Time Trends in Age at Menarche and Related Non-Communicable Disease Risk during the 20th Century in Mexico

Relationship between age at menarche and breast cancer in individuals, as well as in first-degree kin and estrogen receptor status: a Mendelian randomization study

Target

We executed a Mendelian randomization (MR) investigation employing two distinct cohorts of genetic instrumental variables to elucidate the causal nexus between age at menarche (AAM) and the incidence of disparate breast cancer (BC) subtypes, in addition to the incidence of BC among first-degree kin.

Methods

We aggregated statistical data pertaining to AAM and BC from various consortia representing a homogenous population cohort. MR analysis was conducted employing inverse variance weighted (IVW) methodology as the principal approach, complemented by weighted median and MR-Egger regression techniques for an exhaustive evaluation. To evaluate the presence of pleiotropy, we applied the MR-Egger intercept test, MR-PRESSO, and leave-one-out sensitivity analysis.

Results

Upon exclusion of confounding SNP, an increment of one standard deviation in AAM was inversely correlated with the incidence of BC. (odds ratio [OR] 0.896, 95% confidence interval [CI] 0.831-0.968)/(OR 0.998, 95% CI 0.996-0.999) and estrogen receptor-positive (ER+) BC incidence (OR 0.895, 95% CI 0.814-0.983). It was also associated with reducing the risk of maternal BC incidence (OR 0.995, 95% CI 0.990-0.999) and sibling BC incidence (OR 0.997, 95% CI 0.994-0.999). No significant association was found between AAM and estrogen receptor-negative (ER-) BC incidence (OR 0.936, 95% CI 0.845-1.037).

Conclusion

Our study substantiated the causal relationship between a delayed AAM and a diminished risk of BC in probands, as well as in their maternal progenitors and siblings. Furthermore, the analysis suggests that AAM exerts a considerable potential causal influence on the risk of developing Luminal-a/b subtype of BC.

Emerging Perspectives on the Impact of Diabetes Mellitus and Anti-Diabetic Drugs on Premenstrual Syndrome. A Narrative Review

Diabetes mellitus (DM) and premenstrual syndrome (PMS) are global health challenges. Both disorders are often linked to a range of physical and psychological symptoms that significantly impact the quality of life of many women. Yet, the exact relation between DM and PMS is not clear, and the management of both conditions poses a considerable challenge. In this review, we aimed to investigate the interplay between DM, anti-diabetic drugs, and the different theories and symptoms of PMS. Female sex hormones are implicated in the pathophysiology of PMS and can also impair blood glucose control. In addition, patients with diabetes face a higher susceptibility to anxiety and depression disorders, with a significant number of patients experiencing symptoms such as fatigue and difficulty concentrating, which are reported in patients with PMS as well. Complications related to diabetic medications, such as hypoglycemia (with sulfonylurea) and fluid retention (with thiazolidinediones) may also mediate PMS-like symptoms. DM can, in addition, disturb the normal gut microbiota (GM), with a consequent loss of beneficial GM metabolites that guard against PMS, particularly the short-chain fatty acids and serotonin. Among the several available anti-diabetic drugs, those (1) with an anti-inflammatory potential, (2) that can preserve the beneficial GM, and (3) possessing a lower risk for hypoglycemia, might have a favorable outcome in PMS women. Yet, well-designed clinical trials are needed to investigate the anti-diabetic drug(s) of choice for patients with diabetes and PMS.

Decline in pubertal timing and its relationship with excess weight. A study of the secular trend in age at menarche in girls from La Plata district (Buenos Aires, Argentina)

OBJECTIVE

To provide information on the secular trend in age at menarche (AgM) in Argentinean girls in relation to excess weight (EW) and body adiposity.

METHODS

Two cohorts (C) (C1, 2005-2007 and C2, 2015-2019) of children aged 8-14 years from La Plata district were studied using identical methodological criteria. Each participating child was asked about menarche (M) status: M presence (MP) or absence (MA). The AgM was estimated using the status quo method and logistic regression analysis. Body weight, height, and tricipital and subscapular skinfolds were collected to estimate EW (overweight + obesity) according to WHO criteria, and body adiposity (sum of skinfolds, SSK = [tricipital + subscapular]). The prevalence of EW by C was estimated and compared using the Chi-square test. The MP probability in relation to age, C, and EW was analyzed by applying logistic regression. Parents completed a questionnaire to assess family socioeconomic conditions. Data were compared using the Chi-square test.

RESULTS

Differences in MP prevalence between C were significant (C1: 21.1% vs. C2: 28.7%). Median AgM was 12.81 years in C1 and 12.22 in C2. The prevalence of EW was higher in C2 (35.3%) than in C1 (24.6%). The probability of MP was higher in C2 than in C1 and children with EW. Both BMI and SSK showed inter-cohort increases. Socioeconomic conditions were substantially deteriorated between C.

CONCLUSION

In an obesogenic context marked by the significant increase in body adiposity and EW, M prevalence exhibited a positive secular trend and AgM reduced by nearly seven months between the cohorts studied.

Mother's age at menarche is associated with odds of preterm delivery: A case-control study

OBJECTIVE

There is a secular trend towards earlier age of menarche in the US and globally. Earlier age at menarche (AAM) has been associated with metabolic disorders that increase risk for preterm delivery (PTD), yet no studies in the US have investigated whether AAM influences risk of PTD. This study tested the hypothesis that AAM is associated with PTD.

DESIGN

A case-control study.

SETTING

The Boston Medical Center (BMC) in Boston, Massachusetts.

POPULATION OR SAMPLE

8264 mother-newborn dyads enrolled at birth at BMC between 1998 and 2019, of which 2242 mothers had PTD (cases) and 6022 did not have PTD (controls).

METHODS

Multivariable-adjusted logistic regression models and restricted cubic splines were used to examine the association between AAM and risk of PTD. The combined impact of AAM and age at delivery on the risk of PTD was also examined.

MAIN OUTCOME MEASURES

Preterm delivery and gestational age (GA) was defined by maternal last menstrual period and early ultrasound documented in medical records.

RESULTS

Maternal age at delivery was 28.1 ± 6.5 years and AAM was 12.85 ± 1.86 years. Multivariable-adjusted cubic spline suggested an inverse dose-response association of AAM with odds of PTD and, consistently, a positive association with GA. A 1-year earlier AAM was associated with 5% (95% CI 2%-8%) higher odds of PTD, after adjustment for maternal year of birth, parity, maternal place of birth, education, smoking status and Mediterranean-style diet score. The association between AAM and PTD was stronger among older mothers whose age at delivery was ≥35 years.

CONCLUSIONS

Earlier AAM is associated with higher odds for PTD, and this association is stronger among women at advanced reproductive age.

Reproductive risk factors across the female lifecourse and later metabolic health

Metabolic health is characterized by optimal blood glucose, lipids, cholesterol, blood pressure, and adiposity. Alterations in these characteristics may lead to the development of type 2 diabetes mellitus or dyslipidemia. Recent evidence suggests that female reproductive characteristics may be overlooked as risk factors that contribute to later metabolic dysfunction. These reproductive traits include the age at menarche, menstrual irregularity, the development of polycystic ovary syndrome, gestational weight change, gestational dysglycemia and dyslipidemia, and the severity and timing of menopausal symptoms. These risk factors may themselves be markers of future dysfunction or may be explained by shared underlying etiologies that promote long-term disease development. Disentangling underlying relationships and identifying potentially modifiable characteristics have an important bearing on therapeutic lifestyle modifications that could ease long-term metabolic burden. Further research that better characterizes associations between reproductive characteristics and metabolic health, clarifies underlying etiologies, and identifies indicators for clinical application is warranted in the prevention and management of metabolic dysfunction.

Is early age at menarche associated with multimorbidity? Findings from the Azar Cohort study

AIMS

This study aimed to assess the association of age at menarche (AAM) with multimorbidity and chronic diseases.

METHODS

We used data regarding the reproductive history of 8,294 female participants of the Azar Cohort Study. A questionnaire assessed the participants' demographic information, reproductive history, personal behaviors, smoking status, socioeconomic status, activity status, and wealth score index.

RESULTS

Among 8,286 women included in the analysis, the AAM was < 12 years (early) in 648 (7.8%), 12-14 years (normal) in 4,911 (59.3%), and > 14 years (late) in 2,727 (32.9%) individuals. Early menarche was associated with a high risk of diabetes, obesity, and high WHR. On the other hand, late menarche was associated with higher rates of hypertension, stroke, and diabetes but a lower risk of MM, rheumatoid disease, obesity, abdominal obesity, and WHtR.

CONCLUSION

Changes in AAM have significant health implications. Factors predisposing individuals to early menarche and its consequences should be considered in chronic disease prevention strategies for adolescents and young adults.

Plant-Based Diet during the Prepubertal Period and Age at Menarche: A Systematic Review

This systematic review aimed to analyze the effect of a prepubertal plant-based diet, through dietary patterns and its nutritional components, on the age at menarche. Systematic searches through Medline (EBSCO), Embase, Health & Medical Collection (Proquest), Scopus, and Google Scholar for articles published between January 2000 and September 2022 in English using the keywords of plant-based diet, age at menarche, and their synonyms identified 673 articles. Articles were screened through titles and abstracts, as well as full-text reviews based on inclusion/exclusion criteria and assessment of research quality using the JBI Critical Appraisal Tools with a JBI cut-off final score of >50%, leaving 12 articles in this systematic review presented in the PRISMA 2020 flowchart. Data analysis was conducted descriptively by comparing findings between articles. Age at menarche/puberty was reported as an outcome of food intake through a vegetarian diet, Mediterranean diet, vegetable protein, phytoestrogens and isoflavones, and dietary fiber. Based on the analysis of each subgroup, the plant-based diet did not consistently influence the incidence of menarche. In conclusion, a plant-based diet does not significantly affect age at menarche when it is accompanied by a balanced intake of energy and macro-micronutrients. The principles of balanced nutrition and the assistance of nutritionists are needed in practicing a plant-based lifestyle, especially for children and adolescents who are still in the developmental stage.

Age at menarche and its association with blood pressure in adult women of developing countries: a systematic review and meta-analysis

CONTEXT

Evidence about the effect of age at menarche (AAM) on blood pressure (BP) has largely been drawn from studies in developed countries. Studies in developing countries are expanding recently but have not been summarised.

OBJECTIVE

To systematically explore the association between AAM and BP and the potential modifiers in developing countries.

METHODS

We searched PubMed, Embase, and Web of Science for publications until March 2022. A random-effects model was used to calculate the pooled relative risk (RR) with 95% confidence interval (CI).

RESULTS

Twenty studies were eligible. In studies with participants' mean age at BP assessment <55 years, women in the oldest group as compared with the middle or the youngest group of AAM had a higher risk of hypertension in those studies without adjustment for confounders (RR 1.79, 95% CI 1.41-2.28, I²=97.0%), those with adjustment for confounders excluding adiposity (1.25,1.04-1.51, I²=84.8%), and those with adjustment for confounders including adiposity (1.38,1.03-1.86, I²=91.8%). In studies with participants' mean age at BP assessment ≥55 years, no significant differences were found for studies without adjustment for confounders (RR 1.07, 95% CI 0.78-1.47, I²=90.3%), studies with adjustment for confounders excluding adiposity (0.85, 0.78-0.92, I²=12.3%), or studies with adjustment for confounders including adiposity (0.95, 0.80-1.11, I²=45.5%). A similar association was observed between AAM and baseline systolic BP and diabolic BP.

CONCLUSION

Late menarche was associated with a higher risk of BP and this association was modified by age and adiposity in developing countries.

Relationship between DMFT index and reproductive history- a cross-sectional study on enrollment phase of Azar cohort study

Background

Hormonal changes in women throughout life might affect the oral health. The aim of this study is to investigate the relationship between the Decayed, Missing, and Filled Teeth (DMFT) index and reproductive history.

Methods

The present cross-sectional study was performed using data of Azar Cohort Study conducted in 2014, in Shabestar city, East Azerbaijan Province, Iran. In the present study, the data of all 8294 women from the enrollment phase of the Azar cohort were included. All available data related on the variables of reproductive history (including age at the onset of menstruation, age of onset of menopause, age of first pregnancy, and frequency of pregnancy), age at interview, educational level, socioeconomic status, frequency of tooth brushing, chronic diseases, body mass index and DMFT were extracted. Negative binomial regression with loglink was used to analyze the relationship between variables. Three regression models have been applied to adjust the effect of confounding variables. Model 1 adjusted for education, socio-economic status, age, chronic diseases, body mass index and frequency of tooth brushing. Model 2 adjusted for education, socioeconomic status, age, chronic diseases and body mass index. Model 3 adjusted for education, socio-economic status and age.

Results

The mean DMFT of 8294 women was 20.99 ± 8.95. In model 1, there was no significant relationship between DMFT and frequency of pregnancy. However, model 2 and 3 showed that in women who had four or more pregnancies, the DMFT rate was significantly higher than those who did not have a history of pregnancy (P = 0.02, P = 0.04). Age at the onset of menopause, age at the onset of menstruation and age of first pregnancy had no significant relationship with DMFT in the models. Brushing less than once a day and increasing age at interview had significant relationship with DMFT in the models (P < 0.001).

Conclusion

Despite hormonal changes through the life, the history of reproductive showed no significant relationship with women’s DMFT. Oral health education for women is an important step in promoting oral health and it is necessary to pay special attention to preventive programs in oral health policy for women specially with increasing the age.

Contribution of environmental factors and female reproductive history to hypertension and obesity incidence in later life

BACKGROUND

Hypertension (HT) and obesity, which are important risk factors for cardiovascular diseases, are complex traits determined by multiple biological and behavioural factors. However, the role of female reproductive history in evaluating HT and obesity is still unclear.

AIM

To investigate the long-term effects of reproductive factors on the probability of obesity and HT in later life after adjusting for socio-demographic and lifestyle behaviour factors.

SUBJECTS AND METHODS

A total of 503 women (39 - 65 years) were recruited from different localities in Slovakia. Multivariable logistic regression analyses were performed to test the associations.

RESULTS

Early menarche age of 11 years and under was associated with twice higher probability of obesity at midlife, independent of environmental confounders (OR = 2.27, CI = 1.35 - 3.81, p = 0.002). Breastfeeding (Bf) women had a lower likelihood of obesity in later life than non-Bf parous women, independent of environmental confounders (OR = 0.35, CI = 0.17 - 0.72, p = 0.004). Finally, age at menarche was associated with obesity-associated HT.

CONCLUSION

Reproductive factors are significantly associated with obesity and obesity-associated HT in later life. The age at menarche and Bf can be risk factors for early identification of women with increased likelihood of adult cardiovascular risk.

Trend in age at menarche and its association with body weight, body mass index and non-communicable disease prevalence in Indonesia: evidence from the Indonesian Family Life Survey (IFLS)

Background

In western countries, age at menarche (AAM) is nowadays lower than a century ago, coinciding with increased Body Mass Index (BMI) and prevalence of non-communicable diseases (NCD). This study aimed to determine the time trend in AAM, and its association with BMI and NCD prevalence at later age, in Indonesia.

Methods

We used secondary data of 15,744 women aged 15–65 years from the Indonesian Family Life Survey (IFLS) conducted in the period 1993 to 2015. Multiple linear regression was applied to determine the association of AAM with BMI, and Poisson regression with robust variance for investigating the association of AAM with NCD prevalence ratios. Models were adjusted for age, and effect modification by wealth status, living area, and region was investigated.

Results

AAM has significantly declined from 14.4 (SD:2.1) years of age in the 1940s to 13.4 y (SD:1.5) in the 1990s. AAM was inversely associated with BMI (β: − 0.30 kg/m², 95%CI: − 0.37, − 0.22) and body weight (β: − 0.67 kg, 95%CI: − 0.75, − 0.54), but was not associated with height. After adjustment for age, AAM was not associated with NCD, i.e. hypertension, type 2 diabetes mellitus, liver diseases, asthma, chronic lung diseases, cardiovascular diseases, stroke, cancer, or arthritis. Including BMI in the models did not change the results.

Conclusions

From the 1940s to 1990s, AAM has declined with 1 year in Indonesia. Women with earlier AAM had higher BMI and body weight at later age, but AAM was not associated with NCD prevalence in later life in the Indonesian population. Further longitudinal research is needed to disentangle the direction of causality of the associations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-12995-3.

Reproductive health in women with type 2 diabetes mellitus

As type 2 diabetes mellitus (T2DM) reaches epidemic proportions in the developed world and the age at diagnosis decreases, more women of reproductive age are being affected. In this article, we provide a synoptic view on potential mechanisms and relevant factors underlying menstrual cycle disorders and fertility issues in women with T2DM. The article discusses the function of the hypothalamic-pituitary-ovarian (HPO) axis, the central role of the hypothalamus in the homeostasis of this system, the central modulators of the axis, and the peripheral metabolic signals involved in neuroendocrine control of reproduction. The available literature on the relationship between T2DM and the female reproductive lifespan, menstrual cycle disorders, fertility issues, and gestational health in women with T2DM are also discussed. The data so far indicate that there is a "U-shaped" relationship between menarche, menopause, and T2DM, both early and late menarche/menopause being risk factors for T2DM. Hyperglycemia and its consequences may be responsible for the effects of T2DM on reproductive health in women, but the exact mechanisms are not as yet fully understood; thus, more studies are needed in order to identify factors causing disruption of the HPO axis.

Medieval menarche: Changes in pubertal timing before and after the Black Death

OBJECTIVES

Bioarcheological evidence suggests stature increased in males but decreased in females after the Black Death (1348-1350 CE). Because tradeoffs between growth and reproduction can result in earlier ages at menarche and lower limb length, we assess menarcheal age between 1120 and 1540 CE to better understand the health of medieval adolescent females before and after the plague.

MATERIALS AND METHODS

Our sample comprises 74 adolescent females from St. Mary Spital, London (1120-1540 CE) within the age range during which menarche occurs (10-25 years). They were assessed as being pre- or post-menarcheal and divided into three groups: Early Pre-Black Death (n = 13), Late Pre-Black Death (n = 38), and Post-Black Death (n = 23). Changes in the ages of pre- and post-menarcheal females were assessed using Mann-Whitney tests.

RESULTS

The average age of post-menarcheal females increased from the Early- to Late Pre-Black Death periods and declined after the Black Death.

CONCLUSIONS

Short stature can reflect unfavorable growth environments, while younger menarcheal age indicates improved living conditions. The paradoxical pattern of female, but not male, stature reduction after the Black Death might reflect the association of early menarche with lower limb length and signal that adolescent females experienced improved health conditions after the epidemic. Our focus on pre- and post-menarche within a limited age span provides a novel approach for inferring average ages of menarche over time. Pathways to skeletal development and reproductive investment are part of an integrated system, providing a bridge between life history research in bioarchaeology and human biology.

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.

Secular trends in age at menarche in 20th century Mexico: Differences by ethnicity, area of residency, and socioeconomic status

OBJECTIVES

This study aims to assess the secular trend in age at menarche (AAM) in Mexico over the 20th century, and compare the patterns according to area of residence (rural/urban), socioeconomic status (SES), and ethnicity (indigenous/nonindigenous).

METHODS

Data on AAM from 24 380 women aged ≥20 years born between 1906 and 1986 were obtained from the Mexican National Health and Nutrition Survey 2006. Birth cohorts were compared to test for a secular trend and differences in mean AAM by area of residence, SES, and ethnicity were evaluated using the Welch test for heterogeneous variances followed by Tamhane T² for post hoc comparisons.

RESULTS

Mean AAM declined from 13.3 years among Mexican women born before the 1940s to 12.56 years among those born in the 1980s. Across birth cohorts, urban women had significantly earlier AAM than their rural counterparts. Nonindigenous urban women reached menarche the earliest and rural indigenous women the latest of all groups. Nonindigenous urban residents experienced a comparatively earlier decline, while that for the indigenous rural women occurred last. High SES women reached menarche the earliest and low SES women the latest. The historical decline in AAM for high and medium SES groups occurred relatively early, whereas that for the low SES occurred last.

CONCLUSIONS

Mean AAM was associated with area of residence, ethnicity, and SES. Our findings indirectly suggest that advances in living conditions experienced in Mexico during the 20th century appear to have been insufficient to overcome the social and biological inequalities accumulated over centuries in some groups.

Association of puberty timing with type 2 diabetes: A systematic review and meta-analysis

BACKGROUND

Emerging studies have investigated the association between puberty timing, particularly age at menarche (AAM), and type 2 diabetes. However, whether this association is independent of adiposity is unclear. We aimed to systematically review published evidence on the association between puberty timing and type 2 diabetes (T2D) or impaired glucose tolerance (IGT), with and without adjustment for adiposity, and to estimate the potential contribution of puberty timing to the burden of T2D in the United Kingdom (UK).

METHODS AND FINDINGS

We searched PubMed, Medline, and Embase databases for publications until February 2019 on the timing of any secondary sexual characteristic in boys or girls in relation to T2D/IGT. Inverse-variance-weighted random-effects meta-analysis was used to pool reported estimates, and meta-regression was used to explore sources of heterogeneity. Twenty-eight observational studies were identified. All assessed AAM in women (combined N = 1,228,306); only 1 study additionally included men. In models without adjustment for adult adiposity, T2D/IGT risk was lower per year later AAM (relative risk [RR] = 0.91, 95% CI 0.89-0.93, p < 0.001, 11 estimates, n = 833,529, I2 = 85.4%) and higher for early versus later menarche (RR = 1.39, 95% CI 1.25-1.55, p < 0.001, 23 estimates, n = 1,185,444, I2 = 87.8%). Associations were weaker but still evident in models adjusted for adiposity (AAM: RR = 0.97 per year, 95% CI 0.95-0.98, p < 0.001, 12 estimates, n = 852,268, I2 = 51.8%; early menarche: RR = 1.19, 95% CI 1.11-1.28, p < 0.001, 21 estimates, n = 890,583, I2 = 68.1%). Associations were stronger among white than Asian women, and in populations with earlier average AAM. The estimated population attributable risk of T2D in white UK women due to early menarche unadjusted and adjusted for adiposity was 12.6% (95% CI 11.0-14.3) and 5.1% (95% CI 3.6-6.7), respectively. Findings in this study are limited by residual and unmeasured confounding, and self-reported AAM.

CONCLUSIONS

Earlier AAM is consistently associated with higher T2D/IGT risk, independent of adiposity. More importantly, this research has identified that a substantial proportion of T2D in women is related to early menarche, which would be expected to increase in light of global secular trends towards earlier puberty timing. These findings highlight the need to identify the underlying mechanisms linking early menarche to T2D/IGT risk.