Author:
Yokoyama Yoshie,Jelenkovic Aline,Sund Reijo,Sung Joohon,Hopper John L.,Ooki Syuichi,Heikkilä Kauko,Aaltonen Sari,Tarnoki Adam D.,Tarnoki David L.,Willemsen Gonneke,Bartels Meike,van Beijsterveldt Toos C. E. M.,Saudino Kimberly J.,Cutler Tessa L.,Nelson Tracy L.,Whitfield Keith E.,Wardle Jane,Llewellyn Clare H.,Fisher Abigail,He Mingguang,Ding Xiaohu,Bjerregaard-Andersen Morten,Beck-Nielsen Henning,Sodemann Morten,Song Yun-Mi,Yang Sarah,Lee Kayoung,Jeong Hoe-Uk,Knafo-Noam Ariel,Mankuta David,Abramson Lior,Burt S. Alexandra,Klump Kelly L.,Ordoñana Juan R.,Sánchez-Romera Juan F.,Colodro-Conde Lucia,Harris Jennifer R.,Brandt Ingunn,Nilsen Thomas Sevenius,Craig Jeffrey M.,Saffery Richard,Ji Fuling,Ning Feng,Pang Zengchang,Dubois Lise,Boivin Michel,Brendgen Mara,Dionne Ginette,Vitaro Frank,Martin Nicholas G.,Medland Sarah E.,Montgomery Grant W.,Magnusson Patrik K. E.,Pedersen Nancy L.,Aslan Anna K. Dahl,Tynelius Per,Haworth Claire M. A.,Plomin Robert,Rebato Esther,Rose Richard J.,Goldberg Jack H.,Rasmussen Finn,Hur Yoon-Mi,Sørensen Thorkild I. A.,Boomsma Dorret I.,Kaprio Jaakko,Silventoinen Karri
Abstract
We analyzed birth order differences in means and variances of height and body mass index (BMI) in monozygotic (MZ) and dizygotic (DZ) twins from infancy to old age. The data were derived from the international CODATwins database. The total number of height and BMI measures from 0.5 to 79.5 years of age was 397,466. As expected, first-born twins had greater birth weight than second-born twins. With respect to height, first-born twins were slightly taller than second-born twins in childhood. After adjusting the results for birth weight, the birth order differences decreased and were no longer statistically significant. First-born twins had greater BMI than the second-born twins over childhood and adolescence. After adjusting the results for birth weight, birth order was still associated with BMI until 12 years of age. No interaction effect between birth order and zygosity was found. Only limited evidence was found that birth order influenced variances of height or BMI. The results were similar among boys and girls and also in MZ and DZ twins. Overall, the differences in height and BMI between first- and second-born twins were modest even in early childhood, while adjustment for birth weight reduced the birth order differences but did not remove them for BMI.
Publisher
Cambridge University Press (CUP)
Subject
Genetics (clinical),Obstetrics and Gynecology,Pediatrics, Perinatology and Child Health