Karri Silventoinen, Aline Jelenkovic, Reijo Sund, Yoon-Mi Hur, Yoshie Yokoyama, Chika Honda, Jacob vB Hjelmborg, Sören Möller, Syuichi Ooki, Sari Aaltonen, Fuling Ji, Feng Ning, Zengchang Pang, Esther Rebato, Andreas Busjahn, Christian Kandler, Kimberly J Saudino, Kerry L Jang, Wendy Cozen, Amie E Hwang, Thomas M Mack, Wenjing Gao, Canqing Yu, Liming Li, Robin P Corley, Brooke M Huibregtse, Kaare Christensen, Axel Skytthe, Kirsten O Kyvik, Catherine A Derom, Robert F Vlietinck, Ruth Jf Loos, Kauko Heikkilä, Jane Wardle, Clare H Llewellyn, Abigail Fisher, Tom A McAdams, Thalia C Eley, Alice M Gregory, Mingguang He, Xiaohu Ding, Morten Bjerregaard-Andersen, Henning Beck-Nielsen, Morten Sodemann, Adam D Tarnoki, David L Tarnoki, Maria A Stazi, Corrado Fagnani, Cristina D’Ippolito, Ariel Knafo-Noam, David Mankuta, Lior Abramson, S Alexandra Burt, Kelly L Klump, Judy L Silberg, Lindon J Eaves, Hermine H Maes, Robert F Krueger, Matt McGue, Shandell Pahlen, Margaret Gatz, David A Butler, Meike Bartels, Toos Cem van Beijsterveldt, Jeffrey M Craig, Richard Saffery, Duarte L Freitas, José Antonio Maia, Lise Dubois, Michel Boivin, Mara Brendgen, Ginette Dionne, Frank Vitaro, Nicholas G Martin, Sarah E Medland, Grant W Montgomery, Youngsook Chong, Gary E Swan, Ruth Krasnow, Patrik Ke Magnusson, Nancy L Pedersen, Per Tynelius, Paul Lichtenstein, Claire Ma Haworth, Robert Plomin, Gombojav Bayasgalan, Danshiitsoodol Narandalai, K Paige Harden, Elliot M Tucker-Drob, Sevgi Y Öncel, Fazil Aliev, Timothy Spector, Massimo Mangino, Genevieve Lachance, Laura A Baker, Catherine Tuvblad, Glen E Duncan, Dedra Buchwald, Gonneke Willemsen, Finn Rasmussen, Jack H Goldberg, Thorkild Ia Sørensen, Dorret I Boomsma, Jaakko Kaprio
The American Journal of Clinical Nutrition Volume 104, Issue 2, August 2016, Pages 371-379
Abstract
Background: Both genetic and environmental factors are known to affect body mass index (BMI), but detailed understanding of how their effects differ during childhood and adolescence is lacking.
Objectives: We analyzed the genetic and environmental contributions to BMI variation from infancy to early adulthood and the ways they differ by sex and geographic regions representing high (North America and Australia), moderate (Europe), and low levels (East Asia) of obesogenic environments.
Design: Data were available for 87,782 complete twin pairs from 0.5 to 19.5 y of age from 45 cohorts. Analyses were based on 383,092 BMI measurements. Variation in BMI was decomposed into genetic and environmental components through genetic structural equation modeling.
Results: The variance of BMI increased from 5 y of age along with increasing mean BMI. The proportion of BMI variation explained by additive genetic factors was lowest at 4 y of age in boys (a2 = 0.42) and girls (a2 = 0.41) and then generally increased to 0.75 in both sexes at 19 y of age. This was because of a stronger influence of environmental factors shared by co-twins in midchildhood. After 15 y of age, the effect of shared environment was not observed. The sex-specific expression of genetic factors was seen in infancy but was most prominent at 13 y of age and older. The variance of BMI was highest in North America and Australia and lowest in East Asia, but the relative proportion of genetic variation to total variation remained roughly similar across different regions.
Conclusions: Environmental factors shared by co-twins affect BMI in childhood, but little evidence for their contribution was found in late adolescence. Our results suggest that genetic factors play a major role in the variation of BMI in adolescence among populations of different ethnicities exposed to different environmental factors related to obesity.