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

Neurological and metabolic related pathophysiologies and treatment of comorbid diabetes with depression

BACKGROUND

The comorbidity between diabetes mellitus and depression was revealed, and diabetes mellitus increased the prevalence of depressive disorder, which ranked 13th in the leading causes of disability-adjusted life-years. Insulin resistance, which is common in diabetes mellitus, has increased the risk of depressive symptoms in both humans and animals. However, the mechanisms behind the comorbidity are multi-factorial and complicated. There is still no causal chain to explain the comorbidity exactly. Moreover, Selective serotonin reuptake inhibitors, insulin and metformin, which are recommended for treating diabetes mellitus-induced depression, were found to be a risk factor in some complications of diabetes.

AIMS

Given these problems, many researchers made remarkable efforts to analyze diabetes complicating depression from different aspects, including insulin resistance, stress and Hypothalamic-Pituitary-Adrenal axis, neurological system, oxidative stress, and inflammation. Drug therapy, such as Hydrogen Sulfide, Cannabidiol, Ascorbic Acid and Hesperidin, are conducive to alleviating diabetes mellitus and depression. Here, we reviewed the exact pathophysiology underlying the comorbidity between depressive disorder and diabetes mellitus and drug therapy.

METHODS

The review refers to the available literature in PubMed and Web of Science, searching critical terms related to diabetes mellitus, depression and drug therapy.

RESULTS

In this review, we found that brain structure and function, neurogenesis, brain-derived neurotrophic factor and glucose and lipid metabolism were involved in the pathophysiology of the comorbidity. Obesity might lead to diabetes mellitus and depression through reduced adiponectin and increased leptin and resistin. In addition, drug therapy displayed in this review could expand the region of potential therapy.

CONCLUSIONS

The review summarizes the mechanisms underlying the comorbidity. It also overviews drug therapy with anti-diabetic and anti-depressant effects.

Sex differences in the effects of repeated ketamine infusions on bone markers in patients with unipolar and bipolar depression

BACKGROUND

Patients with depression, especially women, are associated with low bone mineral density (BMD). Traditional antidepressants are associated with negative effects on BMD. Few studies have examined the effect of ketamine on BMD, and it remains unclear whether there are sex differences in the effects of ketamine on BMD in patients with depression.

METHODS

A total of 102 patients with unipolar and bipolar depression were administered six infusions of intravenous ketamine over a 12-day period. Plasma levels of eight bone markers were examined at baseline, 24 h after the sixth infusion and again 2 weeks (Days 13 and 26).

RESULTS

Linear mixed models showed all bone markers had significant time main effect (all p < 0.05). Compared with baseline, the whole sample showed increased levels of leptin and osteoprotegerin at Days 13 and 26, as well as Dickkopf-related protein 1 at Day 13, and decreased levels of osteocalcin, sclerostin, osteopontin, parathyroid hormone and fibroblast growth factor 23 at Days 13 and 26 (all p < 0.05). Females had a higher level of leptin at Days 13 and 26, and lower levels of osteocalcin and sclerostin at Day 13 than males (all p < 0.05). Increases of leptin were associated with depressive symptom improvements at Day 13 and Day 26 in females (both p < 0.05). In males, higher baseline osteocalcin levels were associated with greater depressive symptom improvement at Day 26 (β = 0.414, p = 0.009).

CONCLUSIONS

Our results suggest that repeated ketamine infusions may be associated with modulation of bone markers in patients with depression and present sex differences. Baseline osteocalcin level may be served as a predictor for the antidepressant effects of ketamine in males. Trial registration Data were derived from an open label clinical trial, which was registered at Chinese Clinical Trial Registry (ChiCTR-OOC-17012239). Registered 26 May 2017. http://www.chictr.org.cn.

Positive effect of leptin substitution on mood and behaviour in patients with congenital leptin deficiency

BACKGROUND

States of starvation are characterized by reduced physical activity and social withdrawal. This has been suggested to be mediated at least in part via reduced leptin concentrations.

OBJECTIVE

We therefore aimed to ascertain if leptin substitution in patients with congenital leptin deficiency (CLD) can improve physical activity and mood.

METHODS

Seven patients with CLD were filmed prior to and after short- and long-term substitution (2-21 days; 3-4 months) in a play situation. Six independent, blinded investigators ranked each video according to specifically developed scales concerning motor activity, social interaction, emotionality, and mood with higher scores representing improvements.

RESULTS

Short term metreleptin substitution significantly increased mean total score from 17.7 ± 4.1 to 22.6 ± 6.6 (p = 0.039), and mean scores for motor activity (4.1 ± 1.1 to 5.1 ± 1.5, p = 0.023) and social interaction (4.6 ± 1.1 to 6.2 ± 1.7, p = 0.016). After long term substitution means of all four single scales and of total score were even higher than at short-term follow-up. During a treatment pause of 3 months in two children, all four scale scores fell below substitution levels and rose again after restart.

CONCLUSIONS

Metreleptin substitution improved indices of physical activity and psychological wellbeing in patients with CLD. This suggests that reduced leptin concentrations might be in part responsible for emotional and behavioural changes seen during starvation.

The relationship between serum fatty acids and depressive symptoms in obese adolescents

Depression and obesity are highly prevalent and are considered inflammatory pathologies; in addition, they are also associated with dietary patterns including types of fatty acids (FA). Changes in the FA composition in the brain are determined by changes in the content and quality of dietary and serum FA. The aim of this study was to verify the relationships between serum-free FA, inflammatory processes and depressive symptoms in obese adolescents. This was a cross-sectional study that analysed a database composed of 138 post-pubertal adolescents. Data regarding the depressive symptoms, body composition, glucose metabolism, lipid profile, FA profile, leptin concentration, as well as adiponectin, IL-A, IL-6, IL-10, TNF-α, C-reactive protein and plasminogen activator inhibitor-1 levels of the subjects were collected. A total of 54·6 % of the adolescents presented with depressive symptoms, and there were positive correlations between depressive symptoms and serum saturated fatty acids (SFA) content, body fat, and inflammatory adipokines, such as leptin, IL-6, and the leptin/adiponectin ratio. Moreover, the content of n-3 polyunsaturated fatty acids (PUFA) was negatively correlated with depressive symptoms, suggesting that eicosatrienoic acid (C20:2n6) and dihomo-γ-linolenic acid (C20:3n-6) are independently associated with depressive symptom scores and can be critical predictors of poor mental health in humans. These results point to the relationship between SFA and depressive symptoms in obese adolescents. However, longitudinal studies are needed to confirm the causality between dietary SFA and depression in obese individuals.

High-Protein, Low-Glycaemic Meal Replacement Improves Physical Health-Related Quality of Life in High-Risk Persons for Metabolic Syndrome-A Subanalysis of the Randomised-Controlled ACOORH Trial

While obesity impairs health-related quality of life (HRQOL), lifestyle interventions targeting weight reduction have been effective in improving HRQOL. Therefore, we hypothesised that a meal replacement-based lifestyle intervention, which has been shown to successfully reduce weight, would also improve HRQOL more effectively than a lifestyle intervention alone. In the international, multicenter, randomised-controlled ACOORH-trial (Almased-Concept-against- Overweight-and-Obesity-and-Related-Health-Risk), overweight or obese participants with elevated risk for metabolic syndrome (n = 463) were randomised into two groups. Both groups received telemonitoring devices and nutritional advice. The intervention group additionally used a protein-rich, low-glycaemic meal replacement for 6 months. HRQOL was estimated at baseline, after 3 and 12 months, using the SF-36 questionnaire, and all datasets providing HRQOL data (n = 263) were included in this predefined subanalysis. Stronger improvements in the physical component summary (PCS) were observed in the intervention compared to the control group, peaking after 3 months (estimated treatment difference 2.7 [1.2; 4.2]; p < 0.0001), but also in the long-term. Multiple regression analysis demonstrated that insulin levels and the achieved weight loss were associated with the mental component summary (MCS) after 12 months (p < 0.05). Thus, meal replacement-based lifestyle intervention is not only effective in weight reduction but, concomitantly, in enhancing HRQOL.

Association between visceral adipose tissue and major depressive disorder across the lifespan: A scoping review

OBJECTIVES

Increasing evidence supports a bidirectional relationship between major depressive disorder (MDD) and obesity, but the role of visceral adipose tissue (VAT) as a measure of obesity in relation to MDD is not well understood. Here we review literature investigating the link between MDD and VAT in terms of biomarkers, sex differences, and aging.

METHODS

PubMed, EMBASE, PsycINFO, and CINAHL searches were conducted on December 11, 2020. No date or language limits were imposed. Major concepts searched were Depressive Disorder linked with Adipose Tissue, White, Hypothalmo-Hypophyseal System, and Pituitary-Adrenal System in addition to keywords. A final set of 32 items meeting criteria for inclusion.

RESULTS

Converging biological evidence suggests a significant bidirectional relationship between VAT and MDD across the lifespan. In adulthood, greater VAT was associated with increased risk for depression, especially in vulnerable groups such as individuals who are overweight/obese, postmenopausal women, and individuals with comorbid medical or psychiatric illness. In older adults, sarcopenia had an impact on the relationship between abnormal VAT and risk of depression. Additionally, sex differences emerged as a potential factor affecting the strength of the association between VAT and depression.

CONCLUSIONS

Elucidating the pathophysiological mechanisms associated with increased rates of depression in obese individuals will be crucial for developing specific treatment strategies that seek to improve outcomes in individuals with comorbid depression and obesity. Moreover, identifying age- and sex-specific risk factors may contribute to a more personalized medicine approach, thereby improving the quality of clinical care.

Age and sex-specific associations between depressive symptoms, body mass index and cognitive functioning among Korean middle-aged and older adults: a cross-sectional analysis

BACKGROUND

Although depression and body weight have been noted as important predictors of cognitive health, it remains unclear how age and sex influence the mechanism by which depressive symptoms and body weight are associated with cognitive functioning. This study examined whether and how the relationships between depressive symptoms and cognitive functioning mediated by body mass index (BMI) differ in terms of age and sex.

METHODS

A cross-sectional analysis of a large sample of population-based data (N = 5,619; mean age 70.73 [± 9.07]), derived from the Korean Longitudinal Study of Aging, was conducted with hierarchical mediated-moderation regressions and a PROCESS macro approach in SPSS. Depressive symptoms were measured through the 10-item Center for Epidemiologic Studies Depression (CES-D) scale, and cognitive functioning was assessed with the Korean Mini-Mental State Examination (K-MMSE).

RESULTS

The results showed that depressive symptoms were significantly associated with cognitive decline directly and indirectly through reduced BMI. The estimated coefficients indicated that a one standard deviation increase in CES-D scale was associated with about 0.9 decrease in K-MMSE score. However, the indirect relationship between depressive symptoms and cognitive function through BMI emerged only in men or individuals older than 70 years.

CONCLUSIONS

The findings suggest that a careful assessment of BMI is warranted for early detection and prevention of cognitive decline related to depressive symptoms, particularly among older men.

Overweight in mood disorders: Effects on morbidity and treatment response

OBJECTIVE

As it is not clear how body-mass index (BMI) may relate to diagnosis, symptom-severity, illness-course, and treatment-response among psychiatric patients, we related BMI to psychiatric diagnosis and to selected clinical and demographic factors in major affective disorder subjects.

METHODS

We analyzed mean BMI levels vs. diagnosis, and evaluated selected risk factors for association with overweight and obesity among subjects with DSM-5 major affective disorders.

RESULTS

In 1884 subjects, BMI ranged from 23.4 kg/m² with anxiety disorders to 27.6 with psychotic disorders, and averaged 24.1 among 1469 affective disorder subjects. Mood-disorder subjects with BMI ≥ 25 (overweight/obese) were more likely: men, older, married, with more children and siblings, less education, lower socioeconomic status, engaged less in physical exercise, smoked more, and lived in less densely populated areas. They also were more likely to have: BD than MDD, familial mood disorders, no co-occurring ADHD, higher serum triglyceride levels, more time depressed and less improvement in depression ratings with treatment.

CONCLUSIONS

Risk of being overweight or obese was greatest with psychoses, least with anxiety, personality, and minor depressive disorders, and intermediate with major mood disorders. Several plausible risk factors for high BMI were identified in mood disorder subjects, including male sex and with BD > MDD. Striking were selectively greater prospective morbidity and decreased treatment-response for depression vs. mania with BMI ≥ 25.

Higher increase degree of FGF21 post long-term interdisciplinary weight loss therapy preserves the free fat mass and rest metabolic rate in adolescents with obesity

Objective Fibroblast growth factor 21 (FGF21) is among the activators that can stimulate thermogenesis in the white adipose tissue and brown adipose tissue. People with obesity have elevated blood levels of FGF21, but also develop resistance to its action, impairing its beneficial role. Inversely, clinical treatments to weight loss has been pointed out as an important therapy for increasing and recovering sensitivity to FGF21. The aim was to analyse the effect of long-term weight loss interdisciplinary intervention on FGF21 and body composition. Subjects and methods Eighty-six post-pubertal obese adolescents (14-19 years-old), were submitted to 20 weeks of weight loss therapy (clinical, nutritional, psychological and physical exercise support). Anthropometric measures, body composition and rest metabolic rate (RMR) by bioelectrical impedance, and serum FGF21 sample by ELISA were evaluated. The adolescents were grouped according to FGF21 individual delta variations after therapy: Higher Increase (HI); lower increase (LI); lower decrease (LD); higher decrease (HD). Results All groups present weight loss. Only in FGF21 ≥ 76,5 pg/mL variation the free-fat-mass and rest metabolic rate were preserved and to others group these variables were significantly reduced. Conclusion High increase in FGF21 can contribute to preservation of FFM and RMR after weight loss therapy, could have important implications for energy balance regulation. Future studies are necessary to continue determining the role of magnitude effects of FGF21 levels in obesity to improve clinical practice, especially in paediatrics population.

Inflammation and fatness in adolescents with and without Down syndrome: UP & DOWN study

BACKGROUND

The main objective of this study was to describe the inflammatory status of adolescents with Down syndrome (DS) and their relationship with adiposity.

METHODS

Ninety-five adolescents with DS (44.2% girls) and a control group of 113 adolescents (47.8% girls), aged between 11 and 18 years old, from the UP & DOWN study were included in this substudy. Serum C-reactive protein, C3 and C4 complement factors, total proteins, interleukin-6, tumour necrosis factor-α, insulin, cortisol, leptin, adiponectin, galactin-3 and visfatin were analysed; homeostatic model assessment index was calculated. In order to evaluate adiposity, we measured the following body fat variables: weight, height, waist circumference and skinfold thicknesses. Birth weight was obtained by questionnaire. In addition, body mass index, waist-to-height ratio (WHtR) and body fat percentage (BF%) were calculated.

RESULTS

Down syndrome group showed higher levels of body mass index, WHtR, waist circumference, BF% and lower birth weight than controls (P < 0.001). In the general linear model in the total sample, WHtR was positively associated with C3 and C4 (P < 0.001) as well as with leptin levels (P = 0.015). BF% was positively associated with total proteins (P = 0.093) and leptin levels (P < 0.001). DS was positively associated with total proteins (P < 0.001), C3 (P = 0.047) and C4 (P = 0.019). Despite the higher levels of adiposity found in DS group, no direct association was found between BF% and leptin levels, comparing with the control group.

CONCLUSIONS

These findings suggest that abdominal obesity should be controlled in adolescents because of its relationship with acute phase-inflammatory biomarkers but especially in DS adolescents who may show a peculiar metabolic status according to their relationship between adiposity and inflammatory biomarkers.

Peripheral adiponectin levels in anxiety, mood, trauma- and stressor-related disorders: A systematic review and meta-analysis

BACKGROUND

Anxiety, mood, trauma- and stressor-related disorders confer increased risk for metabolic disease. Adiponectin, a cytokine released by adipose tissue is associated with these disorders and obesity via inflammatory processes. Available data describing associations with mental disorders remain limited and conflicted.

METHODS

A systematic search was conducted for English, peer-reviewed articles from inception until February 2019 that assessed for serum or plasma adiponectin levels in adults with an anxiety, mood or trauma-related disorder. Diagnoses were determined by psychiatric interview, based on DSM-IV, DSM-5 or ICD-10 criteria. Analyses were performed using STATA 15 and Standardized mean difference (SMD) with 95% confidence interval was applied to pool the effect size of meta-analysis studies.

RESULTS

In total 65 eligible studies were included in the systematic review and 30 studies in this meta-analysis. 19,178 participants (11,262 females and 7916 males), comprising healthy adults and adults with anxiety, mood and trauma-related disorders, were included. Overall results indicated an inverse association between adiponectin levels and examined mental disorders. Specifically, patients with an anxiety disorder (SMD  = -1.18 µg/mL, 95% CI, -2.34; -0.01, p  = 0.047); trauma or stressor-related disorder (SMD  =  -0.34 µg/mL, 95% CI, -0.52; -0.17, p  = 0.0000) or bipolar disorder (SMD  =  -0.638 µg/mL, 95% CI, -1.16, -0.12, p  = 0.017) had significant lower adiponectin levels compared to healthy adults.

LIMITATIONS

Heterogeneity, potential publication bias, and lack of control for important potential confounders were significant limitations.

CONCLUSION

Peripheral adiponectin levels appear to be inversely associated with anxiety, mood, trauma- and stressor related disorders and may be a promising biomarker for diagnosis and disease monitoring.

Association of Pediatric Obesity Treatment, Including a Dietary Component, With Change in Depression and Anxiety: A Systematic Review and Meta-analysis

IMPORTANCE

Children and adolescents with obesity are at higher risk of developing depression and anxiety, and adolescent dieting is a risk factor for the development of depression. Therefore, determining the psychological effect of obesity treatment interventions is important to consider.

OBJECTIVE

To investigate the association between obesity treatment interventions, with a dietary component, and the change in symptoms of depression and anxiety in children and adolescents with overweight/obesity.

DATA SOURCES

Searches of MEDLINE, Embase, Cochrane Library, and PsychINFO were conducted from inception to August 2018. Hand searching of references was conducted to identify missing studies.

STUDY SELECTION

Obesity treatment interventions, with a dietary component, conducted in children and adolescents (age <18 years) with overweight/obesity, and validated assessment of depression and/or anxiety were included.

DATA EXTRACTION AND SYNTHESIS

Data were independently extracted by 1 reviewer and checked for accuracy. Meta-analysis, using a random-effects model, was used to combine outcome data and moderator analysis conducted to identify intervention characteristics that may influence change in depression and anxiety. The meta-analyses were finalized in May 2019.

MAIN OUTCOMES AND MEASURES

Change in symptoms of depression and anxiety postintervention and at the latest follow-up.

RESULTS

Of 3078 articles screened, 44 studies met inclusion criteria with a combined sample of 3702 participants (age range, 5.6 to 16.6 years) and intervention duration of 2 weeks to 15 months. Studies reported either no change or a statistically significant reduction in symptoms of depression or anxiety. Meta-analyses of 36 studies found a reduction in depressive symptoms postintervention (standardized mean difference [SE], -0.31 [0.04]; P < .001), maintained at follow-up in 11 studies at 6 to 16 months from baseline (standardized mean difference [SE], -0.25 [0.07]; P < .001). Anxiety was reduced postintervention (10 studies; standardized mean difference [SE], -0.38 [0.10]; P < .001) and at follow-up (4 studies; standardized mean difference [SE], -0.32 [0.15]; P = .03). Longer intervention duration was associated with a greater reduction in anxiety (R2 = 0.82; P < .001). Higher body mass index z score at baseline was associated with a greater reduction in depression (R2 = 0.19; P = .03).

CONCLUSIONS AND RELEVANCE

Structured, professionally run pediatric obesity treatment is not associated with an increased risk of depression or anxiety and may result in a mild reduction in symptoms. Treatment of weight concerns should be considered within the treatment plan for young people with depression and obesity.

An Interdisciplinary Weight Loss Program Improves Body Composition and Metabolic Profile in Adolescents With Obesity: Associations With the Dietary Inflammatory Index

Background and Aims: The prevalence of overweight and obesity consitutes a global epidemic and it is growing around the world. Food and nutrition are essential requirements for promoting health and protecting against non-communicable chronic diseases, such as obesity and cardiovascular disease. Specific dietary components may modulate inflammation and oxidative stress in obese individuals. The Dietary Inflammatory Index (DII®) was developed to characterize the anti- and pro-inflammatory effects of individuals' diet. Few studies have investigated the role of diet-associated inflammation in adolescents with obesity. The present study aims to investigate the effects of an interdisciplinary weight loss therapy on DII scores and cardiometabolic risk in obese adolescents and possibles correlations.

Methods: A total of 45 volunteers (14–19 years old) were recruited and enrolled for long-term interdisciplinary therapy including clinical, nutritional, psychological counseling, and exercise training. Adolescents had access to videos about health education weekly. Body composition and inflammatory and serum profiles were evaluated at baseline and after intervention. The food intake was obtained by 24-h food recall. Data was used to calculate energy-adjusted DII (E-DII) scores. Negative scores indicate an anti-inflammatory diet and positive scores indicates a pro-inflammatory diet. The sample was divided according to whether individuals increased or decreased E-DII scores after therapy.

Results: After therapy the body mass index (BMI), body weight, body fat, abdominal, waist, neck, and hip circumferences decreased significantly. The mean of high-density lipoprotein cholesterol (HDL-c) increased after the therapy. There was found an improvement of inflammatory and cardiometabolic parameters. In exploratory analyses, this occurred mainly when the EDII improved.

Conclusion: Long-term interdisciplinary therapy combined with a health education website improved inflammatory serum markers in obese adolescents. Reduction in DII scores was associated with reduction of cardiometabolic parameters, suggesting that an anti-inflammatory diet may be an effective strategy to prevent and treat obesity and related comorbidities.

Trial:http://www.ensaiosclinicos.gov.br/rg/RBR-6txv3v/, Register Number: RBR-6txv3v

Effects of exercise intervention on visceral fat in obese children and adolescents

INTRODUCTION

This meta-analysis study was aimed to assess the effects of exercise intervention on visceral fat in obese children and adolescents.

EVIDENCE ACQUISITION

Electronic database searches were performed in Academic Search Complete, CINAHL, Healthsource, MEDLINE, and SportDiscus, and from the earliest record to November 2017. Keywords included "exercise or training," "visceral fat," and "child or adolescent or youth." The inclusion criteria for eligible studies were as follows: 1) subjects were obese at baseline; 2) aged 6-19 years; 3) visceral fat was reported at baseline and after an intervention; and 4) studies were published in peer-reviewed journals written in English.

EVIDENCE SYNTHESIS

A total of 207 studies were observed at the initial search and 73 effect sizes (ESs) were derived from the 34 selected studies. The overall exercise intervention effect was large (Cohen's d [ES]=-1.003, 95% CI=-1.114, -0.892). Moderator analyses results showed that gender (Qb=8.23, df=2, P=0.016), exercise type (Qb=10.68, df=2, P=0.005), and intervention length (Qb=24.71, df=2, P<0.001) influenced the overall ES.

CONCLUSIONS

The group of both boys and girls (ES=-0.95) who participated combined exercise program (Aerobic + Resistance training; ES=-1.17) for 12 months (ES=-1.24) appeared to be the most effective exercise strategy for reducing visceral fat in obese youth.

Different metabolic responses induced by long-term interdisciplinary therapy in obese adolescents related to ACE I/D polymorphism

Introduction:

The main purpose of the present study was to investigate whether I/D polymorphism of the ACE gene might affect metabolic changes related to the metabolic syndrome through a long-term interdisciplinary therapy in obese adolescents.

Methods:

In total, 125 obese adolescents who entered the interdisciplinary obesity programme were assigned to the following two subgroups: metabolic syndrome or non-metabolic syndrome. They were evaluated at baseline and after 1 year. Genomic DNA was extracted from circulating leukocytes.

Results:

Subjects with the II genotype in the non-metabolic syndrome group were only to increase their fat-free mass after therapy. Regarding lipid profile, subjects with ID and DD genotypes from both groups reduced their low-density lipoprotein cholesterol levels significantly. The metabolic parameters from the ID and DD genotypes of the non-metabolic syndrome group showed a significantly improved insulin response.

Conclusion:

In the present study, we showed that the ACE polymorphism was able to influence the fat-free mass in the I-carry allele in the non-metabolic syndrome group positively. In addition, the I-carry allele was able to improve the insulin resistance of the metabolic syndrome group significantly. These results suggest that the ACE I/D genotypes can influence, in different ways, the specific parameters of metabolism among obese adolescents submitted for long-term interdisciplinary therapy.

Depression and obesity: can the cycle be broken?

Obesity and depression are conditions that have been linked through a great number of interesting mechanisms. To fully understand the implications of treatment choices it is necessary to continue to investigate the physiology of these two conditions. By examining the background of these problems and considering factors such as stress response, neurological change and systemic inflammation, we propose a cycle linking depression and obesity. With reference to this cycle, we discuss management options, focusing particularly on prescribing choices and current guidelines. An assessment of the medication options is provided demonstrating that prescribing choices can have a significant impact on ongoing physical health. The aim of this discussion is to raise awareness of current research and progress and to see whether the cycle of depression and obesity can be broken.

LEARNING OBJECTIVES

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DECLARATION OF INTEREST

None.

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.

Interactions of exercise training and high-fat diet on adiponectin forms and muscle receptors in mice

Background

Metabolic syndrome (MetS) is characterized by systemic disturbances that increase cardiovascular risk. Adiponectin (Ad) exhibits a cardioprotective function because of its anti-inflammatory and anti-atherosclerotic properties. In the bloodstream, this adipocytokine circulates on multimers (Ad_mer), among which high molecular weight (HMW) are the most active forms. Because alterations of Ad plasmatic levels, Ad_mer distribution and receptor (AdipoR) expression have been described in murine models and obese patients, strategies that aim to enhance Ad production or its effect on target tissues are the subject of intense investigations. While exercise training is well known to be beneficial for reducing cardiovascular risk, the contribution of Ad is still controversial. Our aim was to evaluate the effect of exercise training on Ad production, Ad_mer distribution and AdipoR muscle expression in a murine model of MetS.

Methods

At 6 weeks of age, mice were submitted to a standard (SF) or high-fat high-sugar (HF) diet for 10 weeks. After 2 weeks, the SF- and HF-fed animals were randomly assigned to a training program (SFT, HFT) or not (SFC, HFC). The trained groups were submitted to sessions of running on a treadmill 5 days a week.

Results and conclusions

The HF mice presented the key problems associated with MetS (increased caloric intake, body weight, glycemia and fat mass), a change in Ad_mer distribution in favor of the less-active forms and increased AdipoR2 expression in muscle. In contrast, exercise training reversed some of the adverse effects of a HF diet (increased glucose tolerance, better caloric intake control) without any modifications in Ad production and Ad_mer distribution. However, increased AdipoR1 muscle expression was observed in trained mice, but this effect was hampered by HF diet. These data corroborate a recent hypothesis suggesting a functional divergence between AdipoR1 and AdipoR2, with AdipoR1 having the predominant protective action on metabolic function.

Electronic supplementary material

The online version of this article (doi:10.1186/s12986-016-0138-2) contains supplementary material, which is available to authorized users.