Major depressive disorder (MDD) is a common illness accompanied by considerable morbidity, mortality, costs, and heightened risk of suicide. We conducted a genome-wide association meta-analysis based in 135,458 cases and 344,901 controls and identified 44 independent and significant loci. The genetic findings were associated with clinical features of major depression and implicated brain regions exhibiting anatomical differences in cases. Targets of antidepressant medications and genes involved in gene splicing were enriched for smaller association signal. We found important relationships of genetic risk for major depression with educational attainment, body mass, and schizophrenia: lower educational attainment and higher body mass were putatively causal, whereas major depression and schizophrenia reflected a partly shared biological etiology. All humans carry lesser or greater numbers of genetic risk factors for major depression. These findings help refine the basis of major depression and imply that a continuous measure of risk underlies the clinical phenotype.

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Genome-wide association analyses identify 44 risk variants and refine the genetic architecture of major depression

The current obesity epidemic poses a major public health issue since obesity predisposes towards several chronic diseases BMI and total adiposity are positively correlated with cardiometabolic disease risk at the population level However, body fat distribution and an impaired adipose tissue function, rather than total fat mass, better predict insulin resistance and related complications at the individual level Adipose tissue dysfunction is determined by an impaired adipose tissue expandability, adipocyte hypertrophy, altered lipid metabolism, and local inflammation Recent human studies suggest that adipose tissue oxygenation may be a key factor herein A subgroup of obese individuals - the 'metabolically healthy obese' (MHO) - have a better adipose tissue function, less ectopic fat storage, and are more insulin sensitive than obese metabolically unhealthy persons, emphasizing the central role of adipose tissue function in metabolic health However, controversy has surrounded the idea that metabolically healthy obesity may be considered really healthy since MHO individuals are at increased (cardio)metabolic disease risk and may have a lower quality of life than normal weight subjects due to other comorbidities Detailed metabolic phenotyping of obese persons will be invaluable in understanding the pathophysiology of metabolic disturbances, and is needed to identify high-risk individuals or subgroups, thereby paving the way for optimization of prevention and treatment strategies to combat cardiometabolic diseases

/pdf/the-metabolic-phenotype-in-obesity-fat-mass-body-fat-1f28h51lv5.pdf

The Metabolic Phenotype in Obesity: Fat Mass, Body Fat Distribution, and Adipose Tissue Function

Dysfunction of the endothelial lining of lesion-prone areas of the arterial vasculature is an important contributor to the pathobiology of atherosclerotic cardiovascular disease. Endothelial cell dysfunction, in its broadest sense, encompasses a constellation of various nonadaptive alterations in functional phenotype, which have important implications for the regulation of hemostasis and thrombosis, local vascular tone and redox balance, and the orchestration of acute and chronic inflammatory reactions within the arterial wall. In this review, we trace the evolution of the concept of endothelial cell dysfunction, focusing on recent insights into the cellular and molecular mechanisms that underlie its pivotal roles in atherosclerotic lesion initiation and progression; explore its relationship to classic, as well as more recently defined, clinical risk factors for atherosclerotic cardiovascular disease; consider current approaches to the clinical assessment of endothelial cell dysfunction; and outline some promising new directions for its early detection and treatment.

Endothelial Cell Dysfunction and the Pathobiology of Atherosclerosis

https://www.cell.com/cell/pdf/S0092-8674(13)01546-8.pdf

What We Talk About When We Talk About Fat

Over the last 10–15 years, our understanding of the composition and functions of the human gut microbiota has increased exponentially. To a large extent, this has been due to new ‘omic’ technologies that have facilitated large-scale analysis of the genetic and metabolic profile of this microbial community, revealing it to be comparable in influence to a new organ in the body and offering the possibility of a new route for therapeutic intervention. Moreover, it might be more accurate to think of it like an immune system: a collection of cells that work in unison with the host and that can promote health but sometimes initiate disease. This review gives an update on the current knowledge in the area of gut disorders, in particular metabolic syndrome and obesity-related disease, liver disease, IBD and colorectal cancer. The potential of manipulating the gut microbiota in these disorders is assessed, with an examination of the latest and most relevant evidence relating to antibiotics, probiotics, prebiotics, polyphenols and faecal microbiota transplantation.

/pdf/the-gut-microbiota-and-host-health-a-new-clinical-frontier-4pp0uoa4kb.pdf

The gut microbiota and host health: a new clinical frontier

The association between obesity and impaired insulin sensitivity has long been recognized, although a subgroup of obese individuals seems to be protected from insulin resistance. In this study, we ...

Insulin-sensitive obesity

https://www.cell.com/trends/pharmacological-sciences/pdf/S0165-6147(15)00090-5.pdf

Adipokines in health and disease

Purpose of reviewThe prevalence and severity of obesity are dramatically increasing throughout the world. Obesity causes a decline in life expectancy due to its associated metabolic and cardiovascular comorbid disorders. Therefore, it will become more important to distinguish obese individuals at hi

The distinction of metabolically 'healthy' from 'unhealthy' obese individuals.

The incidence of obesity has increased dramatically during recent decades. Obesity will cause a decline in life expectancy for the first time in recent history due to numerous co-morbid disorders. Adipocyte and adipose tissue dysfunction belong to the primary defects in obesity and may link obesity to several health problems including increased risk of insulin resistance, type 2 diabetes, fatty liver disease, hypertension, dyslipidemia, atherosclerosis, dementia, airway disease and some cancers. However, not all obese individuals develop obesity related metabolic or cardiovascular disorders potentially due to a preserved normal adipose tissue architecture and function. The majority of patients with obesity have an impaired adipose tissue function caused by the interaction of genetic and environmental factors which lead to adipocyte hypertrophy, hypoxia, a variety of stresses and inflammatory processes within adipose tissue. Ectopic fat accumulation including visceral obesity may be considered as a consequence of adipose tissue dysfunction, which is further characterized by changes in the cellular composition, increased lipid storage and impaired insulin sensitivity in adipocytes, and secretion of a proinflammatory, atherogenic, and diabetogenic adipokine pattern. This review focuses on the discussion of mechanisms causing or maintaining impaired adipose tissue function in obesity and potentially linking obesity to its associated disorders. A model is proposed how different pathogenic factors and mechanisms may cause dysfunction of adipose tissue.

Adipose tissue dysfunction in obesity.

OBJECTIVE— Vaspin was identified as an adipokine with insulin-sensitizing effects, which is predominantly secreted from visceral adipose tissue in a rat model of type 2 diabetes. We have recently shown that vaspin mRNA expression in adipose tissue is related to parameters of obesity and glucose metabolism. However, the regulation of vaspin serum concentrations in human obesity and type 2 diabetes is unknown. RESEARCH DESIGN AND METHODS— For the measurement of vaspin serum concentrations, we developed an enzyme-linked immunosorbent assay (ELISA). Using this ELISA, we assessed circulating vaspin in a cross-sectional study of 187 subjects with a wide range of obesity, body fat distribution, insulin sensitivity, and glucose tolerance and in 60 individuals with normal glucose tolerance (NGT), impaired glucose tolerance (IGT), or type 2 diabetes before and after a 4-week physical training program. RESULTS— Vaspin serum concentrations were significantly higher in female compared with male subjects. There was no difference in circulating vaspin between individuals with NGT and type 2 diabetes. In the normal glucose-tolerant group, circulating vaspin significantly correlated with BMI and insulin sensitivity. Moreover, physical training for 4 weeks resulted in significantly increased circulating vaspin levels. CONCLUSIONS— We found a sexual dimorphism in circulating vaspin. Elevated vaspin serum concentrations are associated with obesity and impaired insulin sensitivity, whereas type 2 diabetes seems to abrogate the correlation between increased circulating vaspin, higher body weight, and decreased insulin sensitivity. Low circulating vaspin correlates with a high fitness level, whereas physical training in untrained individuals causes increased vaspin serum concentrations.

https://diabetes.diabetesjournals.org/content/diabetes/57/2/372.full.pdf

Matthias Blüher

Papers

Insulin-sensitive obesity

Adipokines in health and disease

The distinction of metabolically 'healthy' from 'unhealthy' obese individuals.

Adipose tissue dysfunction in obesity.

Serum Vaspin Concentrations in Human Obesity and Type 2 Diabetes