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Sholl J, De Block A. The vices and virtues of medical models of obesity. Obes Rev 2024:e13828. [PMID: 39262312 DOI: 10.1111/obr.13828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 08/22/2024] [Accepted: 08/22/2024] [Indexed: 09/13/2024]
Abstract
Despite numerous public health organizations supporting the pathologization of obesity and considering recent obesity rates a health crisis, many researchers in the humanities, social sciences, and even in the health sciences remain unconvinced. In this paper, we address a set of arguments coming from these academic fields that criticize medical models of obesity for their supposedly flawed diagnostic categories that shift focus onto individuals and support moralizing judgements. Clarifying some key claims in these models and explicating the view of obesity in terms of energy dysregulation, we aim to tease apart misunderstandings and argue that not only do these models not say what they are often accused of saying, but their apparent vices may actually be virtues in helping to combat stigma. Building on the social psychology of stigma and disease labeling, we then suggest that current medical models are largely supportive of many moral and political aims promoted by critics of these models.
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Affiliation(s)
- Jonathan Sholl
- Collège Sciences de la Santé, ImmunoConcept, Université de Bordeaux, CNRS UMR, Bordeaux, France
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Muniz Carvalho C, Wendt FR, Pathak GA, Maihofer AX, Stein DJ, Sumner JA, Hemmings SM, Nievergelt CM, Koenen KC, Gelernter J, Belangero SI, Polimanti R. Disentangling sex differences in the shared genetic architecture of posttraumatic stress disorder, traumatic experiences, and social support with body size and composition. Neurobiol Stress 2021; 15:100400. [PMID: 34611531 PMCID: PMC8477211 DOI: 10.1016/j.ynstr.2021.100400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 09/04/2021] [Accepted: 09/14/2021] [Indexed: 11/03/2022] Open
Abstract
There is a well-known association of traumatic experiences and posttraumatic stress disorder (PTSD) with body size and composition, including consistent differences between sexes. However, the biology underlying these associations is unclear. To understand the genetic underpinnings of this complex relationship, we investigated genome-wide datasets informative of African and European ancestries from the Psychiatric Genomic Consortium, the UK Biobank, the GIANT Consortium, and the Million Veteran Program. We used genome-wide association statistics to estimate sex-specific genetic correlations (r g ) of traumatic experiences, social support, and PTSD with multiple anthropometric traits. After multiple testing corrections (false discovery rate, FDR q < 0.05), we observed 58 significant r g relationships in females (e.g., childhood physical abuse and body mass index, BMI r g = 0.245, p = 3.88 × 10-10) and 21 significant r g relationships in males (e.g., been involved in combat or exposed to warzone and leg fat percentage; r g = 0.405, p = 4.42 × 10-10). We performed causal inference analyses of these genetic overlaps using Mendelian randomization and latent causal variable approaches. Multiple female-specific putative causal relationships were observed linking body composition/size with PTSD (e.g., leg fat percentage→PTSD; beta = 0.319, p = 3.13 × 10-9), traumatic experiences (e.g., childhood physical abuse→waist circumference; beta = 0.055, p = 5.07 × 10-4), and childhood neglect (e.g., "someone to take you to doctor when needed as a child"→BMI; beta = -0.594, p = 1.09 × 10-5). In males, we observed putative causal effects linking anthropometric-trait genetic liabilities to traumatic experiences (e.g., BMI→childhood physical abuse; beta = 0.028, p = 8.19 × 10-3). Some of these findings were replicated in individuals of African descent although the limited sample size available did not permit us to conduct a sex-stratified analysis in this ancestry group. In conclusion, our findings provide insights regarding sex-specific causal networks linking anthropometric traits to PTSD, traumatic experiences, and social support.
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Affiliation(s)
- Carolina Muniz Carvalho
- Department of Psychiatry, Yale School of Medicine and VA CT Healthcare Center, West Haven, CT, 06516, USA
- Department of Psychiatry, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - Frank R. Wendt
- Department of Psychiatry, Yale School of Medicine and VA CT Healthcare Center, West Haven, CT, 06516, USA
| | - Gita A. Pathak
- Department of Psychiatry, Yale School of Medicine and VA CT Healthcare Center, West Haven, CT, 06516, USA
| | - Adam X. Maihofer
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA
- Center of Excellence for Stress and Mental Health, Veterans Affairs San Diego Healthcare System, San Diego, CA, USA
| | - Dan J. Stein
- MRC Unit on Risk & Resilience in Mental Disorders, Department of Psychiatry and Neuroscience Institute, University of Cape Town, Cape Town, South Africa
| | - Jennifer A. Sumner
- Department of Psychology, University of California, Los Angeles, CA, USA
| | - Sian M.J. Hemmings
- Department of Psychiatry, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Caroline M. Nievergelt
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA
- Center of Excellence for Stress and Mental Health, Veterans Affairs San Diego Healthcare System, San Diego, CA, USA
| | - Karestan C. Koenen
- Department of Epidemiology, Harvard School of Public Health, Boston, MA, United States
| | - Joel Gelernter
- Department of Psychiatry, Yale School of Medicine and VA CT Healthcare Center, West Haven, CT, 06516, USA
- Departments of Genetics and Neuroscience, Yale University School of Medicine, New Haven, CT, 06510, USA
| | - Sintia I. Belangero
- Department of Psychiatry, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil
- Genetics Division, Department of Morphology and Genetics, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - Renato Polimanti
- Department of Psychiatry, Yale School of Medicine and VA CT Healthcare Center, West Haven, CT, 06516, USA
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Blumenberg C, Martins RC, da Silva SG, da Silva BGC, Wehrmeister FC, Gonçalves H, Hallal PC, Crochemore-Silva I, Menezes AMB. Influence of parental physical activity on offspring's nutritional status: an intergenerational study in the 1993 Pelotas birth cohort. Public Health Nutr 2021; 25:1-8. [PMID: 34569464 PMCID: PMC9991797 DOI: 10.1017/s1368980021004079] [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: 11/01/2020] [Revised: 09/16/2021] [Accepted: 09/23/2021] [Indexed: 11/07/2022]
Abstract
OBJECTIVE To investigate the influence of parental physical activity on offspring's nutritional status in the 1993 Pelotas (Brazil) birth cohort. DESIGN Birth cohort study. SETTING The main outcomes were overweight and obesity status of children. The main exposure was parental physical activity over time, measured during the 11, 15 and 18 years of age follow-ups. The exposure was operationalised as cumulative, and the most recent measure before the birth of child. We adjusted Poisson regression models with robust variance to evaluate crude and adjusted associations between parental physical activity and offspring's nutritional status. All analyses were stratified according to the sex of the parent. PARTICIPANTS A total of 874 members from the 1993 Pelotas (Brazil) birth cohort followed-up at 22 years of age with their first-born child were analysed. RESULTS Children were, on average, 3·1 years old. Crude analyses showed that the mother's cumulative physical activity measure had an indirect association with the prevalence of children's obesity. The most recent maternal physical activity measure before the birth of the child was associated with 41 % lower prevalence of obesity in children, even after adjustment for confounders. CONCLUSIONS The most recent maternal physical activity measure was indirectly associated with the prevalence of obesity in children. No associations were found for fathers, reinforcing the hypothesis of a biological effect of maternal physical activity on offspring's nutritional status.
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Affiliation(s)
- Cauane Blumenberg
- Post-graduate Program in Epidemiology, Federal University of Pelotas (UFPel), 1160 Marechal Deodoro St., 3rd Floor, Centro, Pelotas, RS96020-220, Brazil
- Grupo de Estudos e Pesquisa em Acelerometria (GEPEA), Pelotas, Brazil
| | - Rafaela Costa Martins
- Post-graduate Program in Epidemiology, Federal University of Pelotas (UFPel), 1160 Marechal Deodoro St., 3rd Floor, Centro, Pelotas, RS96020-220, Brazil
- Grupo de Estudos e Pesquisa em Acelerometria (GEPEA), Pelotas, Brazil
| | - Shana Ginar da Silva
- Grupo de Estudos e Pesquisa em Acelerometria (GEPEA), Pelotas, Brazil
- Medical School, Federal University of Fronteira Sul (UFFS), Passo Fundo, Brazil
| | - Bruna Gonçalves Cordeiro da Silva
- Post-graduate Program in Epidemiology, Federal University of Pelotas (UFPel), 1160 Marechal Deodoro St., 3rd Floor, Centro, Pelotas, RS96020-220, Brazil
- Grupo de Estudos e Pesquisa em Acelerometria (GEPEA), Pelotas, Brazil
| | - Fernando C Wehrmeister
- Post-graduate Program in Epidemiology, Federal University of Pelotas (UFPel), 1160 Marechal Deodoro St., 3rd Floor, Centro, Pelotas, RS96020-220, Brazil
| | - Helen Gonçalves
- Post-graduate Program in Epidemiology, Federal University of Pelotas (UFPel), 1160 Marechal Deodoro St., 3rd Floor, Centro, Pelotas, RS96020-220, Brazil
| | - Pedro C Hallal
- Post-graduate Program in Epidemiology, Federal University of Pelotas (UFPel), 1160 Marechal Deodoro St., 3rd Floor, Centro, Pelotas, RS96020-220, Brazil
- Grupo de Estudos e Pesquisa em Acelerometria (GEPEA), Pelotas, Brazil
- Post-graduate Program in Physical Education, Federal University of Pelotas (UFPel), Pelotas, Brazil
| | - Inácio Crochemore-Silva
- Post-graduate Program in Epidemiology, Federal University of Pelotas (UFPel), 1160 Marechal Deodoro St., 3rd Floor, Centro, Pelotas, RS96020-220, Brazil
- Grupo de Estudos e Pesquisa em Acelerometria (GEPEA), Pelotas, Brazil
- Post-graduate Program in Physical Education, Federal University of Pelotas (UFPel), Pelotas, Brazil
| | - Ana MB Menezes
- Post-graduate Program in Epidemiology, Federal University of Pelotas (UFPel), 1160 Marechal Deodoro St., 3rd Floor, Centro, Pelotas, RS96020-220, Brazil
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Morales E, Torres-Castillo N, Garaulet M. Infancy and Childhood Obesity Grade Predicts Weight Loss in Adulthood: The ONTIME Study. Nutrients 2021; 13:nu13072132. [PMID: 34206431 PMCID: PMC8308354 DOI: 10.3390/nu13072132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 06/03/2021] [Accepted: 06/17/2021] [Indexed: 11/16/2022] Open
Abstract
We examined the relationships between intergenerational obesity, weight and size at birth, and obesity from infancy to adolescence with weight loss in response to a dietary intervention. We studied 4264 participants (3369 women; mean age 41.5 ± 12.9 years) of the ONTIME study. Participants followed a weight-loss treatment based on a Mediterranean diet. Associations between grandparental and parental obesity grade, birth weight and size, and obesity grade in infancy, childhood and adolescence with total weight loss in response to treatment were assessed, using multivariate linear regression models. A lower weight loss (kg) in response to treatment was found among participants who were obese during infancy (beta coefficient -2.13 kg; 95% CI, -3.96, -0.30; p = 0.023). Furthermore, obesity during infancy and also during childhood was associated with a slower weekly rate of weight loss during treatment (p < 0.05). In conclusion, obesity in infancy and in childhood impairs the weight-loss response to dietary treatments in adulthood. Tackling obesity throughout early life may improve the effectiveness of weight-loss interventions in adulthood.
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Affiliation(s)
- Eva Morales
- Biomedical Research Institute of Murcia (IMIB-Arrixaca), 30120 Murcia, Spain;
- Department of Public Health Sciences, University of Murcia, 30100 Murcia, Spain
| | - Nathaly Torres-Castillo
- Department of Molecular Biology and Genomics, Institute for Translational Nutrigenetics and Nutrigenomics, Health Sciences University Center, University of Guadalajara, Guadalajara 44340, Jalisco, Mexico;
| | - Marta Garaulet
- Biomedical Research Institute of Murcia (IMIB-Arrixaca), 30120 Murcia, Spain;
- Department of Physiology, Regional Campus of International Excellence, University of Murcia, 30100 Murcia, Spain
- Division of Sleep and Circadian Disorders, Brigham and Women’s Hospital, and Division of Sleep Medicine, Harvard Medical School, Boston, MA 02115, USA
- Correspondence: ; Tel.: +34-868883930
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Dessein A. Clinical utility of polygenic risk scores for predicting NAFLD disorders. J Hepatol 2021; 74:769-770. [PMID: 33653592 DOI: 10.1016/j.jhep.2021.02.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 02/04/2021] [Accepted: 02/14/2021] [Indexed: 01/03/2023]
Affiliation(s)
- Alain Dessein
- GENEPRED Biotechnologies, Bilhigenetics, Marseille, France.
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6
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Metabolic Profile and Body Composition in Twins Concordant and Discordant for Physical Exercise. Twin Res Hum Genet 2020; 23:241-246. [PMID: 32696732 DOI: 10.1017/thg.2020.58] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The aim of this study was to evaluate the differences in the metabolic profile and body composition of monozygotic (MZ) twins concordant and discordant for the practice of physical exercise. The sample consisted of 92 MZ twins (72.5% female and 27.5% male, mean age 25.4 ± 5.69 years), registered with the Brazilian Registry of Twins, residing in Natal, Brazil. Data collection was carried out between the years 2016 and 2018. On day 1, subjects underwent a whole-body fitness evaluation, including measures of weight, height, body composition by Dual-Energy X-ray Absorptiometry and the Cardiorespiratory Exercise Test. On day 2, 10 ml blood samples were collected (overnight fasting) to determine the lipid profile and fasting glucose. The sample was separated into three groups: Active Concordant twins (Concordant A, n = 44 subjects), Inactive Concordant twins (Concordant I, n = 22 subjects) and Discordant pairs for Physical Exercise (Discordant PE, n = 26 subjects). The results demonstrated a difference between the discordant twins for exercise and also between the active versus sedentary groups, indicating a causal effect of exercise on the fat percentage, maximum oxygen consumption (VO2max) and second ventilatory threshold variables. Between groups, a difference was also observed between the groups in ventilatory threshold, very low-density lipoprotein and triglycerides. We concluded that, regardless of genetics, the practice of physical exercise was sufficient to generate alterations in body composition and VO2max in MZ twins, but not in the lipid profile or fasting glucose.
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Abstract
AbstractVirtual twins (VTs) are defined as same-age unrelated siblings raised together from early infancy. This special class of adoptive siblings replays the rearing situation of twins, absent genetic relatedness. The first such pair was identified and studied in 1990 at the University of Minnesota, leading to the creation of the Fullerton Virtual Twin Study (FVTS) at California State University, Fullerton (CSUF) the following year. The registry currently includes 169 VT pairs, mostly children, with new pairs identified on a regular basis. These sibling sets provide a direct estimate of environmental influences on developmental traits and, as such, offer informative comparisons with ordinary monozygotic and dizygotic twins, full siblings and adoptive brothers and sisters. The sample characteristics, assessment battery and findings to date are summarized in this 2019 update.
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Müller MJ, Geisler C, Heymsfield SB, Bosy-Westphal A. Recent advances in understanding body weight homeostasis in humans. F1000Res 2018; 7. [PMID: 30026913 PMCID: PMC6039924 DOI: 10.12688/f1000research.14151.1] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/29/2018] [Indexed: 12/19/2022] Open
Abstract
Presently, control of body weight is assumed to exist, but there is no consensus framework of body weight homeostasis. Three different models have been proposed, with a "set point" suggesting (i) a more or less tight and (ii) symmetric or asymmetric biological control of body weight resulting from feedback loops from peripheral organs and tissues (e.g. leptin secreted from adipose tissue) to a central control system within the hypothalamus. Alternatively, a "settling point" rather than a set point reflects metabolic adaptations to energy imbalance without any need for feedback control. Finally, the "dual intervention point" model combines both paradigms with two set points and a settling point between them. In humans, observational studies on large populations do not provide consistent evidence for a biological control of body weight, which, if it exists, may be overridden by the influences of the obesogenic environment and culture on personal behavior and experiences. To re-address the issue of body weight homeostasis, there is a need for targeted protocols based on sound concepts, e.g. lean rather than overweight subjects should be investigated before, during, and after weight loss and weight regain. In addition, improved methods and a multi-level-multi-systemic approach are needed to address the associations (i) between masses of individual body components and (ii) between masses and metabolic functions in the contexts of neurohumoral control and systemic effects. In the future, simplifications and the use of crude and non-biological phenotypes (i.e. body mass index and waist circumference) should be avoided. Since changes in body weight follow the mismatch between tightly controlled energy expenditure at loosely controlled energy intake, control (or even a set point) is more likely to be about energy expenditure rather than about body weight itself.
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Affiliation(s)
- Manfred J Müller
- Institute of Human Nutrition and Food Science, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Corinna Geisler
- Institute of Human Nutrition and Food Science, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | | | - Anja Bosy-Westphal
- Institute of Human Nutrition and Food Science, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
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Assessing genetic and environmental influences on epicardial and abdominal adipose tissue quantities: a classical twin study. Int J Obes (Lond) 2017; 42:163-168. [PMID: 28852208 DOI: 10.1038/ijo.2017.212] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 06/30/2017] [Accepted: 08/16/2017] [Indexed: 12/19/2022]
Abstract
BACKGROUND/OBJECTIVES Various adipose tissue compartments play an important role in the development of cardiometabolic diseases. The quantity of different fat compartments is influenced by genetic and environmental factors. The aim of our study was to evaluate the magnitude of genetic and environmental effects on epicardial, subcutaneous and visceral adipose tissue (EAT, SAT and VAT) quantities in a cohort of adult twin pairs. SUBJECTS/METHODS In this cross-sectional study we investigated adult twins (57 monozygotic (MZ) and 33 dizygotic (DZ) same-gender twin pairs; 180 twin subjects). We measured EAT volume using electrocardiogram-gated native computed tomography (CT) scan of the heart, and abdominal SAT and VAT areas were quantified between the third and fourth lumbar vertebra on native CT images. We calculated genetic and environmental impact on the size of various adipose tissue compartments by analyzing co-twin correlations in MZ and DZ pairs separately, and furthermore by using genetic structural equation models. RESULTS In co-twin analysis, MZ twins had stronger correlations than DZ twins for EAT (rMZ=0.81, rDZ=0.32), similar to SAT and VAT quantities (rMZ=0.80, rDZ=0.68 and rMZ=0.79, rDZ=0.48, respectively). In multi-trait model fitting analysis, the overall contribution of genetic factors to EAT, SAT and VAT volumes were 80%, 78% and 70%, whereas environmental factors were 20%, 22% and 30%, respectively. Common pathway model analyses indicated that none of the EAT, SAT and VAT phenotypes was independent of the other two. CONCLUSIONS Genetic factors have substantial influence, while environmental factors have only a modest impact on EAT volume, abdominal SAT and VAT quantities. There is a considerable amount of common genetic background influencing the quantities of all three adipose tissue compartments.
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Vaanholt LM, Lane JE, Garner B, Speakman JR. Partitioning the variance in calorie restriction-induced weight and fat loss in outbred mice. Obesity (Silver Spring) 2016; 24:2111-7. [PMID: 27527110 DOI: 10.1002/oby.21579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 05/04/2016] [Accepted: 05/18/2016] [Indexed: 11/08/2022]
Abstract
OBJECTIVE An increased understanding of the factors influencing interindividual variation in calorie restriction (CR)-induced weight loss is necessary to combat the current obesity epidemic. This study investigated the partitioning of the phenotypic variation in CR-induced wight loss. METHODS Two generations of male and female outbred MF1 mice raised by their biological mother or a foster mother were studied. Mice were exposed to 4 weeks of 30% CR when 6 months old. RESULTS Heritability was estimated at 0.43 ± 0.12 for CR-induced changes in body mass and 0.24 ± 0.10 for fat mass using mid-parent-offspring regressions. No significant relationships between weight loss in fathers or foster mothers and offspring were observed. Partitioning of phenotypic variance in weight loss using maximum likelihood modeling indicated 19 ± 17% of the variation could be attributed to additive genetic effects, 8 ± 14% to maternal effects during pregnancy, and <1% to maternal effects during lactation. A narrow-sense heritability around 0.50 was observed for ad libitum food intake and general activity. CONCLUSIONS A large part of individual variation in CR-induced weight loss could be attributed to additive genetic and maternal effects during pregnancy, but not to maternal effects in lactation. Genetic differences in food intake and general activity may play a role in determining these effects.
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Affiliation(s)
- Lobke M Vaanholt
- Integrative Environmental Physiology, Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK
| | - Jeffrey E Lane
- Department of Biology, University of Saskatchewan, Saskatoon, Canada
| | - Bethany Garner
- Integrative Environmental Physiology, Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK
| | - John R Speakman
- Integrative Environmental Physiology, Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK.
- State Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
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11
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Affiliation(s)
- Rui Feng
- Department of Biostatistics and Epidemiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
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12
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Amaral WZ, Krueger RF, Ryff CD, Coe CL. Genetic and environmental determinants of population variation in interleukin-6, its soluble receptor and C-reactive protein: insights from identical and fraternal twins. Brain Behav Immun 2015; 49:171-81. [PMID: 26086344 PMCID: PMC4567498 DOI: 10.1016/j.bbi.2015.05.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 05/19/2015] [Accepted: 05/25/2015] [Indexed: 12/26/2022] Open
Abstract
Interleukin-6 and C-reactive protein are commonly assessed biomarkers linked to illness, obesity, and stressful life events. However, relatively little is known about their heritability. By comparing Caucasian twins from the Midlife in the US project (MIDUS), we estimated the heritability of IL-6, its soluble receptor, and CRP. Based on the hypothesis that adiposity might contribute more to IL-6 than to sIL-6r, we fit heritability models quantifying the extent to which each reflected genetic and environmental factors shared with obesity. Genetic influences on IL-6 and its receptor proved to be distinct. Further, the appearance of a heritable basis for IL-6 was mediated largely via shared paths with obesity. Supporting this conclusion, we confirmed that when unrelated adult controls are carefully matched to twin participants on BMI, age, gender and socioeconomic indices, their IL-6 is similar to the corresponding twins. In contrast, the effect of BMI on CRP was split between shared genetics and environmental influences. In conclusion, IL-6 is strongly affected by factors associated with obesity accounting for its lability and responsiveness to diet, life style and contemporaneous events.
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Affiliation(s)
- Wellington Z Amaral
- Department of Psychology, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Robert F Krueger
- Department of Psychology, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Carol D Ryff
- Department of Psychology, University of Wisconsin-Madison, Madison, WI 53715, USA.
| | - Christopher L Coe
- Department of Psychology, University of Wisconsin-Madison, Madison, WI 53715, USA.
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Chartier CR, Abele S. Tacit coordination in close dyads: The use of social focal points. GROUP PROCESSES & INTERGROUP RELATIONS 2015. [DOI: 10.1177/1368430215581429] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Tacit coordination is crucial for many social interactions, including those among couples. Two different coordination requirements have been distinguished. Matching problems require interdependent actors to choose the same action; mismatching problems require the choice of different actions. We tested the performance of romantic couples relative to complete strangers in both matching and mismatching coordination. Social focal point theory (SFPT) posits that knowledge of social similarity in a domain pertinent to the coordination task will enhance matching coordination while knowledge of divergence will enhance mismatching coordination. Hence, we predicted that couples are more likely to detect and use social focal points in matching but not mismatching tasks, due to their interpersonal similarity and their wealth of mutual social knowledge. Indeed, couples were significantly better than strangers at matching but not at mismatching. Further analyses suggest that interplay between social knowledge and task demands, as delineated in SFPT, determines coordination success.
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Affiliation(s)
- Christopher R. Chartier
- Miami University, USA
- Christopher R. Chartier is now at Ashland University, Department of Psychology
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Abstract
A substantial body of research has explored the relative roles of genetic and environmental factors on phenotype expression in humans. Recent research has also sought to identify gene-environment (or g-by-e) interactions, with mixed success. One potential reason for these mixed results may relate to the fact that genetic effects might be modified by changes in the environment over time. For example, the noted rise of obesity in the United States in the latter part of the 20th century might reflect an interaction between genetic variation and changing environmental conditions that together affect the penetrance of genetic influences. To evaluate this hypothesis, we use longitudinal data from the Framingham Heart Study collected over 30 y from a geographically relatively localized sample to test whether the well-documented association between the rs993609 variant of the FTO (fat mass and obesity associated) gene and body mass index (BMI) varies across birth cohorts, time period, and the lifecycle. Such cohort and period effects integrate many potential environmental factors, and this gene-by-environment analysis examines interactions with both time-varying contemporaneous and historical environmental influences. Using constrained linear age-period-cohort models that include family controls, we find that there is a robust relationship between birth cohort and the genotype-phenotype correlation between the FTO risk allele and BMI, with an observed inflection point for those born after 1942. These results suggest genetic influences on complex traits like obesity can vary over time, presumably because of global environmental changes that modify allelic penetrance.
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Alonso L, Souza E, Oliveira M, do Nascimento L, Dantas P. Heritability of aerobic power of individuals in northeast Brazil. Biol Sport 2014; 31:267-70. [PMID: 25435668 PMCID: PMC4203842 DOI: 10.5604/20831862.1120933] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/15/2014] [Indexed: 01/28/2023] Open
Abstract
The objective of this study was to evaluate the genetic and environmental contribution to variation in aerobic power in monozygotic (MZ) and dizygotic (DZ) twins. The sample consisted of 20 MZ individuals (12 females and 8 males) and 16 DZ individuals (12 females and 4 males), aged from 8 to 26 years, residents in Natal, Rio Grande do Norte. The twins were assessed by a multistage fitness test. The rate of heritability found for aerobic power was 77%. Based on the results, the estimated heritability was largely responsible for the differences in aerobic power. This implies that such measures are under strong genetic influence.
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Affiliation(s)
- L Alonso
- Department of Physical Education, Federal University of Rio Grande do Norte (UFRN) Center for Health Sciences (UFRN), Natal, RN - Brazil
| | - Ec Souza
- Department of Physical Education, Federal University of Rio Grande do Norte (UFRN) Center for Health Sciences (UFRN), Natal, RN - Brazil
| | - Mv Oliveira
- Department of Physical Education, Federal University of Rio Grande do Norte (UFRN) Center for Health Sciences (UFRN), Natal, RN - Brazil
| | - Lfe do Nascimento
- Department of Physical Education, Federal University of Rio Grande do Norte (UFRN) Center for Health Sciences (UFRN), Natal, RN - Brazil
| | - Pms Dantas
- Department of Physical Education, Federal University of Rio Grande do Norte (UFRN) Center for Health Sciences (UFRN), Natal, RN - Brazil
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Rottensteiner M, Pietiläinen KH, Kaprio J, Kujala UM. Persistence or change in leisure-time physical activity habits and waist gain during early adulthood: a twin-study. Obesity (Silver Spring) 2014; 22:2061-70. [PMID: 24839266 PMCID: PMC4149596 DOI: 10.1002/oby.20788] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 04/26/2014] [Indexed: 11/06/2022]
Abstract
OBJECTIVE To determine the relationship between persistence or change in leisure-time physical activity habits and waist gain among young adults. METHODS Population-based cohort study among 3383 Finnish twin individuals (1578 men) from five birth cohorts (1975-1979), who answered questionnaires at mean ages of 24.4 y (SD 0.9) and 33.9 y (SD 1.2), with reported self-measured waist circumference. Persistence or change in leisure-time physical activity habits was defined based on thirds of activity metabolic equivalent h/day during follow-up (mean 9.5 y; SD 0.7). RESULTS Decreased activity was linked to greater waist gain compared to increased activity (3.6 cm, P < 0.001 for men; 3.1 cm, P < 0.001 for women). Among same-sex activity discordant twin pairs, twins who decreased activity gained an average 2.8 cm (95%CI 0.4 to 5.1, P = 0.009) more waist than their co-twins who increased activity (n = 85 pairs); among MZ twin pairs (n = 43), the difference was 4.2 cm (95%CI 1.2 to 7.2, P = 0.008). CONCLUSIONS Among young adults, an increase in leisure-time physical activity or staying active during a decade of follow-up was associated with less waist gain, but any decrease in activity level, regardless baseline activity, led to waist gain that was similar to that associated with being persistently inactive.
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Affiliation(s)
| | - Kirsi H. Pietiläinen
- Obesity Research Unit, Research Programs Unit, Diabetes and Obesity and
Institute for Molecular Medicine, University of Helsinki, Finland; Department of Medicine,
Division of Endocrinology, Helsinki University Central Hospital, Finland
| | - Jaakko Kaprio
- Department of Public Health, The Hjelt Institute, and Institute for
Molecular Medicine, University of Helsinki, Finland; Department of Mental Health and
Substance Abuse Services, National Institute for Health and Welfare, Helsinki, Finland
| | - Urho M. Kujala
- Department of Health Sciences, University of Jyväskylä,
Finland
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17
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Scheid JL, Carr KA, Lin H, Fletcher KD, Sucheston L, Singh PK, Salis R, Erbe RW, Faith MS, Allison DB, Epstein LH. FTO polymorphisms moderate the association of food reinforcement with energy intake. Physiol Behav 2014; 132:51-6. [PMID: 24768648 DOI: 10.1016/j.physbeh.2014.04.029] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Revised: 02/19/2014] [Accepted: 04/14/2014] [Indexed: 11/15/2022]
Abstract
Food reinforcement (RRVfood) is related to increased energy intake, cross-sectionally related to obesity, and prospectively related to weight gain. The fat mass and obesity-associated (FTO) gene is related to elevated body mass index and increased energy intake. The primary purpose of the current study was to determine whether any of 68 FTO single nucleotide polymorphisms (SNPs) or a FTO risk score moderate the association between food reinforcement and energy or macronutrient intake. Energy and macronutrient intake was measured using a laboratory ad libitum snack food consumption task in 237 adults of varying BMI. Controlling for BMI, the relative reinforcing value of reading (RRVreading) and proportion of African ancestry, RRVfood predicted 14.2% of the variance in energy intake, as well as predicted carbohydrate, fat, protein and sugar intake. In individual analyses, six FTO SNPs (rs12921970, rs9936768, rs12446047, rs7199716, rs8049933 and rs11076022, spanning approximately 251kbp) moderated the relationship between RRVfood and energy intake to predict an additional 4.9-7.4% of variance in energy intake. We created an FTO risk score based on 5 FTO SNPs (rs9939609, rs8050136, rs3751812, rs1421085, and rs1121980) that are related to BMI in multiple studies. The FTO risk score did not increase variance accounted for beyond individual FTO SNPs. rs12921970 and rs12446047 served as moderators of the relationship between RRVfood and carbohydrate, fat, protein, and sugar intake. This study shows for the first time that the relationship between RRVfood and energy intake is moderated by FTO SNPs. Research is needed to understand how these processes interact to predict energy and macronutrient intake.
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Affiliation(s)
- Jennifer L Scheid
- Department of Pediatrics, University at Buffalo, School of Medicine and Biomedical Sciences, United States
| | - Katelyn A Carr
- Department of Pediatrics, University at Buffalo, School of Medicine and Biomedical Sciences, United States
| | - Henry Lin
- Department of Pediatrics, University at Buffalo, School of Medicine and Biomedical Sciences, United States
| | - Kelly D Fletcher
- Department of Pediatrics, University at Buffalo, School of Medicine and Biomedical Sciences, United States
| | - Lara Sucheston
- Department of Cancer Prevention and Control, Roswell Park Cancer Institute, United States
| | - Prashant K Singh
- Department of Pharmacology and Therapeutics, Roswell Park Cancer Institute, United States
| | - Robbert Salis
- Department of Pediatrics, Niagara Falls Memorial Hospital, United States
| | - Richard W Erbe
- Department of Pediatrics, University at Buffalo, School of Medicine and Biomedical Sciences, United States
| | - Myles S Faith
- Department of Nutrition, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, United States
| | - David B Allison
- Office of Energetics and Nutrition Obesity Research Center, University of Alabama at Birmingham School of Public Health, United States
| | - Leonard H Epstein
- Department of Pediatrics, University at Buffalo, School of Medicine and Biomedical Sciences, United States.
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Shook RP, Hand GA, Blair SN. Top 10 research questions related to energy balance. RESEARCH QUARTERLY FOR EXERCISE AND SPORT 2014; 85:49-58. [PMID: 24749236 DOI: 10.1080/02701367.2013.872017] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Obesity is the result of a mismatch between the amount of calories consumed and the amount of calories expended during an extended period of time. This relationship is described by the energy balance equation, which states the rate of change in energy storage depots in the body are equal to the rate of energy intake minus the rate of energy expenditure. Although this relationship may appear easy to understand based on simple mathematics, in reality, a variety of known and unknown systems influence the components of energy balance (energy storage, energy intake, energy expenditure). Clearly, if a complete understanding of energy balance was apparent, worldwide levels of obesity would not have reached pandemic proportions due to effective prevention and treatment strategies. The aim of the present article is to provide a brief overview of the components of energy balance and to identify 10 key topics and unanswered questions that would move the research field forward if addressed. These topics are intentionally diverse and range from general themes (e.g., methodological issues) to specific areas (e.g., intensity of exercise required to alter energy intake). Although this list is not meant to be exhaustive, it does provide a research agenda for scientists involved in the study of energy balance and recommendations for public health professionals developing obesity interventions.
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19
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Christensen VT. My sibling, my weight. How gender, sibling gender, sibling weight and sibling weight level perception influence weight perception accuracy. Nutr Diabetes 2014; 4:e103. [PMID: 24418829 PMCID: PMC3904084 DOI: 10.1038/nutd.2013.44] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 11/28/2013] [Accepted: 12/08/2013] [Indexed: 11/17/2022] Open
Abstract
Objective: The objective of this study was to examine the impact of sibling weight level perception and sibling weight on the accuracy of respondent weight level perception dependent on sibling-pair gender composition. Design: A cross-sectional study based on the survey data, which include the children of a nationally representative sample of Danes. Logit regression models were used. Subjects: Two thousand nine hundred and sixty-eight respondents comprising 397 female sibling pairs, 357 male sibling pairs and 730 opposite-sex sibling pairs. The inclusion of both same-sex siblings and opposite-sex siblings is novel for studies on weight perceptions. Measurements: Weight underestimation and weight overestimation were calculated on the basis of difference between actual weight level and self-perceived weight level. Respondent gender, sibling gender, sibling body mass index (BMI) and the siblings' self-perceived weight level were included as the main controls. Results: Women frequently overestimate their weight level, whereas men often underestimate theirs. Women are more likely to overestimate their weight if their sister does the same but less likely if their brother overestimates his weight. Likewise, women are more likely to underestimate their weight if their sister also underestimates her weight but less likely if their brother underestimates his weight. The higher the BMI of their brother and the lower the BMI of their sister, the more likely men are to underestimate their own weight level. Conclusion: Results underline the importance of social context when looking at body formation and weight perceptions. The weight and weight perceptions of siblings influence own weight perception. Gender is central to studies on weight-related issues, not only respondent gender - equally so the gender of interaction.
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Affiliation(s)
- V T Christensen
- KORA, The Danish Institute for Local and Regional Government Research, Copenhagen K, Denmark
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20
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Min J, Chiu DT, Wang Y. Variation in the heritability of body mass index based on diverse twin studies: a systematic review. Obes Rev 2013; 14:871-82. [PMID: 23980914 PMCID: PMC4346225 DOI: 10.1111/obr.12065] [Citation(s) in RCA: 93] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Revised: 06/27/2013] [Accepted: 07/15/2013] [Indexed: 12/22/2022]
Abstract
OBJECTIVES Over the past three decades, twin studies have shown variation in the heritability of obesity. This study examined the difference of body mass index (BMI) heritability (BMI-H) by population characteristics, such as sex, age, time period of observation and average BMI, as well as by broad social-environmental factors as indicated by country-level gross domestic product (GDP) per capita and GDP growth rate. METHODS Twin studies that reported BMI-H and were published in English from January 1990 to February 2011 after excluding those with disease, special occupations or combined heritability estimates for country/ethnic groups were searched in PubMed. 32 studies were identified from Finland (7), the United Kingdom (6), the United States (3), Denmark (3), China (3), Netherlands (2), South Korea (2), Sweden (2) and four from other countries. Meta-regression models with random effects were used to assess variation in BMI-H. RESULTS Heterogeneity of BMI-H is significantly attributable to variations in age (<20, 20-55 and ≥56 years), time period of observation (i.e. year of data collection), average BMI and GDP (≤$20,000, $20,001-26,000 and >$26,000). BMI-H was higher in adolescents (<20 years), in studies done in past years, and in populations with higher average BMIs or higher GDP per capita (≥$26,000) than their counterparts. Consistent lowering effects of high GDP growth rate (>median) on BMI-H were shown through stratified analyses by GDP. BMI-H was lower in countries of mid-level GDP, particularly those experiencing rapid economic growth. CONCLUSIONS BMI-H is sensitive to age, time period of observation, average BMI, GDP and rapid economic growth.
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Affiliation(s)
- J Min
- Johns Hopkins Global Center on Childhood Obesity, Department of International Health Human Nutrition Program, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA; Department of Preventive Medicine, School of Medicine, Ewha Womans University, Seoul, Korea
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21
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Kaiser KA, Gadbury GL. Estimating the range of obesity treatment response variability in humans: methods and illustrations. Hum Hered 2013; 75:127-35. [PMID: 24081228 DOI: 10.1159/000351738] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS The rising prevalence of human obesity worldwide has focused research on a variety of interventions that result in highly varied degrees of weight loss (WL). The advent of genomic testing has quantified estimates of both the contribution of genetic factors to the development of obesity as well as racial/ethnic variation of risk alleles across subpopulations. More recent studies have examined genetic associations with effectiveness of WL interventions, but to date are unable to explain a large proportion of the variance observed. METHODS We describe and provide two illustrations of statistical methods to estimate upper and lower bounds of WL treatment response heterogeneity (TRH) in the absence of genotypic data, using published summary statistics and a raw data set from WL studies. RESULTS Thirty-two studies had some evidence of a positive mean treatment effect with respect to the control intervention. Twelve of these 32 studies reported WL TRH. Of these 12, 3 demonstrated an estimated proportion of >5% of the sampled population having an outcome opposite the mean effect. In the raw data set, bounds estimations for change in waist circumference revealed tighter ranges in men than women. CONCLUSION Future studies may be able to take advantage of multiple approaches, including the method we describe, to identify and quantify the presence of TRH in studies of WL or related outcomes.
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Affiliation(s)
- Kathryn A Kaiser
- Office of Energetics, School of Public Health, University of Alabama at Birmingham, Birmingham, Ala., USA
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22
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Spoto B, Mattace-Raso F, Sijbrands E, Mallamaci F, Leonardis D, Aucella F, Testa A, Gesuete A, Sanguedolce MC, D'Arrigo G, Parlongo RM, Pisano A, Torino C, Enia G, Tripepi G, Postorino M, Zoccali C. The fat-mass and obesity-associated gene (FTO) predicts mortality in chronic kidney disease of various severity. Nephrol Dial Transplant 2013; 27 Suppl 4:iv58-62. [PMID: 23258813 DOI: 10.1093/ndt/gfs550] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Polymorphisms in the FTO (fat-mass and obesity-associated) gene have been associated with the body mass index, cancer, type 2 diabetes and hypertension. METHODS We investigated the relationship between 17 tag single-nucleotide polymorphisms (SNPs) and all-cause mortality in three cohorts of dialysis patients (CREED-1, North Apulian and CREED-2 cohorts; n = 783) and in one cohort of stage 2-5 CKD patients (n = 757). RESULTS We first explored the association between the 17 tag SNPs and all-cause mortality in the CREED-1 cohort and found that patients with the A allele of the FTO rs708259 polymorphism had an elevated risk of mortality (hazard ratio, HR: 1.52, 95% confidence interval (CI) 1.11-2.08; P = 0.008). Similarly, the A allele was associated with an increased risk of death also in the other two dialysis cohorts (North Apulian cohort, risk: +23%; CREED-2 cohort, risk: +21%). The elevated risk portended by this allele was even higher in the stage 2-5 CKD cohort (+97%). However, the risk of mortality associated with the A allele in the three confirmatory cohorts failed to achieve formal statistical significance. In a meta-analysis including the four cohorts (n = 1540; total deaths, n = 381), individuals with the A allele had a 42% excess risk of death (HR: 1.42, 95% CI 1.14-1.76, P = 0.002). CONCLUSION The A allele of the FTO rs708259 polymorphism is an independent predictor of all-cause mortality in patients with CKD of various severity. These data support our hypothesis that the FTO gene may be a relevant genetic risk factor for mortality in this population.
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Affiliation(s)
- Belinda Spoto
- CNR-IBIM and Nephrology, Dialysis and Transplantation Unit of Reggio Calabria, Reggio Calabria, Italy
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23
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Abstract
Virtual twins (VTs) are same-age unrelated siblings reared together from early infancy. These unique sibling sets replicate twinship, but without the genetic link. The first VT pair was identified and studied at the University of Minnesota in 1990, launching the development of the Fullerton Virtual Twin Study at California State University, Fullerton (CSUF) in 1991. The registry currently includes 151 pairs, mostly children, with new pairs identified on a continuous basis. Research with VTs includes studies of general intelligence, body size, interpersonal trust, social coordination, social networks, and parenting. In some cases, VTs have been studied in conjunction with pairs of monozygotic twins, dizygotic twins, full siblings, and friends as part of TAPS (Twins, Adoptees, Peers and Siblings), a collaborative project conducted between CSUF and the University of San Francisco, 2002-2006. VTs will also serve as a comparison group for epigenetic analyses of young Chinese twins reared apart and together.
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24
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Bradley GM, Blackman SM, Watson CP, Doshi VK, Cutting GR. Genetic modifiers of nutritional status in cystic fibrosis. Am J Clin Nutr 2012; 96:1299-308. [PMID: 23134884 PMCID: PMC3497925 DOI: 10.3945/ajcn.112.043406] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Improved nutrition early in life is associated with better pulmonary function for patients with cystic fibrosis (CF). However, nutritional status is poorly correlated with the CFTR genotype. OBJECTIVE We investigated the extent to which modifier genes influence nutrition in children with CF. DESIGN BMI data were longitudinally collected from the CF Twin-Sibling Study and Cystic Fibrosis Foundation Patient Registry for twins and siblings from 2000 to 2010. A nutritional phenotype was derived for 1124 subjects by calculating the average BMI z score from 5-10 y of age (BMI-z(5to10)). The genetic contribution to the variation in BMI-z(5to10) (ie, heritability) was estimated by comparing the similarity of the phenotype in monozygous twins to that in dizygous twins and siblings. Linkage analysis identified potential modifier-gene loci. RESULTS The median BMI-z(5to10) was -0.07 (range: -3.89 to 2.30), which corresponded to the 47th CDC percentile. BMI-z(5to10) was negatively correlated with pancreatic insufficiency, history of meconium ileus, and female sex but positively correlated with later birth cohorts and lung function. Monozygous twins showed greater concordance for BMI-z(5to10) than did dizygous twins and siblings; heritability estimates from same-sex twin-only analyses ranged from 0.54 to 0.82. For 1010 subjects with pancreatic insufficiency, genome-wide significant linkage was identified on chromosomes 1p36.1 [log of odds (LOD): 5.3] and 5q14 (LOD: 5.1). These loci explained ≥16% and ≥15%, respectively, of the BMI variance. CONCLUSIONS The analysis of twins and siblings with CF indicates a prominent role for genes other than CFTR to BMI variation. Specifically, regions on chromosomes 1 and 5 appear to harbor genetic modifiers of substantial effect.
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Affiliation(s)
- Gia M Bradley
- Department of Pediatrics and McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University, Baltimore, MD, USA
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25
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Segal NL, McGuire SA, Stohs JH. What Virtual Twins Reveal About General Intelligence and Other Behaviors. PERSONALITY AND INDIVIDUAL DIFFERENCES 2012; 53:405-410. [PMID: 22711965 DOI: 10.1016/j.paid.2011.11.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
The Fullerton Virtual Twin Study has been assessing the behaviors of an unusual sibship since 1982. Virtual twins (VTs) are same-age, unrelated siblings reared together since infancy. They replicate the rearing situation of twins but without the genetic link, enabling direct assessment of shared environmental effects on behavior. An updated analysis of IQ data, based on an increased sample of 142 VT pairs (7.87 years, SD=8.22), is presented. Intraclass correlations of .28 (IQ) and .11 (subtest profile) indicated modest shared environmental influences on intelligence. Findings from the Twins, Adoptees, Peers and Siblings (TAPS) project that studies virtual twins and other kinships are described.
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Affiliation(s)
- Nancy L Segal
- California State University, Fullerton, Department of Psychology
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26
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Buchwald U, Teupser D, Kuehnel F, Grohmann J, Schmieder N, Beindorff N, Schlumbohm C, Fuhrmann H, Einspanier A. Prenatal stress programs lipid metabolism enhancing cardiovascular risk in the female F1, F2, and F3 generation in the primate model common marmoset (Callithrix jacchus). J Med Primatol 2012; 41:231-40. [DOI: 10.1111/j.1600-0684.2012.00551.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Freedhoff Y, Sharma AM, Kirk SFL, Vallis M, Poirier P, Ball GDC, Cash SB, Christou N. Realistic first steps for effectively managing obesity in Canada. Clin Obes 2012; 2:78-82. [PMID: 25586160 DOI: 10.1111/j.1758-8111.2012.00044.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Y Freedhoff
- Department of Family Medicine, University of Ottawa, Bariatric Medical Institute, Ottawa, ON
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28
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Genetic influences in childhood obesity: recent progress and recommendations for experimental designs. Int J Obes (Lond) 2011; 36:479-84. [PMID: 22158269 DOI: 10.1038/ijo.2011.236] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The increasing prevalence of pediatric obesity around the world has become an area of scientific interest because of public health concern. Although since early stages of the lifespan body weight might be heavily influenced by an individual's behavior, epidemiological research highlights the involvement of genetic influences contributing to variation in fat accumulation and thus body composition. Results from genome-wide association studies and candidate gene approaches have identified specific regions across the human genome influencing obesity-related phenotypes. Reviewing the scientific literature provides support to the belief that at the conceptual level scientists understand that genes and environments do not act independently, but rather synergistically, and that such interaction might be the responsible factor for differences within and among populations. However, there is still limited understanding of genetic and environmental factors influencing fat accumulation and deposition among different populations, which highlights the need for innovative experimental designs, improved body composition measures and appropriate statistical methodology.
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Smith GD. Epidemiology, epigenetics and the 'Gloomy Prospect': embracing randomness in population health research and practice. Int J Epidemiol 2011; 40:537-62. [PMID: 21807641 DOI: 10.1093/ije/dyr117] [Citation(s) in RCA: 161] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Epidemiologists aim to identify modifiable causes of disease, this often being a prerequisite for the application of epidemiological findings in public health programmes, health service planning and clinical medicine. Despite successes in identifying causes, it is often claimed that there are missing additional causes for even reasonably well-understood conditions such as lung cancer and coronary heart disease. Several lines of evidence suggest that largely chance events, from the biographical down to the sub-cellular, contribute an important stochastic element to disease risk that is not epidemiologically tractable at the individual level. Epigenetic influences provide a fashionable contemporary explanation for such seemingly random processes. Chance events-such as a particular lifelong smoker living unharmed to 100 years-are averaged out at the group level. As a consequence population-level differences (for example, secular trends or differences between administrative areas) can be entirely explicable by causal factors that appear to account for only a small proportion of individual-level risk. In public health terms, a modifiable cause of the large majority of cases of a disease may have been identified, with a wild goose chase continuing in an attempt to discipline the random nature of the world with respect to which particular individuals will succumb. The quest for personalized medicine is a contemporary manifestation of this dream. An evolutionary explanation of why randomness exists in the development of organisms has long been articulated, in terms of offering a survival advantage in changing environments. Further, the basic notion that what is near-random at one level may be almost entirely predictable at a higher level is an emergent property of many systems, from particle physics to the social sciences. These considerations suggest that epidemiological approaches will remain fruitful as we enter the decade of the epigenome.
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Affiliation(s)
- George Davey Smith
- MRC Centre for Causal Analyses in Translational Epidemiology, School of Social and Community Medicine, University of Bristol, Oakfield House, Oakfield Grove, Bristol BS8 2BN, UK
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30
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Speakman JR, Levitsky DA, Allison DB, Bray MS, de Castro JM, Clegg DJ, Clapham JC, Dulloo AG, Gruer L, Haw S, Hebebrand J, Hetherington MM, Higgs S, Jebb SA, Loos RJF, Luckman S, Luke A, Mohammed-Ali V, O'Rahilly S, Pereira M, Perusse L, Robinson TN, Rolls B, Symonds ME, Westerterp-Plantenga MS. Set points, settling points and some alternative models: theoretical options to understand how genes and environments combine to regulate body adiposity. Dis Model Mech 2011; 4:733-45. [PMID: 22065844 PMCID: PMC3209643 DOI: 10.1242/dmm.008698] [Citation(s) in RCA: 197] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The close correspondence between energy intake and expenditure over prolonged time periods, coupled with an apparent protection of the level of body adiposity in the face of perturbations of energy balance, has led to the idea that body fatness is regulated via mechanisms that control intake and energy expenditure. Two models have dominated the discussion of how this regulation might take place. The set point model is rooted in physiology, genetics and molecular biology, and suggests that there is an active feedback mechanism linking adipose tissue (stored energy) to intake and expenditure via a set point, presumably encoded in the brain. This model is consistent with many of the biological aspects of energy balance, but struggles to explain the many significant environmental and social influences on obesity, food intake and physical activity. More importantly, the set point model does not effectively explain the 'obesity epidemic'--the large increase in body weight and adiposity of a large proportion of individuals in many countries since the 1980s. An alternative model, called the settling point model, is based on the idea that there is passive feedback between the size of the body stores and aspects of expenditure. This model accommodates many of the social and environmental characteristics of energy balance, but struggles to explain some of the biological and genetic aspects. The shortcomings of these two models reflect their failure to address the gene-by-environment interactions that dominate the regulation of body weight. We discuss two additional models--the general intake model and the dual intervention point model--that address this issue and might offer better ways to understand how body fatness is controlled.
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Affiliation(s)
- John R Speakman
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, AB39 2PN, UK.
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Salsberry PJ, Reagan PB. Effects of heritability, shared environment, and nonshared intrauterine conditions on child and adolescent BMI. Obesity (Silver Spring) 2010; 18:1775-80. [PMID: 20057370 DOI: 10.1038/oby.2009.485] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Heritability studies of BMI, based upon twin samples, have identified genetic and shared environmental components of BMI, but have been largely silent about the nonshared environmental factors. Intrauterine factors have been identified as having significant long-term effects on BMI and may be a critical source of nonshared environmental influence. Extant studies based on samples of either unrelated individuals or twins cannot separate the effects of genetics, shared environments, and nonshared intrauterine conditions because the one lacks variation in the degree of relatedness and the other has insufficient variation in intrauterine conditions. This study improves upon these prior studies by using a large, sibling-based sample to examine heritability, shared environmental, and nonshared intrauterine influences on BMI during two age periods in childhood (6-8 years; 12-14 years). The primary interest was in determining the effects of the intrauterine environment on BMI as a component of the nonshared environment and in determining whether there were sex-specific differences in heritability and/or in the intrauterine factors. These were estimated using regression-based techniques introduced by DeFries and Fulker. Heritability of BMI was estimated to be 0.20-0.28 at 6-8 years and 0.46-0.61 at 12-14 years. Differences in heritability were found at 12-14 years between same-sex as compared to mixed-sex pairs. The shared environmental effect was significant at 6-8 years but insignificant at 12-14 years. Differences in birth weight were significant in all groups at 6-8 years suggesting long-term effects of the nonshared intrauterine environment; at 12-14 years, birth weight was no longer significant for girls.
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Ankra-Badu GA, Shriner D, Le Bihan-Duval E, Mignon-Grasteau S, Pitel F, Beaumont C, Duclos MJ, Simon J, Porter TE, Vignal A, Cogburn LA, Allison DB, Yi N, Aggrey SE. Mapping main, epistatic and sex-specific QTL for body composition in a chicken population divergently selected for low or high growth rate. BMC Genomics 2010; 11:107. [PMID: 20149241 PMCID: PMC2830984 DOI: 10.1186/1471-2164-11-107] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2009] [Accepted: 02/11/2010] [Indexed: 11/30/2022] Open
Abstract
Background Delineating the genetic basis of body composition is important to agriculture and medicine. In addition, the incorporation of gene-gene interactions in the statistical model provides further insight into the genetic factors that underlie body composition traits. We used Bayesian model selection to comprehensively map main, epistatic and sex-specific QTL in an F2 reciprocal intercross between two chicken lines divergently selected for high or low growth rate. Results We identified 17 QTL with main effects across 13 chromosomes and several sex-specific and sex-antagonistic QTL for breast meat yield, thigh + drumstick yield and abdominal fatness. Different sets of QTL were found for both breast muscles [Pectoralis (P) major and P. minor], which suggests that they could be controlled by different regulatory mechanisms. Significant interactions of QTL by sex allowed detection of sex-specific and sex-antagonistic QTL for body composition and abdominal fat. We found several female-specific P. major QTL and sex-antagonistic P. minor and abdominal fatness QTL. Also, several QTL on different chromosomes interact with each other to affect body composition and abdominal fatness. Conclusions The detection of main effects, epistasis and sex-dimorphic QTL suggest complex genetic regulation of somatic growth. An understanding of such regulatory mechanisms is key to mapping specific genes that underlie QTL controlling somatic growth in an avian model.
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Affiliation(s)
- Georgina A Ankra-Badu
- Department of Poultry Science/Institute of Bioinformatics, University of Georgia, Athens, GA 30602, USA
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