Social isolation and depressed mood are associated with elevated serum leptin levels in men but not in women

Impact of social, familial and personal factors on depressive symptoms in middle-aged and older adults from the national CHARLS cohort

BACKGROUND

This study aimed to evaluate whether social, familial and personal factors can predict incident and prevalent depressive symptoms in Chinese adults aged ≥ 45 years using data from the China Health and Retirement Longitudinal Study (CHARLS).

METHODS

Study subjects without depressive symptoms from CHARLS at baseline were enrolled. Depressive symptoms were defined by the 10-item Center for Epidemiologic Studies Depression Scale. Statistical adjustment, subgroup exploration and unmeasured confounding assessment were undertaken to derive reliable estimates.

RESULTS

1681 (27.04%) of 6215 subjects who had no depressive symptoms in 2011, suffered one or more depressive symptoms in 2018. Multivariate analyses showed that number of grandchildren (odds ratio [95% confidence interval]: 1.06 [1.02, 1.10]), social activity score (0.95 [0.91, 0.98]), instrumental activities of daily living (IADL) (1.35 [1.11, 1.65]) and number of comorbidities (1.16 [1.10, 1.22]) were independently and significantly associated with the presence of incident depressive symptoms. Further categorization revealed significance for social activity score (odds ratio [95% confidence interval]: 0.78 [0.69, 0.89] and 0.71 [0.53, 0.95] for 1-5 and > 5 vs. 0), IADL (1.35 [1.11, 1.65] for yes vs. no) and number of comorbidities (1.38 [1.20, 1.58], 1.44 [1.16, 1.81] and 2.42 [1.54, 3.80] for 1-2, 3-4 and > 4 vs. 0) associated with incident depressive symptoms. Restricting analysis to wave IV data in 2018 observed significant association of number of grandchildren, social activity score, IADL and number of comorbidities with prevalent depressive symptoms.

CONCLUSIONS

The present study findings support the marked contribution of social activity score, IADL and number of comorbidities to incident and prevalent depressive symptoms in Chinese middle-aged and older adults.

Association of social isolation and depressive symptoms with workplace productivity loss in a multi-ethnic Asian study

The association of health-related productivity loss (HRPL) with social isolation and depressive symptoms is not well studied. We aimed to examine the association of social isolation and depressive symptoms with productivity loss. Data on employed adults aged 21 years and above were derived from the Population Health Index (PHI) study conducted by the National Healthcare Group (NHG) on community-dwelling adults, residing in the Central and Northern residential areas of Singapore. The severity of depressive symptoms and social isolation were assessed using the 9-item Patient Health Questionnaire (PHQ-9) and Lubben Social Network Scale-6 (LSNS-6) respectively. Productivity loss was assessed using the Work Productivity and Activity Impairment Questionnaire (WPAI). We used Generalised Linear Models, with family gamma, log link for the analysis. Models were adjusted for socio-demographic variables (including age, gender, ethnicity, employment status, housing type) and self-reported chronic conditions (including the presence of diabetes, hypertension, and dyslipidemia). There were 2,605 working (2,143 full-time) adults in this study. The median reported percentage of unadjusted productivity loss was 0.0%, 10.0% and 20.0% for participants with social isolation, depressive symptoms, and both, respectively. In the regression analysis, mean productivity loss scores were 2.81 times (95% Confidence Interval: 2.12, 3.72) higher in participants with depressive symptoms than those without. On the other hand, social isolation was not found to be associated with productivity loss scores (1.17, 95% Confidence Interval: 0.96, 1.42). The interaction term of depressive symptoms with social isolation was statistically significant, with an effect size of 1.89 (95% Confidence Interval: 1.04, 3.44). It appeared that productivity loss was amplified when social isolation and depressive symptoms were concomitant. Our results suggested significant associations of social isolation and depressive symptoms with productivity loss. These findings highlighted the potential impact of social isolation and depressive symptoms on work performance and drew attention to the importance of having a holistic work support system that promotes social connectedness, mental wellbeing and work productivity.

Recurrent depression predicts high leptin concentrations in patients with coronary artery disease over an 18-months follow-up period: Findings from the prospective multicenter randomized controlled SPIRR-CAD Trial

BACKGROUND

Leptin, an adipokine suspected to play a role in coronary artery disease (CAD), may also be associated with deteriorated mental health. We investigated the prospective impact of recurrent depressed mood (RDM) on heightened plasma leptin levels in CAD patients.

METHODS

Derived from the randomized SPIRR-CAD trial, plasma leptin were measured by the Human Leptin DuoSet ELISA at baseline in 539 patients (including 115 (21.3 %) women and 424 (78.7 %) men) and in 373 participants after 18-months follow up (T3). RDM was based on the clinical course from baseline to follow-up assessed by the Hamilton Depression Rating Scale (HAMD). Multivariate binary logistic regression models identified predictors for heightened leptin at T3.

RESULTS

At baseline, highest leptin level (3rd tertile) was associated with type 2 diabetes (p = 0.009), heart failure symptoms (NYHA III) (p < 0.001), female sex and BMI ≥30 (p < 0.001) but not with age and depression. At study endpoint (T3), RDM was associated with a substantially increased risk of experiencing the highest plasma leptin level (OR 2.92 (95 % CI 1.27-6.75)) followed by increased NT-proBNP (the most prominent indicator of CHF) with an OR of 2.73 (1.22-6.11) - both after adjustment for concurrent factors including weight gain (diff BMI T3-T1) over the study period - the latter accounting for an OR of 1.41 (1.17-1.70).

LIMITATIONS

Findings are limited to people of Caucasian ancestry which prevents being generalized to other ethnicities. Although relying upon a prospective design, reverse causality cannot be excluded but is unlikely.

CONCLUSIONS

In CAD patients, RDM is a significant predictor of heightened leptin -a finding opening room for a new pathway of the psychobiological underpinning of depression on CAD risk.

Depression by gender and associated factors among older adults in India: implications for age-friendly policies

Inspite of implementing policies to control mental health problems, depression remains a severe health concern among older adults in India. We examined self-reported differences in the depression among older men and women in India and examined associated factors for gender differences in depression at the population level. We utilized nationally representative data from the Longitudinal Aging Study in India (LASI) wave I, for years 2017-2019. Our analytical sample comprised of 30,637 older adults ages 60 years and above (14,682 men and 15,655 women). We conducted descriptive statistics and Chi-Square tests followed by binary logistic regression and multivariate decomposition analyses to examine our study objectives. Depression was reported in - 7.4% (95% CI 7.0, 7.8) of older men and 9.5% (CI 9.1, 10.0) of older women. Poor self-rated health, multimorbidity status, physical activity, difficulty in activities of daily living (ADL) and instrumental ADL (IADL) were the significant health-related factors associated with depression among older men and women. Not being satisfied with one's life, not being satisfied with their present living arrangement, receiving any type of ill-treatment, and being widowed were the significant factors associated with depression among older men and women. We found gender disparity in self-reported depression. Marital status contributed-to 36.7% of the gender gap in depression among older adults. Additionally, ADL and IADL difficulties among men and women contributed to 17.6% and 34.0%, gender gap, self-rated health contributed to 18.8% gap, whereas not having equal social participation (4.4%) and not satisfied in present living arrangements (8.1%) were other factors that contributed to gender gap for depression in India. Depression is a critical and persistent public health problem among-older females in India. Our findings provide a broader framework for policymakers and health practitioners to focus on gender-specific strategies to mitigate this highly emergent problem.

Appetite hormone dysregulation, body mass index, and emotional dysregulation in nonobese adolescents with first-episode schizophrenia, bipolar disorder, and major depressive disorder: a cross-sectional association study

BACKGROUND

Evidence has suggested that emotional dysregulation is a transdiagnostic feature in schizophrenia and major affective disorders. However, the relationship between emotional dysregulation and appetite hormone disturbance remains unknown in nonobese adolescents with first-episode schizophrenia, bipolar disorder, and major depressive disorder.

METHODS

In total, 22 adolescents with schizophrenia; 31 with bipolar disorder; 33 with major depressive disorder; and 41 healthy age-, sex-, and body mass index (BMI)/BMI percentile-matched controls were enrolled for assessing levels of appetite hormones, namely leptin, ghrelin, insulin, and adiponectin. Emotional regulation symptoms were measured using the parent-reported Child Behavior Checklist-Dysregulation Profile.

RESULTS

Adolescents with first-episode schizophrenia, bipolar disorder, and major depressive disorder exhibited greater emotional dysregulation symptoms than the control group (P = .037). Adolescents with bipolar disorder demonstrated higher log-transformed levels of insulin (P = .029) and lower log-transformed levels of leptin (P = .018) compared with the control group. BMI (P < .05) and log-transformed ghrelin levels (P = .028) were positively correlated with emotional dysregulation symptoms.

DISCUSSION

Emotional dysregulation and appetite hormone disturbance may occur in the early stage of severe mental disorders. Further studies are required to clarify the unidirectional or bidirectional association of emotional dysregulation with BMI/BMI percentile and appetite hormones among patients with severe mental disorder.

Quality of life among Iranian major depressive disorder patients: a qualitative study

Background

Research indicates that the prevalence of Major Depressive Disorder (MDD) is high and it reduces patient’s Quality of Life (QoL). Nowadays, in addition to reducing the symptoms of MDD, emphasis is on the concept of QoL as the purpose of treating these patients. However, we still do not know what these patient’s attitudes and perceptions are about QoL. This study aims to clarify the Iranian patient’s attitudes and perceptions of QoL’s meaning through a qualitative paradigm.

Results

During the data analysis, “Agitation factors”, “Destructive effects”, and “Gratifications” were developed as three main themes with 13 main categories, 39 sub-categories, and 879 codes. According to the findings the main priority of patients with MDD was Agitation factors, which plays a remarkable role in the concept of QoL.

Conclusions

MDD leads to deterioration in the QoL of these individuals in different parts. The novelty of this study leads to the creation of a deep and realistic attitude in national and global nurses towards the QoL of majorly depressed patients in order to remove the aggravating factors of the disorder and create a pleasant life based on the adequate and specialized understanding of the consequences of this disorder according to the preferences of patients and provide a suitable quality of life for these patients.

Relationships between social withdrawal and facial emotion recognition in neuropsychiatric disorders

BACKGROUND

Emotion recognition constitutes a pivotal process of social cognition. It involves decoding social cues (e.g., facial expressions) to maximise social adjustment. Current theoretical models posit the relationship between social withdrawal factors (social disengagement, lack of social interactions and loneliness) and emotion decoding.

OBJECTIVE

To investigate the role of social withdrawal in patients with schizophrenia (SZ) or probable Alzheimer's disease (AD), neuropsychiatric conditions associated with social dysfunction.

METHODS

A sample of 156 participants was recruited: schizophrenia patients (SZ; n = 53), Alzheimer's disease patients (AD; n = 46), and two age-matched control groups (SZc, n = 29; ADc, n = 28). All participants provided self-report measures of loneliness and social functioning, and completed a facial emotion detection task.

RESULTS

Neuropsychiatric patients (both groups) showed poorer performance in detecting both positive and negative emotions compared with their healthy counterparts (p < .01). Social withdrawal was associated with higher accuracy in negative emotion detection, across all groups. Additionally, neuropsychiatric patients with higher social withdrawal showed lower positive emotion misclassification.

CONCLUSIONS

Our findings help to detail the similarities and differences in social function and facial emotion recognition in two disorders rarely studied in parallel, AD and SZ. Transdiagnostic patterns in these results suggest that social withdrawal is associated with heightened sensitivity to negative emotion expressions, potentially reflecting hypervigilance to social threat. Across the neuropsychiatric groups specifically, this hypervigilance associated with social withdrawal extended to positive emotion expressions, an emotional-cognitive bias that may impact social functioning in people with severe mental illness.

Metabolic proteins at birth predict early childhood mental health symptoms

Child mental health disorders are the leading cause of disability in children and adolescents worldwide. Biological correlates predict psychosocial outcomes throughout human development; however, less is known about metabolic proteins. Drawing from a longitudinal birth cohort study, Born in Bradford (BiB), we examined the role of infant metabolic proteins at birth in predicting early childhood mental health symptoms at 3 and 5 years. We found that higher leptin predicted more prosocial behavior at age 3. Additionally, a higher leptin-to-adiponectin ratio predicted increased total symptom difficulties. At age 5, we found that higher adiponectin predicted a decreased likelihood of being rated by teachers as meeting or exceeding expectations in the domain of "managing feelings and behaviors" and marginally predicted lower competency in "making relationships" on national developmental milestone evaluations. To our knowledge, this is among the first few studies to prospectively predict mental health symptoms from cord blood metabolic proteins, and the first examining this association with a leptin-to-adiponectin ratio. Our results provide support for the possibility that metabolic proteins at birth forecast risk for mental health symptoms in early childhood.

The role of leptin in indirectly mediating "somatic anxiety" symptoms in major depressive disorder

BACKGROUND

Leptin is a multifunctional hormone secreted from adipose tissue, which plays a core role in regulating energy intake and expenditure. Evidence has demonstrated that leptin receptors are located in brain areas involved in emotional processing, and major depressive disorder (MDD) is characterized by dysfunction of emotional processing. Taken together, these features suggest that leptin may play a potential role in the pathophysiology of MDD. However, the precise roles of leptin in modulating depressive symptoms in MDD remain unclear.

METHODS

Participants [18 drug-naïve MDD patients, 15 unaffected first-degree relatives of MDD patients (FDR-MDD), and 40 healthy controls] completed clinical assessments and provided blood samples for measurement of leptin levels. We evaluated the effect of leptin on clinical status (MDD or FDR-MDD) and symptomatic dimensionalities of MDD using mediation analysis.

RESULTS

We found that leptin was increased in MDD patients and this only predicted "somatic anxiety" symptoms. Furthermore, leptin was a significant and indirect mediator of the association between clinical status (MDD or FDR-MDD) and "somatic anxiety" symptoms.

CONCLUSION

Our finding that leptin was a significant and indirect mediator of clinical status (MDD or FDR-MDD) and "somatic anxiety" symptoms suggests that leptin may indirectly affect somatic depressive symptoms in MDD. Our findings may provide a theoretical basis for novel clinical interventions in MDD.

Leptin polymorphism rs3828942: risk for anxiety disorders?

Leptin is an anorexigenic hormone well recognized by its role in mediating energy homeostasis. Recently, leptin has been associated with psychiatric disorders and interestingly, leptin treatment has shown antidepressant and anxiolytic effects. We examined the association of leptin levels and leptin (LEP) gene rs3828942 polymorphism with anxiety disorders considering sex differences. A cross-sectional population-based study, including 1067 young adults, of whom 291 presented anxiety disorders diagnosed by the Mini International Neuropsychiatric Interview (MINI 5.0). The rs3828942 polymorphism was genotyped by real-time PCR and ELISA measured leptin levels. Leptin levels were not associated with anxiety disorders after adjusting for sex and body mass index (BMI) [ß = - 0.009 (- 0.090-0.072); p = 0.832]. The distribution of rs3828942 genotypes was not associated with anxiety disorders. However, in a sex-stratified sample, the A-allele of rs3828942 polymorphism was associated with risk for GAD in women even when adjusting for confounding variables [OR = 1.87 (1.17-2.98); p = 0.008]. In a subsample of 202 individuals with GAD and control matched by sex and BMI, results suggest an interaction between genotypes and GAD diagnosis based on leptin levels only in the male group [F (1, 54) = 6.464; p = 0.0139]. Leptin is suggested to be related with the neurobiology of anxiety disorders in a sex-dependent manner since women carrying the A-allele of LEP rs3828942 present a higher risk for GAD, while leptin levels seem to be lower in men with GAD carrying A-allele. Studies on the relationship between leptin polymorphisms and levels are scarce and, therefore, further research is necessary.

Social modulation of ageing: mechanisms, ecology, evolution

Human life expectancy increases, but the disease-free part of lifespan (healthspan) and the quality of life in old people may not show the same development. The situation poses considerable challenges to healthcare systems and economies, and calls for new strategies to increase healthspan and for sustainable future approaches to elder care. This call has motivated innovative research on the role of social relationships during ageing. Correlative data from clinical surveys indicate that social contact promotes healthy ageing, and it is time to reveal the causal mechanisms through experimental research. The fruit fly Drosophila melanogaster is a prolific model animal, but insects with more developed social behaviour can be equally instrumental for this research. Here, we discuss the role of social contact in ageing, and identify lines of study where diverse insect models can help uncover the mechanisms that are involved. This article is part of the theme issue 'Ageing and sociality: why, when and how does sociality change ageing patterns?'

Similarities and Differences of Mental Health in Women and Men: A Systematic Review of Findings in Three Large German Cohorts

In Germany, large, population-based cohort studies have been implemented in order to identify risk and protective factors for maintaining health across the life span. The purpose of this systematic review is to analyse findings from three large ongoing cohorts and to identify sex-specific prevalence rates, risk and protective factors for mental health. Published studies from the Cooperative Health Research in the Region Augsburg (KORA), the Study of Health in Pomerania (SHIP) and the Gutenberg Health Study (GHS)), representing the southern, north-eastern and middle parts of Germany, were identified through searches of the databases PubMed and Web of Science. A total of 52 articles was identified from the start of each cohort until June 2019. Articles reporting prevalence rates of mental health [N = 22], explanatory factors for mental health [N = 25], or both [N = 5] were identified. Consistent across cohorts, higher prevalence rates of internalizing disorders were found for women and more externalizing disorders for men. Risk and protective factors for mental health included social factors, lifestyle, physical health, body mass index (BMI), diabetes, genetic and biological factors. In all areas, differences and similarities were found between women and men. The most evident were the sex-specific risk profiles for depression with mostly external risk factors for men and internal risk factors for women. Gender was not assessed directly, therefore we examined whether socioeconomic and family-related factors reflecting gender roles or institutionalized gender could be used as a proxy for gender. Overall, this systematic review shows differences and similarities in prevalence rates and determinants of mental health indicators between women and men. They underline the importance of focussing on sex specific approaches in mental health research and in the development of prevention measures. Current research on mental health still lacks focus on gender aspects. Therefore, an increased focus on sex and gender in mental health research is of great importance.

Metabolic dysregulation in older adults with depression and loneliness: The ATHLOS study

This study aimed to examine how loneliness contributes to metabolic dysregulation among older adults with depression and determine the relative contribution of loneliness to the development of chronic diseases in late adulthood. Harmonised data from the Ageing Trajectories of Health: Longitudinal Opportunities and Synergies (ATHLOS) project were used. Concretely, the sample comprised 6195 participants (53.95% women; M = 61.30 years, SD = 7.11) from three European cohorts. Three groups were considered: control group (CG); depressive symptom episode group (DEP); and a group with depression and loneliness (DEP + LONE). A metabolic score was estimated using anthropometric and blood indicators, by means of multi-indicator multi-causes (MIMIC) modelling and after controlling for sociodemographic and health-related covariates. Group-comparison was based on measurement-invariance procedures. Multimorbidity development was predicted at follow-up considering the study group and relevant covariates. All the analyses were sex-specific. As a result, measurement invariance revealed the influence of group (ΔCFI = -0.017 for male participants and ΔCFI = -0.009 for female ones) on metabolic scores in both sexes. Metabolic scores were significantly lower (i.e., they had more metabolic risk) in DEP + LONE women in comparison to women from the other groups. DEP men showed the lowest metabolic scores but those from the DEP + LONE group showed meaningfully lower scores than CG men (d = 1.35). In terms of multimorbidity prediction, DEP + LONE group membership significantly predicted the outcome in both sexes; DEP group membership significantly predicted multimorbidity at follow-up in women. In summary, these results highlight the relevant contribution of loneliness in depression-related metabolic dysregulation in the short- (concurrent metabolic risk) and long-term (chronic condition development). Moreover, sex-specific mechanisms seem to be involved in metabolic alterations of depressed people showing loneliness feelings. This study calls for action to reduce the impact of loneliness in old age and to promote healthy ageing.

The course of depression in late life: a longitudinal perspective

Depression in old age deserves special attention in view of the fact of progressive population ageing, because of the way in which depression and risk factors interact in this period of life and the particularly negative impact of late-life depression on health and quality of life. This editorial aims to provide some insight into longitudinal aspects of depression in old age. Depression may follow varying trajectories (e.g. episode emergence, recurrence) across the lifespan. Late-life depression is not an exception. A symptom-based approach is presented as an appropriate research method to study the predictors and course of affective syndromes in old age. Findings from our studies on depressive symptom trajectories in old age revealed that participants with a course of unremitting elevated symptoms showed the highest levels of loneliness across the trajectory groups and that participants with subclinical symptoms also showed higher levels of loneliness than their counterparts with a minimal-symptom course trajectory. This highlights the need to address loneliness as a way of dealing with depression in old age.

Self-quarantine and weight gain related risk factors during the COVID-19 pandemic

Objective

The purpose of this study was to quantify the impact that self-quarantine has on behaviors associated with weight gain.

Methods

This was a quantitative descriptive/correlational research design. Research announcement was sent out via Facebook to 1200 possible participants. Six surveys were condensed into a single Survey Monkey questionnaire for participants to complete. Surveys asked questions relating to risk factors linked to weight gain.

Results

Ninety-one percent of our sample stated they spend more time at home now than before COVID-19. Twenty-two percent of the sample stated they gained 5–10 pounds. Within those who gained 5–10 pounds, there was a significantly higher percentage of the total sample who reported they increased eating in response to sight and smell (p = .048), eating in response to stress (p = .041), and snacking after dinner (p = .016) compared to those who stated they did not change those behaviors at all. There were significant relationships between predictor variables hours of sleep per night and physical activity time on reported weight gain (r = −.195, p = .021, r = −.155, p = .034, respectively).

Conclusion

Risk factors for weight gain during self-quarantine are inadequate sleep, snacking after dinner, lack of dietary restraint, eating in response to stress, and reduced physical activity.

Combined Fluoxetine and Metformin Treatment Potentiates Antidepressant Efficacy Increasing IGF2 Expression in the Dorsal Hippocampus

An increasing number of studies show that selective serotonin reuptake inhibitors (SSRIs) exert their therapeutic action, at least in part, by amplifying the influence of the living environment on mood. As a consequence, when administered in a favorable environment, SSRIs lead to a reduction of symptoms, but in stressful conditions, they show limited efficacy. Therefore, novel therapeutic approaches able to neutralize the influence of the stressful environment on treatment are needed. The aim of our study was to test whether, in a mouse model of depression, the combined administration of SSRI fluoxetine and metformin, a drug able to improve the metabolic profile, counteracts the limited efficacy of fluoxetine alone when administered in stressful conditions. Indeed, metabolic alterations are associated to both the onset of major depression and the antidepressant efficacy. To this goal, adult C57BL/6 male mice were exposed to stress for 6 weeks; the first two weeks was aimed at generating a mouse model of depression. During the remaining 4 weeks, mice received one of the following treatments: vehicle, fluoxetine, metformin, or a combination of fluoxetine and metformin. We measured liking- and wanting-type anhedonia as behavioral phenotypes of depression and assessed the expression levels of selected genes involved in major depressive disorder and antidepressant response in the dorsal and ventral hippocampus, which are differently involved in the depressive symptomatology. The combined treatment was more effective than fluoxetine alone in ameliorating the depressive phenotype after one week of treatment. This was associated to an increase in IGF2 mRNA expression and enhanced long-term potentiation, specifically in the dorsal hippocampus, at the end of treatment. Overall, the present results show that, when administered in stressful conditions, the combined fluoxetine and metformin treatment may represent a more effective approach than fluoxetine alone in a short term. Finally, our findings highlight the relevance of polypharmacological strategy as effective interventions to increase the efficacy of the antidepressant drugs currently available.

Biological Sex Differences in Depression: A Systematic Review

Depression is the leading cause of disability worldwide, and its prevalence is 2 times higher in women than in men. There is, however, a lack of data on sex-specific pathophysiology of this disorder. The purpose of this systematic review is to identify the biological sex differences found in major depressive disorder (MDD) in studies published in the last 10 years. We conducted a literature search using the Medline, PsycInfo, PubMed, and Web of Science databases, selecting English-language studies that included physiological measures compared by sex in addition to MDD. We identified 20 relevant studies, which consisted primarily of mixed methodology and samples. The reported physiological measures comprised a variety of serum biomarkers, gene mRNA expression, and brain activity. Findings suggest different biological patterns in those with MDD depending on sex. Specifically, women presented higher levels of inflammatory, neurotrophic, and serotonergic markers and a stronger correlation between levels of some inflammatory and neurotrophic factors and the severity of symptoms. This review provides information about possible different biological patterns for women and men with depressive disorder and may have important implications for treatment. Future research should include homogeneous samples; make comparisons based on sex, control sex hormone fluctuations and pharmacological treatment; and use consistent criteria for evaluating psychobiological changes in MDD.

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.

Epidemiology in Germany-general development and personal experience

Did you ever hear about epidemiology in Germany? Starting from an epidemiological desert the discipline has grown remarkably, especially during the last 10-15 years: research institutes have been established, research funding has improved, multiple curriculae in Epidemiology and Public Health are offered. This increase has been quite steep, and now the epidemiological infrastructure is much better. Several medium-sized and even big population cohorts are ongoing, and the number and quality of publications from German epidemiologists has reached a respectable level. My own career in epidemiology started in the field of environmental health. After German reunification I concentrated for many years on environmental problems in East Germany and observed the health benefits after improvement of the situation. Later, I concentrated on population-based cohorts in newborns (GINI/LISA) and adults (KORA, German National Cohort), and on biobanking. This Essay describes the development in Germany after worldwar 2, illustrated by examples of research results and build-up of epidemiological infractructures worth mentioning.

Mood disorders: A potential link between ghrelin and leptin on human body?

Leptin and ghrelin are two hormones associated with multiple physiological functions, especially energy balance. Leptin is an adipocyte-secreted hormone discovered in 1950 and ghrelin which was found in 1999, is a peptide hormone produced and secreted in the stomach. A number of previous studies showed that these hormones could be associated with different types of mood disorders. The results of previous studies, nevertheless, are confounded by diverse sample selection and different methodologies. A search for related articles in the PubMed database was attempted. The search covered studies, reports, reviews and editorials published in the last ten years. Older references served as auxiliary sources for comparison purposes. However, due to the different results of the studies, there is a need for more investigation in order to establish the exact biochemical mechanisms that are responsible for these diseases and ghrelin’s and leptin’s effects on mood.

Is there a role for leptin in the reduction of depression symptoms during weight loss therapy in obese adolescent girls and boys?

Several studies have sought to clarify the association between adolescent obesity and psychological distress. Recently, a biological link between leptin resistance and depression has been proposed. The aim of the present study was to examine changes in leptin concentrations as a potential predictor of reduced depression symptoms in obese adolescents during long-term interdisciplinary weight loss therapy. Seventy-five obese adolescents (age: 16.28±2.37 years; BMI: 35.65±4.64 kg/m2) engaged in a long-term interdisciplinary therapy for weight loss. They were evaluated at baseline and after 1 year of treatment for body composition, serum analyses and depression symptomatology. After therapy, body mass BMI, fat mass (% and kg), waist circumference, visceral, subcutaneous and visceral/subcutaneous fat and depression symptoms decreased and lean mass (%) increased significantly. There was an improvement in inflammatory profiles with a significant reduction in leptin and increase in adiponectin. Regression analyses showed that decreased leptin predicted amelioration in depression symptoms independent of age, gender and changes in visceral fat, body mass, fat mass (%) and leptin/adiponectin ratio. These associations appear stronger in girls than boys. The attenuation of hyperleptinemia appears to play an important role in the association between weight loss and depression, particularly in obese girls.

Leptin in depressive episodes: is there a difference between unipolar and bipolar depression?

OBJECTIVE

The present study investigated whether peripheral leptin levels are associated with current depressive episodes in a cross-sectional study nested within a population-based study.

METHODS

The Mini-International Neuropsychiatric Interview (MINI) 5.0 was used to assess the presence of current depressive episodes. The sample was composed of 206 subjects (103 controls and 103 subjects with a current depressive episode) paired by gender, BMI and age. Medication use and lifestyle characteristics were self-reported.

RESULTS

Serum leptin levels were lower in currently depressive subjects (10.9 ± 12.0 ng/ml) than in the control group (20.3 ± 24.0 ng/ml; p = 0.023). According to the clinical diagnosis, individuals with bipolar depression present lower leptin levels (8.4 ± 8.1 ng/ml) than those with unipolar depression (12.0 ± 13.4 ng/ml) and the control group (20.3 ± 24.0 ng/ml; p = 0.031). In addition, ANCOVA showed that leptin is an independent factor associated with current depressive episodes (p = 0.018).

CONCLUSION

A decreased leptin level might be a useful peripheral marker associated with depressive episodes in the context of bipolar disorder.

Changes in circulating leptin levels during acute stress and associations with craving in abstinent smokers: a preliminary investigation

Recent research suggests a role for the appetite hormone leptin in cigarette smoking. This study examined patterns of change in leptin in response to stress and associations with craving during the initial phase of a quit attempt. Thirty-six smokers (average age±SEM, 33.4±2.4) interested in smoking cessation set a quit day and were required to be abstinent for 24h. After, they completed a laboratory session including public speaking and cognitive challenges, and attended 4 weekly post-cessation assessments. Blood samples and self-report measures were collected throughout the laboratory session. The results indicated that leptin levels significantly increased following exposure to acute stress. We also found positive correlations between leptin and craving for cigarettes. No differences were observed in leptin levels between smokers who maintained abstinence for 4 weeks and those who relapsed during this period. These findings suggest that leptin levels may change in response to stress and that leptin could be a useful marker of craving for smoking.

Effects of a caloric restriction weight loss diet on tryptophan metabolism and inflammatory biomarkers in overweight adults

PURPOSE

Recent data suggest that chronic low-grade inflammation, a characteristic of obesity, is associated with altered tryptophan (Trp) and tyrosine (Tyr) metabolism and plays a role in neuropsychiatric symptoms. The present study assessed the effect of an extreme short-term diet on Trp breakdown and inflammatory biomarkers in overweight adults.

METHODS

Thirty-eight overweight participants (16 women, 22 men; average body mass index: 29 kg/m², mean age 52.8 years) were randomized into two diet groups: a very low kcal diet group (VLCD; Ø 600 kcal/day, n = 21) and a low kcal diet group (LCD; Ø 1,200 kcal/day, n = 17). Assays included the measurement of Trp, kynurenine (Kyn), and their ratio, neopterin, phenylalanine (Phe), Tyr, as biologic markers; leptin, plasma insulin, glucose, and homeostatic model assessment-insulin resistance; and interleukin 6, tumor necrosis factor alpha, and C-reactive protein, as biochemical and inflammatory markers at baseline and after 2 weeks of treatment.

RESULTS

Weight loss diet lowered leptin levels in both groups by 46%, although not reaching significance. Trp and Kyn decreased significantly by 21 and 16% for VLCD and by 15 and 17% for the LCD group, respectively. A significant reduction in Phe was only seen after VLCD. Inflammatory biomarkers, neopterin, and Tyr were not significantly altered during the study period. Leptin was significantly correlated with Trp breakdown before and after the intervention (P < 0.02).

CONCLUSIONS

Since disturbed metabolism of Trp affects biosynthesis of serotonin and might be associated with increased susceptibility for mood disturbances and carbohydrate craving, strategies to supplement Trp while dieting could be highly useful in treating uncontrolled weight gain or in preventing neuropsychiatric symptoms.

Peer problems are associated with elevated serum leptin levels in children

BACKGROUND

Leptin is thought to act as an important mediator in stress reactions. To date, no study has examined the association between psychological stress and leptin levels in children. This study aimed to assess the association between emotional symptoms and peer problems and serum leptin levels in children aged 10 years of the two population-based GINI-plus and LISA-plus birth cohorts.

METHOD

Cross-sectional data from 2827 children aged 10 years were assessed with regard to leptin concentrations in serum and behavioral problems using the parent-reported Strengths and Difficulties Questionnaire (SDQ). Linear regression modeling was applied to determine the likelihood of elevated leptin levels in children with emotional symptoms and peer problems, controlling for socio-economic status (SES), body mass index (BMI), fasting serum leptin levels, pubertal development and sex hormones.

RESULTS

We found that increases in emotional symptoms (exp β adj = 1.03, s.e. = 0.02, p < 0.04) and peer problems (exp β adj = 1.05, s.e. = 0.01, p = 0.0001) were significantly associated with higher serum leptin levels controlled for BMI and sociodemographic factors. Similar results were found when the fasting serum leptin sample was examined (exp β adj = 1.08, s.e. = 0.04, p = 0.0294). Gender-stratified analyses showed a significant relationship between serum leptin and peer problems in girls (exp β adj = 1.05, s.e. = 0.02, p = 0.03), and a borderline significant association in boys (exp β adj = 1.04, s.e. = 0.02, p = 0.05).

CONCLUSIONS

Children with peer problems have higher stress and eat more, acquire a higher body fat mass and thus, through increased leptin resistance, exhibit higher leptin levels.

Circulating insulin and leptin in women with and without premenstrual disphoric disorder in the menstrual cycle

Premenstrual dysphoric disorder (PMDD) is a syndrome related with mood and appetite changes during the late luteal phase. Leptin and insulin are the hormones related to appetite, and leptin may have a role in reproductive functions and mood. Our aim was to determine whether there are differences in serum leptin and insulin levels between women with and without PMDD during the follicular and luteal phases. In this study, 20 women with PMDD and 18 women without PMDD were included. Fasting blood glucose, insulin, leptin, progesterone levels and HOMA-IR were measured in the follicular and luteal phases separately. Repeated-measures analysis of variance revealed significant interactions for serum leptin, insulin and HOMA-IR levels between the diagnosis of PMDD and menstrual phases (F = 5.4, p = 0.025; F = 5.4, p = 0.026; and F = 4.7, p = 0.036, respectively). A significant correlation was found between progesterone and insulin levels in subjects without PMDD in the luteal phase (r = 0.58, p = 0.01). Whether the alterations in serum leptin and insulin are related with the changes of appetite and mood in PMDD or secondary to other factors should be clarified.

To live alone and to be depressed, an alarming combination for the renin-angiotensin-aldosterone-system (RAAS)

INTRODUCTION

The renin-angiotensin-aldosterone-system (RAAS) is one of the most important systems involved in the pathogenesis of cardiovascular diseases. Its role in stress response has been generally neglected, although the progression of cardiovascular disease is considerably increased in the presence of stress and especially in the presence of depression risk. With the present analysis we aimed to evaluate whether the activity of the RAAS correlates with depressive symptomatology and with chronic stress. Moreover, we aimed to analyse whether stress response is altered in the presence of depressed symptomatology. We chose "living alone" to be our paradigm of chronic stress.

METHODS AND RESULTS

Aldosterone and renin levels were assessed in 1743 (829 men, 914 women) from the population-based KORA study (Cooperative Health Research in the Region of Augsburg). The relationship between aldosterone, renin levels and the different combinations of living alone and depressive symptomatology was examined in three different multiple linear regression models adjusted for age, sex, creatinine levels, potassium levels, body mass index (BMI) and bio-behavioural factors. Neither "living alone" nor depressive symptomatology alone were associated with an activation of the RAAS, but the combination of living alone and depressive symptomatology yielded a highly significant increase in the aldosterone (p<0.01) and renin level (p=0.03).

CONCLUSION

Our findings show that depressive symptomatology is associated with a hyper-responsiveness to chronic stress. Under the condition of chronic stress depressed individuals have an activated RAAS. Activation of the RAAS might explain the known increased risk of negative cardiovascular disease outcomes in this group.

Association between social isolation and inflammatory markers in depressed and non-depressed individuals: results from the MONICA/KORA study

INTRODUCTION

Depressed individuals not only suffer from chronic low grade inflammation, but also exhibit an inflammatory hyper-responsiveness to acute stress. We investigate whether chronic stress also induces an exaggerated inflammatory response in individuals with increased depression features. As model for chronic stress, social isolation was chosen.

METHODS

Interleukin (IL)-6 and hs-CRP levels were assessed in 1547 subjects (847 men and 700 women), derived from the population-based MONICA/KORA study. Standardized questionnaires were used to assess depressed mood (depression and exhaustion subscale) and social isolation (social network index). The relationship between the two inflammatory markers, social isolation and depressed mood was examined taking into account interactions social isolation × depressed mood using multivariable linear regression models, adjusted for age, BMI, smoking, alcohol, and physical activity. Analyses were performed in men and women separately.

RESULTS

We observed a significant interaction between depressed mood and social isolation regarding IL-6 and hs-CRP, respectively in men (p-value=0.02 for IL-6 and <0.01 for hs-CRP), evidencing a substantial synergistic effect of social isolation, and depressed mood on inflammatory responses. Furthermore, depressed and socially isolated men had highly significantly elevated IL-6 levels (geometric mean: 3.76 vs. 1.92 pg/ml, p-value <0.01) and heightened hs-CRP levels (geometric mean: 2.01 vs. 1.39 mg/l, p=0.08) in comparison with non-depressed and socially integrated men. In women, no significant associations were seen.

CONCLUSION

The interaction of depressed mood and social isolation elicits a substantial synergistic impact on inflammatory markers in men, but not in depressed women.

Sleep disturbances and depressed mood: a harmful combination associated with increased leptin levels in women with normal weight

Leptin, involved in energy regulation and contributor to cardiovascular disease, has been implicated to play a role in depression and sleep disturbances, two closely intertwined conditions. Previous results investigating leptin level alterations either in sleep disorders or in depression have been inconsistent. We investigate the association between leptin levels and the different combinations of depressed mood and sleep disturbances in 1369 subjects (706 men, 663 women), derived from the population-based MONIKA/KORA study. As leptin regulation is known to differ by sex and weight, analyses were performed in normal weight and overweight men and women separately. We found a highly significant association between leptin levels and the combination of depressed mood and sleep disturbances in normal-weight women (BMI ≤ 25) (p<0.01). No associations were found in men and in overweight women. Our results suggest that leptin regulation in depressed mood and sleep disturbances very much depend on sex and weight.

[Depression. An underestimated risk for the development and progression of coronary heart disease]

The aim of this article is to provide an overview on depression as a risk factor for the onset and follow-up of cardiovascular disease (CVD). In brief, the current state of psychobiological mechanisms bridging the gap between affective states and somatic consequences are presented. Four meta-analyses dealing with depression as a CVD risk factor in apparently healthy populations with >100,000 participants included, extracted an adjusted effect estimator of 1.60-1.90. Depressed subjects present with an unhealthier lifestyle (nutrition, smoking, physical activity). Three major psychobiological pathways directly acting on the circulatory system are under discussion: (1) hyperregulation of the autonomic nervous system (e.g., increased mean heart rate, increased heart rate responses, impaired heart rate variability), (2) overshooting stress responses of the endocrine system with impaired feedback mechanisms (e.g., for cortisol release), and (3) the immune system with dysregulated release of acute phase proteins and proinflammatory cytokines, all involved in a bidirectional crosstalk with the patient's affective state and leading to platelet activation and flow mediated endothelial (dys-)function. Nonadherence and adverse side effects of medications also contribute to the lethal properties of depression in CVD.