Age at menarche and risk of major cardiovascular diseases: Evidence of birth cohort effects from a prospective study of 300,000 Chinese women

Early Menarche as a Protective Factor Against Cardiovascular Events: A Systematic Review and Meta-analysis

BACKGROUND

Women are often neglected in cardiovascular health prevention. Age at menarche (AAM) has been linked to cardiovascular (CVD) disease in women and is potentially identified as one of the significant CVD risk factor. However, there is still limited comprehensive evidence addressing this issue. This systematic review and meta-analysis aimed to investigate how early menarche affects the outcome of all-cause mortality, CVD mortality, total cardiovascular disease event, stroke (ischemic, hemorrhagic, and total stroke), and coronary heart disease (CHD).

METHOD

The Cochrane Library, MEDLINE, Embase, ScienceDirect, and Google Scholar databases were searched from March 2013 to March 2023 for cohorts investigating the effect of early onset of menarche on CVD events with a minimum follow-up period of 5 years. Studies that observed specific population and/or included women with a history of CVD at baseline were excluded. The Newcastle-Ottawa scale was used for risk of bias assessment for each cohort included. The data were presented as dichotomous measure using risk ratios. I2 statistics were utilized to evaluate the heterogeneity of presented data.

RESULTS

Thirteen cohorts included 18 626 799 female patients with ages ranging from 43 to 62.6 years. These reported 6 estimates each for CHD (5 483 298 patients) and all-cause mortality (1 595 878 patients), 5 estimates each for total stroke (2 941 321 patients) and CVD mortality (1 706 742 patients), 4 estimates each for total CVD events (3 988 311 patients) and ischemic stroke (2 434 580 patients), and 1 estimate for hemorrhagic stroke (66 104 patients). Our study found that events of CHD were significantly lower in early menarche (RR 0.57; 95% CI 0.41-0.78; P <.00001), as well as total stroke (RR 0.51; 95% CI 0.35-0.73; P =.0003), CVD mortality (RR 0.47; 95% CI 0.22-0.98; P =.04), total CVD events (RR 0.44; 95% CI 0.25-0.76; P =.003), ischemic stroke (RR 0.31; 95% CI 0.15-0.61; P <.0008), and hemorrhagic stroke (RR 0.12; 95% CI 0.07-0.20; P <.00001); and insignificantly higher in all-cause mortality (RR 0.90, 95% CI 0.76-1.06, P =.20).

CONCLUSION

In our study, cardiovascular events are lower in women with early menarche; hence, the later age of menarche is a potential risk factor to be considered when assessing CVD risk in a patient. However, our sample characteristics were heterogenous, and we did not consider other female hormonal factors that might potentially contribute to the CVD outcomes observed; thus, further studies are needed to clarify.

Childhood adversity and accelerated reproductive events: a systematic review and meta-analysis

OBJECTIVE

Accelerated female reproductive events represent the early onset of reproductive events involving puberty, menarche, pregnancy loss, first sexual intercourse, first birth, parity, and menopause. This study aimed to explore the association between childhood adversity and accelerated female reproductive events.

DATA SOURCES

PubMed, Web of Science, and Embase were systematically searched from September 22, 2022 to September 23, 2022.

STUDY ELIGIBILITY CRITERIA

Observational cohort, cross-sectional, and case-control studies in human populations were included if they reported the time of reproductive events for female individuals with experience of childhood adversity and were published in English.

METHODS

Two reviewers independently screened studies, obtained data, and assessed study quality, and conflicts were resolved by a third reviewer. Dichotomous outcomes were evaluated using meta-analysis, and pooled odds ratios and 95% confidence intervals were generated using random-effects models. Moderation analysis and meta-regression were used to investigate heterogeneity.

RESULTS

In total, 21 cohort studies, 9 cross-sectional studies, and 3 case-control studies were identified. Overall, female individuals with childhood adversity were nearly 2 times more likely to report accelerated reproductive events than those with no adversity exposure (odds ratio, 1.91; 95% confidence interval, 1.33-2.76; I2=99.6%; P<.001). Moderation analysis indicated that effect sizes for the types of childhood adversity ranged from an odds ratio of 1.61 (95% confidence interval, 1.23-2.09) for low socioeconomic status to 2.13 (95% confidence interval, 1.14-3.99) for dysfunctional family dynamics. Among the 7 groups based on different reproductive events, including early onset of puberty, early menarche, early sexual initiation, teenage childbirth, preterm birth, pregnancy loss, and early menopause, early sexual initiation had a nonsignificant correlation with childhood adversity (odds ratio, 2.70; 95% confidence interval, 0.88-8.30; I2=99.9%; P<.001). Considerable heterogeneity (I2>75%) between estimates was observed for over half of the outcomes. Age, study type, and method of data collection could explain 35.9% of the variance.

CONCLUSION

The literature tentatively corroborates that female individuals who reported adverse events in childhood are more likely to experience accelerated reproductive events. This association is especially strong for exposure to abuse and dysfunctional family dynamics. However, the heterogeneity among studies was high, requiring caution in interpreting the findings and highlighting the need for further evaluation of the types and timing of childhood events that influence accelerated female reproductive events.

The J shaped association of age at menarche and cardiovascular events: systematic review and meta-analysis

This study aimed to evaluate the association between age at menarche and cardiovascular (CV) events through a systematic review and meta-analysis of observational studies. A comprehensive literature search covering studies published from January 1, 2000, to October 31, 2023, was conducted in PubMed, MEDLINE, Embase, and Scopus. Twenty-nine observational studies involving 4,931,160 adult women aged 18 years or older were included. The meta-analysis revealed a J-shaped association between age at menarche and CV events. Individuals with menarche at 12-13 years exhibited the lowest risk, while those with younger (≤ 11 years) or older ages (14-15 years and ≥ 16 years) showed an increased risk. Notably, individuals with age at menarche of 16 years and older had the highest risk of CV events. The pooled odds of CV mortality in age at menarche categories 14-15 years and ≥ 16 years were 37% (OR: 1.37, 95% CI 1.14-1.64, I2: 76.9%) and 64% (OR: 1.64, 95% CI 1.20-2.24, I2: 87%) higher than referent age at menarche 12-13 years. No statistically significant difference was found in CV mortality risk between individuals with age at menarche ≤ 11 years and those with age at menarche 12-13 years. The ORs for coronary heart disease were significantly higher for age at menarche ≥ 16 years (35% increase), while no significant difference was found for age at menarche ≤ 11 years or 14-15 years compared to age at menarche 12-13 years. Regarding stroke, the ORs for age at menarche ≤ 11, 14-15, and ≥ 16 years were significantly higher (7%, 24%, and 94% increase, respectively) compared to age at menarche 12-13 years. Dose-response meta-analysis and one-stage random-effect cubic spline models confirmed the J-shaped risk pattern. Meta-regression indicated that age and BMI were not significant sources of heterogeneity. Sensitivity analyses and the absence of publication bias further supported the robustness of the findings. This study concludes that age at menarche is independently associated with CV events, with a J-shaped pattern. The findings underscore the significance of considering menarche age as an independent risk factor for CV events. Further research is warranted to validate these findings and explore potential underlying mechanisms.

Association of age at first sexual intercourse and lifetime number of sexual partners with cardiovascular diseases: a bi-directional Mendelian randomization study

Background

Limited studies have explored the association between sexual factors [age at first sexual intercourse (AFS) and lifetime number of sexual partners (LNSP)] and cardiovascular diseases (CVDs), leaving the causality inconclusive.

Methods

We performed a bi-directional Mendelian randomization (MR) study to investigate the causality between sexual factors and CVDs, including coronary artery disease, myocardial infarction, atrial fibrillation (AF), heart failure (HF), and ischemic stroke (IS). Single-nucleotide polymorphisms (SNPs) for sexual factors were extracted from the UK Biobank. Statistics for each CVD were derived from two different databases. MR estimates were calculated per outcome database and were combined through meta-analysis. Several complementary sensitivity analyses were also performed.

Results

The primary analysis suggested that AFS was causally associated with the risk of CVDs; the odds ratios (ORs) ranged from 0.686 [95% confidence interval (CI), 0.611-0.770] for HF to 0.798 (95% CI, 0.719-0.886) for AF. However, the association between AFS and IS (OR, 0.844; 95% CI, 0.632-1.126) was not consistent in the meta-analysis after excluding SNPs related to confounders. Moreover, non-significant associations were found between LNSP and CVDs. Reverse direction MR analysis showed that CVDs were not associated with sexual factors.

Conclusions

Genetic evidence suggested that AFS was causally associated with the risk of CVDs except for IS, whereas non-significant association of LNSP with CVDs was detected. Further investigation into AFS could be warranted in preventing the progression of CVDs.

Age at menarche and metabolic dysfunction-associated fatty liver disease: Evidence from a large population-based epidemiological study in Southwest China

BACKGROUND

The relationship between age at menarche and metabolic dysfunction-associated fatty liver disease remains largely not clear. The objective of this study was to examine the association between age at menarche (AAM) and metabolic dysfunction-associated fatty liver disease (MAFLD) in Chinese women and whether any observed associations were mediated by early adulthood adiposity.

METHODS

The cross-sectional study included 46,873 Chinese women, aged 30-79 from baseline data of the China Multi-Ethnic Cohort study. Logistic regression models were used to evaluate the association between AAM and MAFLD. Mediation analysis was adopted to examine whether early adulthood adiposity (around 25 years) mediated the association between AAM and MAFLD.

RESULTS

AAM was linearly and inversely associated with the risk of MAFLD (P for nonlinearity =0.743). In a multivariable-adjusted model, the odds ratios and 95% confidence interval (ORs (95% CI)) for MAFLD comparing menarche at <12, 12, 13, 15, 16, 17, ≥18 years to menarche at 14 years were 1.290 (1.082-1.537), 1.172 (1.068-1.285), 1.042 (0.960-1.131), 0.937 (0.861-1.020), 0.911(0.835-0.994), 0.868 (0.786-0.959), and 0.738 (0.670-0.814), respectively (P for trend <0.001). The 6.4% increased MAFLD risk was associated with each preceding year in AAM. The association between AAM and MAFLD was modified by age, ethnicity, and menopause. Early adulthood adiposity partially mediated this association.

CONCLUSION

The findings of this study suggest that obesity prevention strategies are needed from young adulthood in women who undergo early menarche to reduce the risk of MAFLD.

The association between early menarche and higher-risk cardiometabolic profile: a dose-response analysis of the Tabari cohort at enrollment phase

Objectives

The association between age at menarche and higher-risk cardiometabolic factors is controversial and more strands of evidence are required. Therefore, in this study, we aimed to investigate the effect of early menarche on cardiometabolic profile in a large-scale cohort population.

Study design

Data collected in the enrollment phase of the Tabari cohort study were utilized for the present study. We analyzed data from 6,103 women aged 35-70 years. Logistic regression and dose-response (trend) analyses were used to investigate the effect of early menarche on prevalence of diabetes, dyslipidemia, obesity, high waist circumference (WC), high waist-to-hip ratio (WHR), and high waist-to-height ratio (WHtR).

Results

The results of the adjusted logistic regression analysis showed that women who experienced early menarche had significantly higher odds of obesity (odds ratio: 1.64, 95% CI: 1.36-1.99, P for trend <0.001), high WC (odds ratio: 1.34, 95% CI: 1.07-1.67, P for trend = 0.035), high WHR (odds ratio: 1.32, 95% CI: 1.05-1.66, P for trend = 0.057), and high WHtR (odds ratio: 1.83, 95% CI: 1.22-2.74, P for trend = 0.006) compared to those aged ≥14 at menarche. The prevalence of dyslipidemia was also higher among women who experienced early menarche than in women aged ≥14 at menarche (79.9% vs. 76.6%), but the difference was not statistically significant (P = 0.098). Additionally, each year of earlier menarche was significantly associated with an increase in the chance of diabetes (by 5%), obesity (10%), high WC (5%), and high WHtR (13%).

Conclusion

The present study showed that early menarche is a strong predictor for later development of obesity and diabetes, and for high WC, WHR, and WHtR. Among all factors examined, age at menarche had the greatest predictive power for WHtR. As an age-dependent anthropometric index for central obesity, WHtR is more suitable as an index for identification of individuals with increased cardiometabolic risk.

Sex-Specific Reproductive Factors Augment Cardiovascular Disease Risk in Women: A Mendelian Randomization Study

Background Observational studies suggest that reproductive factors are associated with cardiovascular disease, but these are liable to influence by residual confounding. This study explores the causal relevance of reproductive factors on cardiovascular disease in women using Mendelian randomization. Methods and Results Uncorrelated (r2<0.001), genome-wide significant (P<5×10-8) single-nucleotide polymorphisms were extracted from sex-specific genome-wide association studies of age at first birth, number of live births, age at menarche, and age at menopause. Inverse-variance weighted Mendelian randomization was used for primary analyses on outcomes of atrial fibrillation, coronary artery disease, heart failure, ischemic stroke, and stroke. Earlier genetically predicted age at first birth increased risk of coronary artery disease (odds ratio [OR] per year, 1.49 [95% CI, 1.28-1.74], P=3.72×10-7) heart failure (OR, 1.27 [95% CI, 1.06-1.53], P=0.009), and stroke (OR, 1.25 [95% CI, 1.00-1.56], P=0.048), with partial mediation through body mass index, type 2 diabetes, blood pressure, and cholesterol traits. Higher genetically predicted number of live births increased risk of atrial fibrillation (OR for <2, versus 2, versus >2 live births, 2.91 [95% CI, 1.16-7.29], P=0.023), heart failure (OR, 1.90 [95% CI, 1.28-2.82], P=0.001), ischemic stroke (OR, 1.86 [95% CI, 1.03-3.37], P=0.039), and stroke (OR, 2.07 [95% CI, 1.22-3.52], P=0.007). Earlier genetically predicted age at menarche increased risk of coronary artery disease (OR per year, 1.10 [95% CI, 1.06-1.14], P=1.68×10-6) and heart failure (OR, 1.12 [95% CI, 1.07-1.17], P=5.06×10-7); both associations were at least partly mediated by body mass index. Conclusions These results support a causal role of a number of reproductive factors on cardiovascular disease in women and identify multiple modifiable mediators amenable to clinical intervention.

Relationships between Age at Menarche and Risk of Cardiovascular Disease Mortality among Japanese Women: The Japan Collaborative Cohort Study for Evaluation of Cancer Risk (JACC) Study

AIM

In this study, we aimed to evaluate the association between age at menarche and risk of cardiovascular disease mortality.

METHODS

In total, 54,937 women aged 40-79 years old between 1988 and 1990 without a history of cardiovascular disease were eligible for analysis and were followed through December 2009. We used the Cox proportional hazards models to examine the association between age at menarche and risk of cardiovascular disease.

RESULTS

Compared with women with age at menarche of 15 years, the hazard ratios (95% confidence intervals) of stroke were 1.22 (0.85-1.75) for women with age at menarche of 9-12 years, 1.08 (0.85-1.36) for those of 13 years, 1.23 (1.02-1.47) for those of 14 years, 1.27 (1.07-1.50) for those of 16 years, 1.16 (0.95-1.41) for those of 17 years, and 1.39(1.16-1.68) for those of 18-20 years (P for trend=0.045). A similar pattern was observed for hemorrhagic stroke, ischemic stroke, and total cardiovascular disease. No such association was found for coronary heart disease. When stratified by age, for women aged 40-59 at baseline, the similar U-shaped association was observed. In contrast, for women aged 60-79 years at baseline, a significantly high hazard ratio was noted in the group of late age at menarche, but not in the group of early age at menarche.

CONCLUSIONS

Both women with early and late age at menarche were determined to have higher risk of death from stroke and cardiovascular disease.

Associations of reproductive factors with incidence of myocardial infarction and ischemic stroke in postmenopausal women: a cohort study

BACKGROUND

To assess the association between the reproductive factors of age at menarche, age at menopause, and reproductive span and the incidence of myocardial infarction (MI) and ischemic stroke (IS).

METHODS

We used a population-based retrospective cohort study from the National Health Insurance Service database of Korea including a total of 1,224,547 postmenopausal women. Associations between age at menarche (≤ 12, 13-14 [reference], 15, 16, and ≥ 17 years), age at menopause (< 40, 40-45, 46-50, 51-54 [reference], and ≥ 55 years), and reproductive span (< 30, 30-33, 34-36, 37-40 [reference], and ≥ 41 years) and the incidence of MI and IS were assessed by Cox proportional hazard models with adjustment for traditional cardiovascular risk factors and various reproductive factors.

RESULTS

During a median follow-up of 8.4 years, 25,181 MI and 38,996 IS cases were identified. Late menarche (≥ 16 years), early menopause (≤ 50 years), and short reproductive span (≤ 36 years) were linearly associated with a 6%, 12-40%, and 12-32% higher risk of MI, respectively. Meanwhile, a U-shaped association between age at menarche and risk of IS was found, with a 16% higher risk in early menarche (≤ 12 years) and a 7-9% higher risk in late menarche (≥ 16 years). Short reproductive span was linearly associated with an increased risk of MI, whereas both shorter and longer reproductive spans were associated with an increased risk of IS.

CONCLUSIONS

This study demonstrated different patterns of association between age at menarche and incidence of MI and IS: a linear association for MI versus a U-shaped association for IS. Female reproductive factors in addition to traditional cardiovascular risk factors should be considered when assessing overall cardiovascular risk in postmenopausal women.

Association of reproductive factors with cardiovascular disease risk in pre-menopausal women: nationwide population-based cohort study

BACKGROUND

Although the morbidity and mortality of cardiovascular diseases (CVD) are rising in young women, the risk factors of CVD among Korean pre-menopausal women have not been intensively investigated.

AIMS

To determine how age at menarche and other female reproductive factors are associated with the risk of CVD in pre-menopausal women.

METHODS AND RESULTS

A total of 1 088 992 pre-menopausal women who participated in health screening in 2009 were included. The study outcomes were myocardial infarction (MI) and ischaemic stroke. Cox proportional hazards regression analysis was conducted with adjustment of traditional CVD risk factors and reproductive factors.

RESULTS

Mean age was 43.8 ± 5.3 years (98.9%, < 55 years), 3.5% were current smokers, and 1.2% were heavy drinkers. During a mean follow-up of 8.3years [9 032 685.9 person-years (PY)], there were 10 876 CVD events (1.0 per 1000 PY).With later menarche, the risk of CVD increased; ≤12 years [adjusted hazard ratio (HR) 1.04, 95% confidence interval 0.93-1.16], 13 years (reference), 14 years (1.06, 0.98-1.14), 15 years (1.15, 1.07-1.24), 16 years (1.23, 1.14-1.34), and ≥17 years (1.33, 1.24-1.44). Compared with non-users, oral contraceptives (OC) users (≥1 year) had an increased risk of CVD (1.11, 1.01-1.22) (P for trend = 0.007).

CONCLUSIONS

Later menarche than the mean age at menarche (13 years old) and the use of OC (≥1 year) were associated with a higher risk of CVD, after adjusting for traditional cardiovascular risk factors. This study suggests that female reproductive factors could be unique risk factors for CVD in pre-menopausal women.

Association of age at menarche with valvular heart disease: An analysis based on electronic health record (CREAT2109)

Background

The association between age at menarche and coronary heart disease has been reported, but the association between age at menarche and valvular heart disease (VHD) has not been described. We aimed to examine the association between age at menarche and VHD.

Methods

By collecting data from four medical centers of the Affiliated Hospital of Qingdao University (QUAH) from January 1, 2016, to December 31, 2020, we sampled 105,707 inpatients. The main outcome of this study was newly diagnosed VHD, which was diagnosed based on ICD-10 coding, and the exposure factor was age at menarche, which was accessed through the electronic health records. We used logistic regression model to investigate the association between age at menarche and VHD.

Results

In this sample (mean age 55.31 ± 13.63 years), the mean age at menarche was 15. Compared with women with age at menarche 14-15 years, the odds ratio of VHD in women with age at menarche ≤13, 16-17, and ≥18 years was 0.68 (95% CI 0.57-0.81), 1.22 (95% CI 1.08-1.38), and 1.31 (95% CI 1.13-1.52), respectively (P for all < 0.001). By restricting cubic splines, we found that later menarche was associated with increased odds of VHD (P < 0.001). Furthermore, in subgroup analysis of different etiologies, the similar trend persisted for non-rheumatic VHD.

Conclusions

In this large inpatient sample, later menarche was associated with higher risk of VHD.

Women's reproductive traits and ischemic stroke: a two-sample Mendelian randomization study

OBJECTIVE

We conducted a Mendelian randomization (MR) study to disentangle causal associations between women's reproductive behaviors and ischemic stroke (IS) and investigate the roles of two modifiable risk factors (body mass index (BMI) and educational attainment (EA)) in these associations.

METHODS

Using summary-level data from large-scale genome-wide association studies, we performed univariable MR to examine whether there is genetic evidence that women's reproductive traits are causally associated with IS and its subtypes. Multivariable MR and MR mediation analysis were used to investigate whether BMI and EA are common mechanisms or mediators for these associations. A set of sensitivity analyses were conducted to test valid MR assumptions.

RESULTS

We observed consistent and statistically significant associations across female and sex-combined analyses for earlier age at first birth (AFB) and age at first sexual intercourse (AFS) with a higher risk of IS and large-artery atherosclerotic stroke (LAS) risk in the primary analysis. The odds ratios of IS per 1 SD increase in genetically predicted early AFB and AFS were 0.93 (95% CI, 0.86-0.99; p = 0.046) and 0.83 (95% CI, 0.70-0.97, p = 0.020), respectively. Further analyses indicated that BMI played a shared role in AFS and IS/LAS while EA played a shared role in AFS/AFB and IS/LAS as well as a mediator in the path from AFS to IS/LAS.

INTERPRETATION

These findings may inform prevention strategies and interventions directed toward relative women's reproductive behaviors and IS. Future studies are warranted to explore other factors related to EA which are responsible for these causalities.

Association between Age at Menarche and Metabolic Syndrome in Southwest Iran: A Population-Based Case-Control Study

BACKGROUND

Age at menarche affects women's health outcomes and could be a risk factor for some diseases, such as metabolic syndrome (MetS). We assessed the association between age at menarche and MetS components in women aged 35-70 in Hoveyzeh, southwest Iran.

STUDY DESIGN

A case-control study.

METHODS

This case-control study was conducted on 5830 women aged 35-70 years in the Hoveyzeh cohort study (HCS), a part of the PERSIAN cohort study, from 2016-2018. The case group included women with MetS, while the controls were women without MetS. The MetS is determined based on standard NCEP-ATP III criteria. Data from demographic, socioeconomic, and reproductive history were gathered face-to-face through trained interviews. Moreover, laboratory, anthropometrics, and blood pressure measurements were assayed for participants. Multiple logistic regression was used to estimate the association between age at menarche and MetS, with adjustment for potential confounding variables.

RESULTS

The mean age at menarche was 12.60 ± 1.76 years old. Urban and rural women differed in age at menarche (12.58 ± 1.71 and 12.63 ± 1.83 years, respectively). The study revealed a statistically significant relationship between MetS and menarche age. The odds of developing MetS were 14% higher in women with menstrual age ≤ 11 years than in other groups.

CONCLUSION

As evidenced by the results of this study, the odds of having MetS were higher in women whose menarche age was ≤ 11 years. Furthermore, the association between MetS components and age groups at menarche was statistically significant.

Age at Menarche and Menopause, Reproductive Lifespan, and Risk of Cardiovascular Events Among Chinese Postmenopausal Women: Results From a Large National Representative Cohort Study

Background

At present, the association between age at menarche and menopause, reproductive lifespan, and cardiovascular disease (CVD) risk among Chinese postmenopausal women is not clear, and some related researches are contradictory.

Methods

A total of 6,198 Chinese postmenopausal women with a mean age of 63.6 years were enrolled at baseline in 2012-2015 and followed up for 5 years. A standardized questionnaire was used to collect relevant information by well-trained interviewers. Physical examination of the participants was performed by trained medical staff. CVD events were observed during follow-up. Cox proportional hazards models were used to estimate hazard ratios between reproductive characteristics and CVD events.

Results

Age at menarche was positively associated with CVD events (HR, 1.106; 95%CI, 1.047-1.167). There was a negative association between age at menopause and CVD risk in postmenopausal women with comorbidity (HR, 0.952; 95%CI, 0.909-0.996). Reproductive lifespan was negatively associated with CVD events (HR, 0.938; 95%CI, 0.880-0.999). The CVD risk increased by 10.6% for every 1-year increase in age at menarche. The CVD risk reduced by 6.2% for every 1-year increase in age at menopause in women with comorbidity. The CVD risk reduced by 3.8% for every 1-year increase in reproductive lifespan.

Conclusions

Based on the large prospective study with a nationally representative sample, Chinese postmenopausal women with late age at menarche and shorter reproductive lifespan have higher risk of CVD events.

Mediator or moderator? The role of obesity in the association between age at menarche and blood pressure in middle-aged and elderly Chinese: a population-based cross-sectional study

OBJECTIVE

We investigated the moderation/mediation between the age of menarche and obesity parameters in predicting blood pressure (BP) in middle-aged and elderly Chinese.

DESIGN

Our study is a population-based cross-sectional study.

SETTING

Participants in this study came from the China Health and Retirement Longitudinal Study (CHARLS).

PARTICIPANTS

The analytical sample included 4513 participants aged 45-96 years.

MAIN OUTCOME MEASUREMENTS

Data were selected from the CHARLS, a cross-sectional study. Between-group differences were evaluated using χ², t-test and one-way analysis of variance. The trend of related variables by characteristics was also tested using contrast analysis, as appropriate. Then, correlations between characteristics, moderator, mediator, and independent and dependent variables were used by Spearman's correlation test and Pearson's correlation test. Finally, the mediation analysis was performed by model 4 in PROCESS V3.3 macro for SSPSS, and moderation analysis was used by model 1 for assessment. All covariates were adjusted in the moderation or mediation models.

RESULTS

In the correlation analysis, body mass index (BMI) and waist circle (WC) level were positively correlated with both systolic blood pressure (SBP) and diastolic blood pressure (DBP) in women (BMI and DBP: r=0.221, p<0.001; WC and DBP: r=0.183, p<0.001; BMI and SBP: r=0.129, p<0.001; WC and SBP: r=0.177, p<0.001). Age of menarche was negatively correlated with DBP (r=-0.060, p<0.001). However, the age of menarche was not significantly correlated with SBP (r=-0.014, p=0.335). In the moderator analysis, after controlling for the potential confounders, the interaction term of obesity parameters×age of menarche was not significant for predicting either DBP (BMI: B=0.0260, SE=0.0229, p=0.2556, 95% CI -0.0189 to 0.071; WC: B=0.0099, SE=0.0074, p=0.1833, 95% CI -0.0047 to 0.0244) or SBP (BMI: B=0.0091, SE=0.0504, p=0.8561, 95% CI -0.0897 to 0.108; WC: B=-0.0032, SE=0.0159, p=0.8427, 95% CI -0.0343 to 0.028). All correlations were significant correlation between age of menarche, obesity parameters and BP except the path of the menarche age→SBP (with the addition of the BMI indicator: β=-0.0004, B=-0.0046, p=0.9797, 95% CI -0.3619 to 0.3526; with the addition of the WC indicator: β=0.0004, B=0.0044, p=0.9804, 95% CI -0.3439 to 0.3526) in crude model. In general, after controlling for potential confounders, BMI (DBP: β=-0.0471, B= -0.2682, p=0.0021, 95% CI -0.4388 to -0.0976; SBP: β=-0.0515, B=-0.6314, p<0.001, 95% CI -0.9889 to -0.2739) and WC (DBP: β=-0.0474, B= -0.2689, p<0.001, 95% CI -0.4395 to -0.0984; SBP: β=-0.0524, B=-0.6320, p<0.001, 95% CI -0.9832 to -0.2807) partly mediated the relationship between age of menarche and BP.

CONCLUSIONS

The interaction term of obesity parameters×age of menarche was not significant for predicting either DBP or SBP in women. Moreover, obesity parameters partly mediated the relationship between the age of menarche and BP.

Metabolomic Differential Compounds Reflecting the Clinical Efficacy of Polyethylene Glycol Recombinant Human Growth Hormone in the Treatment of Childhood Growth Hormone Deficiency

Understanding metabolite profiles may aid in providing a reference for individualized treatment using PEG-rhGH. Therefore, this study aimed to evaluate the clinical efficacy of PEG-rhGH in treating GHD patients by using a metabolomic approach. Fifty-seven pediatric participants treated with PEG-rhGH were enrolled (28 GHD patients with high clinical efficacy and 29 GHD patients with lower clinical efficacy). Serum samples from all patients were first collected at baseline for biochemical detection; then metabolite levels were measured using gas chromatography time-of-flight mass spectrometry. The candidates included heptadecanoic acid, stearic acid, 2-hydroxybutyric acid, myristic acid, palmitoleic acid, D-galactose, dodecanoic acid, and oleic acid. The related metabolic pathways involved fatty acid metabolism and energy metabolism. This study suggested that growth gains of PEG-rhGH treatment might be differentiated by altered serum levels of fatty acid. Collectively, the metabolomic study provides unique insights into the use of PEG-rhGH as a therapeutic strategy for individualized treatment.

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.

Age at menarche, age at menopause, reproductive years and risk of fatal stroke occurrence among Chinese women: the Guangzhou Biobank Cohort Study

Background

The relationship between women’s reproductive characteristics and stroke events is unclear. We aimed to investigate age at menarche, age at menopause and number of reproductive years in relation to fatal stroke occurrence in the Guangzhou Biobank Cohort Study.

Methods

In total, 16,504 postmenopausal women without stroke, heart disease or a cancer history at baseline were included and followed up for a median of 12.0 years. After review of available records, 222 stroke deaths were recorded. Cox proportional hazards regression was used to assess the associations between the risk of fatal stroke occurrence and age at menarche, age at menopause and number of reproductive years.

Results

In the whole cohort, compared with those aged 15 years at menarche, an increased risk of fatal stroke among women at menarche showed respectively in those aged 12 years (aHR (adjusted hazard ratio) = 1.86, 95% confidence interval (CI) 0.96–3.60), aged 13 years (aHR = 1.69, 95% CI 0.98–2.92), aged 17 years (aHR = 1.83, 95% CI 1.10–3.05) and aged ≥ 18 years (aHR = 1.66, 95% CI 1.03–2.70), wherein the associations revealed an atypically U-shaped; similar U-shaped association to the cohort of postmenopausal women born before 1940 released a range of incremental risks of fatal stroke in women at menarche aged ≤ 12 years (aHR = 3.68, 95% CI 1.68–8.05), aged 13 years (aHR = 2.11, 95% CI 1.02–4.34), aged 14 years (aHR = 2.07, 95% CI 1.04), aged 17 years (aHR = 2.30, 95% CI 1.20–4.39) and aged 18 years (aHR = 2.50, 95% CI 1.37–4.57), respectively. Compared with menopausal women aged 51–52 years, those aged < 43 years at menopause had an increased risk for fatal stroke among postmenopausal women born in and after 1940 (aHR = 1.64, 95% CI 0.97–2.78) and postmenopausal women born before 1940 (aHR = 1.97, 95% CI 1.05–3.69). Additionally, compared with those with 32–34 reproductive years, women with ≤ 28 reproductive years had an increased risk for fatal stroke in the whole cohort (aHR = 1.91, 95% CI 1.28–2.86) and the cohort of postmenopausal women born before 1940 (aHR = 1.79, 95% CI 1.15–2.80).

Conclusions

Younger and older age at menarche, younger age at menopause and fewer reproductive ages were related to an increased risk of fatal stroke in postmenopausal women.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12905-021-01579-9.

Natural menopausal age and cardiovascular disease risk factors in older Chinese women: Guangzhou Biobank Cohort Study

OBJECTIVE

To examine the associations of natural menopausal age with cardiovascular disease risk factors and whether the associations varied by parity in older Chinese women.

METHODS

Information of demographic characteristics, lifestyles, and reproductive factors was collected by face-to-face interview. Framingham Risk Score was used as an indicator of cardiovascular disease risk, with a score ≥ 10% considered as high cardiovascular disease risk (vs low, dichotomous). Multivariable logistic and linear regressions were used to examine the associations of menopausal age with cardiovascular disease risk factors.

RESULTS

Of 18,339 women aged 50+ years, the average (standard deviation) age was 61.8 (6.9) years. Compared with women with menopausal age of 45 to 54 years, after adjustment for multiple potential confounders, women with menopausal age <45 years or ≥55 years had higher Framingham Risk Score (0.93%, 95% confidence interval: 0.40-1.46, and 0.69%, 95% confidence interval: 0.18-1.20, respectively). Women with menopausal age <45 or ≥55 years had higher odds of high cardiovascular disease risk (vs low) (odds ratio [95% confidence interval]:1.26 (1.10-1.44) and 1.17 (1.02-1.33), respectively). The associations of menopausal age with the Framingham Risk Score varied by parity (P for interaction ≤0.001). The Framingham Risk Score was higher in those with one to three parity (<45 y: 1.01 [0.43-1.59]; ≥55 y: 1.14 [0.60-1.68]) and lower for parity ≥4 (<45 y: -0.33 [-1.84 to 1.18]; ≥55 y: -2.02 [-3.82 to -0.22]). In nulliparous women, the Framingham Risk Score was highest in menopausal age <45 years (3.97 [1.67-6.26]), but the differences were nonsignificant in menopausal age ≥55 years (0.66 [-1.38 to 2.71]).

CONCLUSIONS

Both early and late natural menopausal ages were associated with a higher cardiovascular disease risk, and the associations were stronger in those with lower parity.

Joint Associations of Actual Age and Genetically Determined Age at Menarche With Risk of Mortality

IMPORTANCE

Previous studies have shown an association between actual age at menarche and risk of all-cause mortality; however, the results are inconsistent, and no study has analyzed the joint associations between genetic susceptibility and actual age at menarche with the risk of mortality in prospective cohorts.

OBJECTIVES

To investigate joint associations of actual age and genetically determined age at menarche with risk of all-cause mortality.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study was conducted using data from the UK Biobank population across the United Kingdom from March 13, 2006, to October 1, 2010. A total of 264 546 women aged between 39 and 71 years with actual menarcheal age were included in this study; 246 676 of these women had genetic data available. Actual age at menarche was obtained from the touchscreen questionnaire at recruitment from 2006 to 2010. Genetically determined age at menarche was assessed by a genetic risk score. Statistical analysis was performed from August 22 to December 12, 2019.

EXPOSURE

Age at menarche.

MAIN OUTCOMES AND MEASURES

A multivariable Cox proportional hazards regression model was used to assess associations of actual or genetically determined age at menarche with risk of all-cause mortality.

RESULTS

The mean (SD) age of the study population at baseline was 56.4 (8.0) years, and the mean (SD) age at menarche included in the analyses was 13.0 (1.6) years. During a median of 9.0 years (range, 8.3-9.7 years) of follow-up, 7761 deaths were documented among the women with actual age at menarche, and 7054 deaths were documented among the women with genetically determined age at menarche. Both the actual age at menarche and the genetically determined age at menarche showed a U-shaped association with the risk of all-cause mortality (lowest actual age [<12 years] vs reference age [15 years]: hazard ratio [HR], 1.16 [95% CI, 1.07-1.26]; highest actual age [≥16 years] vs reference age [15 years]: HR, 1.17 [95% CI, 1.05-1.31]; P < .001 for quadratic trend; genetic risk score [GRS] of 1 vs reference score [GRS of 4]: HR, 1.10 [95% CI, 1.01-1.19; GRS of 6 vs reference score [GRS of 4]: HR, 1.09 [95% CI, 1.00-1.18]; P = .03 for quadratic trend). Significant interactions were also found between actual age at menarche and genetically determined age at menarche with all-cause mortality (HR of mortality associated with age of menarche <12 year was 1.24 [95% CI, 1.10-1.40] in the GRS of 1 group and 1.44 [95% CI, 1.21-1.72] in the GRS of 6 group; P = .001 for interaction). Women with mismatch of actual age and genetically determined age at menarche had the highest mortality risks; participants with the lowest genetic risk score and the highest age at menarche had an HR of 2.12 (95% CI, 1.58-2.83), and participants with the highest GRS and the lowest age at menarche had an HR of 1.44 (95% CI, 1.21-1.72).

CONCLUSIONS AND RELEVANCE

The results suggest that both actual age and genetically determined age at menarche exhibit U-shaped associations with all-cause mortality. Women with mismatch of actual age and genetically determined age at menarche may have the highest risk of all-cause mortality.

Influence of Childhood Adversity and Infection on Timing of Menarche in a Multiethnic Sample of Women

Childhood adversities (CAs) and infections may affect the timing of reproductive development. We examined the associations of indicators of CAs and exposure to tonsillitis and infectious mononucleosis (mono) with age at menarche. A multiethnic cohort of 400 women (ages 40–64 years) reported exposure to parental maltreatment and maladjustment during childhood and any diagnosis of tonsillitis and/or mono; infections primarily acquired in early life and adolescence, respectively. We used linear and relative risk regression models to examine the associations of indicators of CAs individually and cumulatively, and history of tonsillitis/mono with an average age at menarche and early onset of menarche (<12 years of age). In multivariable models, histories of mental illness in the household (RR = 1.44, 95% CI: 1.01–2.06), and tonsillitis diagnosis (RR = 1.67, 95% CI: 1.20–2.33) were associated with early menarche (<12 years), and with an earlier average age at menarche by 7.1 months (95% CI: −1.15, −0.02) and 8.8 months (95% CI: −1.26, −0.20), respectively. Other adversities indicators, cumulative adversities, and mono were not statistically associated with menarcheal timing. These findings provided some support for the growing evidence that early life experiences may influence the reproductive development in girls.

Puberty timing and markers of cardiovascular structure and function at 25 years: a prospective cohort study

BACKGROUND

Whether earlier onset of puberty is associated with higher cardiovascular risk in early adulthood is not well understood. Our objective was to examine the association between puberty timing and markers of cardiovascular structure and function at age 25 years.

METHODS

We conducted a prospective birth cohort study using data from the Avon Longitudinal Study of Parents and Children (ALSPAC). Participants were born between April 1, 1991, and December 31, 1992. Exposure of interest was age at peak height velocity (aPHV), an objective and validated growth-based measure of puberty onset. Outcome measures included cardiovascular structure and function at age 25 years: carotid intima-media thickness (CIMT), left ventricular mass index (LVMI) and relative wall thickness (RWT), pulse wave velocity (PWV) and systolic blood pressure (SBP). Multiple imputation was used to impute missing data on covariates and outcomes. Linear regression was used to examine the association between aPHV and each measure of cardiac structure and function, adjusting for maternal age, gestational age, household social class, maternal education, mother's partner's education, breastfeeding, parity, birthweight, maternal body mass index, maternal marital status, maternal prenatal smoking status and height and fat mass at age 9. All analyses were stratified by sex.

RESULTS

A total of 2752-4571 participants were included in the imputed analyses. A 1-year older aPHV was not strongly associated with markers of cardiac structure and function in males and females at 25 years and most results spanned the null value. In adjusted analyses, a 1-year older aPHV was associated with 0.003 mm (95% confidence interval (CI) 0.00001, 0.006) and 0.0008 mm (95% CI - 0.002, 0.003) higher CIMT; 0.02 m/s (95% CI - 0.05, 0.09) and 0.02 m/s (95% CI - 0.04, 0.09) higher PWV; and 0.003 mmHg (95% CI - 0.60, 0.60) and 0.13 mmHg (95% CI - 0.44, 0.70) higher SBP, among males and females, respectively. A 1-year older aPHV was associated with - 0.55 g/m2.7 (95% CI - 0.03, - 1.08) and - 0.89 g/m2.7 (95% CI - 0.45, - 1.34) lower LVMI and - 0.001 (95% CI - 0.006, 0.002) and - 0.002 (95% CI - 0.006, 0.002) lower RWT among males and females.

CONCLUSIONS

Earlier puberty is unlikely to have a major impact on pre-clinical cardiovascular risk in early adulthood.

Early menarche and its consequence in Korean female: reducing fructose intake could be one solution

The mean age at menarche (AAM) of Korean females has been rapidly decreasing over the last 50 years; currently, the prevalence of early menarche (<12 years) is 22.3%. Female adolescents who experience early menarche are known to be at greater risk of psychosocial and behavioral problems along with several physical health problems such as menstrual problems. They also tend to achieve a shorter final height and develop obesity. Population-based Korean studies have shown a strong association between early menarche and the risk of obesity, insulin resistance, metabolic syndrome, nonalcoholic fatty liver disease, diabetes, breast cancer, and cardiovascular disease in adulthood. Although the exact mechanism of how early menarche causes cardiometabolic derangement in later adulthood is unknown, childhood obesity and insulin resistance might be major contributors. Recent studies demonstrated that an excessive consumption of fructose might underlie the development of obesity and insulin resistance along with an earlier AAM. A positive association was observed between sugar-sweetened beverages (a major source of fructose) intake and obesity, metabolic syndrome, insulin resistance, and cardiometabolic risk in Korean females. In pediatrics, establishing risk factors is important in preventing disease in later life. In this regard, early menarche is a simple and good marker for the management of cardiometabolic diseases in adulthood. Decreasing one's fructose intake might prevent early menarche as well as the development of obesity, insulin resistance, and cardiometabolic diseases.

Is there any association between age at menarche and anthropometric indices? A 15-year follow-up population-based cohort study

Anthropometric indices (AI) have been known to be associated with age at menarche (AAM). The aim of this longitudinal study was to evaluate the changes in AI and its association with AAM in a community-based population in Iran. From among 10,192 women, we included 6818, aged ≥ 10 years, who were post-menarche at the time of entering the study and their AAM ranged between 8 and 18 years. Study subjects were divided into groups by tertiles birth cohort (BC) (born ≤ 1939, 1940-1969, and ≥ 1970) and AAM (≤ 11, 12-15, and ≥ 16 years). Generalized estimating equation analysis was performed to evaluate the association between changes of AI in different BCs with AAM groups. Overall mean of AAM was 13.5 ± 1.4 years. Mean body mass index (BMI) was significantly increased over time more in those with early AAM (≤ 11 years) compared to those with AAM ≥ 16 years; changes in mean BMI of 1.24 kg/m² (95% CI 0.32, 2.15), 2.61 kg/m² (95% CI 1.90, 3.33), and 3.99 kg/m² (95% CI 2.46, 5.51) in BC ≥ 1970, BC (1940-1969), and, BC ≤ 1939, respectively.Conclusion: Our findings showed an inverse association of AAM with mean BMI, waist to height ratio, and waist circumference, an association weaker in younger women compared to other age groups. What is Known: • Limited data are available on the association of menarcheal age with anthropometric indices. • Previous studies reported conflicting and inclusive results of this association. What is New: • Our results can provide beneficial information on the association of menarcheal age with anthropometric indices based on different age groups. • This long follow-up study shows an association of menarcheal age with anthropometric indices which are stronger in older women except for 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.

Childhood Adversity and Pubertal Development Among Puerto Rican Boys and Girls

OBJECTIVE

Evidence stemming largely from retrospective studies suggests that childhood adversity (CA) is associated with earlier age at menarche, a marker of pubertal timing, among girls. Little is known about associations with pubertal tempo among boys or racial/ethnic minorities. We examined the association between CA and timing and tempo of pubertal development among boys and girls.

METHODS

The Boricua Youth Study is a longitudinal study of Puerto Rican youth residing in the San Juan metro area in Puerto Rico and the South Bronx, New York. CA was based on caretaker reports of parental loss and parental maladjustment and youth reports of child maltreatment and exposure to violence. Youth completed the Pubertal Development Scale (PDS) yearly for 3 years. In linear mixed models stratified by sex, we examined the association between CA and pubertal timing and tempo, adjusting for site, socioeconomic status, and age.

RESULTS

Among the 1949 children who were 8 years or older by wave 3, cumulative CA was associated with higher PDS scores among girls compared with girls not exposed to CA (PDS score: 2.63 [95% confidence interval {CI} = 2.55-2.71] versus 2.48 [95% CI = 2.37-2.58]). In contrast, among boys, experiencing adversities was associated with lower pubertal developmental stage or later timing (PDS: 1.77 [95% CI = 1.67-1.87] versus 1.97 [95% CI = 1.85-2.10]) compared with those not exposed to adversities.

CONCLUSIONS

Associations between CA and pubertal development may vary by sex. Understanding the etiological role of adversities on pubertal development and identifying targets for intervention are of utmost importance in ameliorating the impact of CA on child health.

Age at onset of different pubertal signs in boys and girls and differential DNA methylation at age 10 and 18 years: an epigenome-wide follow-up study

STUDY QUESTION

Is the age of onset of pubertal markers related to subsequent changes in DNA methylation (DNAm)?

SUMMARY ANSWER

We identified 273 cytosine-phosphate-guanine (CpG) dinucleotides in girls and 67 CpGs in boys that were related to puberty and that were replicable in two other investigations.

WHAT IS KNOWN ALREADY

Previously, 457 CpGs (not gender-specific) and 347 (in girls) and 50 (in boys), respectively, were found to be associated with puberty, according to investigations of studies from Denmark (20 girls and 31 boys) and North America (30 girls and 25 boys).

STUDY DESIGN SIZE DURATION

The study was based on a birth cohort of 1456 participants born in 1989/90, with follow-up at age 10 and 18 years.

PARTICIPANTS/MATERIALS SETTING METHODS

The follow-up included 470 participants with information on DNAm and age of pubertal onset (244 girls and 226 boys). Age of pubertal onset was ascertained retrospectively at age 18 years. Using the Pubertal Development Scale, both genders were asked about ages of onset of growth spurt, body hair growth and skin changes. Ages at voice deepening and growth of facial hair were inquired from boys; ages at breast development and menarche from girls. Blood samples were collected at 10 and 18 years of age. DNA was extracted using a standard salting out procedure. The methylation level for each CpG site was assessed using one of two different platforms. DNAm was measured by a ratio of intensities denoted as β values for each CpG site. After quality control, 349 455 CpG sites were available for analysis. M values were calculated (log2(β/(1-β)) to approximate a normal distribution, and their levels were adjusted for blood cell proportions. Linear mixed models were applied to test the association between age of pubertal markers and repeated measurement of DNAm at 10 and 18 years.

MAIN RESULTS AND THE ROLE OF CHANCE

In girls, a total of 63 019 CpGs statistically significantly changed after occurrence of any of the five pubertal events and 13 487 were changed subsequent to all five events: the respective number is boys were 3072 and 301. To further exclude false-positive findings, we investigated which CpGs were replicable in prior studies from Denmark or North America, resulting in 273 replicable CpG in girls and 67 CpGs in boys (236 and 68 genes, respectively). Most identified genes are known to be related to biological processes of puberty; however, genetic polymorphisms of only four of these genes were previously linked to pubertal markers in humans.

LIMITATIONS REASONS FOR CAUTION

The relative age of pubertal onset to the age of DNAm measurements does not allow causal inference, since DNAm at an earlier age may have affected the pubertal age or pubertal age may have altered later DNAm. This investigation concentrates on autosomes. CpGs on X and Y chromosomes are not included in the current study.

WIDER IMPLICATIONS OF THE FINDINGS

Assessment of biological processes involved in pubertal transitions should include epigenetic information. Differential DNAm related to puberty needs to be investigated to determine whether it can act as an early marker for adult diseases known to be associated with puberty.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by NIH grants R03HD092776 (Epigenetic characterization of pubertal transitions) and R01AI121226. The 10-year follow-up of this study was funded by National Asthma Campaign, UK (Grant No 364), and the 18-year follow-up by a grant from the National Heart and Blood Institute (R01 HL082925). The authors have no conflicts to report.

Negative Effects of Age at Menarche on Risk of Cardiometabolic Diseases in Adulthood: A Mendelian Randomization Study

CONTEXT

Observational studies have demonstrated that early menarche is associated with cardiometabolic diseases, but confounding factors make it difficult to infer causality.

OBJECTIVE

We used Mendelian randomization (MR) to examine whether age at menarche (AAM) is causally associated with type 2 diabetes (T2D), coronary artery disease (CAD) and cardiometabolic traits.

DESIGN AND METHODS

A 2-sample MR analysis was conducted using genome-wide association study (GWAS) summary statistics from the Diabetes Genetics Replication and Meta-analysis (DIAGRAM) consortium (n = 159 208) for T2D and the Coronary Artery Disease Genome-wide Replication and Meta-analysis plus the Coronary Artery Disease Genetics (CARDIoGRAMplusC4D) consortium (n = 184 305) for CAD. We used 122 instrumental variables (IVs) extracted from a published GWAS meta-analysis incorporating 182 416 women to determine the causal effect of AAM on cardiometabolic diseases, treating childhood and adult body mass index (BMI) as the confounders. Sensitivity analyses were also performed to detect the pleiotropy of the IVs.

RESULTS

Employing the MR approach, we found that later AAM was associated with decreased risk of CAD (OR, 0.92 [95% CI, 0.88-0.96]; P = 2.06 × 10-4) in adults, as well as lower blood levels of log fasting insulin, log homeostatic model assessment of insulin resistance (HOMA-IR), log HOMA of β-cell function (HOMA-B), triglycerides, and diastolic blood pressure, but higher blood level of high-density lipoprotein. However, the associations were substantially attenuated after excluding BMI-related variants. MR analyses provide little evidence on the causal effect between AAM and T2D.

CONCLUSIONS

Our findings showed that AAM did not appear to have a causal effect on the risk of cardiometabolic diseases in adult life, as their associations observed in epidemiological studies might be largely mediated through excessive adiposity. We propose adiposity might be a primary target in future intervention strategy.

Age at menarche and risk of all-cause and cardiovascular mortality: a systematic review and dose-response meta-analysis

OBJECTIVE

The evidence between age at menarche and mortality risk is controversial. We aimed to quantify the dose-response association of age at menarche and risk of all-cause and cardiovascular disease (CVD) mortality based on cohort studies.

METHODS

PubMed, EMBASE, Web of Science, and Scopus databases were searched up to March 15, 2018 for relevant articles. Random-effects models and restricted cubic splines were used for this meta-analysis.

RESULTS

Twelve cohort studies, with 79,363 deaths and 2,341,769 participants, met the inclusion criteria. With each 1-year increase in menarche age, the relative risk (RR) was reduced for all-cause mortality (RR: 0.977, 95% confidence interval [CI]: 0.970-0.984), CVD mortality (RR: 0.993, 95% CI: 0.975-1.011), ischemic heart disease (IHD) mortality (RR: 0.969, 95% CI: 0.947-0.993), and stroke mortality (RR: 0.983, 95% CI: 0.954-1.012). We found a nonlinear dose-response association (Pnonlinearity = 0.001) between age at menarche and all-cause mortality, with the lowest risk observed at menarche age 15 years (RR: 0.849 95% CI: 0.800-0.901), but no evidence of a nonlinear association between menarche age and CVD mortality (Pnonlinearity = 0.543), IHD mortality (Pnonlinearity = 0.310), or stroke mortality (Pnonlinearity = 0.824).

CONCLUSIONS

Age at menarche is inversely associated with all-cause and IHD mortality.

Ages at menarche and menopause, and mortality among postmenopausal women

OBJECTIVES

Although both age at menarche and age at menopause may independently affect the risk of cardiovascular diseases and all-cause mortality, their joint association with mortality is less clear. The objectives of this study were to address the relationship between ages at menarche and at menopause with mortality among postmenopausal women.

STUDY DESIGN

The study included 75,359 U.S. postmenopausal women aged 50-78 years from the Prostate, Lung, Colorectal, and Ovarian (PLCO) cohort. Information on ages at menarche and menopause was self-reported and collected at baseline, by questionnaire.

MAIN OUTCOME MEASURES

All-cause, cardiovascular and cancer mortality.

RESULTS

After a median follow-up of 13 years, we identified 7826 deaths among 75,359 women in the PLCO cohort. Compared with women with an age at menarche of 12-13 years and an age at menopause of 45-54 years, the adjusted hazard ratios (95% confidence interval) for all-cause mortality for women with early menarche (≤11 years) and menopause (≤44 years) and those with late menarche (≥14 years) and menopause (≥55 years) were 1.20 (1.09, 1.32) and 0.82 (0.71, 0.96), respectively. This association remained significant in a sensitivity analysis that excluded women who did not undergo natural menopause. The indexes for the additive effect of the combined association showed no excess risk due to an interaction.

CONCLUSIONS

Early menarche and early menopause seemed to have an exactly additive effect on all-cause mortality. The findings suggest that it is important to evaluate ages at both menarche and menopause rather than to consider either variable on its own in assessing the risk of mortality.

Prevalence of cardiovascular risk factors in non-menopausal and postmenopausal inpatients with type 2 diabetes mellitus in China

BACKGROUND

To investigate the prevalence of cardiovascular disease (CVD) risk factors and assess the 10-year risk of CVD in non-menopausal and postmenopausal women with type 2 diabetes mellitus (T2DM).

METHODS

A total of 569 patients with T2DM at a Chinese tertiary hospital were investigated using the Framingham Risk Score (FRS). We evaluated the 10-year risk of CVD, clinical and menopause characteristics in all subjects.

RESULTS

Among the 569 diabetic patients, the incidence of smoking, dyslipidemia, hypertension, overweight or obesity, and nonalcoholic fatty liver disease (NAFLD) was 0.7, 36.2, 38.1 56.6 and 58.2%, respectively. The usage rate of hypoglycemic agents, antihypertensive agents, lipid modulators and antithrombotic drugs was 88.6, 78.3, 50.0 and 27.1%, respectively. However, only 1.2% of inpatients achieved the three target goals for the control of blood glucose (HbA_1c < 7%), blood pressure (systolic blood pressure < 130 mmHg, diastolic blood pressure < 80 mmHg), and blood lipids (total cholesterol < 174 mg/dL). The 10-year risk of CVD was (1.6 ± 1.5%) and tended to increase along with age (F = 27.726, P <  0.001). For all subjects (n = 569), multiple linear regression analysis showed that menopause (β = 0.275, P <  0.001), low-density lipoprotein cholesterol (LDL-C) (β = 0.212, P <  0.001), fasting plasma glucose (FPG) (β = 0.093, P = 0.018) and waist-to-hip-ratio (β = - 0.078, P = 0.047) were risk factors of 10-year risk of CVD, which may explain the variance of 14.3%. In the postmenopausal group (n = 397), LDL-C (β = 0.227, P <  0.001), FPG (β = 0.139, P = 0.003) and time since menopause (β = 0.230, P <  0.001) were found to be associated with CVD, which may explain the variance of 14.6%.

CONCLUSION

The incidence of dyslipidmia, hypertension, overweight or obesity and NAFLD is high. The level of control of blood glucose, blood pressure, and blood lipids was found to be extremely low and the treatment status was not ideal. Besides menopause, LDL-C, FPG and time since menopause were found to be independent risk factors for the 10-year risk of CVD. Therefore, it is necessary to focus on comprehensive control of multiple risk factors, such as plasma glucose, blood pressure and serum lipid.

The relationship between pubertal timing and markers of vascular and cardiac structure and function in men and women aged 60-64 years

Earlier age at menarche has been associated with higher risk of coronary heart disease, but the mechanisms underlying the association remain unclear. We assessed the relationship of pubertal timing, in both men (n = 672) and women (n = 713), with vascular (carotid intima-media thickness (cIMT), pulse wave velocity (PWV)) and cardiac (left ventricular (LV) structure and function) measures recorded at age 60–64 yrs in a British birth cohort study. Regression models found that earlier menarche was associated with higher (more adverse) LV mass, LV end diastolic volume and left atrial volume, but not with other cardiac measures, cIMT or PWV. Associations were attenuated after adjustment for either adult or childhood BMI (e.g. mean difference in LV mass per year later menarche: −4.2 g (95% CI:−7.0,−1.4) reducing to −2.2 g (95% CI:−4.7,0.4) after adjustment for adult BMI). There were no associations among men, despite those fully mature at 15 yrs having higher blood pressure than the least mature group by 10.21 mmHg (95% CI:19.45,0.98). Any effect of pubertal timing on vascular and cardiac structure and function is likely to be small and primarily confounded by pre-pubertal BMI and/or mediated through adult adiposity.

Age at Menarche and Risk of Cardiovascular Disease Outcomes: Findings From the National Heart Lung and Blood Institute-Sponsored Women's Ischemia Syndrome Evaluation

Background

Previous studies have reported an association between the timing of menarche and cardiovascular disease (CVD). However, emerging studies have not examined the timing of menarche in relation to role of estrogen over a lifetime and major adverse cardiac events (MACE).

Methods and Results

A total of 648 women without surgical menopause undergoing coronary angiography for suspected ischemia in the WISE (Women's Ischemia Syndrome Evaluation) study were evaluated at baseline and followed for 6 years (median) to assess major adverse CVD outcomes. MACE was defined as the first occurrence of all‐cause death, nonfatal myocardial infarction, nonfatal stroke, or heart failure hospitalization. Age at menarche was self‐reported and categorized (≤10, 11, 12, 13, 14, ≥15 years) with age 12 as reference. Total estrogen time and supra–total estrogen time were calculated. Cox regression analysis was performed adjusting for CVD risk factors. Baseline age was 57.9 ± 12 years (mean ± SD), body mass index was 29.5 ± 6.5 kg/m², total estrogen time was 32.2 ± 8.9 years, and supra–total estrogen time was 41.4 ± 8.8 years. MACE occurred in 172 (27%), and its adjusted regression model was J‐shaped. Compared with women with menarche at age 12 years, the adjusted MACE hazard ratio for menarche at ≤10 years was 4.53 (95% CI 2.13‐9.63); and at ≥15 years risk for MACE was 2.58 (95% CI, 1.28‐5.21).

Conclusions

History of early or late menarche was associated with a higher risk for adverse CVD outcomes. These findings highlight age at menarche as a potential screening tool for women at risk of adverse CVD events.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00000554.

Variations in reproductive events across life: a pooled analysis of data from 505 147 women across 10 countries

STUDY QUESTION

How has the timing of women's reproductive events (including ages at menarche, first birth, and natural menopause, and the number of children) changed across birth years, racial/ethnic groups and educational levels?

SUMMARY ANSWER

Women who were born in recent generations (1970-84 vs before 1930) or those who with higher education levels had menarche a year earlier, experienced a higher prevalence of nulliparity and had their first child at a later age.

WHAT IS KNOWN ALREADY

The timing of key reproductive events, such as menarche and menopause, is not only indicative of current health status but is linked to the risk of adverse hormone-related health outcomes in later life. Variations of reproductive indices across different birth years, race/ethnicity and socioeconomic positions have not been described comprehensively.

STUDY DESIGN, SIZE, DURATION

Individual-level data from 23 observational studies that contributed to the International Collaboration for a Life Course Approach to Reproductive Health and Chronic Disease Events (InterLACE) consortium were included.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Altogether 505 147 women were included. Overall estimates for reproductive indices were obtained using a two-stage process: individual-level data from each study were analysed separately using generalised linear models. These estimates were then combined using random-effects meta-analyses.

MAIN RESULTS AND THE ROLE OF CHANCE

Mean ages were 12.9 years at menarche, 25.7 years at first birth, and 50.5 years at natural menopause, with significant between-study heterogeneity (I2 > 99%). A linear trend was observed across birth year for mean age at menarche, with women born from 1970 to 1984 having menarche one year earlier (12.6 years) than women born before 1930 (13.5 years) (P for trend = 0.0014). The prevalence of nulliparity rose progressively from 14% of women born from 1940-49 to 22% of women born 1970-84 (P = 0.003); similarly, the mean age at first birth rose from 24.8 to 27.3 years (P = 0.0016). Women with higher education levels had fewer children, later first birth, and later menopause than women with lower education levels. After adjusting for birth year and education level, substantial variation was present for all reproductive events across racial/ethnic/regional groups (all P values < 0.005).

LIMITATIONS, REASONS FOR CAUTION

Variations of study design, data collection methods, and sample selection across studies, as well as retrospectively reported age at menarche, age at first birth may cause some bias.

WIDER IMPLICATIONS OF THE FINDINGS

This global consortium study found robust evidence on variations in reproductive indices for women born in the 20th century that appear to have both biological and social origins.

STUDY FUNDING/COMPETING INTEREST(S)

InterLACE project is funded by the Australian National Health and Medical Research Council project grant (APP1027196). GDM is supported by the Australian National Health and Medical Research Council Principal Research Fellowship (APP1121844).

Association between duration of endogenous estrogen exposure and cardiovascular outcomes: A population - based cohort study

AIMS

Duration of endogenous estrogen exposure is apparently associated with risk of cardiovascular disease, the longer durations being more cardiovascular disease protective in women. We aimed to investigate the association of cumulative duration of endogenous estrogen exposure over women's reproductive lifespans with cardiovascular disease outcomes.

MAIN METHODS

For the purpose of the present study, of 10,192 female participants, after excluding those using HRT (n = 84), 3656 women, aged ≥30 years, who met eligibility criteria were selected and divided into three groups based on tertiles (T1, T2, T3) of exposure durations to endogenous estrogen. Cox proportional hazards regression model was used to estimate associations between exposure durations and cardiovascular disease outcomes.

KEY FINDINGS

Cardiovascular events occurred in 352 participants over a median follow-up of 14.2 (13.5, 14.6) years (7.7 per 1000 person years; 95% CI: 6.9-8.5). Incidence of outcome was 10.9 per 1000 person years (CI, 9.4-12.8) in T₁, 7.2 per 1000 person years (CI, 6.0-8.7) in T₂, and 5.1 per 1000 person years (CI, 4.1-6.4) in T₃. The hazard ratio of cardiovascular events in T₁ was significantly higher than that inT₃, before and after adjustment for confounding variables. Before adjustment, women in T₂ had a 40% higher risk of CVD, compared to T₃; after adjustment however the risk was similar to that of women in T₃.

SIGNIFICANCE

Shorter durations of exposure to endogenous estrogen may increase the risk of cardiovascular diseases among these women later in life. Future studies should target women with short duration of exposure for timely screening and implementation of preventative interventions.

Age at menarche and childhood body mass index as predictors of cardio-metabolic risk in young adulthood: A prospective cohort study

OBJECTIVE

This study aimed to examine the association between age at menarche and a range of cardiovascular disease (CVD) risk factors at 17 and 20 years of age, and whether this was influenced by childhood body mass index (BMI).

METHODS

Of the 1413 girls born in the Western Australian Pregnancy Cohort (Raine) Study, 846 had age at menarche recorded. Subsequently 557 underwent metabolic assessment at 17 years and 541 at 20 years. Associations between age at menarche and cardiovascular risk factors, and being in a high-risk metabolic cluster at 17 and 20 years, or having the metabolic syndrome at 20 years, were investigated by linear mixed effects and logistic regressions, respectively.

RESULTS

Each year later of onset of menarche was associated with a 0.75 kg/m2 reduction in BMI (coefficient -0.75 [95%CI -1.06, -0.44]), and an approximate 30% reduction in the odds of being in the high-risk metabolic cluster at 17 years (OR = 0.73 [95%CI 0.57, 0.94]) and 20 years of age (OR = 0.68 [95%CI 0.52, 0.87]), and a 40% reduction in the odds of having the metabolic syndrome at 20 years (OR = 0.60 [95% CI 0.41, 0.88]). These data show earlier age at menarche was associated with increased BMI and odds of being in the high-risk metabolic cluster at 17 and 20 years, and increased odds of having the metabolic syndrome at 20 years. However, these associations were no longer statistically significant after adjustment for BMI at age 8 years. Current smoking, alcohol consumption, physical activity, socio-economic status, or hormonal contraceptives use did not affect these associations.

CONCLUSIONS

Earlier age at menarche may be indicative of a higher risk profile for CVD in young adulthood. Our findings suggest that targeted interventions to reduce BMI in girls who experience menarche at younger age may reduce CVD risk in the future.

Menopause Characteristics, Total Reproductive Years, and Risk of Cardiovascular Disease Among Chinese Women

Supplemental Digital Content is available in the text.

Background—

Previous studies, mostly of Western women, have reported inconsistent findings on the association of menopause characteristics (status, age, and time since menopause) and total reproductive years with risk of cardiovascular disease (CVD).

Methods and Results—

The China Kadoorie Biobank recruited 302 632 women in 2004 to 2008 from 10 regions across China. During 9-year follow-up, 19 393 incident cases of stroke, 18 611 of ischemic heart disease, and 4978 CVD deaths occurred. Cox regression yielded adjusted hazard ratios relating each menopause characteristic and total reproductive years to CVD risk. Among 274 233 women with no prior CVD at baseline, 134 010 were naturally postmenopausal women (mean [SD] age at menopause of 48.6 [4.0] years and total reproductive years 32.7 [4.4]). Compared with premenopausal women, naturally peri- or postmenopausal women were at a higher risk of either fatal or nonfatal CVD. Among women who had had menopause, inverse associations were observed between age at menopause and risks of CVD mortality, incident ischemic heart disease, stroke, and subtypes of stroke, with 1.5% higher risk of CVD death (P<0.001), 0.7% for incident ischemic heart disease (P=0.002), and 0.5% for incident stroke (P=0.02) for every 1 year lower age at menopause. Compared with women who had menopause at age 48 to 50 years, lower age at menopause (ie, <43 years) was associated with 14% higher risk of CVD death and 6% higher risks of both incident ischemic heart disease and stroke. Higher risks of both fatal and nonfatal CVD were also found in women with 5 to 10, 10 to 15, 15 to 20, or >20 years since menopause compared with <5 years since menopause. Total reproductive years were inversely associated with risks of both fatal and nonfatal CVD, with 1.4% lower risk of CVD death per additional reproductive year (P<0.001).

Conclusions—

Women with younger age at menopause, longer time since menopause, or fewer total reproductive years had a higher risk of CVD.

Sex Differences in the Burden and Complications of Diabetes

PURPOSE OF THE REVIEW

To review the latest evidence on sex differences in the burden and complications of diabetes and discuss the potential explanations for the sex differences described.

RECENT FINDINGS

Diabetes is a strong risk factor for vascular disease, with compelling evidence that the relative risks of vascular diseases conferred by diabetes are considerably greater in women than men. The mechanisms underpinning women's excess relative risk of vascular disease from diabetes are unknown. Sex differences in the health care provided for the prevention, management, and treatment of diabetes and its complications could contribute to women's greater excess relative risks of diabetes complications. However, since the excess risk of vascular disease is not seen for other major vascular risk factors, inherent biological factors may be more likely to be involved. In addition to other cardiometabolic pathways, the sex dimorphism in body composition and fat distribution may be particularly important in explaining women's greater excess risk of the vascular complications of diabetes. There is strong evidence to suggest that diabetes is a stronger risk factor for vascular disease in women than men. Although several mechanisms may be involved, further research is needed to provide new and deeper insights into the mechanisms underpinning sex differences in the association between diabetes and vascular diseases. Such research will inform patients, health care professionals, and policy makers to ensure that women are not disproportionately affected by diabetes, and will help to reduce the burden in both sexes.

Validity of self-reported age at menarche in computer-assisted interview among Chinese schoolgirls: a cross-sectional study

OBJECTIVE

The attitudes of girls regarding menarche vary according to their cultural backgrounds. Asian girls may hesitate to discuss menarche. Computer-assisted self-administered interviewing (CASI) is considered a valid and effective tool for investigating the timing of menarche; however, the validity of self-reported menarche data from CASI in Chinese culture is currently unknown. We aimed to validate the status and age of menarche attainment by comparing CASI with face-to-face interviewing (FFI).

METHODS

Based on a cross-sectional study, we collected information regarding the status and age of menarche attainment using CASI and FFI among Chinese schoolgirls. We explored the tools of standard epidemiological indices, including sensitivity, specificity, predictive values and accuracy to examine the capacity of CASI for correctly classifying the status of menarche. Both Pearson and Spearman correlations were calculated for the correlation of age at menarche using CASI with FFI. A Bland-Altman plot was drawn to measure the agreement between the two interview techniques.

RESULTS

In this study, CASI and FFI were conducted in 3478 schoolgirls with an average age (SD) of 14.3 years (2.46). Menarche attainment was reported in 2496 (71.2%) and 2538 (73.0%) girls using CASI and FFI, respectively. Compared with FFI, the sensitivity, specificity, positive predictive value (PPV), negative predictive value and the accuracy of CASI were 0.97, 0.80, 0.96 and 0.92, respectively. The correlation of age at menarche between CASI and FFI was 0.728. Approximately >95% and 76.3% of the difference in the age at menarche was within 12 months and 3 months, respectively, between the two interview methods. Among primary schoolgirls in grade 5, the sensitivity, specificity, PPV, accuracy and the correlation (0.335) of CASI was lower than those in other subgroups.

CONCLUSIONS

Overall, the timing of menarche investigated using CASI was valid among all Chinese schoolgirls, except for those in grade 5 or lower.

Women's reproductive factors and incident cardiovascular disease in the UK Biobank

BACKGROUND

Studies have suggested that women's reproductive factors are associated with the risk of cardiovascular disease (CVD); however, findings are mixed. We assessed the relationship between reproductive factors and incident CVD in the UK Biobank.

METHODS

Between 2006 and 2010, the UK Biobank recruited over 500 000 participants aged 40-69 years across the UK. During 7 years of follow-up, 9054 incident cases of CVD (34% women), 5782 cases of coronary heart disease (CHD) (28% women), and 3489 cases of stroke (43% women) were recorded among 267 440 women and 215 088 men without a history of CVD at baseline. Cox regression models yielded adjusted hazard ratios (HRs) for CVD, CHD and stroke associated with reproductive factors.

RESULTS

Adjusted HRs (95% CI) for CVD were 1.10 (1.01 to 1.30) for early menarche (<12 years), 0.97 (0.96 to 0.98) for each year increase in age at first birth, 1.04 (1.00 to 1.09) for each miscarriage, 1.14 (1.02 to 1.28) for each stillbirth, and 1.33 (1.19 to 1.49) for early menopause (<47 years). Hysterectomy without oophorectomy or with previous oophorectomy had adjusted HRs of 1.16 (1.06 to 1.28) and 2.30 (1.20 to 4.43) for CVD. Each additional child was associated with a HR for CVD of 1.03 (1.00 to 1.06) in women and 1.03 (1.02 to 1.05) in men.

CONCLUSIONS

Early menarche, early menopause, earlier age at first birth, and a history of miscarriage, stillbirth or hysterectomy were each independently associated with a higher risk of CVD in later life. The relationship between the number of children and incident CVD was similar for men and women.

Association Between Duration of Reproductive Years and Metabolic Syndrome

BACKGROUND

The incidence of metabolic syndrome (MetS) has gradually increased in recent years. MetS has been associated with age at menarche and menopause; however, the association between MetS and the reproductive span remains unclear.

MATERIALS AND METHODS

This study examined MetS and the reproductive span among 1,214 participants of the 2014 Korea National Health and Nutrition Examination Surveys, a stratified, complex, multistage, probability cluster survey conducted by the Division of Chronic Disease Surveillance of the Korea Center for Disease Control and Prevention since 1998. MetS was defined by using the joint interim statement of the International Diabetes Federation; National Heart, Lung, and Blood Institute; and American Heart Association. The reproductive span or duration of reproductive years was calculated from age at menarche to age at menopause for postmenopausal women.

RESULTS

The prevalence of MetS in this study was 36% (437 of 1,214). In multivariate analysis adjusted for age, longer reproductive years were associated with a higher prevalence of MetS (odds ratio [OR] 1.059, 95% confidence interval [CI] 1.055-1.063). However, after adjusting for covariates (age, residential area, income, dyslipidemia medication, education, current smoking, regular exercise, alcohol consumption, body mass index, years after menopause, aspartate aminotransferase, alanine aminotransferase, and white and red blood cell counts), longer reproductive years were associated with a lower prevalence of MetS (OR 0.751, 95% CI 0.745-0.747).

CONCLUSION

Longer reproductive years were significantly associated with a decreased prevalence of MetS.

Age at menarche and cardiovascular risk factors using Mendelian randomization in the Guangzhou Biobank Cohort Study

Observational studies show earlier age at menarche associated with higher risk of cardiovascular disease although these studies could be confounded by childhood obesity or childhood socioeconomic position. We tested the hypothesis that earlier age at menarche is associated with poorer cardiovascular risk factors using a Mendelian randomization design. We conducted a Mendelian randomization study in a large Southern Chinese cohort, the Guangzhou Biobank Cohort Study (n=12,279), to clarify the causal role of menarche in cardiovascular disease risk factors including blood pressure, lipids, fasting glucose, adiposity and type 2 diabetes. A genetic allele score was obtained from single nucleotide polymorphisms associated with age at menarche using stepwise regression and with cross validation. Estimates of the association of age at menarche with cardiovascular disease risk factors were obtained using two stage least squares regression. Height was included as a positive control outcome. The F-statistic for the allele score (rs17268785, rs1859345, rs2090409, rs4452860 and rs4946651) was 19.9. Older age at menarche was associated with lower glucose (-0.39mmol/L per year older menarche, 95% confidence interval (CI) -0.78 to -0.001) but not clearly with any other cardiovascular risk factors. Older age at menarche was also associated with taller height. Age at menarche did not appear to affect cardiovascular disease risk factors except for glucose in an inverse manner. However, these results need to be confirmed in larger Mendelian randomization studies.