Article

Examining the evidence for recent secular changes in the timing of puberty of U.S. children in light of increases in the prevalence of obesity

Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, 1300 South 2nd St., Suite 300, Minneapolis, MN 55454-1015, USA.
Molecular and Cellular Endocrinology (Impact Factor: 4.41). 08/2006; 254-255:13-21. DOI: 10.1016/j.mce.2006.04.013
Source: PubMed

ABSTRACT

This report reviews the available evidence from large population studies regarding a secular change in the timing and progress of puberty since 1960 in US children in light of concurrent increases in the prevalence of obesity. There probably was a secular decrease in the median age of onset and progression of genital development in Mexican-American boys and breast development Mexican-American girls in the 1980s and 1990s. The data are insufficient to do more than suggest corresponding trends in black boys and black girls, but there is no evidence of breast changes in white girls. Mean age of menarche decreased by approximately 3 months in US white girls and 5.5 months in US black girls between the late 1960s and approximately 1990. Evidence from a single study indicates the secular changes in age at menarche are consistent with the magnitude of secular change in obesity, although other evidence is equivocal.

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    • "For the past four decades, age at which puberty occurs among girls—manifested as breast development, appearance of pubic hair, and onset of menarche—has been commencing earlier. Although evidence points to non-linear variability in menarcheal age from decade to decade [1], the mean age at onset of menarche (AOM) in the United States decreased by an average of 3 to 5½ months from 1960 to 1990 [2]. Breast development, typically considered an earlier manifestation of puberty compared to menarche, is also commencing at a younger age [3]. "
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    ABSTRACT: Background Early onset of menarche may negatively influence the future health of adolescent girls. Several factors affect the timing of menarche but it is not clear if soy foods consumption around pubertal years plays a role; thus, we examined its relation to age at onset of menarche (AOM) in a high soy-consuming population. Methods We conducted a cross-sectional study on 339 girls ages 12–18 years attending middle and high schools near two Seventh-day Adventist universities in California and Michigan using a web-based dietary questionnaire and physical development tool. Soy consumption (categorized as total soy, meat alternatives, tofu/traditional soy, and soy beverages) was estimated from the questionnaire, while AOM was self-reported. Data analyses included descriptive statistics, Cox proportional hazards ratios, Kaplan-Meier curves and Poisson regression with adjustment for relevant confounders. Results Mean (SD) intakes were: total soy,12.9 (14.4) servings/week; meat alternatives, 7.0 (8.9) servings/week; tofu/traditional soy foods, 2.1 (3.8) servings/week; soy beverages, 3.8 (6.3) servings/week. Mean AOM was 12.5 (1.4) y for those who reached menarche. Consumption of total soy and the 3 types of soy foods was not significantly associated with AOM and with the odds for early- or late-AOM. Adjustment for demographic and dietary factors did not change the results. Conclusion Soy intake is not associated with AOM in a population of adolescent girls who have a wide range of, and relatively higher, soy intake than the general US population. Our finding suggests that the increasing popularity of soy in the US may not be associated with AOM.
    Full-text · Article · Jun 2014 · Nutrition Journal
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    • "Perinatal exposure to chemicals such as DDT (Ouyang et al., 2005), polybrominated biphenyls (Blanck et al., 2000), and persistent halogenated organic chemicals (Den and Schoeters, 2006) have been suggested to either accelerate puberty in girls (Buck Louis et al., 2008) or delay puberty in boys (Buck Louis et al., 2008; Korrick et al., 2011). Obesity also accelerates the age of puberty onset (Battaglia et al., 2005; Himes, 2006; Biro et al., 2006), possibly by an increase in leptin levels that has a permissive role in puberty onset (Ahmed et al., 2009). Furthermore , the increased insulin resistance observed in obese or overweight individuals predisposes toward early puberty (Ahmed et al., 2009). "
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    ABSTRACT: Differences in the physiology and biological susceptibilities of adults and infants have led to growing interest in safety evaluation methods for exposures from infant formula packaging. In addition to potential physiological differences, infants aged 0 - 6 months may consume a sole source of food, infant formula or breast milk, and consume higher amounts of food relative to body weight compared to adults. While the duration of the exposure is short compared to the expected lifespan of the individual, it occurs during a period of important developmental processes. The purpose of this document is to (1) review key biological and exposure elements that may impact the evaluation of safety for food contact products intended for use by infants, (2) summarize the current reproductive and developmental toxicity testing protocols available, and (3) identify potential data gaps concerning this period of development.
    Full-text · Article · May 2014 · Food and chemical toxicology: an international journal published for the British Industrial Biological Research Association
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    • "Perinatal exposure to chemicals such as DDT (Ouyang et al., 2005), polybrominated biphenyls (Blanck et al., 2000), and persistent halogenated organic chemicals (Den and Schoeters, 2006) have been suggested to either accelerate puberty in girls (Buck Louis et al., 2008) or delay puberty in boys (Buck Louis et al., 2008; Korrick et al., 2011). Obesity also accelerates the age of puberty onset (Battaglia et al., 2005; Himes, 2006; Biro et al., 2006), possibly by an increase in leptin levels that has a permissive role in puberty onset (Ahmed et al., 2009). Furthermore , the increased insulin resistance observed in obese or overweight individuals predisposes toward early puberty (Ahmed et al., 2009). "
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    ABSTRACT: Differences in the physiology and biological susceptibilities of adults and infants have led to growing interest in safety evaluation methods for exposures from infant formula packaging. In addition to potential physiological differences, infants aged 0–6 months may consume a sole source of food, infant formula or breast milk, and consume higher amounts of food relative to body weight compared to adults. While the duration of the exposure is short compared to the expected lifespan of the individual, it occurs during a period of important developmental processes. The purpose of this document is to (1) review key biological and exposure elements that may impact the evaluation of safety for food contact products intended for use by infants, (2) summarize the current reproductive and developmental toxicity testing protocols available, and (3) identify potential data gaps concerning this period of development.
    Full-text · Article · Jan 2014
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