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

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.

Reproductive factors and their association with physical and comprehensive frailty in middle-aged and older women: a large-scale population-based study

STUDY QUESTION

Are women's reproductive factors associated with physical frailty and comprehensive frailty in middle-age and later life?

SUMMARY ANSWER

Early menarche at <13 years, age at menopause <45 years, surgical menopause, experiencing miscarriage and a shorter reproductive period of <35 years were associated with increased odds of frailty, while having two or three children was related to decreased likelihood of frailty.

WHAT IS KNOWN ALREADY

Evidence has shown that women are frailer than men in all age groups and across different populations, although women have longer lifespans. Female-specific reproductive factors may be related to risk of frailty in women.

STUDY DESIGN SIZE DURATION

A population-based cross-sectional study involved 189 898 women from the UK Biobank.

PARTICIPANTS/MATERIALS SETTING METHODS

Frailty phenotype and frailty index were used to assess physical frailty and comprehensive frailty (assessed using 38 health indicators for physical and mental wellbeing), respectively. Multivariable logistic regression models were used to estimate odds ratios (ORs) and 95% CI between reproductive factors and likelihood of physical frailty and comprehensive frailty. Restricted cubic spline models were used to test the non-linear associations between them. In addition, we examined the combined effect of categorized age at menopause and menopause hormone therapy (MHT) on frailty.

MAIN RESULTS AND THE ROLE OF CHANCE

There was a J-shape relationship between age at menarche, reproductive period, and frailty; age at menarche <13 years and >16 years, and reproductive period <35 years or >40 years were all associated with increased odds of frailty. There was a negative linear relationship between menopausal age (either natural or surgical) and odds of frailty. Surgical menopause was associated with 30% higher odds of physical frailty (1.34, 1.27-1.43) and 30% higher odds of comprehensive frailty (1.30, 1.25-1.35). Having two or three children was linked to the lowest likelihood of physical frailty (0.48, 0.38-0.59) and comprehensive frailty (0.72, 0.64-0.81). Experiencing a miscarriage increased the odds of frailty. MHT use was linked to increased odds of physical frailty in women with normal age at natural menopause (after 45 years), while no elevated likelihood was observed in women with early natural menopause taking MHT.

LIMITATIONS REASONS FOR CAUTION

The reproductive factors were self-reported and the data might be subject to recall bias. We lacked information on the types and initiation time of MHT, could not identify infertile women who later became pregnant, and the number of infertile women may be underestimated. Individuals participating in the UK Biobank are not representative of the general UK population, limiting the generalization of our findings.

WIDER IMPLICATION OF THE FINDINGS

The reproductive factors experienced by women throughout their life course can potentially predict frailty in middle and old age. Identifying these reproductive factors as potential predictors of frailty can inform healthcare providers and policymakers about the importance of considering a woman's reproductive history when assessing their risk for frailty.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by the National Key Research and Development Program of China (2022YFC2703800), National Natural Science Foundation of China (82273702), Science Fund Program for Excellent Young Scholars of Shandong Province (Overseas) (2022HWYQ-030), Taishan Scholars Project Special Fund (No. tsqnz20221103), and the Qilu Young Scholar (Tier-1) Program (202099000066). All authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

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.