Rapid infant weight gain and advanced skeletal maturation in childhood.
OBJECTIVE
To test the hypothesis that rapid infant weight gain is associated with advanced skeletal maturity in children from the United States and South Africa.


METHODS
Longitudinal data from 467 appropriate-for-gestational-age infants in the Fels Longitudinal Growth Study (Dayton, Ohio) and 196 appropriate-for-gestational-age infants in the Birth to Twenty birth cohort study (Johannesburg, South Africa) were used. Multiple linear regression models tested the association between internal SD score change in weight from 0 to 2 years and relative skeletal age at 9 years, adjusting for body mass index, stature, and other covariates.


RESULTS
In both studies, faster infant weight gain was associated with more advanced skeletal maturity (approximately 0.2 years or 2.4 months per SD score) at age 9 years (P <.0001-.005), even when adjusting for the positive associations of both birth weight and body mass index at age 9 years. This effect appeared to be accounted for by the greater childhood stature of subjects with more rapid infant weight gain.


CONCLUSIONS
Relatively rapid infant weight-gain is associated with advanced skeletal development in late childhood, perhaps via effects on stature.
Demerath
Ellen W
EW
Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, MN 55454-1015, USA. ewd@umn.edu
Jones
Laura L
LL
Hawley
Nicola L
NL
Norris
Shane A
SA
Pettifor
John M
JM
Duren
Dana
D
Chumlea
W Cameron
WC
Towne
Bradford
B
Cameron
Noel
N
D000293:Adolescent; D000367:Age Factors; D001724:Birth Weight; D015992:Body Mass Index; D049628:Body Size; D001846:Bone Development / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008297:Male; D013019:South Africa; D014481:United States; D015430:Weight Gain / Q000502:physiology*; D055815:Young Adult