Biosocial correlates of age at menarche in a British cohort

Trends in age at menarche from 1943 through 1989 in Taiwan: A retrospective population-based analysis

BACKGROUND

Recent studies have demonstrated a global decline in the age at menarche. Our study aimed to determine the age at menarche of Taiwanese women born between 1943 and 1989.

METHODS

Data were obtained from the Taiwan Biobank. To view the trends in age at menarche, we analyzed data from 74,799 women. The mean, standard deviation, and annual percentage change in age at menarche were calculated for birth-year cohorts.

RESULTS

The mean age at menarche of Taiwanese women born in 1943 was 14.85 years. The age at menarche decreased to 12.20 years for those born in 1989. The mean age at menarche declined by 2.65 years across the 47-year study period; hence, the reduction rate was 0.56 years per decade. This study demonstrated a downward secular trend in the age at menarche of Taiwanese women born between 1943 and 1989. This trend occurred in three stages of decline: fast (1943-1953), slow (1953-1965), and moderate (1965-1989).

CONCLUSION

The age at menarche decreased by 2.65 years among Taiwanese women born in 1943 compared with those born in 1989. This decline occurred in three stages: fast (1943-1953), slow (1953-1965), and moderate (1965-1989). This significant downward secular trend in age at menarche reflects Taiwan's socioeconomic development.

The rise and fall of SES gradients in heights around the world

We use data from a large sample of low- and middle-income countries to study the association (or "gradient") between child height and maternal education. We show that the gap in height between high- and low-SES children is small at birth, rises throughout childhood, and declines in adolescence as girls and boys go through puberty. This inverted U-shaped pattern is consistent with a degree of catch-up in linear height among children of low- relative to high-SES families, in partial contrast to the argument that height deficits cannot be overcome after the early years of life. This finding appears to be explained by the association between SES and the timing of puberty and therefore of the adolescent growth spurt: low-SES children start their adolescent growth spurt later and stop growing at later ages as well.

Psychosocial and energetic factors on human female pubertal timing: a systematized review

Childhood psychosocial stressors have been proposed to favour fast life history strategies promoting earlier puberty in females. However, studies demonstrating this association often do not elucidate causal mechanisms, nor account for greater childhood energetic availability - also known to promote rapid growth and earlier puberty. To assess the extent to which such confounding has been considered, we conducted a systematized review to identify studies examining measures of both prepubertal growth (e.g. weight, height) and psychosocial stressors (e.g. adversity, father absence) in relation to female pubertal timing. A total of 1069 non-duplicated studies were identified across five databases. Twenty studies met selection criteria for critical review following independent screening of titles, abstracts and manuscripts. Within these studies, measures indicative of rapid childhood growth were more consistently associated with earlier pubertal timing than were measures of psychosocial stress. We discuss future research directions to investigate the impact of psychosocial stress on pubertal timing more robustly, including methodological and mechanistic considerations, and contextualization of findings by socioecological environments.

Family environmental antecedents of pubertal timing in girls and boys: A review and open questions

Across nonhuman species, pubertal timing is affected by the social environment, with consequences for reproductive success and behavior. In human beings, variations in pubertal timing have not been systematically examined in relation to social environmental antecedents, although their psychological consequences are well documented. This paper focuses on links in human beings between pubertal timing and the childhood social environment, with several sections: A review of studies relating pubertal timing to the family context, a key aspect of the social environment; challenges in studying the issue; and opportunities for future work that takes advantage of and creates links with evidence in other species. The review shows that pubertal timing in girls is accelerated by adversity in aspects of the early family social context, with effects small in size; data in boys are not sufficient to enable conclusions. Inferences from existing studies are limited by variations in conceptualizations and measurement of relevant aspects of puberty and of the family social environment, and by methodological issues (e.g., reliance on existing data, use of retrospective reports, nonrandom missing data). Open questions remain about the nature, mechanisms, and specificity of the links between early family social environment and pubertal timing (e.g., form of associations, consideration of absence of positive experiences, role of timing of exposure). Animal studies provide a useful guide for addressing these questions, by delineating potential hormonal mechanisms that underlie links among social context, pubertal timing, and behavior, and encouraging attention to aspects of the social environment outside the family, especially peers.

Growth and socio-economic status, influence on the age at menarche in school going girls

INTRODUCTION

Onset age at menarche has been considered an important indicator of reproductive maturity in females and reflects the health status of the population. The purpose of this study was to determine the mean menarcheal age and to examine whether anthropometric and socio-economic status (SES) influences age at menarche in the girls from Punjab province of Pakistan.

METHODS

In this population-based cross-sectional study, 10,050 school-going girls aged 8-16 years from 35 schools across 12 districts of Punjab were recruited. Menarcheal data was obtained by using a questionnaire, while the anthropometric data were obtained by the measurements of standing height, body weight, waist, and hip circumference. The anthropometric indices of pre- and post-menarcheal girls were compared. Student's t-test, ANOVA, and post-hoc Tukey's test was applied for comparison between two and multiple groups respectively, P < 0.05 was considered statistically significant.

RESULTS

There was a normal distribution of age at menarche and mean was 12.4 years in the study population. The girls who reached menarche were found to be taller and heavier with higher BMIs, having a greater waist and hip circumference as compared to their pre-menarcheal peers. Waist-hip-ratio was less, and the waist-to-height ratio was higher in post-menarcheal as compared to pre-menarcheal girls. The girls belonging to low SES had delayed onset of menarche as compared to those belonging to middle/high SES.

CONCLUSION

The age at menarche was associated with SES and changes in various anthropometric measurements reflecting the growth status of girls.

How can two biological variables have opposing secular trends, yet be positively related? A demonstration using timing of puberty and adult height

Timing of puberty and adult height have opposing secular trends yet are positively associated in individuals. We demonstrate this using data from a single sample and discuss possible statistical and epidemiological reasons behind it. The sample comprised 365 females from Fels Longitudinal Study born 1929-1992. We used Super-Imposition by Translation and Rotation (SITAR) to estimate individual age at peak height velocity (PHV) and PHV from serial height data (8149 observations between 5 and 24 years). General linear regression was used to investigate the association between height and age at PHV, and secular trends in height, age at PHV and PHV. Although adult height increased 0.42 (95% CI: 0.08, 0.77) cm per decade, and age at PHV decreased 1.14 (-3.74, 1.45) weeks per decade, adult height increased by 2.44 (1.78, 3.10) cm per year higher age at PHV. We found tentative evidence of the positive association between age at PHV and adult height strengthened 0.25 (-0.09, 0.59) cm each decade. Secular trends in related variables may differ if the between-individual and between-cohort associations are different. To understand if a secular trend in one variable has contributed to a trend in another, each needs to be modelled over time, together with the changing association between them.

A Systematic Literature Review of Factors Affecting the Timing of Menarche: The Potential for Climate Change to Impact Women's Health

Menarche is the first occurrence of a woman’s menstruation, an event that symbolizes reproductive capacity and the transition from childhood into womanhood. The global average age for menarche is 12 years and this has been declining in recent years. Many factors that affect the timing menarche in girls could be affected by climate change. A systematic literature review was performed regarding the timing of menarche and four publication databases were interrogated: EMBASE, SCOPUS, PubMed, and Cochrane Reviews. Themes were identified from 112 articles and related to environmental causes of perturbations in menarche (either early or late), disease causes and consequences of perturbations, and social causes and consequences. Research from climatology was incorporated to describe how climate change events, including increased hurricanes, avalanches/mudslides/landslides, and extreme weather events could alter the age of menarche by disrupting food availability or via increased toxin/pollutant release. Overall, our review revealed that these perturbations in the timing of menarche are likely to increase the disease burden for women in four key areas: mental health, fertility-related conditions, cardiovascular disease, and bone health. In summary, the climate does have the potential to impact women’s health through perturbation in the timing of menarche and this, in turn, will affect women’s risk of disease in future.

Father’s social and economic position has strongest impact on age at menarche in girls from Central India

We assessed the impact of socio-economic factors on age at menarche among the adolescent female population from the state of Madhya Pradesh, Central India. Records such as date of birth, chronological age, caste affiliation, size of place of residence, parents’ level of education and occupation, number of siblings, body height and weight, and age at menarche were collected for 330 students of A Central University, Sagar. The impact of socio-economic factors on age at menarche was analysed using analysis of variance. To establish the probability of menarche occurrence at a given age, time-to-event analysis was carried out using Kaplan-Meier curves and the log-rank test for curve comparison. The association between probability of attaining menarche and the independent variables was investigated using Cox proportional-hazard model. ANOVA and the Kaplan-Meier curves showed statistically significant differences in age at menarche according to size of the place of residence, number of siblings, parental level of education, father’s occupation and females’ BMI. The Cox proportional hazard model revealed that father’s occupation was the strongest factor affecting age at menarche among all SES characteristics under study. Irrespective of rapid economic progress over the past few decades, Indian society is still patriarchal with societal male dominance. This translates into participation of fewer women in the paid workforce and labour market, their lower wage rates and smaller contribution to the household budget compared to their male counterparts.