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Regan JA, Shah SH. Obesity Genomics and Metabolomics: a Nexus of Cardiometabolic Risk. Curr Cardiol Rep 2020; 22:174. [PMID: 33040225 DOI: 10.1007/s11886-020-01422-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/14/2020] [Indexed: 12/24/2022]
Abstract
PURPOSE OF REVIEW Obesity is a significant international public health epidemic with major downstream consequences on morbidity and mortality. While lifestyle factors contribute, there is an evolving understanding of genomic and metabolomic pathways involved with obesity and its relationship with cardiometabolic risk. This review will provide an overview of some of these important findings from both a biologic and clinical perspective. RECENT FINDINGS Recent studies have identified polygenic risk scores and metabolomic biomarkers of obesity and related outcomes, which have also highlighted biological pathways, such as the branched-chain amino acid (BCAA) pathway that is dysregulated in this disease. These biomarkers may help in personalizing obesity interventions and for mitigation of future cardiometabolic risk. A multifaceted approach is necessary to impact the growing epidemic of obesity and related diseases. This will likely include incorporating precision medicine approaches with genomic and metabolomic biomarkers to personalize interventions and improve risk prediction.
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Affiliation(s)
- Jessica A Regan
- Department of Medicine, Duke University, Durham, NC, USA.,Duke Molecular Physiology Institute, Duke University, 300 N. Duke Street, DUMC, Box 104775, Durham, NC, 27701, USA
| | - Svati H Shah
- Department of Medicine, Duke University, Durham, NC, USA. .,Duke Molecular Physiology Institute, Duke University, 300 N. Duke Street, DUMC, Box 104775, Durham, NC, 27701, USA.
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Tam V, Turcotte M, Meyre D. Established and emerging strategies to crack the genetic code of obesity. Obes Rev 2019; 20:212-240. [PMID: 30353704 DOI: 10.1111/obr.12770] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 08/27/2018] [Accepted: 08/28/2018] [Indexed: 12/11/2022]
Abstract
Tremendous progress has been made in the genetic elucidation of obesity over the past two decades, driven largely by technological, methodological and organizational innovations. Current strategies for identifying obesity-predisposing loci/genes, including cytogenetics, linkage analysis, homozygosity mapping, admixture mapping, candidate gene studies, genome-wide association studies, custom genotyping arrays, whole-exome sequencing and targeted exome sequencing, have achieved differing levels of success, and the identified loci in aggregate explain only a modest fraction of the estimated heritability of obesity. This review outlines the successes and limitations of these approaches and proposes novel strategies, including the use of exceptionally large sample sizes, the study of diverse ethnic groups and deep phenotypes and the application of innovative methods and study designs, to identify the remaining obesity-predisposing genes. The use of both established and emerging strategies has the potential to crack the genetic code of obesity in the not-too-distant future. The resulting knowledge is likely to yield improvements in obesity prediction, prevention and care.
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Affiliation(s)
- V Tam
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
| | - M Turcotte
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
| | - D Meyre
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada.,Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
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Kim HJ, Yoo YJ, Ju YS, Lee S, Cho SI, Sung J, Kim JI, Seo JS. Combined linkage and association analyses identify a novel locus for obesity near PROX1 in Asians. Obesity (Silver Spring) 2013; 21:2405-12. [PMID: 23818313 DOI: 10.1002/oby.20153] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 10/24/2012] [Indexed: 12/22/2022]
Abstract
OBJECTIVE Although genome-wide association studies (GWAS) have substantially contributed to understanding the genetic architecture, unidentified variants for complex traits remain an issue. One of the efficient approaches is the improvement of the power of GWAS scan by weighting P values with prior linkage signals. Our objective was to identify the novel candidates for obesity in Asian populations by using genemapping strategies that combine linkage and association analyses. DESIGN AND METHODS To obtain linkage information for body mass index (BMI) and waist circumference (WC), we performed a multipoint genome-wide linkage study in an isolated Mongolian sample of 1,049 individuals from 74 families. Next, a family-based GWAS, which integrates within- and between-family components, was performed using the genotype data of 756 individuals of the Mongolian sample, and P values for association were weighted using linkage information obtained previously. RESULTS For both BMI (LOD = 3.3) and WC (LOD = 2.6), the highest linkage peak was discovered at chromosome 10q11.22. In family-based GWAS combined with linkage information, six single-nucleotide polymorphisms (SNPs) for BMI and five SNPs for WC reached a significant level of association (linkage weighted P < 1 × 10(-5) ). Of these, only one of the SNPs associated with WC (rs1704198) was replicated in 327 Korean families comprising 1,301 individuals. This SNP was located in the proximity of the prosperorelated homeobox 1 (PROX1) gene, the function of which was validated previously in a mouse model. CONCLUSION Our powerful strategic analysis enabled the discovery of a novel candidate gene, PROX1, associated with WC in an Asian population.
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Affiliation(s)
- Hyun-Jin Kim
- Genomic Medicine Institute (GMI), Medical Research Center, Seoul National University, Seoul, Republic of Korea; Department of Biomedical Sciences, Seoul National University Graduate School, Seoul, Republic of Korea
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Wu C, Gong Y, Yuan J, Gong H, Zou Y, Ge J. Identification of shared genetic susceptibility locus for coronary artery disease, type 2 diabetes and obesity: a meta-analysis of genome-wide studies. Cardiovasc Diabetol 2012; 11:68. [PMID: 22697793 PMCID: PMC3481354 DOI: 10.1186/1475-2840-11-68] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Accepted: 05/28/2012] [Indexed: 01/10/2023] Open
Abstract
Type 2 diabetes (2DM), obesity, and coronary artery disease (CAD) are frequently coexisted being as key components of metabolic syndrome. Whether there is shared genetic background underlying these diseases remained unclear. We performed a meta-analysis of 35 genome screens for 2DM, 36 for obesity or body mass index (BMI)-defined obesity, and 21 for CAD using genome search meta-analysis (GSMA), which combines linkage results to identify regions with only weak evidence and provide genetic interactions among different diseases. For each study, 120 genomic bins of approximately 30 cM were defined and ranked according to the best linkage evidence within each bin. For each disease, bin 6.2 achieved genomic significanct evidence, and bin 9.3, 10.5, 16.3 reached suggestive level for 2DM. Bin 11.2 and 16.3, and bin 10.5 and 9.3, reached suggestive evidence for obesity and CAD respectively. In pooled all three diseases, bin 9.3 and 6.5 reached genomic significant and suggestive evidence respectively, being relatively much weaker for 2DM/CAD or 2DM/obesity or CAD/obesity. Further, genomewide significant evidence was observed of bin 16.3 and 4.5 for 2DM/obesity, which is decreased when CAD was added. These findings indicated that bin 9.3 and 6.5 are most likely to be shared by 2DM, obesity and CAD. And bin 16.3 and 4.5 are potentially common regions to 2DM and obesity only. The observed shared susceptibility regions imply a partly overlapping genetic aspects of disease development. Fine scanning of these regions will definitely identify more susceptibility genes and causal variants.
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Affiliation(s)
- Chaoneng Wu
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai 200032, China
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Li A, Meyre D. Challenges in reproducibility of genetic association studies: lessons learned from the obesity field. Int J Obes (Lond) 2012; 37:559-67. [DOI: 10.1038/ijo.2012.82] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Xi B, Shen Y, Zhang M, Liu X, Zhao X, Wu L, Cheng H, Hou D, Lindpaintner K, Liu L, Mi J, Wang X. The common rs9939609 variant of the fat mass and obesity-associated gene is associated with obesity risk in children and adolescents of Beijing, China. BMC MEDICAL GENETICS 2010; 11:107. [PMID: 20598163 PMCID: PMC2914647 DOI: 10.1186/1471-2350-11-107] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 11/24/2009] [Accepted: 07/05/2010] [Indexed: 12/18/2022]
Abstract
Background Previous genome-wide association studies for type 2 diabetes susceptibility genes have confirmed that a common variant, rs9939609, in the fat mass and obesity associated (FTO) gene region is associated with body mass index (BMI) in European children and adults. A significant association of the same risk allele has been described in Asian adult populations, but the results are conflicting. In addition, no replication studies have been conducted in children and adolescents of Asian ancestry. Methods A population-based survey was carried out among 3503 children and adolescents (6-18 years of age) in Beijing, China, including 1229 obese and 2274 non-obese subjects. We investigated the association of rs9939609 with BMI and the risk of obesity. In addition, we tested the association of rs9939609 with weight, height, waist circumference, waist-to-height ratio, fat mass percentage, birth weight, blood pressure and related metabolic traits. Results We found significant associations of rs9939609 variant with weight, BMI, BMI standard deviation score (BMI-SDS), waist circumference, waist-to-height ratio, and fat mass percentage in children and adolescents (p for trend = 3.29 × 10-5, 1.39 × 10-6, 3.76 × 10-6, 2.26 × 10-5, 1.94 × 10-5, and 9.75 × 10-5, respectively). No significant associations were detected with height, birth weight, systolic and diastolic blood pressure and related metabolic traits such as total cholesterol, triglycerides, HDL-cholesterol, LDL-cholesterol and fasting plasma glucose (all p > 0.05). Each additional copy of the rs9939609 A allele was associated with a BMI increase of 0.79 [95% Confidence interval (CI) 0.47 to 1.10] kg/m2, equivalent to 0.25 (95%CI 0.14 to 0.35) BMI-SDS units. This rs9939609 variant is significantly associated with the risk of obesity under an additive model [Odds ratio (OR) = 1.29, 95% CI 1.11 to 1.50] after adjusting for age and gender. Moreover, an interaction between the FTO rs9939609 genotype and physical activity (p < 0.001) was detected on BMI levels, the effect of rs9939609-A allele on BMI being (0.95 ± 0.10), (0.77 ± 0.08) and (0.67 ± 0.05) kg/m2, for subjects who performed low, moderate and severe intensity physical activity. Conclusion The FTO rs9939609 variant is strongly associated with BMI and the risk of obesity in a population of children and adolescents in Beijing, China.
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Affiliation(s)
- Bo Xi
- Department of Epidemiology, Capital Institute of Pediatrics, 2 Ya Bao Road, 100020 Beijing China
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van Vliet-Ostaptchouk JV, Hofker MH, van der Schouw YT, Wijmenga C, Onland-Moret NC. Genetic variation in the hypothalamic pathways and its role on obesity. Obes Rev 2009; 10:593-609. [PMID: 19712437 DOI: 10.1111/j.1467-789x.2009.00597.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Over recent decades, the prevalence of obesity has increased dramatically worldwide. Although this epidemic is mainly attributable to modern (western) lifestyle, multiple twin and adoption studies indicate the significant role of genes in the individual's predisposition to becoming obese. As the hypothalamus plays a central role in controlling body weight, its regulatory circuits may represent a crucial system in the pathogenesis of the disorder. Genetic variations in genes in the hypothalamic pathways may therefore contribute to the susceptibility for obesity in humans and animals. We summarize current knowledge on the physiological role of the hypothalamus in body-weight regulation and review genetic studies on the hypothalamic candidate genes in relation to obesity. Together, data from functional and genetic studies as well as the new, common, obesity loci identified in genome-wide association scans support an important role for the hypothalamic genes in predisposing to obesity. However, findings are still inconclusive for many candidate genes. To improve our understanding of the genetic architecture of common obesity, we suggest that specific obesity phenotypes should be considered and different analytical approaches used. Such studies should consider multiple genes from the same physiological pathways, together with environmental risk factors.
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Affiliation(s)
- J V van Vliet-Ostaptchouk
- Molecular Genetics, Medical Biology Section, Department of Pathology and Medical Biology, University Medical Center and University of Groningen, Groningen, the Netherlands.
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Choquette AC, Lemieux S, Tremblay A, Drapeau V, Bouchard C, Vohl MC, Pérusse L. GAD2 gene sequence variations are associated with eating behaviors and weight gain in women from the Quebec family study. Physiol Behav 2009; 98:505-10. [DOI: 10.1016/j.physbeh.2009.08.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Revised: 04/23/2009] [Accepted: 08/06/2009] [Indexed: 10/20/2022]
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Böttcher Y, Unbehauen H, Klöting N, Ruschke K, Körner A, Schleinitz D, Tönjes A, Enigk B, Wolf S, Dietrich K, Koriath M, Scholz GH, Tseng YH, Dietrich A, Schön MR, Kiess W, Stumvoll M, Blüher M, Kovacs P. Adipose tissue expression and genetic variants of the bone morphogenetic protein receptor 1A gene (BMPR1A) are associated with human obesity. Diabetes 2009; 58:2119-28. [PMID: 19502417 PMCID: PMC2731538 DOI: 10.2337/db08-1458] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2008] [Accepted: 05/19/2009] [Indexed: 12/05/2022]
Abstract
OBJECTIVE Members of the family of bone morphogenetic proteins (BMPs) are important regulators of adipogenesis. We examined the role of the BMP receptor 1A gene (BMPR1A) in the pathophysiology of human obesity. RESEARCH DESIGN AND METHODS We measured BMPR1A mRNA expression in paired samples of visceral and subcutaneous adipose tissue from 297 subjects and sequenced the BMPR1A in 48 nonrelated white subjects. Twenty-one representative variants including HapMap tagging single nucleotide polymorphisms (SNPs) were then genotyped for association studies in German whites (n = 1,907). For replication analyses, we used a population of Sorbs from Germany (n = 900) and German childhood cohorts (n = 1,029 schoolchildren and 270 obese children). RESULTS mRNA expression of the BMPR1A was significantly increased in both visceral and subcutaneous adipose tissue of overweight and obese subjects compared with lean subjects (P < 0.05). In a case-control study, four SNPs (rs7095025, rs11202222, rs10788528, and rs7922846) were nominally associated with obesity (adjusted P < 0.05). For three SNPs (rs7095025, rs11202222, and rs10788528), the association with obesity was confirmed in the independent cohort of Sorbs (adjusted P < 0.005). Consistent with this, BMPR1A SNPs were nominally associated with obesity-related quantitative traits in nondiabetic subjects in both adult cohorts. Furthermore, homozygous carriers of the obesity risk alleles had higher BMPR1A mRNA expression in fat than noncarriers. CONCLUSIONS Our data suggest that genetic variation in the BMPR1A may play a role in the pathophysiology of human obesity, possibly mediated through effects on mRNA expression.
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Affiliation(s)
- Yvonne Böttcher
- Department of Medicine, University of Leipzig, Leipzig, Germany
| | - Hanne Unbehauen
- Department of Medicine, University of Leipzig, Leipzig, Germany
| | - Nora Klöting
- Department of Medicine, University of Leipzig, Leipzig, Germany
| | - Karen Ruschke
- Department of Medicine, University of Leipzig, Leipzig, Germany
| | - Antje Körner
- University Hospital for Children and Adolescents, University of Leipzig, Leipzig, Germany
| | - Dorit Schleinitz
- Interdisciplinary Centre for Clinical Research, University of Leipzig, Germany
| | - Anke Tönjes
- Department of Medicine, University of Leipzig, Leipzig, Germany
- Coordination Centre for Clinical Trials, University of Leipzig, Germany
| | - Beate Enigk
- Interdisciplinary Centre for Clinical Research, University of Leipzig, Germany
| | - Sara Wolf
- Department of Medicine, University of Leipzig, Leipzig, Germany
| | - Kerstin Dietrich
- Interdisciplinary Centre for Clinical Research, University of Leipzig, Germany
| | - Moritz Koriath
- Department of Medicine, University of Leipzig, Leipzig, Germany
| | | | - Yu-Hua Tseng
- Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts
| | - Arne Dietrich
- Department of Surgery, University of Leipzig, Leipzig, Germany
| | | | - Wieland Kiess
- University Hospital for Children and Adolescents, University of Leipzig, Leipzig, Germany
| | | | - Matthias Blüher
- Department of Medicine, University of Leipzig, Leipzig, Germany
| | - Peter Kovacs
- Interdisciplinary Centre for Clinical Research, University of Leipzig, Germany
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Witchel SF, White C, Libman I. Association of the -243 A-->G polymorphism of the glutamate decarboxylase 2 gene with obesity in girls with premature pubarche. Fertil Steril 2009; 91:1869-76. [PMID: 18371956 PMCID: PMC2756597 DOI: 10.1016/j.fertnstert.2008.01.085] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2007] [Revised: 01/22/2008] [Accepted: 01/22/2008] [Indexed: 11/18/2022]
Abstract
OBJECTIVE To test the a priori hypothesis that the frequency of a single-nucleotide polymorphism (SNP) located in the promoter region of the glutamate decarboxylase 2 (GAD2) gene (-243A-->G) would be overrepresented among children with higher body mass index (BMI) values. DESIGN Genotype-phenotype correlation study. SETTING University-based pediatric endocrinology practice. PATIENT(S) Eighty-seven girls with PP and 70 adolescent girls with hyperandrogenism. INTERVENTION(S) Blood was obtained for genotype analysis, glucose measurement, and hormone (Delta(4)-A, insulin, 17-hydroxyprogesterone, and T) determinations. MAIN OUTCOME MEASURE(S) Frequency of this SNP in the GAD2 gene and correlation of this SNP with BMI and hormone concentrations. RESULT(S) Among the girls followed longitudinally, the presence of one or more G alleles was associated with increased BMI at both initial and recent visits and with greater BMI z score at the initial visit. No associations were found between androgen concentrations and the G-allele variant. CONCLUSION(S) Similar to the findings among French children, this SNP in the GAD2 gene was associated with increased BMI in late childhood and adolescence in this population of girls from western Pennsylvania. Additional prospective studies that replicate our findings are crucial. Verification of our findings will encourage the use of lifestyle interventions for young girls who carry the G allele.
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Affiliation(s)
- Selma Feldman Witchel
- Department of Pediatrics, Division of Endocrinology, Children's Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA.
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Speakman JR, Rance KA, Johnstone AM. Polymorphisms of the FTO gene are associated with variation in energy intake, but not energy expenditure. Obesity (Silver Spring) 2008; 16:1961-5. [PMID: 18551109 DOI: 10.1038/oby.2008.318] [Citation(s) in RCA: 239] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The FTO gene has significant polymorphic variation associated with obesity, but its function is unknown. We screened a population of 150 whites (103F/47M) resident in NE Scotland, United Kingdom, for variants of the FTO gene and linked these to phenotypic variation in their energy expenditure (basal metabolic rate (BMR) and maximal oxygen consumption VO(2)max) and energy intake. There was no significant association between the FTO genotype and BMR or VO(2)max. The FTO genotype was significantly associated (P = 0.024) with variation in energy intake, with average daily intake being 9.0 MJ for the wild-type TT genotype and 10.2 and 9.5 MJ for the "at risk" AT and AA genotypes, respectively. Adjusting intake for BMR did not remove the significance (P = 0.043). FTO genotype probably affects obesity via effects on food intake rather than energy expenditure.
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Affiliation(s)
- John R Speakman
- Division of Obesity and Metabolic Health, Rowett Research Institute, Aberdeen, Scotland, UK.
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Hunt SC, Stone S, Xin Y, Scherer CA, Magness CL, Iadonato SP, Hopkins PN, Adams TD. Association of the FTO gene with BMI. Obesity (Silver Spring) 2008; 16:902-4. [PMID: 18239580 PMCID: PMC4476623 DOI: 10.1038/oby.2007.126] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Variants in the FTO gene have been strongly associated with obesity in a very large sample (38,759) of diabetic and control subjects. To replicate these findings, the previously reported SNP in the FTO gene (rs9939609, T/A) was genotyped in 5,607 subjects from five different Utah studies. The studies included a random sample of the Utah population, families selected for aggregation of extreme thinness, families selected for severe obesity, a series of unrelated severe obesity subjects, and families participating in a 25-year longitudinal study of cardiovascular disease and aging. Results show a strong significant increase in the rs9939609 A allele frequency with increasing BMI (P < 0.0001). In the longitudinal study, FTO genotypes were significantly associated with BMI at a baseline exam, a 2(1/2)-year follow-up exam and a 25-year follow-up exam using an additive genetic model. The mean genotype difference in BMI ranged from 1.3 to 2.1 kg/m(2) across exams. The genotype difference in BMI means was established in youth, and at-risk subjects under age 20 at baseline had a significantly larger 25-year BMI increase (10.0 for A/A; 9.7 for A/T, and 8.5 kg/m(2) for T/T, P = 0.05). We conclude that the BMI increases associated with FTO genotypes begin in youth and are maintained throughout adulthood.
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Affiliation(s)
- Steven C Hunt
- Cardiovascular Genetics Division, Department of Internal Medicine, University of Utah, Salt Lake City, Utah, USA.
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Abstract
Type 2 diabetes (T2D) and obesity are recognized as conditions of growing biomedical importance to societies worldwide. Despite this, lack of understanding concerning the processes which normally serve to maintain weight and to regulate glucose concentrations, and ignorance about the mechanisms by which these homeostatic processes fail, remains a significant obstacle to the development of improved tools for management and prevention. There has been a long-standing belief that the identification of the specific genes influencing development of these conditions has the potential to reveal these fundamental processes, thereby providing vital clues to support clinical advances. Furthermore, there has been the hope that this information will translate into the capacity to deliver more 'personalized' medical care, whereby management can be tailored in accordance with an appreciation of individual molecular pathogenesis. As this review indicates, these developments are already a reality for selected monogenic forms of diabetes and obesity. Recent advances in the identification of genes underlying multifactorial forms of these conditions will accelerate efforts to effect similar clinical translation across the full spectrum of disease.
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Boesgaard TW, Castella SI, Andersen G, Albrechtsen A, Sparsø T, Borch-Johnsen K, Jørgensen T, Hansen T, Pedersen O. A -243A-->G polymorphism upstream of the gene encoding GAD65 associates with lower levels of body mass index and glycaemia in a population-based sample of 5857 middle-aged White subjects. Diabet Med 2007; 24:702-6. [PMID: 17459095 DOI: 10.1111/j.1464-5491.2007.02110.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AIMS The glutamate decarboxylase gene (GAD2) encodes GAD65, an enzyme catalysing the production of the gamma-aminobutyric acid (GABA) which interacts with neuropeptide Y to stimulate food intake. It has been suggested that in pancreatic islets, GABA serves as a functional regulator of pancreatic hormone release. Conflicting results have been reported concerning the potential impact of GAD2 variation on estimates of energy metabolism. The aim of this study was to elucidate potential associations between the GAD2-243A-->G polymorphism and levels of body mass index (BMI) and estimates of glycaemia. METHODS Using high-throughput chip-based matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, the GAD2-243A-->G (rs2236418) polymorphism was genotyped in a population-based sample (Inter99) of 5857 middle-aged, unrelated Danish White subjects. RESULTS The G-allele was associated with modestly lower BMI (P = 0.01). In a case-control study of obesity, the G-allele frequency in 2582 participants with BMI < 25 kg/m2 was 19.5% (18.4-20.6) compared with 17.1% (15.5-18.8) in 968 participants having BMI > or = 30 kg/m2 (P = 0.03), odds ratio 0.9 (0.7-1.0). Of the 5857 subjects, GG carriers had lower fasting plasma glucose levels (mmol/l) [AA (n = 3859) 5.6 +/- 0.8; AG (n = 1792) 5.5 +/- 0.8; GG (n = 206) 5.5 +/- 0.8, P = 0.008] and lower 30-min oral glucose tolerance test (OGTT)-related plasma glucose levels (AA 8.7 +/- 1.9; AG 8.6 +/- 1.9; GG 8.6 +/- 2.0, P = 0.04), adjusted for sex, age and BMI. Analysing subjects who were both normoglycaemic and glucose tolerant (n = 4431) GG carriers still had lower fasting plasma glucose concentrations: AA (n = 2895) 5.3 +/- 0.4; AG (n = 1383) 5.3 +/- 0.4; GG (n = 153) 5.2 +/- 0.4 (P = 9.10(-5)). CONCLUSION The present study suggests that the GAD2-243A-->G polymorphism in a population of middle-aged White people associates with a modest reduction in BMI and fasting and OGTT-related plasma glucose levels.
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Frayling TM, Timpson NJ, Weedon MN, Zeggini E, Freathy RM, Lindgren CM, Perry JRB, Elliott KS, Lango H, Rayner NW, Shields B, Harries LW, Barrett JC, Ellard S, Groves CJ, Knight B, Patch AM, Ness AR, Ebrahim S, Lawlor DA, Ring SM, Ben-Shlomo Y, Jarvelin MR, Sovio U, Bennett AJ, Melzer D, Ferrucci L, Loos RJF, Barroso I, Wareham NJ, Karpe F, Owen KR, Cardon LR, Walker M, Hitman GA, Palmer CNA, Doney ASF, Morris AD, Smith GD, The Wellcome Trust Case Control Consortium, Hattersley AT, McCarthy MI. A common variant in the FTO gene is associated with body mass index and predisposes to childhood and adult obesity. Science 2007; 316:889-94. [PMID: 17434869 PMCID: PMC2646098 DOI: 10.1126/science.1141634] [Citation(s) in RCA: 3184] [Impact Index Per Article: 176.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Obesity is a serious international health problem that increases the risk of several common diseases. The genetic factors predisposing to obesity are poorly understood. A genome-wide search for type 2 diabetes-susceptibility genes identified a common variant in the FTO (fat mass and obesity associated) gene that predisposes to diabetes through an effect on body mass index (BMI). An additive association of the variant with BMI was replicated in 13 cohorts with 38,759 participants. The 16% of adults who are homozygous for the risk allele weighed about 3 kilograms more and had 1.67-fold increased odds of obesity when compared with those not inheriting a risk allele. This association was observed from age 7 years upward and reflects a specific increase in fat mass.
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Affiliation(s)
- Timothy M. Frayling
- Genetics of Complex Traits, Institute of Biomedical and Clinical Science, Peninsula Medical School, Magdalen Road, Exeter, UK
- Diabetes Genetics, Institute of Biomedical and Clinical Science, Peninsula Medical School, Barrack Road, Exeter, UK
| | - Nicholas J. Timpson
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, UK
- MRC Centre for Causal Analyses in Translational Epidemiology, Bristol University, Canynge Hall, Whiteladies Road, Bristol, UK
| | - Michael N. Weedon
- Genetics of Complex Traits, Institute of Biomedical and Clinical Science, Peninsula Medical School, Magdalen Road, Exeter, UK
- Diabetes Genetics, Institute of Biomedical and Clinical Science, Peninsula Medical School, Barrack Road, Exeter, UK
| | - Eleftheria Zeggini
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, UK
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, UK
| | - Rachel M. Freathy
- Genetics of Complex Traits, Institute of Biomedical and Clinical Science, Peninsula Medical School, Magdalen Road, Exeter, UK
- Diabetes Genetics, Institute of Biomedical and Clinical Science, Peninsula Medical School, Barrack Road, Exeter, UK
| | - Cecilia M. Lindgren
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, UK
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, UK
| | - John R. B. Perry
- Genetics of Complex Traits, Institute of Biomedical and Clinical Science, Peninsula Medical School, Magdalen Road, Exeter, UK
- Diabetes Genetics, Institute of Biomedical and Clinical Science, Peninsula Medical School, Barrack Road, Exeter, UK
| | - Katherine S. Elliott
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, UK
| | - Hana Lango
- Genetics of Complex Traits, Institute of Biomedical and Clinical Science, Peninsula Medical School, Magdalen Road, Exeter, UK
- Diabetes Genetics, Institute of Biomedical and Clinical Science, Peninsula Medical School, Barrack Road, Exeter, UK
| | - Nigel W. Rayner
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, UK
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, UK
| | - Beverley Shields
- Diabetes Genetics, Institute of Biomedical and Clinical Science, Peninsula Medical School, Barrack Road, Exeter, UK
| | - Lorna W. Harries
- Diabetes Genetics, Institute of Biomedical and Clinical Science, Peninsula Medical School, Barrack Road, Exeter, UK
| | - Jeffrey C. Barrett
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, UK
| | - Sian Ellard
- Diabetes Genetics, Institute of Biomedical and Clinical Science, Peninsula Medical School, Barrack Road, Exeter, UK
- Molecular Genetics Laboratory, Royal Devon and Exeter National Health Service Foundation Trust, Old Pathology Building, Barrack Road, Exeter, UK
| | - Christopher J. Groves
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, UK
| | - Bridget Knight
- Diabetes Genetics, Institute of Biomedical and Clinical Science, Peninsula Medical School, Barrack Road, Exeter, UK
| | - Ann-Marie Patch
- Diabetes Genetics, Institute of Biomedical and Clinical Science, Peninsula Medical School, Barrack Road, Exeter, UK
- Molecular Genetics Laboratory, Royal Devon and Exeter National Health Service Foundation Trust, Old Pathology Building, Barrack Road, Exeter, UK
| | - Andrew R. Ness
- Department of Oral and Dental Science, University of Bristol Dental School, Lower Maudlin Street, Bristol, UK
| | - Shah Ebrahim
- Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK
| | - Debbie A. Lawlor
- Department of Social Medicine, University of Bristol, Canynge Hall, Whiteladies Road, Bristol, UK
| | - Susan M. Ring
- Department of Social Medicine, University of Bristol, Canynge Hall, Whiteladies Road, Bristol, UK
| | - Yoav Ben-Shlomo
- Department of Social Medicine, University of Bristol, Canynge Hall, Whiteladies Road, Bristol, UK
| | - Marjo-Riitta Jarvelin
- Department of Epidemiology and Public Health, Imperial College London, Norfolk Place, London W2 1PG, UK
- Department of Public Health Science and General Practice, Fin-90014, University of Oulu, Finland
| | - Ulla Sovio
- Department of Epidemiology and Public Health, Imperial College London, Norfolk Place, London W2 1PG, UK
- Department of Public Health Science and General Practice, Fin-90014, University of Oulu, Finland
| | - Amanda J. Bennett
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, UK
| | - David Melzer
- Genetics of Complex Traits, Institute of Biomedical and Clinical Science, Peninsula Medical School, Magdalen Road, Exeter, UK
- Epidemiology and Public Health Group, Peninsula Medical School, Barrack Road, Exeter, UK
| | - Luigi Ferrucci
- Longitudinal Studies Section, Clinical Research Branch, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Ruth J. F. Loos
- Medical Research Council Epidemiology Unit, Strangeways Research Laboratories, Cambridge, UK
| | - Inês Barroso
- Metabolic Disease Group, Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK
| | - Nicholas J. Wareham
- Medical Research Council Epidemiology Unit, Strangeways Research Laboratories, Cambridge, UK
| | - Fredrik Karpe
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, UK
| | - Katharine R. Owen
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, UK
| | - Lon R. Cardon
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, UK
| | - Mark Walker
- Diabetes Research Group, School of Clinical Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, UK
| | - Graham A. Hitman
- Centre for Diabetes and Metabolic Medicine, Barts and The London, Royal London Hospital, Whitechapel, London, UK
| | - Colin N. A. Palmer
- Population Pharmacogenetics Group, Biomedical Research Centre, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK
| | - Alex S. F. Doney
- Diabetes Research Group, Division of Medicine and Therapeutics, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK
| | - Andrew D. Morris
- Diabetes Research Group, Division of Medicine and Therapeutics, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK
| | - George Davey Smith
- MRC Centre for Causal Analyses in Translational Epidemiology, Bristol University, Canynge Hall, Whiteladies Road, Bristol, UK
| | | | - Andrew T. Hattersley
- Genetics of Complex Traits, Institute of Biomedical and Clinical Science, Peninsula Medical School, Magdalen Road, Exeter, UK
- Diabetes Genetics, Institute of Biomedical and Clinical Science, Peninsula Medical School, Barrack Road, Exeter, UK
| | - Mark I. McCarthy
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, UK
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, UK
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Walley AJ, Blakemore AIF, Froguel P. Genetics of obesity and the prediction of risk for health. Hum Mol Genet 2006; 15 Spec No 2:R124-30. [PMID: 16987875 DOI: 10.1093/hmg/ddl215] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Obesity has always existed in human populations, but until very recently was comparatively rare. The availability of abundant, energy-rich processed foods in the last few decades has, however, resulted in a sharp rise in the prevalence of obesity in westernized countries. Although it is the obesogenic environment that has resulted in this major healthcare problem, it is acting by revealing a sub-population with a pre-existing genetic predisposition to excess adiposity. There is substantial evidence for the heritability of obesity, and research in both rare and common forms of obesity has identified genes with significant roles in its aetiology. Application of this understanding to patient care has been slower. Until very recently, the health risks of obesity were thought to be well understood, with a straightforward correlation between increasing obesity and increasing risk of health problems such as type 2 diabetes, coronary heart disease, hypertension, arthritis and cancer. It is becoming clear, however, that the location of fat deposition, variation in the secretion of adipokines and other factors govern whether a particular obese person develops such complications. Prediction of the health risks of obesity for individual patients is not straightforward, but continuing advances in understanding of genetic factors influencing obesity risk and improved diagnostic technologies mean that the future for such prediction is looking increasingly bright.
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Affiliation(s)
- Andrew J Walley
- Section of Genomic Medicine, Division of Medicine, Imperial College London, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK.
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