33 research outputs found
Characterization of Puberty in an Australian Population-Based Cohort Study
Purpose:
Current knowledge of the characteristics of puberty beyond age at menarche and thelarche is limited, particularly within population-based cohorts. Secular trends and concerns of the health effects of early puberty reinforce the value of contemporary studies characterizing the timing, tempo, duration, and synchronicity of puberty.
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Methods:
The Childhood to Adolescence Transition Study is a unique Australian cohort of individuals followed annually from late childhood to late adolescence, with up to eight assessments of pubertal stage from 9 to 19 years of age (N = 1,183; 636 females). At each assessment, females reported their Tanner Stage of breast and pubic hair development, while males reported on genital/pubic hair development. Nonlinear mixed-effects models characterized pubertal trajectories and were used to derive each individual’s estimates of timing, tempo, and synchronicity. Parametric survival models were used to estimate the overall duration of puberty.
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Results:
Timing of mid-puberty (Tanner Stage 3) ranged from 12.5 to 13.5 years, with females developing approximately 6 months before males. Pubertal tempo (at mid-puberty) was similar across sex (between half and one Tanner Stage per year), but the overall duration of puberty was slightly shorter in males. Most females exhibited asynchronous changes of breast and pubic hair development.
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Discussion:
Estimates of pubertal timing and tempo are consistent with reports of cohorts from two or more decades ago, suggesting stabilization of certain pubertal characteristics in predominantly White populations. However, our understanding of the duration of puberty and individual differences in pubertal characteristics (e.g., synchronicity of physical changes) remains limited
Short Report Risk factors for metachronous colorectal cancer following a primary colorectal cancer: A prospective cohort study
Minimal underlying dataset for "Modelling timing and tempo of adrenarche in a prospective cohort study"
Histogram of log detectable values for DHEA-S overlaid with a normal distribution curve.
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Percentage of individuals who changed class after excluding hormone measurements not collected at school setting (n = 149).
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Number (%) of females and males in classes based on hormone levels (L1: Low-level, L2: Mid-level, or L3: High-level compared to population) at age 9 years old and rate of progression during follow-up period (R1: Slow/normal rate, R2: Fast rate compared to population).
Number (%) of females and males in classes based on hormone levels (L1: Low-level, L2: Mid-level, or L3: High-level compared to population) at age 9 years old and rate of progression during follow-up period (R1: Slow/normal rate, R2: Fast rate compared to population).</p
Estimates of standard deviation and correlation parameters in the mixed-effects models for adrenal hormone measured at age 9 years old.
Estimates of standard deviation and correlation parameters in the mixed-effects models for adrenal hormone measured at age 9 years old.</p
Percentage of individuals who changed class after excluding hormone measurements collected after 11am (n = 51).
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