The association between leptin and depressive symptoms is modulated by abdominal adiposity

Association between visceral adiposity and generalized anxiety disorder (GAD)

BACKGROUND AND OBJECTIVES

Due to an increased rate of inflammation in generalized anxiety disorder (GAD), insight into the mediating factors in the onset and recurrence of the inflammatory response can help to achieve novel treatments for alleviating the risk of GAD. In the current study, we aimed to evaluate the possible relationship between visceral adipose tissue (VAT) as an important intermediary in inflammation pathways and GAD in participants of the Employees' Health Cohort Study of Iran (EHCSIR).

METHOD

We analyzed the data from 3889 included participants aged > 18 years in the EHCSIR study, which were collected from 2017 to 2020. Lifetime and 12-month GAD were assessed using the Composite International Diagnostic Interview (CIDI-2.1) questionnaire. The adjusted prevalence ratio was computed to evaluate the association between GAD and visceral adiposity index (VAI), GAD and visceral fat area (VFA), GAD and body mass index (BMI) and ultimately GAD and waist circumference (WC) in males and females using STATA software.

RESULTS

Log-binomial analysis showed a higher prevalence ratio of 12-month GAD associated with VFA in women [PR: 1.42, CI: 1.07-1.87, P: 0.015]. The prevalence of lifetime GAD was higher in obese women (BM1 > 30) [PR: 2.35, CI: 1.07-5.13, P:0.03] than in women with normal BMI. Women with higher VAI were also significantly more likely to suffer lifetime GAD [PR: 1.25, CI: 1.05]. 1.48, P:0.01]. In males, the prevalence of lifetime diagnosed GAD per 1 standard deviation increase in VFA was 0.65 [CI: 0.46-0.91, P: 0.01].

CONCLUSION

Visceral adiposity as a positive agent was associated with GAD prevalence in women. The presence of GAD symptoms showed no relationship to VFA in men.

Gender Difference of the Association between Energy Intake Expenditure Balance and Depression among Korean Adults: A Cross-Sectional Study from the 2014, 2016, and 2018 Korea National Health and Nutrition Examination Survey

BACKGROUND

Diet and physical activity are key factors related to depressive mood. Previous studies have demonstrated the effects of diet and physical activity on depression. However, the effect of energy intake-expenditure balance (EIEB) on mental health has not been fully evaluated. This study aimed to analyze the association between EIEB and depression.

METHODS

A total of 13,460 participants (5,660 men and 7,800 women) aged ≥19 years were obtained from the 2014, 2016, and 2018 Korea National Health and Nutrition Examination Survey (KNHANES). EIEB was defined as the difference between the daily energy intake and energy expenditure. Energy intake was calculated and provided by the KNHANES using a 24-hour recall survey. Energy expenditure was estimated as the sum of basal metabolic rate and physical activity. Logistic regression analyses were used to investigate the association between sex-specific quartile groups (Q1-Q4) of EIEB and depression after adjusting for socioeconomic status, body mass index, lifestyle factors, and underlying diseases.

RESULTS

Women in Q3 of EIEB (211-669 kcal) had a significantly lower risk of depression (odd ratio [OR], 0.78; 95% confidence interval [CI], 0.67-0.92) than those in Q1 of EIEB (<-167 kcal). The adjusted ORs of depression were 0.87 (95% CI, 0.75-1.02) in Q2 and 0.86 (95% CI, 0.74-1.01) in Q4, with P for trend=0.030. There were no significant associations between the EIEB quartile groups and depression in men after adjusting for potential confounders (P for trend=0.564).

CONCLUSION

Our results suggested that the EIEB is negatively associated with depression in Korean women.

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.

Leptin, but not ghrelin, is associated with food addiction scores in a population-based subject sample

BACKGROUND

Ghrelin and leptin are both peptide hormones and act as opposing players in the regulation of hunger, satiety and energy expenditure. Leptin reduces appetite and feelings of hunger and is secreted mainly by adipocytes, while ghrelin increases appetite and food intake and reduces metabolic rate. Both hormones have been implicated in addictive disorders. Ghrelin was shown to have pro-addictive effects while leptin's role in addiction yields more conflicting results. Their involvement in the regulation of both food intake and addictive behaviors make them interesting candidates when investigating the regulation of food addiction. However, only few human studies have been performed and large-scale studies are lacking to date. We aimed to investigate the association between total ghrelin and leptin serum levels with scores in the Yale Food Addiction Scale (YFAS).

METHODS

Subjects were recruited in the LIFE Adult cohort. 909 subjects were included in the analysis and we performed univariate multiple linear regression models, adjusted for age, sex (in total group analyses only), alcohol consumption, smoking status, BMI scores, cortisol concentrations, Center for Epidemiological Studies Depression Scale (CES-D) and the 7-item Generalized Anxiety Disorder Scale (GAD-7) sum scores. The dependent variable was the YFAS score.

RESULTS

In men, leptin serum levels showed a significant positive association (standardized β = 0.146; p = 0.012) with the YFAS score. This finding was confirmed in an extreme-group comparison: men in the highest quartile of leptin levels had significantly higher YFAS sum scores than men in the lowest quartile (1.55 vs. 1.18; p = 0.00014). There was no association with YFAS sum score in the total group (standardized β = -0.002; p = 0.974) or in women (standardized β = -0.034; p = 0.674). Total serum ghrelin showed no association with YFAS sum score neither in the total group (standardized β = -0.043; p = 0.196) nor in men (n = 530; standardized β = -0.063; p = 0.135) or women (n = 379; standardized β = -0.035; p = 0.494).

CONCLUSION

Our findings are in line with previous literature and suggest that total ghrelin serum levels are not associated with food addiction scores. Leptin had been previously shown to be associated with food addiction and we confirmed this finding for men in a large, population-based approach.

Association Between Self-rating Depression Scores and Total Ghrelin and Adipokine Serum Levels in a Large Population-Based Sample

Background

Ghrelin and the adipokines leptin and adiponectin have been suggested to be involved in mood and anxiety regulation and to be altered in affective disorders. However, studies investigating the association between ghrelin, leptin and adiponectin and depressive symptomatology are scarce but might contribute to a better understanding of their involvement in mood regulation. We thus aimed investigating the association between depressive symptomatology and total ghrelin as well as leptin and adiponectin serum levels in a large population-based sample.

Methods

Total serum ghrelin, adiponectin and leptin levels were determined in 1666 subjects of a population-based cross-sectional study ("LIFE"). The Center for Epidemiological Studies Depression Scale (CES-D) and the Inventory of Depressive Symptoms - Self Rating (IDS-SR) were administered. Multiple linear regression analyses were conducted to examine the association between total serum ghrelin, leptin and adiponectin and the intensity of depressive symptoms.

Results

In the total sample (n = 1,092), neither ghrelin nor leptin or adiponectin serum levels showed a significant association with CES-D or IDS-SR sum scores (N = 1,092) or in depressed/non-depressed subjects. Leptin serum levels showed a significantly positive association with IDS-SR sum scores in elderly men (≥60 years; β = 0.122, 95% CI: 0.009; 0.236; p = 0.035).

Conclusion

Our study suggests that peripheral levels of ghrelin and adipokines in a cross-sectional study design might not be sufficient to measure their involvement in depression, suggesting that associations are more complex and multi-layered.

Childhood immuno-metabolic markers and risk of depression and psychosis in adulthood: A prospective birth cohort study

BACKGROUND

Metabolic and inflammatory disorders commonly co-occur with depression and psychosis, with emerging evidence implicating immuno-metabolic dysfunction in their aetiology. Previous studies have reported metabolic dysfunction and inflammation in adults with depression and psychosis. However, longitudinal studies testing the direction of association, and the effects of different dimensions of early-life immuno-metabolic dysfunction on adult psychopathology are limited.

METHODS

Using data from 3258 birth cohort participants we examined longitudinal associations of three metabolic hormones (leptin, adiponectin, insulin) at age 9 with risks for depression- and psychosis-spectrum outcomes at age 24. In addition, using nine immuno-metabolic biomarkers (leptin, adiponectin, insulin, interleukin-6, C-Reactive protein, low density lipoprotein, high density lipoprotein, triglycerides, and BMI), we constructed an exploratory bifactor model showing a general immuno-metabolic factor and three specific factors (adiposity, inflammation, and insulin resistance), which were also used as exposures.

RESULTS

Childhood leptin was associated with adult depressive episode (adjusted odds ratio (aOR)= 1.31; 95% CI, 1.02-1.71) and negative symptoms (aOR=1.15; 95% CI, 1.07-1.24), but not positive psychotic symptoms. The general immuno-metabolic factor was associated with atypical depressive symptoms (aOR=1.07; 95% CI, 1.01-1.14) and psychotic experiences (aOR=1.21; 95% CI, 1.02-1.44). The adiposity factor was associated with negative symptoms (aOR=1.07; 95% CI 1.02-1.12). Point estimates tended to be larger in women, though 95% credible intervals overlapped with those for men. In women, the inflammatory factor was associated with depressive episodes (aOR=1.27; 95% CI, 1.03-1.57).

CONCLUSIONS

While general immuno-metabolic dysfunction in childhood may contribute to risks for both psychotic and depressive symptoms in adulthood, childhood adiposity and inflammation appear to be particularly linked to affective (depressive and negative), but not positive psychotic symptoms.

Ghrelin, leptin and high-molecular-weight adiponectin in relation to depressive symptoms in older adults: Results from the Longitudinal Aging Study Amsterdam

BACKGROUND

Ghrelin, leptin and high-molecular-weight (HMW) adiponectin have been linked to depression in middle-aged adults. Pathophysiological mechanisms of depression change as age progresses and it is unclear whether the same associations exist in older adults.

METHODS

We analyzed the associations between ghrelin, leptin and HMW adiponectin and depressive symptoms (Center for Epidemiologic Studies Depression (CES-D) score ≥ 16) in a community-dwelling cohort of 898 participants in a multivariable logistic regression analysis at baseline and after three years of follow-up, were applicable stratified by sex, age and waist-hip-ratio (WHR).

RESULTS

At baseline no significant associations were found. After three years of follow-up ghrelin was associated with higher odds for depressive symptoms (fully adjusted continuous analysis OR 2.27, 95% CI 1.42 - 3.61). There was effect modification for age and WHR, with significant associations in participants younger than 69.7 years (median) and with a WHR below 0.9554 (mean). In the sex-stratified analysis for leptin we found significant associations in men (fully adjusted continuous analysis OR 1.07, 95% CI 1.02 - 1.12). For HMW adiponectin there were no significant associations in the multivariable analysis.

LIMITATIONS

As our cohort consisted of relatively healthy participants with intact cognitive function, selection bias may have contributed to lack of significant baseline associations.

CONCLUSIONS

Our results show significant associations between ghrelin and - for men only - leptin and depressive symptoms after three years of follow up. This may provide a new therapeutic window for treatment of depressive symptoms in older adults, as both ghrelin and leptin are positively influenced by weight loss.

Short Term Caloric Restriction and Biofeedback Enhance Psychological Wellbeing and Reduce Overweight in Healthy Women

Obesity is highly prevalent, causing substantial cardiovascular and mental health morbidity. Women show increased risk for mental health disorders, that is multiplied in obesity and related to cellular and psychological stress that can be targeted by non-pharmacological interventions. A total of 43 women underwent two weeks of caloric restriction, half of which also received 7 h of individualized clinical psychological intervention including psychoeducation, mindfulness, and heart-rate-variability biofeedback. Effects on body mass index (BMI), fatty liver index (FLI), bioimpedance measures, serum parameters, perceived stress (PSS), burn-out susceptibility (burn out diagnostic inventory) and dimensional psychiatric symptom load (brief symptom inventory, BSI) were analyzed with linear mixed effects models. Caloric restriction led to a reduction in BMI, body fat and FLI, decreased serum concentrations of leptin, PSS score, BSI dimensions and global severity index (all p ≤ 0.0001, withstanding Bonferroni–Holm correction). Benefits of add-on biofeedback were observed for BMI reduction (p = 0.041). Caloric restriction was effective in ameliorating both psychological wellbeing and metabolic functions following a BMI reduction. Biofeedback boosted effects on BMI reduction and the combinative therapy may be protective against common progression to mental health and cardiovascular disorders in overweight women while comparing favorably to pharmacological interventions in terms of side-effects and acceptability.

Correlation of lower 2 h C-peptide and elevated evening cortisol with high levels of depression in type 2 diabetes mellitus

BACKGROUND

A number of studies have explored the association between depression and ghrelin, leptin, and cortisol; further, postprandial C-peptide levels have a therapeutic effect on type 2 diabetes mellitus (T2DM). However, the relationship between C-peptide and depression in patients with diabetes, remains unclear. The aim of this study was to explore the association between depression and ghrelin, leptin, cortisol, and C-peptide in patients with diabetes.

METHODS

We enrolled 50 adults without T2DM, 77 non-depressed adults with T2DM (free of Axis-I psychiatric disorders as assessed using the Mental Illness Needs Index (MINI), Patient Health Questionnaire (PHQ-9 score ≤ 4)) and 59 patients with T2DM and depression (PHQ-9 ≥ 7 and positive by the Structured Clinical Interview for DSM-5). The age range of the participants was 45-59 years of age. We compared the above three groups and explored the association between ghrelin, leptin, cortisol, C-peptide, and depression in patients with diabetes. A post-hoc power-analysis was finished.

RESULTS

Compared with the non-depression T2DM group, the depression T2DM group had significantly higher blood glucose fluctuations. Further, compared with the non-depression T2DM and non-diabetic groups, the depression T2DM group had significantly lower levels of post-meal 2-h C-peptide and elevated evening cortisol (p < 0.01). Regression analysis revealed a significant negative correlation between depression severity and 2-h postprandial C-peptide in patients with diabetes (p < 0.01) and a significant positive correlation with midnight cortisol levels (p < 0.01). A post hoc power analysis showed that we had an adequate sample size and met the minimum requirement to attain 80% power. A post hoc power calculation also demonstrated that this study basically achieved power of 80% at 5% alpha level.

CONCLUSIONS

Our findings indicate a correlation of low fasting levels of 2-h C-peptide as well as higher midnight cortisol levels with higher depression severity in middle-aged patients with T2DM.

Depression Heterogeneity and Its Biological Underpinnings: Toward Immunometabolic Depression

Epidemiological evidence indicates the presence of dysregulated homeostatic biological pathways in depressed patients, such as increased inflammation and disrupted energy-regulating neuroendocrine signaling (e.g., leptin, insulin). Alterations in these biological pathways may explain the considerable comorbidity between depression and cardiometabolic conditions (e.g., obesity, metabolic syndrome, diabetes) and represent a promising target for intervention. This review describes how immunometabolic dysregulations vary as a function of depression heterogeneity by illustrating that such biological dysregulations map more consistently to atypical behavioral symptoms reflecting altered energy intake/expenditure balance (hyperphagia, weight gain, hypersomnia, fatigue, and leaden paralysis) and may moderate the antidepressant effects of standard or novel (e.g., anti-inflammatory) therapeutic approaches. These lines of evidence are integrated in a conceptual model of immunometabolic depression emerging from the clustering of immunometabolic biological dysregulations and specific behavioral symptoms. The review finally elicits questions to be answered by future research and describes how the immunometabolic depression dimension could be used to dissect the heterogeneity of depression and potentially to match subgroups of patients to specific treatments with higher likelihood of clinical success.

Appetite changes reveal depression subgroups with distinct endocrine, metabolic, and immune states

There exists little human neuroscience research to explain why some individuals lose their appetite when they become depressed, while others eat more. Answering this question may reveal much about the various pathophysiologies underlying depression. The present study combined neuroimaging, salivary cortisol, and blood markers of inflammation and metabolism collected prior to scanning. We compared the relationships between peripheral endocrine, metabolic, and immune signaling and brain activity to food cues between depressed participants experiencing increased (N = 23) or decreased (N = 31) appetite and weight in their current depressive episode and healthy control participants (N = 42). The two depression subgroups were unmedicated and did not differ in depression severity, anxiety, anhedonia, or body mass index. Depressed participants experiencing decreased appetite had higher cortisol levels than subjects in the other two groups, and their cortisol values correlated inversely with the ventral striatal response to food cues. In contrast, depressed participants experiencing increased appetite exhibited marked immunometabolic dysregulation, with higher insulin, insulin resistance, leptin, CRP, IL-1RA, and IL-6, and lower ghrelin than subjects in other groups, and the magnitude of their insulin resistance correlated positively with the insula response to food cues. These findings provide novel evidence linking aberrations in homeostatic signaling pathways within depression subtypes to the activity of neural systems that respond to food cues and select when, what, and how much to eat. In conjunction with prior work, the present findings strongly support the existence of pathophysiologically distinct depression subtypes for which the direction of appetite change may be an easily measured behavioral marker.

The moderator effect of age in the association between mood and adiposity in the elderly is specific for the subcutaneous adipose compartment: An MRI study

The positive association between obesity and depressive mood in young- and middle-age individuals is a phenomenon with major clinical implications in public health. Interestingly, the trend of this association in older individuals is not clear, given the conflicting results of multiple studies. Since aging is accompanied by changes in body fat distribution, we questioned whether age is a modulator of such association. This study explores the role of age in the association between mood and general (body mass index [BMI]) and abdominal adiposity (waist circumference [WC]) in older adults characterizing the different abdominal adipose tissue compartments (subcutaneous adipose tissue [SAT] and visceral adipose tissue [VAT]) with magnetic resonance imaging (MRI) techniques.

METHODS

One hundred twenty aged community-dwelling individuals (≥50 y of age) were assessed regarding depressive mood (Geriatric Depression Scale) and adiposity (BMI and WC). From these, 96 were assessed for SAT and VAT using MRI.

RESULTS

Using multiple linear regression models, depressive mood was positively associated with BMI, WC, and VAT. Age was a significant moderator of the association between depressive mood and BMI, WC, and SAT: positive in younger participants and null or negative in older participants. On the other hand, higher VAT was significantly associated with a more depressive mood, independently of age.

CONCLUSIONS

This study identifies age as a relevant moderator in the association between depressive mood and adiposity in the elderlies. Furthermore, the body fat compartment analysis revealed that the effect of age is specific for the SAT, suggesting its protective role in depressive mood.

Correlations of serum leptin and leptin resistance with depression and anxiety in patients with type 2 diabetes

AIM

The associations of serum leptin/soluble leptin receptor (sObR) and leptin resistance with symptoms of depression and anxiety were investigated in patients with type 2 diabetes (T2D).

METHODS

We report the results of two cross-sectional studies, performed 2 years apart, that included 216 and 237 T2D patients, respectively. Symptoms of depression and anxiety were assessed with specific questionnaires (Patient Health Questionnaire-9, Center for Epidemiologic Studies Depression Scale, and Generalized Anxiety Disorder-7, respectively). Laboratory data (including leptin and sObR) were collected, and free leptin index (FLI), as an estimate of leptin resistance, was calculated. One hundred forty patients had laboratory data available on both occasions, and were evaluated longitudinally. Simple and multiple correlations between depression/anxiety and parameters of interest were performed.

RESULTS

In both studies, serum leptin levels were higher, whereas resting energy expenditure/leptin ratios were lower in T2D patients with depressive and moderate-severe anxiety symptoms. In the second study, patients with depressive symptoms had higher FLI and lower sObR levels, while those with moderate-severe anxiety only had higher FLI. Depression scores correlated with serum leptin (r = 0.29, [95%CI: 0.14-0.42]; r = 0.32, [95%CI: 0.18-0.45]) and FLI (r = 0.30, [95%CI: 0.15-0.43]; r = 0.32, [95%CI: 0.17-0.45]; P < 0.0001 for all). Multiple regression analyses identified leptin (β = 0.167; t ratio = 1.98) and FLI (β = 2.935, t ratio = 2.44) (P < 0.05 for both) as variables that significantly contributed to depressive symptoms. Depressive symptoms were present in significantly more patients with leptin levels in the highest versus the lowest quartiles on both evaluations (odds ratio: 5.98, 95%CI [1.76-20.32], P < 0.01).

CONCLUSION

Depressive and moderate-severe anxiety symptoms were associated with high leptin concentrations and leptin resistance in T2D patients.

Plasma levels of leptin and adiponectin and depressive symptoms in young adults

Circulating levels of adipokines are known to be associated with depression. This study aimed to investigate a possible association between leptin, adiponectin and dimensional measures of depressive symptoms in young adults with and without psychiatric illness. Total plasma adiponectin and leptin levels were measured in 194 young adults seeking psychiatric ambulatory care and 57 healthy controls. Depressive symptoms were assessed using the Montgomery-Åsberg Depression Self-Rating Scale (MADRS-S). Analysis was performed on men and women separately. P-leptin levels were significantly elevated in patients compared with controls and correlated with total MADRS-S scores in the women. Women with P-leptin in the highest quartile reached a significantly higher MADRS-S score than women in the lowest quartile, but this difference disappeared after adjusting for body mass index (BMI) and antidepressant use. MADRS-S score was associated with P-leptin in female patients without antidepressant use, independently of BMI. There was no association between P-leptin levels and current major depression. P-adiponectin levels were not associated with depressive symptoms or current major depression. The findings indicate that P-leptin levels are associated with depressive symptom severity in young women; however, the association is linked to other factors, which challenges its usefulness as a biomarker for depression in clinical psychiatry.

The association of short-term memory and cognitive impairment with ghrelin, leptin, and cortisol levels in non-diabetic and diabetic elderly individuals

AIMS

This study assessed short-term memory and biochemical indicators with the levels of ghrelin, leptin, and cortisol between cognitive impairment and normal older adults with or without diabetes.

METHODS

We enrolled 286 older adults (aged 65-85 years) with or without diabetes from the local community. Short-term memory was assessed using pictures of common objects; cognitive functioning was assessed using the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA). The physiological indexes assessed were plasma levels of fasting ghrelin and leptin, ghrelin level at 2_h after breakfast, 24-h urinary cortisol value, body mass index, and plasma cortisol levels at 8:00 a.m., 4:00 p.m., and 12:00 p.m.

RESULTS

In both non-diabetic and diabetic subjects, short-term memory was significantly lower in the impaired cognition group (5.99 ± 2.90 in non-diabetic subjects and 4.71 ± 2.14 in diabetic subjects) than in the normal cognition group (8.14 ± 2.23 in non-diabetic subjects and 7.82 ± 3.37 in diabetic subjects). Baseline ghrelin level was significantly lower in the impaired cognition group (9.07 ± 1.13 ng/mL in non-diabetic subjects and 7.76 ± 1.34 ng/mL in diabetic subjects) than in the normal cognition group (10.94 ± 1.53 ng/mL in non-diabetic subjects and 9.93 ± 1.76 ng/mL in diabetic subjects); plasma cortisol levels at 8:00 a.m., 4:00 p.m., and 12:00 p.m. were significantly higher in the impaired cognition group than in the normal cognition group, while no significant difference was observed in plasma levels of fasting leptin between different groups.

CONCLUSIONS

Fasting plasma ghrelin and cortisol levels may be markers of cognitive decline and memory loss. It is possible that adjusting their levels may have a therapeutic effect, and this should be investigated in future studies.

Eating styles in major depressive disorder: Results from a large-scale study

Depressed persons have been found to present disturbances in eating styles, but it is unclear whether eating styles are different in subgroups of depressed patients. We studied the association between depressive disorder, severity, course and specific depressive symptom profiles and unhealthy eating styles. Cross-sectional and course data from 1060 remitted depressed patients, 309 currently depressed patients and 381 healthy controls from the Netherlands Study of Depression and Anxiety were used. Depressive disorders (DSM-IV based psychiatric interview) and self-reported depressive symptoms (Inventory of Depressive Symptomatology) were related to emotional, external and restrained eating (Dutch Eating Behavior Questionnaire) using analyses of covariance and linear regression. Remitted and current depressive disorders were significantly associated with higher emotional eating (Cohen's d = 0.40 and 0.60 respectively, p < 0.001) and higher external eating (Cohen's d = 0.20, p = 0.001 and Cohen's d = 0.32, p < 0.001 respectively). Little differences in eating styles between depression course groups were observed. Associations followed a dose-response association, with more emotional and external eating when depression was more severe (both p-values <0.001). Longer symptom duration was also associated to more emotional and external eating (p < 0.001 and p = 0.001 respectively). When examining individual depressive symptoms, neuro-vegetative depressive symptoms contributed relatively more to emotional and external eating, while mood and anxious symptoms contributed relatively less to emotional and external eating. No depression associations were found with restrained eating. Intervention programs for depression should examine whether treating disordered eating specifically in those with neuro-vegetative, atypical depressive symptoms may help prevent or minimize adverse health consequences.

Genetic Association of Major Depression With Atypical Features and Obesity-Related Immunometabolic Dysregulations

IMPORTANCE

The association between major depressive disorder (MDD) and obesity may stem from shared immunometabolic mechanisms particularly evident in MDD with atypical features, characterized by increased appetite and/or weight (A/W) during an active episode.

OBJECTIVE

To determine whether subgroups of patients with MDD stratified according to the A/W criterion had a different degree of genetic overlap with obesity-related traits (body mass index [BMI] and levels of C-reactive protein [CRP] and leptin).

DESIGN, SETTING, AND PATIENTS

This multicenter study assembled genome-wide genotypic and phenotypic measures from 14 data sets of the Psychiatric Genomics Consortium. Data sets were drawn from case-control, cohort, and population-based studies, including 26 628 participants with established psychiatric diagnoses and genome-wide genotype data. Data on BMI were available for 15 237 participants. Data were retrieved and analyzed from September 28, 2015, through May 20, 2017.

MAIN OUTCOMES AND MEASURES

Lifetime DSM-IV MDD was diagnosed using structured diagnostic instruments. Patients with MDD were stratified into subgroups according to change in the DSM-IV A/W symptoms as decreased or increased.

RESULTS

Data included 11 837 participants with MDD and 14 791 control individuals, for a total of 26 628 participants (59.1% female and 40.9% male). Among participants with MDD, 5347 (45.2%) were classified in the decreased A/W and 1871 (15.8%) in the increased A/W subgroups. Common genetic variants explained approximately 10% of the heritability in the 2 subgroups. The increased A/W subgroup showed a strong and positive genetic correlation (SE) with BMI (0.53 [0.15]; P = 6.3 × 10-4), whereas the decreased A/W subgroup showed an inverse correlation (-0.28 [0.14]; P = .06). Furthermore, the decreased A/W subgroup had a higher polygenic risk for increased BMI (odds ratio [OR], 1.18; 95% CI, 1.12-1.25; P = 1.6 × 10-10) and levels of CRP (OR, 1.08; 95% CI, 1.02-1.13; P = 7.3 × 10-3) and leptin (OR, 1.09; 95% CI, 1.06-1.12; P = 1.7 × 10-3).

CONCLUSIONS AND RELEVANCE

The phenotypic associations between atypical depressive symptoms and obesity-related traits may arise from shared pathophysiologic mechanisms in patients with MDD. Development of treatments effectively targeting immunometabolic dysregulations may benefit patients with depression and obesity, both syndromes with important disability.

Leptin Dysregulation Is Specifically Associated With Major Depression With Atypical Features: Evidence for a Mechanism Connecting Obesity and Depression

BACKGROUND

Obesity-related dysregulation of leptin signaling (e.g., hyperleptinemia due to central functional resistance) may affect mood. However, evidence for leptin dysregulation in major depressive disorder (MDD) is conflicting. Inconclusive findings may be attributable to heterogeneity of MDD, aggregating biologically different subtypes. We examined the relationship of leptin with MDD, its common subtypes (typical and atypical), and clinical features.

METHODS

The sample consisted of participants (aged 18 to 65 years) from the Netherlands Study of Depression and Anxiety with current (n = 1062) or remitted (n = 711) MDD and healthy control subjects (n = 497). Diagnoses of MDD and subtypes were based on DSM-IV symptoms. Additional symptoms were measured with the Inventory of Depressive Symptomatology. Blood levels of leptin and adiposity indexes (body mass index and waist circumference) were assessed.

RESULTS

As compared to control subjects, higher leptin was associated with the atypical MDD subtype both for remitted (n = 144, odds ratio = 1.53, 95% confidence interval = 1.16-2.03, p = .003) and current (n = 270, odds ratio = 1.90, 95% confidence interval = 1.51-2.93, p = 5.3e-8) cases. This association was stronger for increasing adiposity levels (leptin by body mass index interaction, p < .02), strengthening the hypothesis of the involvement of leptin resistance. No association with leptin was found for overall MDD or the typical subtype. Among currently depressed patients, higher leptin was associated with key symptoms identifying the atypical subtype, such as hyperphagia, increased weight, and leaden paralysis.

CONCLUSIONS

Leptin dysregulation (resistance) may represent an underlying mechanism connecting obesity and MDD with atypical features. Development of treatment effectively targeting leptin resistance may benefit patients with atypical depression characterized by obesity-related metabolic alterations.

Gender-Specific Relationship between Obesity and Major Depression

OBJECTIVE

Prior research suggests a bidirectional relationship between obesity and major depressive disorder (MDD), but the results have been heterogeneous. Differences between males and females in the association of MDD with obesity may contribute to inconsistent results. Thus, this study was designed to determine whether sex has a differential effect on the relationship between MDD and obesity, and to explore the potential mechanisms.

METHODS

All participants were diagnosed with MDD, and depression severity was measured using the 17-item Hamilton Depression Rating Scale. Body weight and height were measured to calculate body mass index (BMI). Body composition, including total fat, trunk fat, android fat, and visceral fat mass, was measured by dual-energy X-ray absorptiometry. Subjects provided blood samples, and serum was extracted for measuring the inflammatory factors using human immunoassay kits.

RESULTS

Among all obesity measures, depressed women had greater BMI and total body fat. By contrast, depressed men had greater visceral fat mass. However, only in depressed women was depression correlated with several measures of obesity, including BMI, total body fat, and visceral fat mass. A stepwise multiple regression analysis was conducted, and only visceral fat entered the regression model and was most predictive of depression in women (β = 0.60, p = 0.007). Moreover, compared with depressed men, depressed women had higher leptin levels after controlling for BMI, total body fat, and visceral fat.

CONCLUSION

These results highlight gender differences in determining the association between obesity and depression, and elevated leptin level is a potential mechanism linking MDD to obesity in depressed women. Understanding a gender-specific relationship between obesity and MDD would allow clinicians to target and personalize therapies in the hope of improving health outcomes.

Estimating relative risk of a log-transformed exposure measured in pools

Pooling biospecimens prior to performing laboratory assays is a useful tool to reduce costs, achieve minimum volume requirements and mitigate assay measurement error. When estimating the risk of a continuous, pooled exposure on a binary outcome, specialized statistical techniques are required. Current methods include a regression calibration approach, where the expectation of the individual-level exposure is calculated by adjusting the observed pooled measurement with additional covariate data. While this method employs a linear regression calibration model, we propose an alternative model that can accommodate log-linear relationships between the exposure and predictive covariates. The proposed model permits direct estimation of the relative risk associated with a log-transformation of an exposure measured in pools. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Increased Ghrelin Levels and Unchanged Adipocytokine Levels in Major Depressive Disorder

OBJECTIVE

One of the hypotheses of the pathophysiology of major depressive disorder (MDD) proposes that there is a relationship between adipocytokine and ghrelin levels and depression.

METHODS

Patients with major depression with a BMI ≤25 kg/m² between the ages of 11 and 18 years (n = 30) were compared with a healthy control group (n = 30). Both groups were evaluated across a pretreatment period (MD-PT) and an improved period (MD-I). We measured serum leptin, adiponectin, resistin, and ghrelin levels and other parameters related to metabolic syndrome, such as glucose, insulin, insulin resistance (homeostasis model assessment [HOMA]), triglycerides (TG), and total cholesterol (TCHOL).

RESULTS

Leptin, adiponectin, and resistin levels did not differ across groups; however, ghrelin levels were increased in the MD-I group compared with the control and MD-PT groups (p < 0.05). HOMA levels were also higher in the MD-PT group than in the control group (p < 0.05). After treatment, there was no difference in this measurement.

CONCLUSIONS

The relationship between adipocytokines and major depression may be dependent on ghrelin levels as a result of antidepressant treatment and subsequent obesity.

The Association Between Serum Leptin Levels and Post-Stroke Depression: A Retrospective Clinical Study

Objective

To investigate the question of whether serum leptin levels might be associated with post-stroke depression.

Methods

We studied 130 patients who experienced a first episode of stroke of more than three months' duration, without any previous history of depression or speech disorders. Data were collected regarding the patient demographics, depressive mood (Diagnostic and Statistical Manual of Mental Disorders 4th edition [DSM-IV] criteria and Beck Depression Inventory) and serum leptin levels measured by an enzyme-linked immunosorbent assay (ELISA). In addition, the Korean version of Modified Barthel Index (K-MBI) and Korean version of Mini-Mental State Examination (K-MMSE) were used to assess the subjects' independence, in regard to the activities of daily living and cognition. A statistical analysis was performed to determine differences the serum leptin levels between patients with depression and those without depression, and to determine the difference in the MBI and K-MMSE scores between the groups separated according to the serum leptin levels.

Results

Higher serum leptin levels were observed in patients with depression, compared with those without depression (38.5 ng/mL [range, 25.1-59.2 ng/mL] vs. 8.2 ng/mL [range, 4.9-17.8 ng/mL]; p<0.01. The serum leptin level showed an association with depression (odds ratio, 1.21; 95% confidence interval, 1.01-1.45; p=0.021). The K-MMSE and K-MBI improvement scores were lower, with statistical significance, in the group with the highest leptin level (>30 mg/dL), compared to the other two groups.

Conclusion

High serum leptin levels are associated with depression after stroke, and patients with elevated serum leptin levels were disadvantaged in regard to functional and cognitive outcomes.

The role of adiposity in the relationship between serum leptin and severe major depressive episode

To assess the role that adiposity plays in the association between leptin and major depressive episode (MDE), we analyzed the data of 1046 men and 1359 women aged 20-39 years, who completed an interview and had blood collected as a part of the National Health and Nutrition Examination Survey (NHANES) between 1991 and 1994. Waist-hip ratio (WHR) was used as an indicator of adiposity. MDE was assessed with the Diagnostic Interview Schedule. For normal-WHR women, the prevalence of MDE was reversely associated with leptin levels, 13.7(4.4)%, 12.2(4.0)% and 2.3(1.8)% respectively for lower, interquartile, and upper quartile. For abnormal-WHR women, the prevalence of MDE was positively associated with leptin, 6.1(2.3)%, 9.1(2.4)% and 20.0 (3.8) respectively for the three leptin levels. Compared to women with lower quartile of leptin, the odds ratio of MDE for women with upper quartile was 0.09 (0.01-0.98) for normal-WHR women but 4.35 (1.55-12.2) for abnormal-WHR women. No moderating effects were observed among men. Using BMI in place of WHR revealed similar findings. The association between MDE and leptin is moderated by adiposity. High leptin levels are associated with low odds of MDE among women with normal adiposity but high odds among women with abnormal adiposity.

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.

Is there a "metabolic-mood syndrome"? A review of the relationship between obesity and mood disorders

Obesity and mood disorders are highly prevalent and co-morbid. Epidemiological studies have highlighted the public health relevance of this association, insofar as both conditions and its co-occurrence are associated with a staggering illness-associated burden. Accumulating evidence indicates that obesity and mood disorders are intrinsically linked and share a series of clinical, neurobiological, genetic and environmental factors. The relationship of these conditions has been described as convergent and bidirectional; and some authors have attempted to describe a specific subtype of mood disorders characterized by a higher incidence of obesity and metabolic problems. However, the nature of this association remains poorly understood. There are significant inconsistencies in the studies evaluating metabolic and mood disorders; and, as a result, several questions persist about the validity and the generalizability of the findings. An important limitation in this area of research is the noteworthy phenotypic and pathophysiological heterogeneity of metabolic and mood disorders. Although clinically useful, categorical classifications in both conditions have limited heuristic value and its use hinders a more comprehensive understanding of the association between metabolic and mood disorders. A recent trend in psychiatry is to move toward a domain specific approach, wherein psychopathology constructs are agnostic to DSM-defined diagnostic categories and, instead, there is an effort to categorize domains based on pathogenic substrates, as proposed by the National Institute of Mental Health (NIMH) Research Domain Criteria Project (RDoC). Moreover, the substrates subserving psychopathology seems to be unspecific and extend into other medical illnesses that share in common brain consequences, which includes metabolic disorders. Overall, accumulating evidence indicates that there is a consistent association of multiple abnormalities in neuropsychological constructs, as well as correspondent brain abnormalities, with broad-based metabolic dysfunction, suggesting, therefore, that the existence of a "metabolic-mood syndrome" is possible. Nonetheless, empirical evidence is necessary to support and develop this concept. Future research should focus on dimensional constructs and employ integrative, multidisciplinary and multimodal approaches.

Psychiatric symptoms and leptin in obese patients who were bariatric surgery candidates

OBJECTIVE

There is a significant relationship between obesity and common mental symptoms (depression and anxiety symptoms). But the association between depression (or anxiety symptoms) and serum leptin is still unclear and controversial, despite the growing body of evidence supporting the existence of "leptin resistance" in obese persons. So we investigated whether common mental symptoms, obesity, and the interactive effect of these two factors have a relationship with leptin in obese patients who were candidates for bariatric surgery.

METHODS

In all, 139 participants (mean age: 31.4 years, standard deviation: 9.3 years, 73.4% female) were enrolled at an obesity treatment center in southern Taiwan. Serum leptin levels and body mass index (BMI) were measured. The Chinese Health Questionnaire and Taiwanese Depression Questionnaire were administered.

RESULTS

The mean BMI of our participants was 39.4 kg/m(2) (±6.8), and the mean leptin level was 24.5 ng/mL (±9.4). In the multivariate regression models, Chinese Health Questionnaire-by-BMI and Taiwanese Depression Questionnaire-by-BMI interaction terms remained significant predictors of leptin level (β=0.16, P<0.0001; β=0.04, P<0.0001, respectively), after adjustment for age, sex, and history of hypertension, diabetes, and hyperlipidemia, despite the inverse correlation between Chinese Health Questionnaire (or Taiwanese Depression Questionnaire) and leptin. In addition, female patients had significantly higher leptin levels than male patients.

CONCLUSION

The present findings confirmed that the relationship between common mental symptoms and leptin is modulated by obesity in severely obese patients. Future studies should focus on further measures of leptin receptors or signaling on the basis of these interactive effects in psychiatry.

Adipokines as emerging depression biomarkers: a systematic review and meta-analysis

Adiponectin, leptin and resistin may play a role in the pathophysiology of major depressive disorder (MDD). However, differences in peripheral levels of these hormones are inconsistent across diagnostic and intervention studies. Therefore, we performed meta-analyses of diagnostic studies (i.e., MDD subjects versus healthy controls) and intervention investigations (i.e., pre-vs. post-antidepressant treatment) in MDD. Adiponectin (N = 1278; Hedge's g = -0.35; P = 0.16) and leptin (N = 893; Hedge's g = -0.018; P = 0.93) did not differ across diagnostic studies. Meta-regression analyses revealed that gender and depression severity explained the heterogeneity observed in adiponectin diagnostic studies, while BMI and the difference in BMI between MDD individuals and controls explained the heterogeneity of leptin diagnostic studies. Subgroup analyses revealed that adiponectin peripheral levels were significantly lower in MDD participants compared to controls when assayed with RIA, but not ELISA. Leptin levels were significantly higher in individuals with mild/moderate depression versus controls. Resistin serum levels were lower in MDD individuals compared to healthy controls (N = 298; Hedge's g = -0.25; P = 0.03). Leptin serum levels did not change after antidepressant treatment. However, heterogeneity was significant and sample size was low (N = 108); consequently meta-regression analysis could not be performed. Intervention meta-analyses could not be performed for adiponectin and resistin (i.e., few studies met inclusion criteria). In conclusion, this systematic review and meta-analysis underscored that relevant moderators/confounders (e.g., BMI, depression severity and type of assay) should be controlled for when considering the role of leptin and adiponectin as putative MDD diagnostic biomarkers.

Controversies about a common etiology for eating and mood disorders

Obesity and depression represent a growing health concern worldwide. For many years, basic science and medicine have considered obesity as a metabolic illness, while depression was classified a psychiatric disorder. Despite accumulating evidence suggesting that obesity and depression may share commonalities, the causal link between eating and mood disorders remains to be fully understood. This etiology is highly complex, consisting of multiple environmental and genetic risk factors that interact with each other. In this review, we sought to summarize the preclinical and clinical evidence supporting a common etiology for eating and mood disorders, with a particular emphasis on signaling pathways involved in the maintenance of energy balance and mood stability, among which orexigenic and anorexigenic neuropeptides, metabolic factors, stress responsive hormones, cytokines, and neurotrophic factors.

The association between serum leptin and post stroke depression: results from a cohort study

BACKGROUND

Depression is a frequent mood disorder that affects around a third of stroke patients and has been associated with poorer outcomes. Our aim was to determine whether there was a relationship between inflammatory markers (leptin) and post-stroke depression (PSD).

METHODS

One hundred and ninety-one ischemic stroke patients admitted to the hospital within the first 24 hours after stroke onset were consecutively recruited and followed up for 3 months. Enzyme-linked immunosorbent assay (ELISA) was used to measure serum levels of leptin at admission. Based on the symptoms, diagnoses of depression were made in accordance with DSM-IV criteria for post-stroke depression at 3 month.

RESULTS

Forty-four patients (23.0%) were diagnosed as having major depression at 3 month. Patients with depression showed higher serum leptin levels at 3 month after stroke (32.2 [IQR, 20.8-57.7] v. 9.9 [IQR, 4.6-13.1]ng/ml, respectively; P = 0.000). Serum levels of leptin ≥20 ng/ml were independently associated with PSD [odds ratio (OR) 20.23, 95% confidence interval (CI) 9.11-51.26, P =  0.000], after adjusting for possible confounders.

CONCLUSIONS

Serum leptin levels elevated at admission were found to be associated with PSD and may provide a new proposal for the treatment of PSD.