Characteristics of Menarcheal Age, Menstrual Hygiene and Socio-Demographic Factors in Girls with Down Syndrome in Morocco

The purpose of this study was to determine the characteristics of menarcheal age, menstrual hygiene and their associated socio-demographic factors in girls with Down syndrome (DS) in Morocco. An analytical cross-sectional study was conducted between May 2014 and November 2017, including 59 parents/guardians of girls with Down syndrome aged 9-32 years. Data were collected through a standardized questionnaire providing information about socio-demographic and cultural conditions of parents, nutritional status and some functional abilities of girls. The median age at menarche was estimated using retrospective and status-quo methods, respectively. Data were entered and analyzed using the statistical program SPSS statistics software for Windows (version 20.0). Chi-square (χ2) and Mann-Whitney tests were used for testing statistical significance. The age at menarche ranged from 9 to 16 years old. The median was 13.0 (IQR, 11.0-14.0) years. The median age of menarche by probit analysis was 12.55 years. The relationship between menarcheal age, menstrual hygiene and the selected parameters showed a significant difference in age at menarche only regarding the parameter of number of siblings (Z = 2.14; p = .03), and in menstrual hygiene regarding mother's level of education, family size and age of talking (χ2 = 5.04, p = .02; χ2 = 3.75, p = .05 and χ2 = 4.99, p = .02, respectively). Most girls with DS attain menarche at the usual age as their counterparts in the general population and do not have enough knowledge about menstruation. Mobilization of all interventionists is urgent to develop adolescent skills about practices related to menstruation and menstrual hygiene.

Age at menarche, age at natural menopause, and risk of rheumatoid arthritis - a Mendelian randomization study

BACKGROUND

Hormonal reproductive factors have been suggested to play an important role in the etiology of rheumatoid arthritis (RA), an autoimmune inflammatory disorder affecting primarily women. We conducted a two-sample Mendelian randomization (MR) study examining three relevant exposures, age at menarche (AAM), age at natural menopause (ANM), and age at first birth (AFB) with the risk of RA.

METHODS

We collected summary statistics from the hitherto largest GWAS conducted in AAM (N = 329,345), ANM (N = 69,360), AFB (N = 251,151), and RA (N_case = 14,361, N_control = 43,923), all of European ancestry. We constructed strong instruments using hundreds of exposure-associated genetic variants and estimated causal relationship through different MR approaches including an inverse-variance weighted method, an MR-Egger regression and a weighted median method. We conducted a multivariable MR to control for pleiotropic effect acting in particular through obesity and socioeconomic status. We also performed important sensitivity analyses to verify model assumptions.

RESULTS

We did not find any evidence in support for a causal association between genetically predicted reproductive factors and risk of RA (OR_{per-SD increment in AAM} = 1.06 [0.98-1.15]; OR_{per-SD increment in ANM} = 1.05 [0.98-1.11], OR _{per-SD increment in AFB} = 0.85 [0.65-1.10]). Results remained consistent after removing palindromic SNPs (OR_{per-SD increment in AAM} = 1.06 [0.97-1.15], OR_{per-SD increment in ANM} = 1.05 [0.98-1.13], OR_{per-SD increment in AFB} = 0.81 [0.61-1.07]) or excluding SNPs associated with potential confounding traits (OR_{per-SD increment in AAM} = 1.03 [0.94-1.12], OR_{per-SD increment in ANM} = 1.04 [0.95-1.14]). No outlying instrument was identified through the leave-one-out analysis.

CONCLUSIONS

Our MR study does not convincingly support a casual effect of reproductive factors, as reflected by age at menarche, age at menopause, and age at first birth, on the development of RA. Despite the largely augmented set of instruments we used, these instruments only explained a modest proportion of phenotypic variance of exposures. Our knowledge regarding this topic is still insufficient and future studies with larger sample size should be designed to replicate or dispute our findings.

Age at menarche and risk of vasomotor menopausal symptoms: a pooled analysis of six studies

OBJECTIVE

To examine the association between age at menarche and risk of vasomotor menopausal symptoms (VMS) and whether midlife body mass index (BMI) modified the association.

DESIGN

A pooled analysis of six cohort studies.

SETTING

The International collaboration on the Life course Approach to reproductive health and Chronic disease Events (InterLACE).

POPULATION

18 555 women from the UK, USA and Australia.

METHODS

VMS frequency data (never, rarely, sometimes and often) were harmonised from two studies (n = 13 602); severity data (never, mild, moderate and severe) from the other four studies (n = 4953). Multinominal logistic regression models were used to estimate relative risk ratios (RRRs) and 95% CIs adjusted for confounders and incorporated study as random effects.

MAIN OUTCOME MEASURES

Hot flushes and night sweats.

RESULTS

Frequency data showed that early menarche ≤11 years was associated with an increased risk of 'often' hot flushes (RRR 1.48, 95% CI 1.24-1.76) and night sweats (RRR 1.59, 95% CI 1.49-1.70) compared with menarche at ≥14 years. Severity data showed similar results, but appeared less conclusive, with RRRs of 1.16 (95% CI 0.94-1.42) and 1.27 (95% CI 1.01-1.58) for 'severe' hot flushes and night sweats, respectively. BMI significantly modified the association as the risk associated with early menarche and 'often' VMS was stronger among women who were overweight or obese than those of normal weight, while this gradient across BMI categories was not as strong with the risk of 'severe' VMS.

CONCLUSIONS

Early age at menarche is a risk factor for VMS, particularly for frequent VMS, but midlife BMI may play an important role in modifying this risk.

TWEETABLE ABSTRACT

Overweight and obesity exacerbate the risk of vasomotor symptoms associated with early menarche.

The Influence of Age at Menarche on the Menstrual Pattern of Polish University Students

PURPOSE

The aim of the study was to examine the relationships between age at menarche and menstrual cycle characteristics in young female subjects.

METHODS

Anthropometric measurements were performed, and questionnaire data were collected from 1,323 women, aged 19-25 years.

RESULTS

No differences were found in terms of cycle duration or the number of days of bleeding between women with early, average, or late menarche. Each of those groups had a similar percentage of women who declared that their cycles last longer than 35 days, those who declared that their cycles are shorter than 21 days, and those who reported prolonged bleeding. Irregular cycles were associated with late age at menarche. Women with early age at menarche complained about menstrual cramps more frequently. The existence of a relationship between age at menarche and menstrual cycle disorders was confirmed by the results of logistic regression.

CONCLUSIONS

Both early and late age at menarche are associated with increased risk of menstrual cycle disorders.

Knowledge of peri-menarcheal changes and a comparative analysis of the age at menarche among young adolescent school girls in urban and rural Cameroon

Background

Menarche is an expected event that occurs during the development of every normal young girl. We designed this study to evaluate the knowledge of young school girls on puberty, menarche, and menstruation, and to update data on the age at menarche in a rural and urban setting in Cameroon.

Methods

We conducted a cross-sectional survey from February to March 2017, targeting female students aged 9 to 16 years in Yaoundé (urban) and Bamougoum (rural). Participants were included using a randomised cluster sampling and data collected using an auto-administrable questionnaire. Student t-test or the Kruskal-Wallis test was used to compare means, and the odds ratio used as the measure of association between age at menarche and selected covariates.

Results

1157 participants were included in the study; 49.3% from an urban setting and 50.7% from a rural setting. Regarding the knowledge of our participants on puberty, menarche, and menstruation, 67.20% of rural participants had good knowledge, whereas only 46.00% had good knowledge in the urban setting. Mean age at menarche was 12.76 ± 1.33 years, with the mean age at menarche in the urban setting of 12.48 ± 1.12 years and the rural setting of 13.03 ± 1.46 years. Mean age at menarche was significantly lower in participants aged below 14 years (p-value = 0.000), those with both parents alive (p-value = 0.0461), those whose fathers had skilled occupations (p-value = 0.005), those of urban resident (p-value = 0.000), and those who watched TV everyday (p-value = 0.030). Urban residence and age below 14 years were significantly associated with an earlier onset of menarche.

Conclusion

Rural participants had better knowledge of puberty, menarche, and the menstrual cycle than their counterparts in the urban setting. The mean age at menarche over the last two decades has dropped by 7.4 and 4.2 months per decade in urban and rural Cameroon respectively. Mean age at menarche varies significantly with age group, urban/rural residence, state of both parents (both alive/at least one dead), occupation of the father, and frequency of watching TV. Age and urban/rural residence are associated with age at onset of menarche. The continually declining age at menarche is an alarm for future early menarche-linked morbidities.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-020-09787-y.

Age at menarche in Nigerian demographic surveys

Age at menarche was investigated using data collected from demographic surveys (WFS, DHS) conducted in Nigeria between 1982 and 2018, all of which were based on large representative samples of the female population. Linear-logistic regressions were used to estimate mean age at menarche, its trends and its risk factors. Mean age at menarche had underwent a marked secular decline from 15.02 years for girls born in 1933 to 13.78 years for girls born in 2003. In multivariate analysis, height (stature), body mass index (BMI), level of education and household wealth had independent effects on age at menarche, whereas urban residence had no effect. Socioeconomic gradients were large: +9 years of schooling was associated with a -0.52 year decrease in age at menarche, and +2 standard deviations in household wealth with a -0.33 year decrease. The impact of anthropometry was even greater: +2 standard deviations in height was associated with a -0.99 year decrease in age at menarche, and +2 standard deviations in BMI with a -1.42 year decrease. Northern provinces had a higher mean age at menarche than southern provinces. Compared with independent sources, long-term trends in age at menarche, as well as their fluctuations, appeared to be correlated with trends and fluctuations in income per capita and in under-five mortality, but not with divergent trends in adult height.

Effect of age at menarche on the mother's weight status two and four years after delivery: a cohort study

We aimed to estimate the effect of age at menarche on the risk of excess body weight in Brazilian women two and four years after delivery. This was a cohort study that used data from adult women of the Predictors of Maternal and Child Excess Body Weight (PREDI) Study obtained at baseline (2012) and at 1^st(2014) and 2^nd(2016) follow-up. A total of 435 women attending a public maternity hospital in Joinville-Brazil were initially included in the study (baseline) and 215 of them continued to participate in the 2^nd follow-up carried out in the homes of the participants. Regression analysis was used to estimate the association between age at menarche (<12; ≥12 years) and excess body weight (≥25 kg/m²) trajectory during the follow-ups. Unadjusted analysis showed that mothers with age at menarche <12 years were 1.29 times (p = .018) more likely to be overweight/obese than those with age at menarche ≥12 years. After adjustment, age at menarche continued to exert an independent effect on the mother's body mass index (RR = 1.23; p = .037) four years after delivery. Strategies designed to attenuate the rising prevalence of maternal overweight and obesity, especially after pregnancy, could help improve the mother's health status in the future.

Association of exposure to secondhand smoke at home with early age at menarche in South Korea

OBJECTIVES

The secular trend in age at menarche (AAM) has declined both worldwide and in Korea. Early AAM is associated with the risk of several diseases, reproductive capacity, and psychological problems. We aimed to investigate the relationship between secondhand smoke (SHS) exposure at home and early puberty onset using AAM in Korean adolescents.

STUDY DESIGN

This is a retrospective cross-sectional study.

METHODS

This study used data from the Korea Youth Risk Behavior Web-based Survey 2014-2015. We used the mean AAM (12.2 years) as a determinant of early AAM. After the exclusion of girls without menarche or who did not respond, the total population comprised 63,618 participants. We categorized AAM as 'early' and 'average or late.' Adolescents with SHS exposure were assigned to the 'never exposed,' 'light exposure,' and 'heavy exposure' groups. Multiple logistic regression analyses were performed.

RESULTS

We observed a positive association, approximately 1.12 times, between early AAM and high SHS exposure (odds ratio [OR], 1.12; 95% confidence interval [CI], 1.05-1.19). Girls who started smoking before the age of 12 years (OR, 1.68; 95% CI, 1.41-1.99) showed a stronger association with early AAM than non-smokers. Active smoking showed a stronger association with early AAM. Never smokers with high SHS exposure at home were 1.13 times likelier to have an early AAM (OR, 1.13; 95% CI, 1.05-1.22) than those without SHS exposure.

CONCLUSIONS

In addition to active smoking, SHS may also be a risk factor for early AAM. Education aimed at active and secondhand smoking prevention is needed to protect children against early AAM.

Gut microbiome associations with breast cancer risk factors and tumor characteristics: a pilot study

OBJECTIVE

To investigate the association between gut microbiome with breast tumor characteristics (receptor status, stage and grade) and known breast cancer risk factors.

METHODS

In a pilot cross-sectional study of 37 incident breast cancer patients, fecal samples collected prior to chemotherapy were analyzed by 16S ribosomal RNA (rRNA) gene-based sequencing protocol. Alpha diversity and specific taxa by tumor characteristics and breast cancer risk factors were tested by Wilcoxon rank sum test, and by differential abundance analysis, using a zero-inflated negative binomial regression model with adjustment for total counts, age and race/ethnicity.

RESULTS

There were no significant alpha diversity or phyla differences by estrogen/progesterone receptor status, tumor grade, stage, parity and body mass index. However, women with human epidermal growth factor receptor 2 positive (HER2+) (n = 12) compared to HER2- (n = 25) breast cancer showed 12-23% lower alpha diversity [number of species (OTU) p = 0.033, Shannon index p = 0.034], lower abundance of Firmicutes (p = 0.005) and higher abundance of Bacteroidetes (p = 0.089). Early menarche (ages ≤ 11) (n = 11) compared with later menarche (ages ≥ 12) (n = 26) was associated with lower OTU (p = 0.036), Chao1 index (p = 0.020) and lower abundance of Firmicutes (p = 0.048). High total body fat (TBF) (> 46%) (n = 12) compared to lower (≤ 46%) TBF was also associated with lower Chao 1 index (p = 0.011). There were other significant taxa abundance differences by HER2 status, menarche age, as well as other tumor and breast cancer risk factors.

CONCLUSIONS AND RELEVANCE

Further studies are needed to identify characteristics of the human microbiome and the interrelationships between breast cancer hormone receptor status and established breast cancer risk factors.

Early age at menarche and risk of postpartum hemorrhage: a retrospective study in Chinese women

Objective: The objective of this study is to investigate whether early age at menarche is associated with increased risk of postpartum hemorrhage among Chinese women.Materials and methods: Clinical data from 6,383 Chinese women who gave birth to live singleton infants at The First Affiliated Hospital of Chengdu Medical College between October 2016 and October 2019 were extracted from the electronic medical records system. Patients were categorized into four groups according to their age at menarche (≤12, 13, 14 and ≥15 years). Logistic regression analysis was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for postpartum hemorrhage for the different menarche age groups.Results: After controlling for potential confounders, women with menarche at an early age (≤12 years) had a significantly higher risk of developing postpartum hemorrhage than women with an age at menarche of 13 years, and the ORs (95% CIs) for postpartum hemorrhage across the menarche age categories (≤12, 13, 14 and ≥15 years) were 1.27 (1.02-1.81), 1.00 (reference), 0.95 (0.61-1.57), and 0.91 (0.51-1.58), respectively. Moreover, age at menarche was inversely associated with the risk of postpartum hemorrhage after adjustment for all relevant confounding factors, and the OR (95% CI) for postpartum hemorrhage per year of increasing in the age at menarche was 0.93 (0.74-0.99).Conclusion: Early age at menarche was associated with a significantly increased risk of postpartum hemorrhage after adjustment for known confounding factors. This finding could help obstetricians and midwives to identify pregnant women at higher risk of developing postpartum hemorrhage, and allow early preventative strategies to be implemented.

Racial/Ethnic Differences in Age at Menarche and Lifetime Nonmedical Marijuana Use: Results from the NHANES 2005-2016

Early age at menarche has been linked to many adverse health outcomes among women, including substance use. However, little is known on the association between age at menarche and nonmedical use of marijuana, and no study has assessed the potential racial/ethnic differences. In this study, the 2005-2016 National Health and Nutrition Examination Survey data were used to investigate the association between age at menarche and the risk of lifetime nonmedical use of marijuana. Logistic regression models were used to examine such association adjusting for sociodemographic factors. Interactions between age at menarche and race/ethnicity were also assessed. Among the 10,302 women included, 53.9% had lifetime nonmedical use of marijuana. The regression model shows that women with early menarche had 1.26 (95% CI 1.09, 1.45) times the odds of having lifetime nonmedical use of marijuana compared with women with normal age at menarche. When assessing the association by race/ethnicity, marginally positive associations were observed for both the early and late menarche groups among non-Hispanic White women. However, among women with race/ethnicity other than non-Hispanic White, early menarche is significantly associated with increased risks of lifetime nonmedical marijuana use, while late menarche is significantly associated with decreased risks. This study suggests that early menarche may be a risk factor of lifetime nonmedical use of marijuana, and racial/ethnic differences may exist in the association. Future studies are warranted to examine and confirm these findings.

Urban-Rural Differences in Bone Mineral Density and its Association with Reproductive and Menstrual Factors Among Older Women

PURPOSE

This study aimed to compare the bone mineral density (BMD) of older women living in rural and urban areas, and evaluate the potential factors affecting the risk of osteoporosis.

METHODS

We recruited 574 women aged 65 years or older from rural areas and 496 from urban areas in Shanghai, China. The BMD values of the lumbar vertebrae and total left hip were measured by a dual energy X-ray absorptiometry densitometer. We also recorded information about education level, family income, medications, reproductive and menstrual history, diet, smoking, and alcohol consumption.

RESULTS

Women in urban areas had significantly higher BMD in their lumbar spine, and there was a dramatic increase in the proportion of women with osteoporosis in rural areas. The age at menarche was significantly higher among women living in rural areas, and there were more years from menarche to menopause among urban women. Rural women had significantly higher numbers of both pregnancies and parity, and a significantly lower age at first parity. In multiple linear regression analyses, years from menarche to menopause was independently related to high lumbar spine BMD, while age at menarche and parity was independently related to low lumbar spine BMD.

CONCLUSION

More older women in rural areas had osteoporosis. Later menarche, less years from menarche to menopause and higher parity might partially contribute to decreased BMD among women in rural areas. More attention should be paid to women in rural areas to prevent bone loss and further bone and health impairment.

The levelling-off of the secular trend of age at menarche among Italian girls

OBJECTIVE

The main aim of this study was to verify whether the secular trend stopped in Italy by comparing the results of a 1990-2000 birth cohort versus a 1980-1990 birth cohort of Italian young women. The results were used to speculate about age at menarche as adaptive response to non-genetic factors.

METHODS

In 2016, a study was set on 413, 18-to-26 year-old women (1990-2000 birth cohort) attending two Italian Universities by web-based, self-reported questionnaires. Previously in 2000, a research including 3,783 high school female students (1980-1990 birth cohort) was led. The age at menarche distribution was performed by Kaplan-Meier analysis. The comparison between the findings of the two birth cohorts was performed by Wilcoxon sum-rank test. Mixed models analysis was applied to evaluate the effect of cohort and socio-economic status on age at menarche.

RESULTS

1990-2000 cohort's age at menarche median was 12.44y (95%CI 12.37; 12.59y). There was no significant difference with age at menarche of the previous cohort (p = 0.56). Consistently, the advance of age at menarche in comparison to the mothers' one was not significantly different between the two cohorts (-0.27y±0.10y vs -0.25y±0.03y, p = 0.33). The socio-economic level was not significantly associated with menarcheal age.

CONCLUSIONS

The findings of this study confirm that, like in other developed countries, the advance of age at menarche has stopped in Italy, consistently with the stop of the improvement of socio-economic conditions. Further studies are needed to explore the differential effect of each non-genetic factor to outline future scenarios of human sexual maturation.

TRIAL REGISTRATION

the Comitato Etico per la Sperimentazione Clinica (CESC) della Provincia di Padova of the Veneto Region (Italy), n°3993/U16/16.

Early menarche is associated with insulin resistance in advanced maternal age before delivery

Purpose: With the wide implementation of the universal two-child policy in China, the number of pregnant women in advanced maternal age (AMA) will increase gradually. We aimed to assess the association between age at menarche (AAM) and insulin resistance (IR) before delivery in AMA. Methods: A total of 80 pregnant women in AMA were consecutively enrolled before delivery in Zhongda hospital. Pregnant women were stratified into early menarche group and late menarche group according to the age of regular menstruation (about 13 years). At delivery, serum glucose and lipid levels were measured. IR was calculated by the method of homeostasis model assessment 2(HOMA2). Results: The fasting blood insulin (17.68(9.72-36.71) and 10.35(7.76-15.10), respectively; p = .006) and HOMA-IR (2.08(1.18-4.37) and 1.24(0.89-1.78), respectively; p = .005) were higher in early menarche group than in late menarche group. AAM was inversely associated with HOMA-IR in AMA (r= -0.27, p = .014). In the multivariable analysis, AAM in late menarche group was negatively related to the level of HOMA-IR compared to those in early menarche group (β= -2.275, p≤.0001). Conclusions: Taken together, our findings suggest that AAM was inversely associated with HOMA-IR in AMA. Furthermore, pregnant women in AMA with early menarche might have higher HOMA-IR levels than those with late menarche. Clinical trial registration: Chinese Clinical Trial Registry (No. ChiCTR-RRC-16008714), retrospectively registered.

Early age at menarche and its associated factors in school girls (age, 10 to 12 years) in Bangladesh: a cross-section survey in Rajshahi District, Bangladesh

Background

Early onset of menarche is one of the most important factors for breast cancer and other associated health hazards. The aim of this study was to investigate the early age at menarche and its associated factors in school girls (age, 10–12 years) in Rajshahi District, Bangladesh.

Methods

Data was collected from Rajshahi District, Bangladesh, using multistage random sampling. Independent sample t test and binary logistic regression model were used in this study. A total number of 386 school girls aged 10–12 years were considered as a sample for this study.

Results

This study revealed that more than 48% girls already attained menarche within the age of 12 years, among them 25.6%, 41.0%, and 58.3% girls experienced menarche at the age of 10, 11, and 12 years, respectively. It was observed that the menarcheal girls were significantly taller (p < 0.01) and heavier (p < 0.01) than non-menarcheal girls. The menarcheal girls’ mothers were heavier (p < 0.01), shorter (p < 0.01), had more BMI (p < 0.01), reached menarche (p < 0.05) earlier than non-menarcheal girls’ mothers. Menarcheal girls had less number of siblings (p < 0.01) and lower order of birth (p < 0.05) than non-menarcheal girls. After controlling the effect of other factors, multiple logistic regression model demonstrated that obese girls were more likely to attain menarche than under- [AOR = 0.279, CI 95% 0.075–0.986; p < 0.05] and normal [AOR = 0.248, CI 95% 0.082–0.755; p < 0.05] weight girls. Urban school girls had more chance to get menarche than rural school girls at same age (AOR = 0.012, 95% CI 0.003–0.047; p < 0.01).

Conclusions

Therefore, modern lifestyle changes may have the important factors for early age at menarche of the studied girls in Bangladesh.

Trends in age at menarche and adult height in selected African countries (1950-1980)

Background: The mean age at menarche remains poorly documented in Africa.Aim: To document levels, trends, and determinants of mean age at menarche in selected African populations.Subjects and methods: The World Fertility Surveys recorded the age at menarche in 12 African countries. These surveys were conducted from 1977 to 1983 and were based on large representative samples of national populations. Demographic and Health Surveys provided trends in adult height for the same cohorts.Results: The mean age at menarche was higher in sub-Saharan Africa (14.5 years) than in North-Africa (13.5 years). Age at menarche was declining significantly in all sub-Saharan African countries, but only in one North-African country. The speed of decline in sub-Saharan Africa averaged 0.47 years for a 30-year period, comparable to the speed of decline in Europe. Sub-Saharan African countries with higher increase in female adult height also had larger declines in mean age at menarche. In multivariate analysis, trends in age at menarche were correlated with trends in adult height and child survival.Conclusion: In sub-Saharan Africa, age at menarche was undergoing a transition similar to that of European countries in the nineteenth century and was associated with improving health of young women. North-African countries were more advanced.

Family composition and age at menarche: Findings from the international Health Behaviour in School-aged Children study

Background

Early menarche has been associated with father absence, stepfather presence and adverse health consequences in later life. This article assesses the association of different family compositions with the age at menarche. Pathways are explored which may explain any association between family characteristics and pubertal timing.

Methods

Cross-sectional, international data on the age at menarche, family structure and covariates (age, psychosomatic complaints, media consumption, physical activity) were collected from the 2009–2010 Health Behaviour in School-aged Children (HBSC) survey. The sample focuses on 15-year old girls comprising 36,175 individuals across 40 countries in Europe and North America (N = 21,075 for age at menarche). The study examined the association of different family characteristics with age at menarche. Regression and path analyses were applied incorporating multilevel techniques to adjust for the nested nature of data within countries.

Results

Living with mother (Cohen’s d = .12), father (d = .08), brothers (d = .04) and sisters (d = .06) are independently associated with later age at menarche. Living in a foster home (d = −.16), with ‘someone else’ (d = −.11), stepmother (d = −.10) or stepfather (d = −.06) was associated with earlier menarche. Path models show that up to 89% of these effects can be explained through lifestyle and psychological variables.

Conclusions

Earlier menarche is reported amongst those with living conditions other than a family consisting of two biological parents. This can partly be explained by girls’ higher Body Mass Index in these families which is a biological determinant of early menarche. Lower physical activity and elevated psychosomatic complaints were also more often found in girls in these family environments.

Maternal pre-pregnancy body mass index, smoking in pregnancy, and alcohol intake in pregnancy in relation to pubertal timing in the children

Background

Earlier pubertal timing has been observed in many countries. We aimed to explore if prenatal exposure to maternal obesity, smoking, and alcohol intake was associated with timing of puberty by use of a novel marker of pubertal timing: ‘the height difference in standard deviations’ (HD:SDS).

Methods

HD:SDS is the difference between pubertal height in standard deviations and adult height in standard deviations, and it correlates well with age at peak height velocity. Pubertal height was measured by health care professionals at approximately 13 years in boys and 11 years in girls, and the children’s adult height was predicted from parental height reported by the mothers during pregnancy. Information on HD:SDS was available for 42,849 of 56,641 eligible boys and girls from the Danish National Birth Cohort born 2000–2003. In a subsample, HD:SDS was validated against age at the following self-reported pubertal milestones: Tanner stages, menarche, first ejaculation, voice break, acne, and axillary hair. Prenatal exposures were reported by mothers during pregnancy.

Results

HD:SDS correlated moderately with the pubertal milestones considered (correlation coefficients: − 0.20 to − 0.53). With normal weight (body mass index (BMI): 18.5–24.9 kg/m²) as the reference, maternal pre-pregnancy obesity (BMI: 30.0+ kg/m²) was associated with earlier pubertal timing: 0.23 (95% confidence interval (CI): 0.18, 0.28) higher HD:SDS in boys and 0.19 (95% CI, 0.14, 0.24) higher HD:SDS in girls. Maternal smoking was not associated with pubertal timing. Compared to alcohol abstainers, maternal intake of > 3 units of alcohol weekly was associated with later puberty in boys only: 0.14 (95% CI, 0.05, 0.24) lower HD:SDS.

Conclusion

As correlations between HD:SDS and the considered pubertal milestones were comparable to those reported in the literature between age a peak height velocity and the considered pubertal milestones, the validity of HD:SDS seems acceptable. Maternal pre-pregnancy obesity was associated with earlier pubertal timing in both sexes, and maternal alcohol intake during pregnancy was associated with later pubertal timing in boys. Maternal smoking has been linked to earlier timing of puberty, but this was not replicated in our setting using HD:SDS as a marker of pubertal timing.

Heritability of Age at Menarche in South Korean Female Twins

Genetic and environmental influences on age at menarche (AAM) have rarely been examined in Asian females. This study aimed to investigate the heritability of AAM in South Korean female twins. The AAM data from 1370 female twins (933 monozygotic [MZ] twins, 294 dizygotic [DZ] twins and 160 female members of opposite-sex DZ twins) born between 1988 and 2001 were analyzed. The age of the sample at the time of the assessment ranged from 16 to 28 years with a mean of 19.3 (SD = 2.2) years. The mean AAM in the total sample was 12.49 (SD = 1.41) years. Although the mean AAM decreased with increasing birth years, it levelled off in birth years 2000-2001. Maximum likelihood MZ and DZ twin correlations were 0.72 [95% CI (0.67, 0.76)] and 0.35 [95% CI (0.19, 0.50)], respectively. The results of model-fitting analysis indicated that the additive genetic and individual-specific environmental effects were 72% [95% CI (67%, 76%)] and 28% [95% CI (24%, 33%)], respectively. Neither nonadditive genetic nor shared environmental effects were significant.

Systematic review and meta-analysis of the association between childhood physical activity and age at menarche

AIM

To systematically appraise and summarise published evidence on the association between childhood physical activity (PA) and subsequent age at menarche (AAM).

METHODS

We searched PubMed (1990-2018) for studies that reported the relationship between childhood PA and AAM. We performed tabular synthesis of population-based studies and a random-effects meta-analysis of results of athlete/nonathlete studies.

RESULTS

One randomised controlled trial was identified, in which an intervention to prevent obesity reduced the likelihood of menarche during the two-year study period (relative risk: 0.75, 95% CI: 0.66-0.87; n = 422 girls). One of five prospective cohort studies (total n = 4492) reported a significant association between self-reported PA duration and subsequent menarche timing. Four of five historical cohort studies (total n = 89 470) reported significant associations between recalled premenarcheal PA and later AAM. Meta-analysis across 12 athlete/nonathlete studies showed that menarche occurred 1.13 years later (95% CI: 0.80-1.47) in athletes compared to nonathletes.

CONCLUSION

These findings suggest that AAM is a behaviourally modifiable trait. However, the quality of reported population-based study evidence is low and estimation of the true relationship between childhood PA and AAM is likely confounded by concomitant changes in diet and lifestyle behaviours.

Reproductive history and breast cancer survival: a prospective patient cohort study in Japan

BACKGROUND

Reproductive factors may influence breast cancer progression and patient survival; however, evidence has been limited.

METHODS

The associations of reproductive factors with tumor characteristics and patient survival were analyzed among 1468 breast cancer patients diagnosed during 1997-2013 at a single institute in Japan. The patients were followed until 2016. During a median follow-up period of 8.6 years, 272 all-cause and 199 breast cancer deaths were documented.

RESULTS

In case-case comparisons, later age at menarche was inversely associated with advanced tumors. Nulliparous patients tended to have receptor-positive [estrogen receptor (ER)+ or progesterone receptor (PR)+] tumors. Conversely, the Cox proportional-hazards model including adjustment for tumor characteristics revealed U-shaped relationship between parity number and the risk of all-cause death among the patients overall [hazard ratio (HR) = 2.10 for nulliparous, 1.28 for 2, and 1.50 for ≥ 3 vs. one child]. According to hormone receptor, later age at menarche and later age at last birth were positively associated with the risk of all-cause death among patients with ER- and PR- cancer (menarche, HR = 2.18 for ≥ 15 vs. ≤ 12 years, p_trend = 0.03; last birth, HR = 3.10 for ≥ 35 vs. ≤ 29 years, p_trend = 0.01). A shorter time since last birth was associated with the risk of death among receptor-positive patients (HR = 5.72 for ≤ 4 vs. ≥ 10 years, p_trend = 0.004).

CONCLUSION

The results indicate that the timing of menarche and parity have significant effects on patient survival, providing clues for understanding the association between women's life course and breast cancer outcome.

Early lead exposure and pubertal development in a Mexico City population

BACKGROUND

Previous studies have examined the association between blood lead levels and pubertal timing in adolescent girls; however, the evidence is lacking on the role of lead exposure during sensitive developmental periods on sexual maturation.

OBJECTIVES

To examine the association of prenatal and early childhood lead exposure with pubertal stages among 264 boys and 283 girls aged 9.8-18.0 years in Mexico City.

METHODS

We measured maternal bone lead (a proxy for cumulative fetal exposure to lead from maternal bone stores mobilized during pregnancy) at 1 month postpartum. Blood lead was measured annually from 1 to 4 years. Pubertal stage was assessed by a pediatrician. We examined the association between lead and pubertal stages of breast, pubic hair and genitalia using ordinal regression. Age at menarche was evaluated using Cox proportional-hazard models.

RESULTS

Multivariate models showed that maternal patella lead and early childhood blood lead were inversely associated with breast growth (patella OR = 0.72, 95% CI: 0.51-1.00; blood OR = 0.70, 95% CI: 0.53-0.93) in girls. Girls with maternal patella lead in the 3rd tertile and child blood lead in the 2nd tertile had a later age at menarche compared with girls in the 1st tertile (patella HR = 0.60, 95% CI: 0.41-0.88; blood HR = 0.65, 95% CI 0.46-0.91). Additionally, early childhood blood lead was negatively associated with pubic hair growth (OR = 0.68, 95% CI: 0.51-0.90) in girls. No associations were found in boys.

CONCLUSIONS

These data suggest that higher prenatal and early childhood exposure to lead may be associated with delayed pubertal development in girls but not boys. Our findings are consistent with previous analyses and reinforce the reproductive effects of lead for girls.

Age at Menarche and Menstrual Abnormalities in Adolescence: Does it Matter? The Evidence from a Large Survey among Italian Secondary Schoolgirls

OBJECTIVE

To explore the independent role of age at menarche on menstrual abnormalities among adolescents.

METHODS

The present study was a multicenter cross-sectional study on a large sample (n = 3782) of Italian girls aged 13-21 y attending secondary school who already had menarche. Girls were asked to fill in a questionnaire on menarcheal age and menstrual features during the latest three menses. The gynecological age was computed as the difference between age at the survey and the age at menarche. Main outcome measures were: prevalence of oligomenorrhea, polymenorrhea, menstrual cycle irregularity, abnormal bleeding length and dysmenorrhea. Irregularity in the recent past and since menarche was also studied. Multiple logistic models were used to identify any independent association between each abnormal feature and age at menarche or gynecological age. Adjusted ORs and 95%CI were performed.

RESULTS

After adjusting for covariates, menarcheal age was not independently associated with polymenorrhea (OR = 0.81; 95%CI 0.63-1.04), oligomenorrhea (OR = 1.16; 95%CI 0.94-1.43), menstrual cycle irregularity (OR = 0.99; 95%CI 0.86-1.14), abnormal bleeding length (OR = 0.96; 95%CI 0.87-1.06) and dysmenorrhea (OR = 1.03; 95%CI 0.85-1.24). The multivariate analysis suggests that the higher prevalence of oligomenorrhea and menstrual cycle irregularity among the girls who were older at menarche might be purely explained by their younger gynecological age.

CONCLUSIONS

No evidence of any independent influence of age at menarche on menstrual abnormalities among young girls was shown by the investigation. The findings suggest that, after menarche, adolescent girls' menstrual health should be checked to monitor the endocrine system maturation and to early intercept latent disorders becoming symptomatic.

Early age at menarche is associated with insulin resistance: a systemic review and meta-analysis

OBJECTIVES

We aimed to conduct a systemic review and meta-analysis of the relevant studies to further investigate the association between age at menarche and insulin resistance.

METHODS

PubMed, EMBASE, and Web of Science (SCI) databases were systemically searched until December 2017. Observational studies comparing the incidences of insulin resistance in patients with early, average, and late menarchal ages were identified. Weighted mean difference (WMD) for HOMA-IR scores and fasting serum insulin levels in early vs late, early vs average. and average vs late comparisons were calculated with a random- or fixed-effects model.

RESULTS

A total of eight articles involving 5504 subjects were finally included. In the analysis of HOMA-IR, the pooled WMDs in five studies were 0.45 (95% confidence interval [CI] 0.31-0.60, p < 0.001), 0.40 (95% CI 0.28-0.52, p < 0.001), and -0.01 (95% CI -0.09 to 0.07, p = 0.854) for early vs late, early vs average, and average vs late comparisons, respectively. The fasting serum insulin levels in eight studies were analyzed, and it was significantly higher in subjects with earlier age at menarche (WMD 1.28, 95% CI 0.92-1.63, p < 0.001 for early vs late comparison, WMD 1.28, 95% CI 1.13-1.43, p < 0.001 for early vs average comparison) with mild and acceptable heterogeneity (I² = 42.5% and 7.4%, respectively). Publication bias was not detected via funnel plots and Egger's tests.

CONCLUSIONS

Our study revealed that earlier age at menarche was significantly associated with insulin resistance.

TRIAL REGISTRATION NUMBER

CRD42018083874.

Age at menarche and osteoporosis: A Mendelian randomization study

PURPOSE

Traditional epidemiological studies suggest that there is an association between age at menarche (years) (AAM) and bone mineral density (BMD) at the sites of the femoral neck and lumbar spine (FNK and LS BMD), indicating a potentially important relationship between AAM and the development of osteoporosis (OP). However, these findings may be influenced by unmeasured confounding factors that can obscure the true relationship between the phenotypic traits. Therefore, we performed Mendelian randomization (MR) analyses to determine whether there is a causal relationship between AAM and BMD (FNK and LS BMD), where late AAM may increase the risk of developing OP.

METHODS

Adopting a two-sample MR approach we incorporated genome-wide association (GWAS) summary statistics from the Reproductive Genetics (ReproGen) Consortium (n = 182,416) (females only) and the GEnetic Factors for OSteoporosis (GEFOS) Consortium (n = 53,236) (both males and females).

RESULTS

Using this MR approach we discovered that each additional year in AAM is associated with a modest reduction in FNK BMD (β = -0.072 se = 0.022, 95% CI (-0.115, -0.030), p = 0.001) and LS BMD ((β = -0.072, se = 0.025, 95% CI (-0.121, -0.023), p = 0.004), and therefore influences OP susceptibility.

CONCLUSIONS

This study demonstrates that AAM in females may play a causal role in OP etiology and provides novel insights into the pathophysiology of bone related diseases like osteoporosis, osteopenia and fracture.

SUMMARY

Our study demonstrates that AAM in females may play a causal role in OP etiology and provides novel insights into the pathophysiology of bone related diseases like osteoporosis, osteopenia and fracture. By adopting Mendelian Randomization approaches, our study was not susceptible to bias from unmeasured confounders or reverse causation.