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Endocrine Reviews Jul 2022Lipid disorders involving derangements in serum cholesterol, triglycerides, or both are commonly encountered in clinical practice and often have implications for...
Lipid disorders involving derangements in serum cholesterol, triglycerides, or both are commonly encountered in clinical practice and often have implications for cardiovascular risk and overall health. Recent advances in knowledge, recommendations, and treatment options have necessitated an updated approach to these disorders. Older classification schemes have outlived their usefulness, yielding to an approach based on the primary lipid disturbance identified on a routine lipid panel as a practical starting point. Although monogenic dyslipidemias exist and are important to identify, most individuals with lipid disorders have polygenic predisposition, often in the context of secondary factors such as obesity and type 2 diabetes. With regard to cardiovascular disease, elevated low-density lipoprotein cholesterol is essentially causal, and clinical practice guidelines worldwide have recommended treatment thresholds and targets for this variable. Furthermore, recent studies have established elevated triglycerides as a cardiovascular risk factor, whereas depressed high-density lipoprotein cholesterol now appears less contributory than was previously believed. An updated approach to diagnosis and risk assessment may include measurement of secondary lipid variables such as apolipoprotein B and lipoprotein(a), together with selective use of genetic testing to diagnose rare monogenic dyslipidemias such as familial hypercholesterolemia or familial chylomicronemia syndrome. The ongoing development of new agents-especially antisense RNA and monoclonal antibodies-targeting dyslipidemias will provide additional management options, which in turn motivates discussion on how best to incorporate them into current treatment algorithms.
Topics: Cardiovascular Diseases; Cholesterol; Diabetes Mellitus, Type 2; Dyslipidemias; Humans; Risk Factors; Triglycerides
PubMed: 34676866
DOI: 10.1210/endrev/bnab037 -
Nature Reviews. Genetics Feb 2022The prevalence of obesity has tripled over the past four decades, imposing an enormous burden on people's health. Polygenic (or common) obesity and rare, severe,... (Review)
Review
The prevalence of obesity has tripled over the past four decades, imposing an enormous burden on people's health. Polygenic (or common) obesity and rare, severe, early-onset monogenic obesity are often polarized as distinct diseases. However, gene discovery studies for both forms of obesity show that they have shared genetic and biological underpinnings, pointing to a key role for the brain in the control of body weight. Genome-wide association studies (GWAS) with increasing sample sizes and advances in sequencing technology are the main drivers behind a recent flurry of new discoveries. However, it is the post-GWAS, cross-disciplinary collaborations, which combine new omics technologies and analytical approaches, that have started to facilitate translation of genetic loci into meaningful biology and new avenues for treatment.
Topics: Animals; Eating; Gene-Environment Interaction; Genetic Predisposition to Disease; Genetic Variation; Genome, Human; Genome-Wide Association Study; Humans; Multifactorial Inheritance; Obesity; Overweight; Whole Genome Sequencing
PubMed: 34556834
DOI: 10.1038/s41576-021-00414-z -
Molecular Diagnosis & Therapy Dec 2020Obesity represents a major health burden to both developed and developing countries. Furthermore, the incidence of obesity is increasing in children. Obesity contributes... (Review)
Review
Obesity represents a major health burden to both developed and developing countries. Furthermore, the incidence of obesity is increasing in children. Obesity contributes substantially to mortality in the United States by increasing the risk for type 2 diabetes, cardiovascular-related diseases, and other comorbidities. Despite environmental changes over past decades, including increases in high-calorie foods and sedentary lifestyles, there is very clear evidence of a genetic predisposition to obesity risk. Childhood obesity cases can be categorized in one of two ways: syndromic or non-syndromic. Syndromic obesity includes disorders such as Prader-Willi syndrome, Bardet-Biedl syndrome, and Alström syndrome. Non-syndromic cases of obesity can be further separated into rarer instances of monogenic obesity and much more common forms of polygenic obesity. The advent of genome-wide association studies (GWAS) and next-generation sequencing has driven significant advances in our understanding of the genetic contribution to childhood obesity. Many rare and common genetic variants have been shown to contribute to the heritability in obesity, although the molecular mechanisms underlying most of these variants remain unclear. An important caveat of GWAS efforts is that they do not strictly represent gene target discoveries, rather simply the uncovering of robust genetic signals. One clear example of this is with progress in understanding the key obesity signal harbored within an intronic region of the FTO gene. It has been shown that the non-coding region in which the variant actually resides in fact influences the expression of genes distal to FTO instead, specifically IRX3 and IRX5. Such discoveries suggest that associated non-coding variants can be embedded within or next to one gene, but commonly influence the expression of other, more distal effector genes. Advances in genetics and genomics are therefore contributing to a deeper understanding of childhood obesity, allowing for development of clinical tools and therapeutic agents.
Topics: Child; Genetic Predisposition to Disease; Genetic Variation; Genome-Wide Association Study; Humans; Multifactorial Inheritance; Pediatric Obesity; Risk Factors
PubMed: 33006084
DOI: 10.1007/s40291-020-00496-1 -
Minerva Endocrinologica Sep 2020Obese or overweight people exceed one-third of the global population and obesity along with diabetes mellitus consist basic components of metabolic syndrome, both of... (Review)
Review
Obese or overweight people exceed one-third of the global population and obesity along with diabetes mellitus consist basic components of metabolic syndrome, both of which are known cardio-cerebrovascular risk factors with detrimental consequences. These data signify the pandemic character of obesity and the necessity for effective treatments. Substantial advances have been accomplished in preclinical research of obesity by using animal models, which mimic the human disease. In particular, rodent models have been widely used for many decades with success for the elucidation of the pathophysiology of obesity, since they share physiological and genetic components with humans and appear advantageous in their husbandry. The most representative rodents include the laboratory mouse and rat. Within this review, we attempted to consolidate the most widely used mice and rat models of obesity and highlight their strengths as well as weaknesses in a critical way. Our aim was to bridge the gap between laboratory facilities and patient's bed and help the researcher find the appropriate animal model for his/her obesity research. This tactful selection of the appropriate model of obesity may offer more translational derived results. In this regard, we included, the main diet induced models, the chemical/mechanical ones, as well as a selection of monogenic or polygenic models.
Topics: Animals; Diet; Disease Models, Animal; Humans; Metabolic Syndrome; Mice; Obesity; Rats; Rodentia
PubMed: 31738033
DOI: 10.23736/S0391-1977.19.03058-X -
Comptes Rendus Biologies Feb 2017Obesity and its related health complications is a major problem worldwide. Hypothalamus and their signalling molecules play a critical role in the intervening and... (Review)
Review
Obesity and its related health complications is a major problem worldwide. Hypothalamus and their signalling molecules play a critical role in the intervening and coordination with energy balance and homeostasis. Genetic factors play a crucial role in determining an individual's predisposition to the weight gain and being obese. In the past few years, several genetic variants were identified as monogenic forms of human obesity having success over common polygenic forms. In the context of molecular genetics, genome-wide association studies (GWAS) approach and their findings signified a number of genetic variants predisposing to obesity. However, the last couple of years, it has also been noticed that alterations in the environmental and epigenetic factors are one of the key causes of obesity. Hence, this review might be helpful in the current scenario of molecular genetics of human obesity, obesity-related health complications (ORHC), and energy homeostasis. Future work based on the clinical discoveries may play a role in the molecular dissection of genetic approaches to find more obesity-susceptible gene loci.
Topics: Energy Metabolism; Genetic Predisposition to Disease; Genetics, Medical; Genome-Wide Association Study; Humans; Obesity
PubMed: 28089486
DOI: 10.1016/j.crvi.2016.11.007 -
International Journal of Molecular... Sep 2022Obesity is a complex multifactorial disorder with genetic and environmental factors. There is an increase in the worldwide prevalence of obesity in both developed and... (Review)
Review
Obesity is a complex multifactorial disorder with genetic and environmental factors. There is an increase in the worldwide prevalence of obesity in both developed and developing countries. The development of genome-wide association studies (GWAS) and next-generation sequencing (NGS) has increased the discovery of genetic associations and awareness of monogenic and polygenic causes of obesity. The genetics of obesity could be classified into syndromic and non-syndromic obesity. Prader-Willi, fragile X, Bardet-Biedl, Cohen, and Albright Hereditary Osteodystrophy (AHO) syndromes are examples of syndromic obesity, which are associated with developmental delay and early onset obesity. Non-syndromic obesity could be monogenic, polygenic, or chromosomal in origin. Monogenic obesity is caused by variants of single genes while polygenic obesity includes several genes with the involvement of members of gene families. New advances in genetic testing have led to the identification of obesity-related genes. Leptin (), the leptin receptor (), proopiomelanocortin (), prohormone convertase 1 (), the melanocortin 4 receptor (), single-minded homolog 1 (), brain-derived neurotrophic factor (), and the neurotrophic tyrosine kinase receptor type 2 gene () have been reported as causative genes for obesity. NGS is now in use and emerging as a useful tool to search for candidate genes for obesity in clinical settings.
Topics: Brain-Derived Neurotrophic Factor; Genome-Wide Association Study; Humans; Leptin; Obesity; Pro-Opiomelanocortin; Proprotein Convertase 1; Receptor, Melanocortin, Type 4; Receptor, trkB; Receptors, Leptin
PubMed: 36232301
DOI: 10.3390/ijms231911005 -
Cell Apr 2019Severe obesity is a rapidly growing global health threat. Although often attributed to unhealthy lifestyle choices or environmental factors, obesity is known to be...
Severe obesity is a rapidly growing global health threat. Although often attributed to unhealthy lifestyle choices or environmental factors, obesity is known to be heritable and highly polygenic; the majority of inherited susceptibility is related to the cumulative effect of many common DNA variants. Here we derive and validate a new polygenic predictor comprised of 2.1 million common variants to quantify this susceptibility and test this predictor in more than 300,000 individuals ranging from middle age to birth. Among middle-aged adults, we observe a 13-kg gradient in weight and a 25-fold gradient in risk of severe obesity across polygenic score deciles. In a longitudinal birth cohort, we note minimal differences in birthweight across score deciles, but a significant gradient emerged in early childhood and reached 12 kg by 18 years of age. This new approach to quantify inherited susceptibility to obesity affords new opportunities for clinical prevention and mechanistic assessment.
Topics: Adolescent; Body Mass Index; Body Weight; Child; Databases, Factual; Female; Genome-Wide Association Study; Humans; Infant, Newborn; Longitudinal Studies; Male; Middle Aged; Multifactorial Inheritance; Obesity; Risk Factors; Severity of Illness Index
PubMed: 31002795
DOI: 10.1016/j.cell.2019.03.028 -
Nutrients Oct 2020Genome-wide single nucleotide polymorphism (SNP) data are now quickly and inexpensively acquired, raising the prospect of creating personalized dietary recommendations... (Review)
Review
Genome-wide single nucleotide polymorphism (SNP) data are now quickly and inexpensively acquired, raising the prospect of creating personalized dietary recommendations based on an individual's genetic variability at multiple SNPs. However, relatively little is known about most specific gene-diet interactions, and many molecular and clinical phenotypes of interest (e.g., body mass index [BMI]) involve multiple genes. In this review, we discuss direct to consumer genetic testing (DTC-GT) and the current potential for precision nutrition based on an individual's genetic data. We review important issues such as dietary exposure and genetic architecture addressing the concepts of penetrance, pleiotropy, epistasis, polygenicity, and epigenetics. More specifically, we discuss how they complicate using genotypic data to predict phenotypes as well as response to dietary interventions. Then, several examples (including caffeine sensitivity, alcohol dependence, non-alcoholic fatty liver disease, obesity/appetite, cardiovascular, Alzheimer's disease, folate metabolism, long-chain fatty acid biosynthesis, and vitamin D metabolism) are provided illustrating how genotypic information could be used to inform nutritional recommendations. We conclude by examining ethical considerations and practical applications for using genetic information to inform dietary choices and the future role genetics may play in adopting changes beyond population-wide healthy eating guidelines.
Topics: Diet, Healthy; Eating; Female; Genetic Testing; Humans; Male; Nutrigenomics; Nutritional Physiological Phenomena; Polymorphism, Single Nucleotide; Precision Medicine; Recommended Dietary Allowances
PubMed: 33065985
DOI: 10.3390/nu12103118 -
Obesity (Silver Spring, Md.) Oct 2019Lipedema is a chronic progressive disease characterized by abnormal fat distribution resulting in disproportionate, painful limbs. It almost exclusively affects women,... (Review)
Review
Lipedema is a chronic progressive disease characterized by abnormal fat distribution resulting in disproportionate, painful limbs. It almost exclusively affects women, leading to considerable disability, daily functioning impairment, and psychosocial distress. Literature shows both scarce and conflicting data regarding its prevalence. Lipedema has been considered a rare entity by several authors, though it may be a far more frequent condition than thought. Despite the clinical impact on women's health, lipedema is in fact mostly unknown, underdiagnosed, and too often misdiagnosed with other similarly presenting diseases. Polygenic susceptibility combined with hormonal, microvascular, and lymphatic disorders may be partly responsible for its development. Furthermore, consistent information on lipedema pathophysiology is still lacking, and an etiological treatment is not yet available. Weight loss measures exhibit minimal effect on the abnormal body fat distribution, resulting in eating disorders, increased obesity risk, depression, and other psychological complaints. Surgical techniques, such as liposuction and excisional lipectomy, represent therapeutic options in selected cases. This review aims to outline current evidence regarding lipedema epidemiology, pathophysiology, clinical presentation, differential diagnosis, and management. Increased awareness and a better understanding of its clinical presentation and pathophysiology are warranted to enable clinicians to diagnose and treat affected patients at an earlier stage.
Topics: Body Fat Distribution; Diagnosis, Differential; Female; Humans; Lipectomy; Lipedema; Male; Obesity
PubMed: 31544340
DOI: 10.1002/oby.22597 -
Nutrients Mar 2023Overweight and obesity in childhood and adolescence represents one of the most challenging public health problems of our century owing to its epidemic proportions and... (Review)
Review
Overweight and obesity in childhood and adolescence represents one of the most challenging public health problems of our century owing to its epidemic proportions and the associated significant morbidity, mortality, and increase in public health costs. The pathogenesis of polygenic obesity is multifactorial and is due to the interaction among genetic, epigenetic, and environmental factors. More than 1100 independent genetic loci associated with obesity traits have been currently identified, and there is great interest in the decoding of their biological functions and the gene-environment interaction. The present study aimed to systematically review the scientific evidence and to explore the relation of single-nucleotide polymorphisms (SNPs) and copy number variants (CNVs) with changes in body mass index (BMI) and other measures of body composition in children and adolescents with obesity, as well as their response to lifestyle interventions. Twenty-seven studies were included in the qualitative synthesis, which consisted of 7928 overweight/obese children and adolescents at different stages of pubertal development who underwent multidisciplinary management. The effect of polymorphisms in 92 different genes was assessed and revealed SNPs in 24 genetic loci significantly associated with BMI and/or body composition change, which contribute to the complex metabolic imbalance of obesity, including the regulation of appetite and energy balance, the homeostasis of glucose, lipid, and adipose tissue, as well as their interactions. The decoding of the genetic and molecular/cellular pathophysiology of obesity and the gene-environment interactions, alongside with the individual genotype, will enable us to design targeted and personalized preventive and management interventions for obesity early in life.
Topics: Adolescent; Child; Humans; Pediatric Obesity; Overweight; Body Mass Index; Genotype; Polymorphism, Single Nucleotide
PubMed: 36986146
DOI: 10.3390/nu15061416