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The CODATwins Project: The Cohort Description of Collaborative Project of Development of Anthropometrical Measures in Twins to Study Macro-Environmental Variation in Genetic and Environmental Effects on Anthropometric Traits. Twin Res Hum Genet 2015; 18:348-60. [PMID: 26014041 DOI: 10.1017/thg.2015.29] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
For over 100 years, the genetics of human anthropometric traits has attracted scientific interest. In particular, height and body mass index (BMI, calculated as kg/m2) have been under intensive genetic research. However, it is still largely unknown whether and how heritability estimates vary between human populations. Opportunities to address this question have increased recently because of the establishment of many new twin cohorts and the increasing accumulation of data in established twin cohorts. We started a new research project to analyze systematically (1) the variation of heritability estimates of height, BMI and their trajectories over the life course between birth cohorts, ethnicities and countries, and (2) to study the effects of birth-related factors, education and smoking on these anthropometric traits and whether these effects vary between twin cohorts. We identified 67 twin projects, including both monozygotic (MZ) and dizygotic (DZ) twins, using various sources. We asked for individual level data on height and weight including repeated measurements, birth related traits, background variables, education and smoking. By the end of 2014, 48 projects participated. Together, we have 893,458 height and weight measures (52% females) from 434,723 twin individuals, including 201,192 complete twin pairs (40% monozygotic, 40% same-sex dizygotic and 20% opposite-sex dizygotic) representing 22 countries. This project demonstrates that large-scale international twin studies are feasible and can promote the use of existing data for novel research purposes.
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Rokholm B, Silventoinen K, Tynelius P, Sørensen TIA, Rasmussen F. Modifiable environmental influences on body mass index shared by young adult brothers. Int J Obes (Lond) 2012; 37:211-5. [PMID: 22945609 DOI: 10.1038/ijo.2012.151] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVES Twin and adoption studies suggest that family environment has little, if any, influence on body mass index (BMI) in adulthood. We investigated the hypothesis that the differences in the years of birth between siblings influence their similarity in BMI at comparable ages, which would give evidence for a possibly modifiable influence of the environment shared by family members. METHODS Swedish full-brother pairs (N=261 712) born between 1951 and 1983 were measured for BMI in conscription examination at 16-26 years (median: 18.2 years) of age and were divided into quartiles by the difference between their birth-years (< 2.25 years, 2.25-3.33 years, 3.34-5.08 years and >5.08 years). Furthermore, 1961 dizygotic twin brother pairs from the same population representing brothers born at the same time were included. In addition, the log BMI of the younger brother was modeled as a linear function of the log BMI of the older brother. Subsequently, the significance of the interaction between birth-year difference and the BMI of the older brother was tested. RESULTS Intraclass correlation for BMI in dizygotic twin pairs was higher (0.431, 95% confidence interval (CI) 0.394-0.466) than the correlation for full-brothers in the first quartile of birth-year difference (0.376, CI 0.342-0.408). Among full-brothers, the BMI correlation decreased from 0.376 (CI 0.342-0.408) [corrected] in the first quartile to 0.338 (CI 0.331-0.345) in the last quartile. The regression analysis showed a statistically significant decrease in correlation with increasing birth-year difference (P<0.001). CONCLUSION The influence on BMI in young men of the environment shared by dizygotic twin brothers is greater than between non-twin full-brothers, indicating important influences of concomitant exposure to the same early life environment before and/or after birth. Among non-twin siblings there is a slight possibly modifiable influence as evidenced by declining correlations by increasing distance in years of birth.
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Affiliation(s)
- B Rokholm
- Institute of Preventive Medicine, Copenhagen University Hospital, Copenhagen, Denmark.
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Birnie K, Cooper R, Martin RM, Kuh D, Sayer AA, Alvarado BE, Bayer A, Christensen K, Cho SI, Cooper C, Corley J, Craig L, Deary IJ, Demakakos P, Ebrahim S, Gallacher J, Gow AJ, Gunnell D, Haas S, Hemmingsson T, Inskip H, Jang SN, Noronha K, Osler M, Palloni A, Rasmussen F, Santos-Eggimann B, Spagnoli J, Starr J, Steptoe A, Syddall H, Tynelius P, Weir D, Whalley LJ, Zunzunegui MV, Ben-Shlomo Y, Hardy R. Childhood socioeconomic position and objectively measured physical capability levels in adulthood: a systematic review and meta-analysis. PLoS One 2011; 6:e15564. [PMID: 21297868 PMCID: PMC3027621 DOI: 10.1371/journal.pone.0015564] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Accepted: 11/12/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Grip strength, walking speed, chair rising and standing balance time are objective measures of physical capability that characterise current health and predict survival in older populations. Socioeconomic position (SEP) in childhood may influence the peak level of physical capability achieved in early adulthood, thereby affecting levels in later adulthood. We have undertaken a systematic review with meta-analyses to test the hypothesis that adverse childhood SEP is associated with lower levels of objectively measured physical capability in adulthood. METHODS AND FINDINGS Relevant studies published by May 2010 were identified through literature searches using EMBASE and MEDLINE. Unpublished results were obtained from study investigators. Results were provided by all study investigators in a standard format and pooled using random-effects meta-analyses. 19 studies were included in the review. Total sample sizes in meta-analyses ranged from N = 17,215 for chair rise time to N = 1,061,855 for grip strength. Although heterogeneity was detected, there was consistent evidence in age adjusted models that lower childhood SEP was associated with modest reductions in physical capability levels in adulthood: comparing the lowest with the highest childhood SEP there was a reduction in grip strength of 0.13 standard deviations (95% CI: 0.06, 0.21), a reduction in mean walking speed of 0.07 m/s (0.05, 0.10), an increase in mean chair rise time of 6% (4%, 8%) and an odds ratio of an inability to balance for 5s of 1.26 (1.02, 1.55). Adjustment for the potential mediating factors, adult SEP and body size attenuated associations greatly. However, despite this attenuation, for walking speed and chair rise time, there was still evidence of moderate associations. CONCLUSIONS Policies targeting socioeconomic inequalities in childhood may have additional benefits in promoting the maintenance of independence in later life.
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Affiliation(s)
- Kate Birnie
- Department of Social Medicine, University of Bristol, Bristol, United Kingdom
| | - Rachel Cooper
- Medical Research Council Unit for Lifelong Health and Ageing and Division of Population Health, University College London, London, United Kingdom
| | - Richard M. Martin
- Department of Social Medicine, University of Bristol, Bristol, United Kingdom
| | - Diana Kuh
- Medical Research Council Unit for Lifelong Health and Ageing and Division of Population Health, University College London, London, United Kingdom
| | - Avan Aihie Sayer
- Medical Research Council Lifecourse Epidemiology Unit, University of Southampton, Southampton, United Kingdom
| | - Beatriz E. Alvarado
- Department of Community Health and Epidemiology, Queen's University, Kingston, Canada
| | - Antony Bayer
- Department of Primary Care and Public Health, Centre for Health Sciences Research, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Kaare Christensen
- The Danish Twin Registry and The Danish Aging Research Center, Institute of Public Health, University of Southern Denmark, Odense, Denmark
| | - Sung-il Cho
- Department of Epidemiology, School of Public Health and Institute of Health and Environment, Seoul National University, Seoul, Republic of Korea
| | - Cyrus Cooper
- Medical Research Council Lifecourse Epidemiology Unit, University of Southampton, Southampton, United Kingdom
- National Institute for Health and Research Musculoskeletal Biomedical Research Unit, University of Oxford, Oxford, United Kingdom
| | - Janie Corley
- Department of Psychology and Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Leone Craig
- Institute of Applied Health Sciences and Rowett Institute of Nutrition and Health, University of Aberdeen, Foresterhill, Aberdeen, United Kingdom
| | - Ian J. Deary
- Department of Psychology and Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Panayotes Demakakos
- Department of Epidemiology and Public Health, University College London, London, United Kingdom
| | - Shah Ebrahim
- Department of Non-Communicable Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - John Gallacher
- Department of Primary Care and Public Health, Centre for Health Sciences Research, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Alan J. Gow
- Department of Psychology and Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom
| | - David Gunnell
- Department of Social Medicine, University of Bristol, Bristol, United Kingdom
| | - Steven Haas
- School of Social and Family Dynamics, Arizona State University, Tempe, Arizona, United States of America
| | - Tomas Hemmingsson
- Division of Occupational and Environmental Medicine, Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden
| | - Hazel Inskip
- Medical Research Council Lifecourse Epidemiology Unit, University of Southampton, Southampton, United Kingdom
| | - Soong-nang Jang
- Department of Society, Human Development and Health, Harvard School of Public Health, Boston, Massachusetts, United States of America
| | - Kenya Noronha
- Economics Department, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Merete Osler
- Research Center for Prevention and Health, Glostrup University Hospital, Glostrup, Denmark
| | - Alberto Palloni
- Center for Demography and Ecology, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Finn Rasmussen
- Department of Public Health Sciences, Karolinska Institute, Stockholm, Sweden
| | - Brigitte Santos-Eggimann
- Institute of Social and Preventive Medicine, University Hospital Center and University of Lausanne, Lausanne, Switzerland
| | - Jacques Spagnoli
- Institute of Social and Preventive Medicine, University Hospital Center and University of Lausanne, Lausanne, Switzerland
| | - John Starr
- Department of Geriatric Medicine and Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Andrew Steptoe
- Department of Epidemiology and Public Health, University College London, London, United Kingdom
| | - Holly Syddall
- Medical Research Council Lifecourse Epidemiology Unit, University of Southampton, Southampton, United Kingdom
| | - Per Tynelius
- Department of Public Health Sciences, Karolinska Institute, Stockholm, Sweden
| | - David Weir
- Institute for Social Research, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Lawrence J. Whalley
- Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | | | - Yoav Ben-Shlomo
- Department of Social Medicine, University of Bristol, Bristol, United Kingdom
| | - Rebecca Hardy
- Medical Research Council Unit for Lifelong Health and Ageing and Division of Population Health, University College London, London, United Kingdom
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Silventoinen K, Magnusson PKE, Tynelius P, Kaprio J, Rasmussen F. Heritability of body size and muscle strength in young adulthood: a study of one million Swedish men. Genet Epidemiol 2008; 32:341-9. [PMID: 18271028 DOI: 10.1002/gepi.20308] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Moderate heritability for skeletal muscle strength has been reported in twin studies, but genetic co-variation between muscle strength at different parts of body and body size is not well known. Further, representativeness of twin cohorts needs to be critically evaluated. Height, weight, elbow flexion, hand grip and knee extension strength were measured in young adulthood in 1,139,963 Swedish men born between 1951 and 1976. We identified 154,970 full-brother pairs and 1582 monozygotic (MZ) and 1864 same-sex dizygotic (DZ) complete twin pairs. The data were analyzed using quantitative genetic modeling for twin and family data. Twins compared to singletons and MZ twins compared to DZ twins were shorter, lighter and had lower muscle strength. In singletons, there was more variation in weight and the strength measures compared to twins with known zygosity but not when compared to twins with unknown zygosity. Full-sib correlations for these traits were lower than DZ correlations. Additive genetic factors explained 81% of variation in height, 59% in body mass index and 50-60% in the strength measures. Additive genetic correlations varied from 0.13 between height and elbow flexion strength to 0.78 between elbow flexion and hand grip strength. Our results suggest that extra variation may exist in general populations not found in twin samples, probably because of selection due to non-participation. This may have inflated heritability estimates in previous twin studies. Nonetheless, we showed that genetic factors affect muscle strength and part of these genes are common to different strength indicators and body size.
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Silventoinen K, Haukka J, Dunkel L, Tynelius P, Rasmussen F. Genetics of pubertal timing and its associations with relative weight in childhood and adult height: the Swedish Young Male Twins Study. Pediatrics 2008; 121:e885-91. [PMID: 18381517 DOI: 10.1542/peds.2007-1615] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE Previous studies have suggested that the timing of puberty is associated with BMI in childhood and adult stature. Because the genetic background of these associations is not thoroughly investigated, we aimed to analyze it in a longitudinal twin cohort. METHODS We studied a Swedish cohort of 99 monozygotic and 76 dizygotic twin pairs born between 1973 and 1979 with weight and length or height measured annually from birth to age 18 years. Age at onset of pubertal growth spurt, age at peak height velocity, and final height were estimated by a parametric JPA2 growth model. The genetic architecture and mutual associations of these traits and childhood BMI were analyzed by linear structural equation modeling. RESULTS The heritability estimate was 0.91 for age at onset of pubertal growth spurt, 0.93 for age at peak height velocity, and 0.97 for adult height. Age at onset of pubertal growth spurt was negatively associated with BMI from 1 to 10 years of age and stature in early adulthood. For age at peak height velocity, we found similar associations with childhood BMI and stature in early adulthood. These associations were explained by common genetic factors. CONCLUSION Growth during puberty is strictly genetically regulated. These genetic factors also explain why boys who matured early had higher BMI through childhood and taller stature in early adulthood.
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