risk of metabolic syndrome and thus have important public health implications, as sleep habits are amenable to behavioral interventions. The available data are sparse, and further studies, especially longitudinal studies, are needed to facilitate a better understanding of these associations.

Early life stress interacts with the diet deficiency of omega-3 fatty acids during the life course increasing the metabolic vulnerability in adult rats

Early stress can cause metabolic disorders in adulthood. Omega-3 polyunsaturated fatty acids (n-3 PUFAs) deficiency has also been linked to the development of metabolic disorders. The aim of this study was to assess whether an early stressful event such as maternal separation interacts with the nutritional availability of n-3 PUFAs during the life course on metabolic aspects. Litters were randomized into: maternal separated (MS) and non-handled (NH). The MS group was removed from their dam for 3 hours per day and put in an incubator at 32°C on days 1° to 10° postnatal (PND). On PND 35, males were subdivided into diets that were adequate or deficient in n-3 PUFAs, and this intervention was applied during the subsequent 15 weeks. Animal's body weight and food consumption were measured weekly, and at the end of the treatment tissues were collected. MS was associated with increased food intake (p = 0.047) and weight gain (p = 0.012), but no differences were found in the NPY hypothalamic content between the groups. MS rats had also increased deposition of abdominal fat (p<0.001) and plasma triglycerides (p = 0.018) when compared to the NH group. Interactions between early life stress and n-3 PUFAs deficiency were found in plasma insulin (p = 0.033), HOMA index (p = 0.049), leptin (p = 0.010) and liver PEPCK expression (p = 0.050), in which the metabolic vulnerability in the MS group was aggravated by the n-3 PUFAs deficient diet exposure. This was associated with specific alterations in the peripheral fatty acid profile. Variations in the neonatal environment interact with nutritional aspects during the life course, such as n-3 PUFAs diet content, and persistently alter the metabolic vulnerability in adulthood.

Synergistic relationships among stress, depression, and troubled relationships: insights from psychoneuroimmunology

Stress and depression consistently elevate inflammation and are often experienced simultaneously, which is exemplified by people in troubled relationships. Troubled relationships also elevate inflammation, which may be partially explained by their ability to engender high levels of stress and depression. People who are stressed, depressed, or in troubled relationships are also at greater risk for health problems than their less distressed counterparts. Inflammation, a risk factor for a variety of age-related diseases including cardiovascular disease, Type II diabetes, metabolic syndrome, and frailty, may be one key mechanistic pathway linking distress to poor health. Obesity may further broaden the health implications of stress and depression; people who are stressed or depressed are often overweight, and adipose tissue is a major source of proinflammatory cytokines. Stress, depression, and troubled relationships may have synergistic inflammatory effects: loneliness, subclinical depression, and major depression enhance inflammatory responses to an acute stressful event. The relationship between distress and inflammation is bidirectional; depression enhances inflammation and inflammation promotes depression. Interesting questions emerge from this literature. For instance, some stressors may be more potent than others and thus may be more strongly linked to inflammation. In addition, it is possible that psychological and interpersonal resources may buffer the negative inflammatory effects of stress. Understanding the links among stress, depression, troubled relationships, and inflammation is an exciting area of research that may provide mechanistic insight into the links between distress and poor health.

Symptomatic menopausal transition increases the risk of new-onset depressive disorder in later life: a nationwide prospective cohort study in Taiwan

INTRODUCTION

The role of the menopausal transition and associated menopausal symptoms in the occurrence of depressive disorders has been discussed and debated for a long time. Most previous clinical studies had limited case samples, and did not control the attributable risk of medical comorbidities.

METHODS

Patients with a diagnosis of symptomatic menopausal transition and without a psychiatric history were enrolled in 2000 in Taiwan, and compared with age-matched controls (1∶4). These subjects were followed to the end of 2010 to investigate the association between symptomatic menopausal transition and new-onset depressive disorder; the effect of medical comorbidities was also assessed.

RESULTS

A total of 5,837 women with symptomatic menopausal transition were identified, and compared with 23,348 age-matched controls in 2000. The follow-up showed that symptomatic menopausal transition was an independent risk factor for major depression (hazard ratio[HR]: 2.18, 95%CI: 1.79∼2.65) and any depressive disorder (HR: 2.34, 95%CI: 2.08∼2.63) after adjusting age at enrollment, monthly income, residence location, level of urbanization, and comorbid medical diseases. In addition, medical comorbidities, including cerebrovascular disease (HR: 1.77, 95% CI: 1.52∼2.07), cardiovascular diseases (HR: 1.35, 95% CI: 1.15∼1.57), congestive heart failure (HR: 1.35, 95% CI: 1.04∼1.75), and liver diseases (HR: 1.19, 95% CI: 1.03∼1.36) increased the risk of developing any depressive disorder.

CONCLUSION

Our population cohort study, with the largest study sample and medical record diagnosis thus far, supports an association between symptomatic menopausal transition and depressive disorder in midlife women, and an increased risk of depressive disorder with medical comorbidities.