Epidemiology
Obesity (2008) 16 4, 847–852. doi:10.1038/oby.2007.135
Genetic Influences on Growth Traits of BMI: A Longitudinal Study of Adult Twins
Jacob v.B. Hjelmborg1, Corrado Fagnani2, Karri Silventoinen3, Matt McGue4, Maarit Korkeila3, Kaare Christensen1, Aila Rissanen3 and Jaakko Kaprio3,5
- 1Statistics and Epidemiology, Institute of Public Health, University of Southern Denmark, Odense, Denmark
- 2National Centre of Epidemiology, Surveillance and Health Promotion—Italian Institute of Health, Rome, Italy
- 3Department of Public Health, University of Helsinki, Helsinki, Finland
- 4Department of Psychology, University of Minnesota, Minneapolis, Minnesota, USA
- 5Department of Mental Health and Alcohol Research, National Public Health Institute, Helsinki, Finland
Correspondence: Jacob v.B. Hjelmborg (jhjelmborg@health.sdu.dk)
Received 6 July 2007; Accepted 19 November 2007; Published online 31 January 2008.
Abstract
Objective:
To investigate the interplay between genetic factors influencing baseline level and changes in BMI in adulthood.
Methods and Procedures:
A longitudinal twin study of the cohort of Finnish twins (N = 10,556 twin individuals) aged 20–46 years at baseline was conducted and followed up 15 years. Data on weight and height were obtained from mailed surveys in 1975, 1981, and 1990.
Results:
Latent growth models revealed a substantial genetic influence on BMI level at baseline in males and females (heritability (h2) 80% (95% confidence interval 0.79–0.80) for males and h2 = 82% (0.81, 0.84) for females) and a moderate-to-high influence on rate of change in BMI (h2 = 58% (0.50, 0.69) for males and h2 = 64% (0.58, 0.69) for females). Only very weak evidence for genetic pleiotropy was observed; the genetic correlation between baseline and rate of change in BMI was very modest (-0.070 (–0.13, –0.068) for males and 0.04 (0.00, 0.08) for females.
Discussion:
Our population-based results provide a basis for identifying genetic variants for change in BMI, in particular weight gain. Furthermore, they demonstrate for the first time that such genetic variants for change in BMI are likely to be different from those affecting level of BMI.
