Early-life soy exposure and age at menarche.
Abstract
This study examines the timing of menarche in relation to infant-feeding methods,
specifically addressing the potential effects of soy isoflavone exposure through soy-based
infant feeding. Subjects were participants in the Avon Longitudinal Study of Parents
and Children (ALSPAC). Mothers were enrolled during pregnancy and their children have
been followed prospectively. Early-life feeding regimes, categorised as primarily
breast, early formula, early soy and late soy, were defined using infant-feeding questionnaires
administered during infancy. For this analysis, age at menarche was assessed using
questionnaires administered approximately annually between ages 8 and 14.5. Eligible
subjects were limited to term, singleton, White females. We used Kaplan-Meier survival
curves and Cox proportional hazards models to assess age at menarche and risk of menarche
over the study period. The present analysis included 2920 girls. Approximately 2%
of mothers reported that soy products were introduced into the infant diet at or before
4 months of age (early soy). The median age at menarche [interquartile range (IQR)]
in the study sample was 153 months [144-163], approximately 12.8 years. The median
age at menarche among early soy-fed girls was 149 months (12.4 years) [IQR, 140-159].
Compared with girls fed non-soy-based infant formula or milk (early formula), early
soy-fed girls were at 25% higher risk of menarche throughout the course of follow-up
(hazard ratio 1.25 [95% confidence interval 0.92, 1.71]). Our results also suggest
that girls fed soy products in early infancy may have an increased risk of menarche
specifically in early adolescence. These findings may be the observable manifestation
of mild endocrine-disrupting effects of soy isoflavone exposure. However, our study
is limited by few soy-exposed subjects and is not designed to assess biological mechanisms.
Because soy formula use is common in some populations, this subtle association with
menarche warrants more in-depth evaluation in future studies.
Type
Journal articleSubject
AdolescentAge Factors
Child
Endocrine Disruptors
European Continental Ancestry Group
Female
Humans
Infant
Infant Formula
Infant Nutritional Physiological Phenomena
Isoflavones
Kaplan-Meier Estimate
Longitudinal Studies
Male
Menarche
Pregnancy
Prospective Studies
Risk Factors
Soy Milk
Surveys and Questionnaires
Time Factors
United Kingdom
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https://hdl.handle.net/10161/5992Published Version (Please cite this version)
10.1111/j.1365-3016.2011.01244.xPublication Info
Adgent, Margaret A; Daniels, Julie L; Rogan, Walter J; Adair, Linda; Edwards, Lloyd
J; Westreich, Daniel; ... Marcus, Michele (2012). Early-life soy exposure and age at menarche. Paediatr Perinat Epidemiol, 26(2). pp. 163-175. 10.1111/j.1365-3016.2011.01244.x. Retrieved from https://hdl.handle.net/10161/5992.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
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