Examination of US Puberty-Timing Data from 1940 to 1994 for Secular Trends: Panel Findings

Abstract

Whether children, especially girls, are entering and progressing through puberty earlier today than in the mid-1900s has been debated. Secular trend analysis, based on available data, is limited by data comparability among studies in different populations, in different periods of time, and using different methods. As a result, conclusions from data comparisons have not been consistent. An expert panel was asked to evaluate the weight of evidence for whether the data, collected from 1940 to 1994, are sufficient to suggest or establish a secular trend in the timing of puberty markers in US boys or girls. A majority of the panelists agreed that data are sufficient to suggest a trend toward an earlier breast development onset and menarche in girls but not for other female pubertal markers. A minority of panelists concluded that the current data on girls' puberty timing for any marker are insufficient. Almost all panelists concluded, on the basis of few studies and reliability issues of some male puberty markers, that current data for boys are insufficient to evaluate secular trends in male pubertal development. The panel agreed that altered puberty timing should be considered an adverse effect, although the magnitude of change considered adverse was not assessed. The panel recommended (1) additional analyses of existing puberty-timing data to examine secular trends and trends in the temporal sequence of pubertal events; (2) the development of biomarkers for pubertal timing and methods to discriminate fat versus breast tissue, and (3) establishment of cohorts to examine pubertal markers longitudinally within the same individuals.

Age, sex and ethnic differences in the prevalence of underweight and overweight, defined by using the CDC and IOTF cut points in Asian children

“…Second, differences in maturational timing across populations might contribute to the ethnic difference. As there is a trend of decreased maturational age with an increase in BMI, body fat or socioeconomic status (Wyshak and Frisch, 1982;Kaplowitz, 2006;Euling et al, 2008aEuling et al, , 2008b, which advances from Vietnam, Indonesia, China, to the US (World Bank, 2008), Chinese adolescents might reach maturation age earlier compared with the Vietnamese and Indonesians, but latter compared with Americans. An adjustment for maturation age in these populations would lead to an increase in ageand sex-specific mean BMI (Daniels et al, 1997;Wang and Adair, 2001), and thus an increase in the consistency between the CDC and IOTF cut points.…”

Risky, early, controversial. Puberty in medical discourses

“…A century-long trend reduced the age of menarche from 17 to about 12 years: its variations depend on country, social categories, ethnicity or national origin, nutritional factors (Parent et al, 2003;Carelet al, 2002;INSERM, 2007a;Euling et al, 2008). The criteria for defining the five stages of puberty in boys and girls proposed by Tanner in 1969 and1970 remain the standard.…”

Resiliência e apoio social de mães adolescentes em vulnerabilidade social

“…Diversos estudos nacionais e internacionais têm apontado a tendência secular de diminuição da idade da menarca e do surgimento dos sinais de maturação sexual (Biro et al, 2012;Castilho et al, 2012;Euling et al, 2008;Graham et al, 1999;Hwang et al, 2003;Morris, 2011). Essa tendência à antecipação da idade da menarca é apontada por muitos estudiosos como consequência da melhora da nutrição e dos padrões de vida decorrente de melhores padrões socioeconômicos da população (Duarte, 1993;Euling et al, 2008;Graham et al, 1999;Hwang et al, 2003;Morris, 2011).…”

“…Essa tendência à antecipação da idade da menarca é apontada por muitos estudiosos como consequência da melhora da nutrição e dos padrões de vida decorrente de melhores padrões socioeconômicos da população (Duarte, 1993;Euling et al, 2008;Graham et al, 1999;Hwang et al, 2003;Morris, 2011). O evento da menarca depende de uma porcentagem adequada de gordura no corpo, aproximadamente 17% do peso corporal total, para ocorrer e são necessários de 20% a 22% de gordura corporal para manter a menstruação (Vitalle et al, 2003).…”