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Dong Z, Zhao H, DeWan AT. A mediation analysis framework based on variance component to remove genetic confounding effect. J Hum Genet 2024; 69:301-309. [PMID: 38528049 DOI: 10.1038/s10038-024-01232-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 02/15/2024] [Accepted: 02/16/2024] [Indexed: 03/27/2024]
Abstract
Identification of pleiotropy at the single nucleotide polymorphism (SNP) level provides valuable insights into shared genetic signals among phenotypes. One approach to study these signals is through mediation analysis, which dissects the total effect of a SNP on the outcome into a direct effect and an indirect effect through a mediator. However, estimated effects from mediation analysis can be confounded by the genetic correlation between phenotypes, leading to inaccurate results. To address this confounding effect in the context of genetic mediation analysis, we propose a restricted-maximum-likelihood (REML)-based mediation analysis framework called REML-mediation, which can be applied to either individual-level or summary statistics data. Simulations demonstrated that REML-mediation provides unbiased estimates of the true cross-trait causal effect, assuming certain assumptions, albeit with a slightly inflated standard error compared to traditional linear regression. To validate the effectiveness of REML-mediation, we applied it to UK Biobank data and analyzed several mediator-outcome trait pairs along with their corresponding sets of pleiotropic SNPs. REML-mediation successfully identified and corrected for genetic confounding effects in these trait pairs, with correction magnitudes ranging from 7% to 39%. These findings highlight the presence of genetic confounding effects in cross-trait epidemiological studies and underscore the importance of accounting for them in data analysis.
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Affiliation(s)
- Zihan Dong
- Department of Biostatistics, Yale School of Public Health, New Haven, CT, USA
- Center for Perinatal, Pediatric and Environmental Epidemiology, Yale School of Public Health, New Haven, CT, USA
| | - Hongyu Zhao
- Department of Biostatistics, Yale School of Public Health, New Haven, CT, USA.
| | - Andrew T DeWan
- Center for Perinatal, Pediatric and Environmental Epidemiology, Yale School of Public Health, New Haven, CT, USA.
- Department of Chronic Disease Epidemiology, Yale School of Public Health, New Haven, CT, USA.
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Górczyńska-Kosiorz S, Lejawa M, Goławski M, Tomaszewska A, Fronczek M, Maksym B, Banach M, Osadnik T. The Impact of Haplotypes of the FTO Gene, Lifestyle, and Dietary Patterns on BMI and Metabolic Syndrome in Polish Young Adult Men. Nutrients 2024; 16:1615. [PMID: 38892547 PMCID: PMC11174437 DOI: 10.3390/nu16111615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 05/21/2024] [Accepted: 05/22/2024] [Indexed: 06/21/2024] Open
Abstract
BACKGROUND Variants in fat mass and the obesity-associated protein (FTO) gene have long been recognized as the most significant genetic predictors of body fat mass and obesity. Nevertheless, despite the overall evidence, there are conflicting reports regarding the correlation between different polymorphisms of the FTO gene and body mass index (BMI). Additionally, it is unclear whether FTO influences metabolic syndrome (MetS) through mechanisms other than BMI's impact. In this work, we aimed to analyze the impact of the following FTO polymorphisms on the BMI as well as MetS components in a population of young adult men. METHODS The patient group consisted of 279 Polish young adult men aged 28.92 (4.28) recruited for the MAGNETIC trial. The single-nucleotide polymorphisms (SNPs), located in the first intron of the FTO gene, were genotyped, and the results were used to identify "protective" and "risk" haplotypes and diplotypes based on the literature data. Laboratory, as well as anthropometric measurements regarding MetS, were performed. Measured MetS components included those used in the definition in accordance with the current guidelines. Data regarding dietary patterns were also collected, and principal components of the dietary patterns were identified. RESULTS No statistically significant correlations were identified between the analyzed FTO diplotypes and BMI (p = 0.53) or other MetS components (waist circumference p = 0.55; triglycerides p = 0.72; HDL cholesterol p = 0.33; blood glucose p = 0.20; systolic blood pressure p = 0.06; diastolic blood pressure p = 0.21). Stratification by the level of physical activity or adherence to the dietary patterns also did not result in any statistically significant result. CONCLUSIONS Some studies have shown that FTO SNPs such as rs1421085, rs1121980, rs8050136, rs9939609, and rs9930506 have an impact on the BMI or other MetS components; nevertheless, this was not replicated in this study of Polish young adult males.
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Affiliation(s)
- Sylwia Górczyńska-Kosiorz
- Department of Internal Medicine, Diabetology and Nephrology, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, 40-055 Katowice, Poland
| | - Mateusz Lejawa
- Department of Pharmacology, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, 40-055 Katowice, Poland; (M.L.); (M.G.); (M.F.); (B.M.); (T.O.)
| | - Marcin Goławski
- Department of Pharmacology, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, 40-055 Katowice, Poland; (M.L.); (M.G.); (M.F.); (B.M.); (T.O.)
| | - Agnieszka Tomaszewska
- Prenatal Diagnostic and Genetic Clinic, Medical Center, Medical University of Silesia, 41-800 Zabrze, Poland;
| | - Martyna Fronczek
- Department of Pharmacology, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, 40-055 Katowice, Poland; (M.L.); (M.G.); (M.F.); (B.M.); (T.O.)
| | - Beata Maksym
- Department of Pharmacology, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, 40-055 Katowice, Poland; (M.L.); (M.G.); (M.F.); (B.M.); (T.O.)
| | - Maciej Banach
- Department of Preventive Cardiology and Lipidology, Medical University of Lodz (MUL), 90-549 Lodz, Poland;
- Ciccarone Center for the Prevention of Cardiovascular Disease, Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, 600 N. Wolfe St., Carnegie 591, Baltimore, MD 21287, USA
| | - Tadeusz Osadnik
- Department of Pharmacology, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, 40-055 Katowice, Poland; (M.L.); (M.G.); (M.F.); (B.M.); (T.O.)
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Roumi Z, Salimi Z, Mahmoudi Z, Mobarakeh KA, Ladaninezhad M, Zeinalabedini M, Keshavarz Mohammadian M, Shamsi‐Goushki A, Saeedirad Z, Bahar B, Khoshdooz S, Kalantari N, Azizi Tabesh G, Doaei S, Gholamalizadeh M. Efficacy of a Comprehensive Weight Reduction Intervention in Male Adolescents With Different FTO Genotypes. Endocrinol Diabetes Metab 2024; 7:e00483. [PMID: 38556726 PMCID: PMC10982462 DOI: 10.1002/edm2.483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/29/2024] [Accepted: 03/07/2024] [Indexed: 04/02/2024] Open
Abstract
BACKGROUND The FTO gene polymorphisms may influence the effects of lifestyle interventions on obesity. The present study aimed to assess the influence of the rs9930506 FTO gene polymorphism on the success of a comprehensive weight loss intervention in male adolescents with overweight and obesity. METHODS This study was carried out on 96 adolescent boys with overweight and obesity who were randomly assigned to the intervention (n = 53) and control (n = 43) groups. The blood samples of the participants were collected, and the FTO gene was genotyped for the rs9930506 polymorphism. A comprehensive lifestyle intervention including changes in diet and physical activity was performed for 8 weeks in the intervention group. RESULTS Following the lifestyle intervention, BMI and fat mass decreased significantly in the intervention group compared with the control group (both p < 0.05), while no change was found in weight, height or body muscle percentage between the groups. The participants in the intervention group with the AA/AG genotype and not in carriers of the GG genotype had a significantly higher reduction in BMI (-1.21 vs. 1.87 kg/m2, F = 4.07, p < 0.05) compared with the control group. CONCLUSION The intervention in individuals with the AA/AG genotype has been significantly effective in weight loss compared with the control group. The intervention had no association effect on anthropometric indices in adolescents with the GG genotype of the FTO rs9930506 polymorphism. TRIAL REGISTRATION Name of the registry: National Nutrition and Food Technology Research Institute; Trial registration number: IRCT2016020925699N2; Date of registration: 24/04/2016; URL of trial registry record: https://www.irct.ir/trial/21447.
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Affiliation(s)
- Zahra Roumi
- Department of Nutrition, Science and Research BranchIslamic Azad UniversityTehranIran
| | - Zahra Salimi
- Nutrition and Metabolic Diseases Research CenterAhvaz Jundishapur University of Medical SciencesAhvazIran
| | - Zahra Mahmoudi
- Department of Nutrition, Science and Research BranchIslamic Azad UniversityTehranIran
| | - Khadijeh Abbasi Mobarakeh
- Food Security Research Center and Department of Community Nutrition, School of Nutrition and Food ScienceIsfahan University of Medical SciencesIsfahanIran
| | - Maryam Ladaninezhad
- School of Nutritional Sciences and DieteticsTehran University of Medical SciencesTehranIran
| | - Mobina Zeinalabedini
- Department of Cellular and Molecular Nutrition, School of Nutritional Sciences and DieteticsTehran University of Medical SciencesTehranIran
| | | | - Ali Shamsi‐Goushki
- Department of Nutrition, School of MedicineMashhad University of Medical SciencesMashhadIran
| | - Zahra Saeedirad
- Department of Clinical Nutrition and DieteticsTehran University of Medical SciencesTehranIran
| | - Bojlul Bahar
- Nutrition Sciences and Applied Food Safety Studies, Research Centre for Global Development, School of Sport & Health SciencesUniversity of Central LancashirePrestonUK
| | - Sara Khoshdooz
- Faculty of MedicineGuilan University of Medical ScienceRashtIran
| | - Naser Kalantari
- Department of Community Nutrition, Faculty of Nutrition and Food TechnologyNational Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical SciencesTehranIran
| | - Ghasem Azizi Tabesh
- Genomic Research CenterShahid Beheshti University of Medical SciencesTehranIran
| | - Saeid Doaei
- Department of Community Nutrition, Faculty of Nutrition and Food TechnologyNational Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical SciencesTehranIran
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Park HG, Choi JH. Genetic variant rs9939609 in FTO is associated with body composition and obesity risk in Korean females. BMJ Open Diabetes Res Care 2023; 11:e003649. [PMID: 37993268 PMCID: PMC10668161 DOI: 10.1136/bmjdrc-2023-003649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Accepted: 10/14/2023] [Indexed: 11/24/2023] Open
Abstract
INTRODUCTION The fat mass and obesity-associated (FTO) gene is a significant locus in obesity. However, the association between FTO genetic variants and body composition has not been fully elucidated. RESEARCH DESIGN AND METHODS This observational study examined the associations of FTO rs9939609 T>A with obesity and body composition markers in Koreans. A total of 6474 participants from the Korean Genome and Epidemiology Study were analyzed for their general characteristics, body composition and FTO genotype with a sex-stratified approach. RESULTS Females with the obesity risk A allele showed significantly greater body weight, hip circumference, and body mass index and were at a 1.28-fold higher risk of obesity (95% CI=1.088 to 1.507) than those with the TT genotype. Analyses of body composition also showed that females with the A allele had a greater body fat mass and percentage, abdominal fat percentage, and degree of obesity, and this association and FTO genetic variation and adiposity was observed in females, especially aged under 50 years. However, the effect of the variant allele on non-fat tissue markers was not evident in females and was not associated with any parameters examined in males. CONCLUSIONS The FTO rs9939609 variant is associated with body composition in Koreans, especially body fat markers in females. These results support that the FTO rs9939609 variant is a genetic risk factor in the etiology of obesity.
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Affiliation(s)
- Hyeon-Gyo Park
- Department of Food Science and Nutrition, Keimyung University, Daegu, Korea (the Republic of)
| | - Jeong-Hwa Choi
- Department of Food Science and Nutrition, Keimyung University, Daegu, Korea (the Republic of)
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Trevisano RG, Gregnani MF, de Azevedo BC, de Almeida SS. The Association of Fat Mass and Obesity-Associated Gene Polymorphism (rs9939609) on the Body Composition of Older People: Systematic Review. Curr Aging Sci 2022; 15:229-241. [PMID: 35362391 DOI: 10.2174/1874609815666220331090135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 01/13/2022] [Accepted: 02/17/2022] [Indexed: 11/22/2022]
Abstract
BACKGROUND Population aging is growing faster than any other age group. Associated with aging, the prevalence of overweight and obesity is a potential risk factor for the development and aggravation of numerous pathologies. A genetic factor often associated with obesity is the Fat mass and obesity associated (FTO) (rs9939609) gene polymorphism, which has been extensively investigated in children, young, and adults. However, few studies have been carried out with the older population. This review aimed to verify the influence of the FTO (rs9939609) gene polymorphism on the body composition of the older population. METHODS We conducted a systematic review and Meta-analysis of PubMed, Scielo, and LILACS databases. Statistical analysis for meta-analysis was performed using mean values of Body Mass Index (BMI) and standard deviations. RESULTS The results did not show significant differences between FTO genotypes and BMI values (-0.32, 95%CI -0.45 to -0.19, I2 = 0%, p = 0.52). However, 59% of the studies identified some influence on body composition, obesity, or comorbidities. CONCLUSION Few publications verify FTO polymorphism effects on specific groups of the older, suggesting a reduction in the influence of this gene in the BMI with advancing age. However, we believe that more controlled studies in older populations should be performed.
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Affiliation(s)
| | | | | | - Sandro Soares de Almeida
- Department of Biophysics, Federal University of São Paulo, São Paulo, Brazil.,Albert Einstein Israeli Hospital, São Paulo, Brazil.,Ibirapuera University, São Paulo, Brazil
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Omura T, Araki A. Skeletal muscle as a treatment target for older adults with diabetes mellitus: The importance of a multimodal intervention based on functional category. Geriatr Gerontol Int 2022; 22:110-120. [PMID: 34986525 DOI: 10.1111/ggi.14339] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 12/01/2021] [Accepted: 12/16/2021] [Indexed: 12/21/2022]
Abstract
Although the lifespan of people with diabetes has increased in many countries, the age-related increase in comorbidities (sarcopenia, frailty and disabilities) and diabetic complications has become a major issue. Diabetes accelerates the aging of skeletal muscles and blood vessels through mechanisms, such as increased oxidative stress, chronic inflammation, insulin resistance, mitochondrial dysfunction, genetic polymorphism (fat mass and obesity-associated genes) and accumulation of advanced glycation end-products. Diabetes is associated with early onset, and progression of muscle weakness and sarcopenia, thus resulting in diminished daily life function. The type and duration of diabetes, insulin section/resistance, hyperglycemia, diabetic neuropathy, malnutrition and low physical activity might affect muscular loss and weakness. To prevent the decline in daily activities in older adults with diabetes, resistance training or multicomponent exercise should be recommended. To maintain muscle function, optimal energy and sufficient protein intake are necessary. Although no specific drug enhances muscle mass and function, antidiabetic drugs that increase insulin sensitivity or secretion could be candidates for improvement of sarcopenia. The goals of glycemic control for older patients are determined based on three functional categories through an assessment of cognitive function and activities of daily living, and the presence or absence of medications that pose a hypoglycemic risk. As these functional categories are associated with muscle weakness, frailty and mortality risk, providing multimodal interventions (exercise, nutrition, social network or support and optimal medical treatment) is important, starting at the category II stage for maintenance or improvement in daily life functions. Geriatr Gerontol Int 2022; ••: ••-••.
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Affiliation(s)
- Takuya Omura
- Department of Diabetes, Metabolism and Endocrinology, Tokyo Metropolitan Geriatric Hospital, Tokyo, Japan
| | - Atsushi Araki
- Department of Diabetes, Metabolism and Endocrinology, Tokyo Metropolitan Geriatric Hospital, Tokyo, Japan
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The importance of gene-environment interactions in human obesity. Clin Sci (Lond) 2017; 130:1571-97. [PMID: 27503943 DOI: 10.1042/cs20160221] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 05/23/2016] [Indexed: 12/16/2022]
Abstract
The worldwide obesity epidemic has been mainly attributed to lifestyle changes. However, who becomes obese in an obesity-prone environment is largely determined by genetic factors. In the last 20 years, important progress has been made in the elucidation of the genetic architecture of obesity. In parallel with successful gene identifications, the number of gene-environment interaction (GEI) studies has grown rapidly. This paper reviews the growing body of evidence supporting gene-environment interactions in the field of obesity. Heritability, monogenic and polygenic obesity studies provide converging evidence that obesity-predisposing genes interact with a variety of environmental, lifestyle and treatment exposures. However, some skepticism remains regarding the validity of these studies based on several issues, which include statistical modelling, confounding, low replication rate, underpowered analyses, biological assumptions and measurement precision. What follows in this review includes (1) an introduction to the study of GEI, (2) the evidence of GEI in the field of obesity, (3) an outline of the biological mechanisms that may explain these interaction effects, (4) methodological challenges associated with GEI studies and potential solutions, and (5) future directions of GEI research. Thus far, this growing body of evidence has provided a deeper understanding of GEI influencing obesity and may have tremendous applications in the emerging field of personalized medicine and individualized lifestyle recommendations.
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Assessing gene-environment interaction effects of FTO, MC4R and lifestyle factors on obesity using an extreme phenotype sampling design: Results from the HUNT study. PLoS One 2017; 12:e0175071. [PMID: 28384342 PMCID: PMC5383228 DOI: 10.1371/journal.pone.0175071] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 03/19/2017] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Our aim was to assess the influence of age, gender and lifestyle factors on the effect of the obesity-promoting alleles of FTO and MCR4. METHODS The HUNT study comprises health information on the population of Nord-Trøndelag county, Norway. Extreme phenotype participants (gender-wise lower and upper quartiles of waist-hip-ratio and BMI ≥ 35 kg/m2) in the third survey, HUNT3 (2006-08), were genotyped for the single-nucleotide polymorphisms rs9939609 (FTO) and rs17782313 (MC4R); 25686 participants were successfully genotyped. Extreme sampling was chosen to increase power to detect genetic and gene-environment effects on waist-hip-ratio and BMI. Statistical inference was based on linear regression models and a missing-covariate likelihood approach for the extreme phenotype sampling design. Environmental factors were physical activity, diet (artificially sweetened beverages) and smoking. Longitudinal analysis was performed using material from HUNT2 (1995-97). RESULTS Cross-sectional and longitudinal genetic effects indicated stronger genetic associations with obesity in young than in old, as well as differences between women and men. We observed larger genetic effects among physically inactive compared to active individuals. This interaction was age-dependent and seen mainly in 20-40 year olds. We observed a greater FTO effect among men with a regular intake of artificially sweetened beverages, compared to non-drinkers. Interaction analysis of smoking was mainly inconclusive. CONCLUSIONS In a large all-adult and area-based population survey the effects of obesity-promoting minor-alleles of FTO and MCR4, and interactions with life style factors are age- and gender-related. These findings appear relevant when designing individualized treatment for and prophylaxis against obesity.
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Abstract
AbstractBody mass and fat intake are multifactorial traits that have genetic and environmental components. The gene with the greatest effect on body mass is FTO (fat mass and obesity-associated), but several studies have shown that the effect of FTO (and of other genes) on body mass can be modified by the intake of nutrients. The so-called gene–environment interactions may also be important for the effectiveness of weight-loss strategies. Food choices, and thus fat intake, depend to some extent on individual preferences. The most important biological component of food preference is taste, and the role of fat sensitivity in fat intake has recently been pointed out. Relatively few studies have analysed the genetic components of fat intake or fatty acid sensitivity in terms of their relation to obesity. It has been proposed that decreased oral fatty acid sensitivity leads to increased fat intake and thus increased body mass. One of the genes that affect fatty acid sensitivity is CD36 (cluster of differentiation 36). However, little is known so far about the genetic component of fat sensing. We performed a literature review to identify the state of knowledge regarding the genetics of fat intake and its relation to body-mass determination, and to identify the priorities for further investigations.
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Kamura Y, Iwata M, Maeda S, Shinmura S, Koshimizu Y, Honoki H, Fukuda K, Ishiki M, Usui I, Fukushima Y, Takano A, Kato H, Murakami S, Higuchi K, Kobashi C, Tobe K. FTO Gene Polymorphism Is Associated with Type 2 Diabetes through Its Effect on Increasing the Maximum BMI in Japanese Men. PLoS One 2016; 11:e0165523. [PMID: 27820839 PMCID: PMC5098825 DOI: 10.1371/journal.pone.0165523] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 10/13/2016] [Indexed: 12/29/2022] Open
Abstract
Aim Several studies have demonstrated that polymorphisms within the fat-mass and obesity-associated gene (FTO) are associated with type 2 diabetes (T2D). However, whether the effects of the FTO locus on T2D susceptibility are independent of fat-mass increases remains controversial. To investigate this issue, we examined the association of FTO variants with T2D and various aspects of BMI history during adult life in a Japanese population. Methods We genotyped SNPs within FTO (rs1121980 and rs1558902) in 760 Japanese patients with T2D who had reached a lifetime maximum BMI (BMImax) before or at the time of diagnosis and 693 control individuals with information regarding their BMImax. Results The BMImax showed the strongest association with T2D risk among the BMIs evaluated in this study. In the sex-combined analysis, FTO SNPs were not associated with any of the BMI variables or with T2D, but in sex-stratified analyses, both SNPs were significantly associated with the BMImax and rs1558902 was associated with T2D in men. The association of the SNPs with T2D remained significant after adjustments for the current BMI and age, whereas the T2D association of the SNP was no longer significant after adjustments for BMImax and age. Conclusions These results suggest that the effects of FTO polymorphisms on T2D susceptibility in Japanese men are mediated through their effect on increasing the BMImax before or at the time of diagnosis.
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Affiliation(s)
- Yutaka Kamura
- First Department of Internal Medicine, Faculty of Medicine, University of Toyama, Toyama, Japan
| | - Minoru Iwata
- First Department of Internal Medicine, Faculty of Medicine, University of Toyama, Toyama, Japan
- Health Administration Center, University of Toyama, Toyama, Japan
- * E-mail:
| | - Shiro Maeda
- Laboratory for Endocrinology and Metabolism, RIKEN Center for Genomic Medicine, Yokohama, Kanagawa, Japan
- Department of Advanced Genomic and Laboratory Medicine, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan
- Division of Clinical Laboratory and Blood Transfusion, University of the Ryukyus Hospital, Okinawa, Japan
| | - Satomi Shinmura
- First Department of Internal Medicine, Faculty of Medicine, University of Toyama, Toyama, Japan
| | - Yukiko Koshimizu
- First Department of Internal Medicine, Faculty of Medicine, University of Toyama, Toyama, Japan
| | - Hisae Honoki
- First Department of Internal Medicine, Faculty of Medicine, University of Toyama, Toyama, Japan
| | - Kazuhito Fukuda
- First Department of Internal Medicine, Faculty of Medicine, University of Toyama, Toyama, Japan
| | - Manabu Ishiki
- First Department of Internal Medicine, Faculty of Medicine, University of Toyama, Toyama, Japan
| | - Isao Usui
- First Department of Internal Medicine, Faculty of Medicine, University of Toyama, Toyama, Japan
| | - Yasuo Fukushima
- Department of Internal Medicine, Asahi General Hospital, Asahi-machi, Toyama, Japan
| | - Atsuko Takano
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Saiseikai Takaoka Hospital, Takaoka, Toyama, Japan
| | - Hiromi Kato
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Japan Community Health care Organization Takaoka Fushiki Hospital, Takaoka, Toyama, Japan
| | - Shihou Murakami
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Toyama Rosai Hospital, Uozu, Toyama, Japan
| | - Kiyohiro Higuchi
- Department of Internal Medicine, Kouseiren Itoigawa General Hospital, Itoigawa, Niigata, Japan
| | - Chikaaki Kobashi
- Department of Internal Medicine, Kamiichi General Hospital, Kamiichi-machi, Toyama, Japan
| | - Kazuyuki Tobe
- First Department of Internal Medicine, Faculty of Medicine, University of Toyama, Toyama, Japan
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The FTO gene is associated with a paradoxically favorable cardiometabolic risk profile in frail, obese older adults. Pharmacogenet Genomics 2016; 26:154-160. [PMID: 26709911 DOI: 10.1097/fpc.0000000000000201] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVE Fat mass and obesity-associated (FTO) gene polymorphisms have been reported to be associated with differences in BMI, obesity, and type 2 diabetes. However, previous studies have been predominantly conducted in younger individuals across a spectrum of body weights, whereas little information is available on the older population. We examined the association of FTO gene polymorphisms with cardiometabolic risks among adults who were both obese (BMI≥30 kg/m) and older (age≥65 years). METHODS A total of 165 frail, obese older adults were genotyped for FTO (rs9939609 and rs8050136) single nucleotide polymorphisms and studied for associations with body weight and body composition, components and prevalence of the metabolic syndrome, insulin response to an oral glucose tolerance test, and levels of adipocytokines (e.g. leptin) and vitamin D. RESULTS Carriers of the A allele (CA/AA) of the FTO single nucleotide polymorphism rs8050136 had lower body weight, BMI, body fat, and trunk fat than those without the A allele (CC genotype; all P's<0.05). Moreover, genotype CA/AA was associated with lower levels of triglycerides and higher levels of high-density lipoprotein-cholesterol and carriers of this genotype showed a trend toward a lower waist circumference, resulting in a lower prevalence of metabolic syndrome than in CC genotype carriers. The insulin area under the curve during the oral glucose tolerance test was lower for genotype CA/AA. Despite the lower insulin levels, the glucose area under the curve was unchanged, resulting in a higher insulin sensitivity index. Leptin levels were also lower and adiponectin and 25-hydroxyvitamin levels tended to be higher for genotype CA/AA than for genotype CC. No differences were observed for rs9939609. CONCLUSION Unlike the results from studies in younger individuals, the risk A allele may confer a favorable cardiometabolic risk profile in obese older adults, suggesting selective survival of obese adults into old age. If confirmed in a larger sample of surviving obese older adults, these findings may have implications in the clinical approach to obesity in this population.
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Petkeviciene J, Smalinskiene A, Klumbiene J, Petkevicius V, Kriaucioniene V, Lesauskaite V. Physical activity, but not dietary intake, attenuates the effect of the FTO rs9939609 polymorphism on obesity and metabolic syndrome in Lithuanian adult population. Public Health 2016; 135:23-9. [PMID: 27003669 DOI: 10.1016/j.puhe.2016.02.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 01/28/2016] [Accepted: 02/11/2016] [Indexed: 01/22/2023]
Abstract
OBJECTIVES This study aimed to examine the associations between the fat mass and obesity associated (FTO) gene rs9939609 variant with obesity and metabolic syndrome and interactions between FTO alleles, dietary intake and physical activity in Lithuanian adult population. STUDY DESIGN Cross-sectional study. METHODS A health survey was carried out in randomly selected municipalities of Lithuania. The random sample was obtained from the lists of 25-64 year-old inhabitants. The data from 1020 individuals were analyzed. The single-nucleotide polymorphism, rs9939609, in the FTO gene was assessed using a real-time polymerase chain reaction. 24-hour recall was used for evaluation of dietary habits. Information on physical activity at work, traveling to and from work and at leisure time was gathered by a standard questionnaire. RESULTS The carriers of the AA genotype had the highest mean values of body mass index (BMI) and waist circumference (WC). They had 1.72 time higher odds of obesity (P = 0.009) and 1.67 time higher odds of increased WC (P = 0.013) than those with the TT genotype. Carriers of the T allele had lower prevalence of metabolic syndrome compared to carriers of the AA genotype (33.8% and 42.5% respectively; P = 0.018). No interaction between the rs9939609 variant and energy or dietary intakes on weight status was found. Significant effect of the interactions 'genotype×age' and 'genotype×physical activity' on BMI was demonstrated. The FTO rs9939609 polymorphism was associated with anthropometric parameters and metabolic syndrome in the younger age group (25-44 years) and in individuals having low level of physical activity. CONCLUSIONS Age and physical activity modulated the effect of the FTO polymorphism on weight status and metabolic syndrome in Lithuanian adult population.
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Affiliation(s)
- J Petkeviciene
- Faculty of Public Health, Medical Academy, Lithuanian University of Health Sciences, Tilzes 18, LT-47181 Kaunas, Lithuania.
| | - A Smalinskiene
- Laboratory of Molecular Cardiology, Institute of Cardiology, Medical Academy, Lithuanian University of Health Sciences, Sukileliu 17, LT-50009 Kaunas, Lithuania.
| | - J Klumbiene
- Faculty of Public Health, Medical Academy, Lithuanian University of Health Sciences, Tilzes 18, LT-47181 Kaunas, Lithuania.
| | - V Petkevicius
- Department of Gastroenterology, Lithuanian University of Health Sciences, Eiveniu 2A, LT-50009 Kaunas, Lithuania.
| | - V Kriaucioniene
- Faculty of Public Health, Medical Academy, Lithuanian University of Health Sciences, Tilzes 18, LT-47181 Kaunas, Lithuania.
| | - V Lesauskaite
- Laboratory of Molecular Cardiology, Institute of Cardiology, Medical Academy, Lithuanian University of Health Sciences, Sukileliu 17, LT-50009 Kaunas, Lithuania.
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Shin C, Kim NH, Baik I. Sex-Specific Association between Longitudinal Changes in Adiposity, FTO rs9939609 Polymorphism, and Leukocyte Telomere Length. J Am Coll Nutr 2015; 35:245-54. [PMID: 26260984 DOI: 10.1080/07315724.2015.1005197] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
OBJECTIVE A longitudinal study was conducted to examine sex-specific associations between changes in adiposity over a 10-year period, the FTO rs9939609 polymorphism, and leukocyte telomere length (LTL). METHODS A population-based cohort including 2128 middle-aged and older Korean men (n = 1087) and women (n = 1041) participated in a prospective study. Anthropometric measurements of weight, height, and waist and hip circumference were taken at baseline (from 2001 to 2003) and at the 10-year follow-up period (from 2011 to 2012). The FTO rs9939609 polymorphism was genotyped using DNA samples collected at baseline and LTL was assessed at the 10-year follow-up period. Multiple linear regression analysis was used with adjustments for age, baseline body mass index, and other potential confounders. RESULTS Presence of the FTO rs9939609 polymorphism risk allele was inversely associated with LTL (p < 0.01) in all participants, with a significant association seen only in women when the genders were modeled separately. Conversely, a significant inverse association between changes in waist circumference and LTL was found in men (p < 0.001) but not in women. No significant interaction between adiposity measures and the FTO polymorphism in association with LTL was identified for either sex. CONCLUSIONS These data suggest that biological aging in men may be accelerated by increasing waist circumference, whereas in women, aging may be affected by genetic variations in FTO regardless of adiposity changes over time.
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Affiliation(s)
- Chol Shin
- a Department of Internal Medicine , Korea University Ansan Hospital , Ansan , REPUBLIC OF KOREA.,b Institute of Human Genomic Study , Korea University Ansan Hospital , Ansan , REPUBLIC OF KOREA
| | - Nan Hee Kim
- a Department of Internal Medicine , Korea University Ansan Hospital , Ansan , REPUBLIC OF KOREA
| | - Inkyung Baik
- c Department of Foods and Nutrition, College of Natural Sciences , Kookmin University , Seoul , REPUBLIC OF KOREA
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Rask-Andersen M, Almén MS, Lind L, Schiöth HB. Association of the LINGO2-related SNP rs10968576 with body mass in a cohort of elderly Swedes. Mol Genet Genomics 2015; 290:1485-91. [DOI: 10.1007/s00438-015-1009-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 02/10/2015] [Indexed: 01/27/2023]
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Shahid A, Rana S, Saeed S, Imran M, Afzal N, Mahmood S. Common variant of FTO gene, rs9939609, and obesity in Pakistani females. BIOMED RESEARCH INTERNATIONAL 2013; 2013:324093. [PMID: 24102053 PMCID: PMC3775403 DOI: 10.1155/2013/324093] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Revised: 07/21/2013] [Accepted: 07/21/2013] [Indexed: 11/17/2022]
Abstract
Numerous studies confirmed the association of FTO (fat mass and obesity associated gene) common variant, rs9939609, with obesity in European populations. However, studies in Asian populations revealed conflicting results. We examined the association of rs9939609 variant of FTO gene with obesity and obesity-related anthropometric and metabolic parameters in Pakistani population. Body weight, height, waist circumference, hip circumference, and blood pressure (BP) were measured. BMI and waist-to-hip ratio (WHR) were calculated. Levels of fasting blood glucose (FBG), insulin, leptin, and leptin receptors were measured by enzyme linked immunosorbent assay (ELISA), and homeostasis model assessment of insulin resistance (HOMA-IR) was calculated. The results showed association of FTO gene, rs9939609, with obesity in females (>18 years of age). FTO minor allele increased the risk of obesity by 2.8 times (95% CI = 1.3-6.0) in females. This allele showed association with body weight, BMI, waist circumference, hip circumference, WHR, BP, plasma FBG levels, HOMA-IR, plasma insulin levels, and plasma leptin levels. In conclusion, FTO gene, rs9939609, is associated with BMI and risk of obesity in adult Pakistani females. Association of rs9939609 variant with higher FBG, plasma insulin, and leptin levels indicates that this polymorphism may disturb the metabolism in adult females and predispose them to obesity and type 2 diabetes. However, the above-mentioned findings were not seen in children or males.
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Affiliation(s)
- Adeela Shahid
- Department of Physiology and Cell Biology, University of Health Sciences, Khayaban-e-Jamia Punjab, Lahore-54600, Pakistan
- Department of Physiology, Shalamar Medical and Dental College, Shalimar Link Road, Mughalpura, Lahore-54840, Pakistan
| | - Sobia Rana
- Department of Physiology and Cell Biology, University of Health Sciences, Khayaban-e-Jamia Punjab, Lahore-54600, Pakistan
| | - Shahid Saeed
- Department of Physiology, King Edward Medical University, Nelagumbad, Anarkali, Lahore-54000, Pakistan
| | - Muhammad Imran
- Department of Physiology and Cell Biology, University of Health Sciences, Khayaban-e-Jamia Punjab, Lahore-54600, Pakistan
| | - Nasir Afzal
- Department of Physiology, College of Medicine, University of Dammam, Dammam 34100, Saudi Arabia
| | - Saqib Mahmood
- Department of Human Genetics & Molecular Biology, University of Health Sciences, Khayaban-e-Jamia Punjab, Lahore-54600, Pakistan
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Marcadenti A, Fuchs FD, Matte U, Sperb F, Moreira LB, Fuchs SC. Effects of FTO RS9939906 and MC4R RS17782313 on obesity, type 2 diabetes mellitus and blood pressure in patients with hypertension. Cardiovasc Diabetol 2013; 12:103. [PMID: 23849767 PMCID: PMC3711897 DOI: 10.1186/1475-2840-12-103] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 07/10/2013] [Indexed: 02/07/2023] Open
Abstract
Background Genetic variants of the FTO gene rs9939609 A/T and the MC4R gene rs17782313 C/T have been associated with obesity. Individuals with mutations in MC4R gene have lower blood pressure (BP), independently of obesity. This study aimed to investigate the association of FTO rs9939609 and MC4R rs17782313 with anthropometric indexes, BP, and type 2 diabetes mellitus among hypertensive patients. Methods We genotyped 217 individuals (86 men and 131 women) with hypertension (systolic or diastolic BP ≥ 140/90 mmHg or using antihypertensive drugs). Diabetes mellitus was diagnosed according to the American Diabetes Association criteria. Waist and neck circumferences (cm), Body Adiposity Index (BAI,%), Lipid Accumulation Product Index (LAP, cm.mmol.l) and body mass index (BMI, kg/m2) were analyzed using analysis of covariance or modified Poisson’s regression. Results Rare allele frequencies were 0.40 for A for FTO rs9939609 and 0.18 for C for MC4R rs17782313. A positive association of FTO rs9939609 and MC4R rs17782313 with BMI was observed in the overall sample. Among men and women, neck circumference was associated with the FTO genotype and, for women, MC4R genotype. In contrast, in men we found a negative association of MC4R rs17782313 with diastolic BP (TT 90.1 ±12.2, TC/CC 83.2 ±12.1; P = 0.03) and borderline association for systolic BP after controlling for age and BMI. Conclusions Common genetic variants of FTO rs9939609 have positive associations with BMI and neck circumference and MC4R rs17782313 in women, but a negative association with diastolic and mean blood pressure in men with hypertension.
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Jacobsson JA, Schiöth HB, Fredriksson R. The impact of intronic single nucleotide polymorphisms and ethnic diversity for studies on the obesity gene FTO. Obes Rev 2012; 13:1096-109. [PMID: 22931202 DOI: 10.1111/j.1467-789x.2012.01025.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In 2007, the first common genetic variants were identified, which undoubtedly affect our susceptibility to obesity. These variants are located in the fat mass and obesity-associated gene FTO. Since then, over 50 loci for common obesity have been identified. As the research on these loci is still at an early stage, there is a great need to review, for clarification purposes, the current research on FTO, as this is likely to influence future studies. Based on the current knowledge, FTO seems to be directly involved in the regulation of energy intake, but there is an urgent need for the identification of regulatory polymorphisms. Thus, herein, we discuss current knowledge and highlight putative functional regions in FTO based on published data and computer-based analysis.
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Affiliation(s)
- J A Jacobsson
- Department of Neuroscience, Unit of Functional Pharmacology, Uppsala University, Uppsala, Sweden.
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Livshits G, Malkin I, Moayyeri A, Spector TD, Hammond CJ. Association of FTO gene variants with body composition in UK twins. Ann Hum Genet 2012; 76:333-41. [PMID: 22817777 PMCID: PMC3532623 DOI: 10.1111/j.1469-1809.2012.00720.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The association of FTO gene variants with body mass index (BMI) and other obesity characteristics is well established. However, uncertainties remain whether the association is present only in young populations and whether it is attributable to body fat mass specifically. We aimed to clarify these two questions in a large sample (N= 4,523 individuals) of middle-aged and older (range 40–80 years) British female twins. The women were assessed for BMI, waist and hip circumference, total lean (LBM) and fat (FBM) body mass. Since the majority of FTO association signals have been reported in a haploblock bordering 52,355–52,408 kb (on chromosome 16q12.2), we examined five genotyped and 43 imputed SNPs mapped to this block. Canonical correlation and other association analyses showed significant and consistent association between the selected SNP and studied body composition phenotypes, with p-values reaching p= 0.000004. Of particular interest, in addition to the expected significant associations between FTO variants and FBM, we also identified significant associations with LBM. These results suggest that the association between FTO variants and body composition phenotypes is present across a wide range of ages, and that FTO appears primarily to affect the amount of body soft tissue, influencing both fat and lean mass.
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Affiliation(s)
- Gregory Livshits
- Department of Twin Research and Genetic Epidemiology, King's College London, UK
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Lifestyle factors modify obesity risk linked to PPARG2 and FTO variants in an elderly population: a cross-sectional analysis in the SUN Project. GENES AND NUTRITION 2012; 8:61-7. [PMID: 22528626 DOI: 10.1007/s12263-012-0296-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Accepted: 04/04/2012] [Indexed: 10/28/2022]
Abstract
Genetic factors may interact with lifestyle factors to modify obesity risk. FTO and PPARG2 are relevant obesogenes. Our aim was to explore the effect of Pro12Ala (rs1801282) of PPARG2 and rs9939609 of FTO on obesity risk and to examine their interaction with lifestyle factors in an elderly population. Subjects (n = 978; aged 69 ± 6) were recruited from the SUN (Seguimiento Universidad de Navarra) Project. DNA was obtained from saliva, and lifestyle and dietary data were collected by validated self-reported questionnaires. Genotyping was assessed by RT-PCR plus allele discrimination. Subjects carrying the Ala allele of PPARG2 gene had a significantly increased obesity risk compared to non-carrier (Pro12Pro) subjects (OR, 1.66; 95 % CI, 1.01-2.74; p = 0.045). Greater obesity risk was also found in inactive or high carbohydrate intake subjects with the Ala12 allele of PPARG2 gene. Interestingly, subjects carrying the Ala allele of the PPARG2 gene and with a high CHO (>246 g/day) intake had an increased obesity risk compared to Pro12Pro subjects (OR, 2.67; 95 % CI, 1.3-5.46; p = 0.007; p for [CHO × PPARG2] interaction = 0.046). Moreover, in subjects with a high CHO intake, the co-presence of the Ala allele of PPARG2 gene and one minor A allele (rs9939609) of FTO gene did increase obesity risk (OR, 3.26; 95 % CI, 1.19-8.89; p = 0.021) when compared to non-carrier (Pro12Pro/TT) subjects. In conclusion, it appears that lifestyle factors may act as effect modifiers for obesity risk linked to Ala12 allele of the PPARG2 gene and the minor A allele of FTO gene in an elderly population.
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Sällman Almén M, Rask-Andersen M, Jacobsson JA, Ameur A, Kalnina I, Moschonis G, Juhlin S, Bringeland N, Hedberg LA, Ignatovica V, Chrousos GP, Manios Y, Klovins J, Marcus C, Gyllensten U, Fredriksson R, Schiöth HB. Determination of the obesity-associated gene variants within the entire FTO gene by ultra-deep targeted sequencing in obese and lean children. Int J Obes (Lond) 2012; 37:424-31. [PMID: 22531089 PMCID: PMC3595467 DOI: 10.1038/ijo.2012.57] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND The Fat mass and obesity-associated gene (FTO) was the first gene reliably associated with body mass index in genome-wide association studies on a population level. At present, the genetic variations within the FTO gene are still the common variants that have the largest influence on body mass index. METHODS In the current study, we amplified the entire FTO gene, in total 412 Kbp, in over 200 long-range PCR fragments from each individual, from 524 severely obese and 527 lean Swedish children, and sequenced the products as two DNA pools using massive parallel sequencing (SOLiD). RESULTS The sequencing achieved very high coverage (median 18 000 reads) and we detected and estimated allele frequencies for 705 single nucleotide polymorphisms (SNPs) (19 novel) and 40 indels (24 novel) using a sophisticated statistical approach to remove false-positive SNPs. We identified 19 obesity-associated SNPs within intron one of the FTO gene, and validated our findings with genotyping. Ten of the validated obesity-associated SNPs have a stronger obesity association (P<0.007) than the commonly studied rs9939609 SNP (P<0.012). CONCLUSIONS This study provides a comprehensive obesity-associated variation map of FTO, identifies novel lead SNPs and evaluates putative causative variants. We conclude that intron one is the only region within the FTO gene associated with obesity, and finally, we establish next generation sequencing of pooled DNA as a powerful method to investigate genetic association with complex diseases and traits.
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Affiliation(s)
- M Sällman Almén
- Department of Neuroscience, Functional Pharmacology, Uppsala University, BMC, Uppsala, Sweden
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Caruso V, Chen H, Morris MJ. Early hypothalamic FTO overexpression in response to maternal obesity--potential contribution to postweaning hyperphagia. PLoS One 2011; 6:e25261. [PMID: 21980407 PMCID: PMC3182187 DOI: 10.1371/journal.pone.0025261] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 08/30/2011] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Intrauterine and postnatal overnutrition program hyperphagia, adiposity and glucose intolerance in offspring. Single-nucleotide polymorphisms (SNPs) of the fat mass and obesity associated (FTO) gene have been linked to increased risk of obesity. FTO is highly expressed in hypothalamic regions critical for energy balance and hyperphagic phenotypes were linked with FTO SNPs. As nutrition during fetal development can influence the expression of genes involved in metabolic function, we investigated the impact of maternal obesity on FTO. METHODS Female Sprague Dawley rats were exposed to chow or high fat diet (HFD) for 5 weeks before mating, throughout gestation and lactation. On postnatal day 1 (PND1), some litters were adjusted to 3 pups (vs. 12 control) to induce postnatal overnutrition. At PND20, rats were weaned onto chow or HFD for 15 weeks. FTO mRNA expression in the hypothalamus and liver, as well as hepatic markers of lipid metabolism were measured. RESULTS At weaning, hypothalamic FTO mRNA expression was increased significantly in offspring of obese mothers and FTO was correlated with both visceral and epididymal fat mass (P<0.05); body weight approached significance (P = 0.07). Hepatic FTO and Fatty Acid Synthase mRNA expression were decreased by maternal obesity. At 18 weeks, FTO mRNA expression did not differ between groups; however body weight was significantly correlated with hypothalamic FTO. Postnatal HFD feeding significantly reduced hepatic Carnitine Palmitoyltransferase-1a but did not affect the expression of other hepatic markers investigated. FTO was not affected by chronic HFD feeding. SIGNIFICANCE Maternal obesity significantly impacted FTO expression in both hypothalamus and liver at weaning. Early overexpression of hypothalamic FTO correlated with increased adiposity and later food intake of siblings exposed to HFD suggesting upregulation of FTO may contribute to subsequent hyperphagia, in line with some human data. No effect of maternal obesity was observed on FTO in adulthood.
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Affiliation(s)
- Vanni Caruso
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Hui Chen
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
- School of Medical and Molecular Bioscience, Faculty of Science, University of Technology, Sydney, New South Wales, Australia
| | - Margaret J. Morris
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
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