Body size of twins compared with siblings and the general population: from birth to late adolescence.
OBJECTIVE
We examined whether and when differences in body size disappear over time and whether twins attain normal final height and body mass index (BMI).


METHODS
Height, weight, and BMI data of twins at ages 1, 4, and 18 years were compared with data from their nontwin siblings. Second, twin and sibling data were compared with population standards. In addition to height, weight, and BMI, data on body proportions at age 18 years were analyzed.


RESULTS
At the age of 18 years, twins were as tall as their siblings but were significantly leaner. Compared with children from the general population, adolescent twins attained the same height and BMI. Birth weight was shown to have a considerable effect on height in adolescent twins.


CONCLUSIONS
Twins attained normal final height compared with siblings and children from the general population. No differences in BMI were shown between 18-year-old twins and children from the general population, whereas the siblings of twins had increased BMI values compared with the general population.
Estourgie-van Burk
G Frederiek
GF
Department of Pediatrics, VU University Medical Center, Amsterdam, The Netherlands. f.estourgie@vumc.nl
Bartels
Meike
M
Boomsma
Dorret I
DI
Delemarre-van de Waal
Henriette A
HA
D000293:Adolescent; D041923:Adolescent Development / Q000502:physiology*; D049628:Body Size / Q000502:physiology*; D002648:Child; D002657:Child Development / Q000502:physiology*; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009426:Netherlands; D035781:Siblings; D014427:Twins / Q000502:physiology*