A genetic analysis of relative weight among 4,020 twin pairs, with an emphasis on sex effects.
This study replicated previous findings showing a high heritability of obesity, as measured by body mass index (kg/m2), using a measure of relative weight that does not assume a constant regression of height on weight across different populations, and evaluated whether there are sex-limited genetic effects. Subjects were 4,020 adult twin pairs. Alternative causal structural equation models were fitted to variance-covariance matrices. The ADE model (additive genetic effects, dominant/nonadditive genetic effects, and unique environment) fit best. Allowing for sex-specific effects (common sex-limitation model) significantly improved the fit, X2(6) = 230.5, p < .001. The heritability of that portion of weight unrelated to height was large: .61 for men and .73 for women.
Obesity Research Center, St. Luke's/Roosevelt Hospital, Columbia University College of Physicians and Surgeons, New York, New York 10025.
D B
DB
Allison
S
S
Heshka
M C
MC
Neale
D T
DT
Lykken
S B
SB
Heymsfield
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D005260:Female; D006801:Humans; D008297:Male; D008957:Models, Genetic; D009765:Obesity / Q000453:epidemiology / Q000235:genetics*; D012737:Sex Factors; D014427:Twins / Q000235:genetics*