1) To estimate the heritability of body mass index (BMI) in twins aged 16y and 17y, with a special emphasis on gender-specific genetic effects and 2) to compare heights, weights, BMls, and prevalences of'overweight' (BMI >= 25 kg/m2) in these twins and in singletons aged 16.5 y. DESIGN : Cross-sectional and longitudinal epidemiological questionnaire study of twins at ages 16y and 17y, and cross-sectional study of singletons at age 16.5 y. MEASUREMENTS : BMI (kg/m2) was calculated from self-reported heights (m) and weights (kg).
4884 twins (2299 boys, 2585 girls) at baseline (age 16 y), 4401 twins (2002 boys, 2399 girls) at age 17 y, and 2509 singletons (1147 boys, 1362 girls) at age 16.5y.
Both twin and singleton samples are nationally representative.
At the ages of 16 y and 17 y, genetic effects accounted for over 80% of the interindividual variation of BMI.
The correlations for male-female pairs were smaller than for either male-male or female-female dizygotic pairs.
The singletons, especially the boys, had a higher BMI than the twins.
Nine percent of singleton boys, but only 4-6% of twin boys and twin and singleton girls were'overweight' (BMI >= 25 kg/m2).
Among adolescents, genetic factors play a significant role in the causes of variation in BMI.
The genetic modelling suggested that the sets of genes explaining the variation of BMI may differ in males and females. (...)
Mots-clés Pascal : Obésité, Déterminisme génétique, Indice masse corporelle, Poids corporel, Taille corporelle, Etude comparative, Jumeau, Sexe, Etude longitudinale, Epidémiologie, Héritabilité, Finlande, Europe, Adolescent, Homme, Etat nutritionnel, Trouble nutrition
Mots-clés Pascal anglais : Obesity, Genetic determinism, Body mass index, Body weight, Body size, Comparative study, Twin, Sex, Follow up study, Epidemiology, Heritability, Finland, Europe, Adolescent, Human, Nutritional status, Nutrition disorder
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 99-0118599
Code Inist : 002B30A01A2. Création : 16/11/1999.