Open AccessGenetic Influences on Changes in Body Mass Index: A Longitudinal Analysis of Women Twins
Author(s) -
Austin Melissa A.,
Friedlander Yechiel,
Newman Beth,
Edwards Karen,
MayerDavis Elizabeth J.,
King MaryClaire
Publication year - 1997
Publication title -
obesity research
Language(s) - English
Resource type - Journals
eISSN - 1550-8528
pISSN - 1071-7323
DOI - 10.1002/j.1550-8528.1997.tb00559.x
Subject(s) - heritability , demography , body mass index , twin study , longitudinal study , dizygotic twins , medicine , intraclass correlation , gerontology , biology , genetics , clinical psychology , obstetrics , sociology , pathology , psychometrics
AUSTIN, MELISSA A, YECHIEL FRIEDLANDER, BETH NEWMAN, KAREN EDWARDS, ELIZABETH J MAYER‐DAVIS, MARY‐CLAIRE KING. Genetic influences on changes in body mass index: a longitudinal analysis of women twins. Numerous studies have demonstrated genetic influences on body fat, but there also may be genetic effects on its intraindividual variation over time. This study examined changes in body mass index (BMI) using longitudinal data from two examinations of the Kaiser Permanente Women Twins Study, performed a decade apart. The analysis included 630 women, 185 monozygotic and 130 dizygotic twin pairs, with average ages of 41 years and 51 years at the two examinations, respectively. Age adjusted heritability estimates for the change in BMI over the decade ranged from 0.57 to 0.86 (all ρ≤0.001) using three different statistical analysis approaches, indicating that at least half, and possibly as much as 85%, of the variance in the change in BMI is attributable to genetic influences under a polygenic model. These estimates remained statistically significant after adjusting for environmental factors (ranging from 0.57 to 0.78) and with additional adjustment for BMI at baseline (ranging from 0.41 to 0.79), although dizygotic intraclass correlations were low after these adjustments. Thus, in addition to known environmental and behavioral influences, these results provide evidence for genetic influences on changes in BMI over a decade in women.