The preventive effect of breast-feeding for longer than 6 months on early pubertal development among children aged 7-9 years in Korea.
OBJECTIVE
The present study was performed to investigate whether breast-feeding is associated with early pubertal development among children 7-9 years old in Korea.


METHODS
Children were divided into those who did and did not receive breast-feeding for 6 months or longer in accordance with the recommendations of the WHO. Pubertal status was determined by clinical examination using Tanner staging.


METHODS
Prospective observational study.


METHODS
We conducted a follow-up study of children aged 7-9 years in 2011 who had taken part in the Ewha Birth & Growth Cohort study.


RESULTS
Fifty (22.8%) of the total of 219 children were in early puberty, with the proportion being slightly higher for girls (24.1%) than boys (21.4%). Children who had entered early puberty were taller, weighed more and had a higher concentration of insulin-like growth factor 1. Moreover, the change in weight Z-score from birth to follow-up was significantly lower in children who were breast-fed than in those who were not (weight Z-score change: 0.32 (sd 1.59) v. 0.77 (sd 1.61), respectively, P=0.04). Comparison of breast-feeding by puberty status indicated a preventive association with early puberty in children who were breast-fed for 6 months or longer (OR=0.37; 95% CI 0.18, 0.74). This association remained significant after adjustment for relevant covariates.


CONCLUSIONS
These results demonstrate a beneficial association between breast-feeding and early pubertal development, especially in those breast-fed for 6 months or longer. The study suggests that interventions would need to start early in life to prevent early pubertal development.
1Department of Preventive Medicine,School of Medicine,Ewha Womans University,1071 Anyangcheon-ro,Yangcheon-ku,Seoul 158-710,Republic of Korea.
Hye Ah
HA
Lee
2Obstetrics and Gynecology,School of Medicine,Ewha Womans University,Seoul,Republic of Korea.
Young Ju
YJ
Kim
3Anatomy,School of Medicine,Ewha Womans University,Seoul,Republic of Korea.
Hwayoung
H
Lee
4Colleage of Pharmacy,Ewha Womans University,Seoul,Republic of Korea.
Hye Sun
HS
Gwak
5Internal Medicine,School of Medicine,Ewha Womans University,Seoul,Republic of Korea.
Young Sun
YS
Hong
6Department of Pediatrics,School of Medicine,Ewha Womans University,Seoul,Republic of Korea.
Hae Soon
HS
Kim
6Department of Pediatrics,School of Medicine,Ewha Womans University,Seoul,Republic of Korea.
Eun Ae
EA
Park
6Department of Pediatrics,School of Medicine,Ewha Womans University,Seoul,Republic of Korea.
Su Jin
SJ
Cho
1Department of Preventive Medicine,School of Medicine,Ewha Womans University,1071 Anyangcheon-ro,Yangcheon-ku,Seoul 158-710,Republic of Korea.
Eun Hee
EH
Ha
1Department of Preventive Medicine,School of Medicine,Ewha Womans University,1071 Anyangcheon-ro,Yangcheon-ku,Seoul 158-710,Republic of Korea.
Hyesook
H
Park
D001827:Body Height / Q000208:ethnology; D001942:Breast Feeding / Q000208:ethnology; D002648:Child; D002657:Child Development; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007231:Infant, Newborn; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D008297:Male; D008425:Maternal Behavior / Q000208:ethnology; D018673:Nutrition Policy; D010349:Patient Compliance / Q000208:ethnology; D011446:Prospective Studies; D011629:Puberty, Precocious / Q000097:blood / Q000453:epidemiology / Q000208:ethnology / Q000517:prevention & control*; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D015430:Weight Gain / Q000208:ethnology; D014944:World Health Organization
C583557:IGF1 protein, human; D007334:Insulin-Like Growth Factor I
Breast-feeding; Cohort study; Early puberty development