Female reproductive factors and risk of all-cause and cause-specific mortality among women: The Japan Public Health Center–based Prospective Study (JPHC study)

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.

Changes in cardiovascular disease risk factors during menopausal transition in Japanese women: the Circulatory Risk in Communities Study (CIRCS)

OBJECTIVE

We aimed to longitudinally clarify the changes in cardiovascular disease risk factors associated with menopause in Japanese women in the 2000s.

METHODS

Of the 4,596 women who underwent health examinations between 2007 and 2012 in three communities of the Circulatory Risk in Communities Study, 263 women who reported going through menopause during that period were included in the study. We randomly selected 1,665 men as control subjects who participated in a health examination at least once between 2001 and 2009 and at least once between 2010 and 2018 by 1:1 pair-matching for age, community, and examination year. The health examination data from 3 to 6 years before (2001-2009) and after menopause age (2010-2018) were compared in terms of body mass index, systolic and diastolic blood pressure levels, serum total cholesterol, high-density lipoprotein cholesterol, non-high-density lipoprotein cholesterol, triglycerides, uric acid, hemoglobin A 1c , hemoglobin, aspartate aminotransferase, alanine aminotransferase, and current smoker status.

RESULTS

Compared with the men, the women showed a greater increase in serum total cholesterol (+16.7 vs -3.1 mg/dL, P < 0.001), non-high-density lipoprotein cholesterol (+15.9 vs -6.3 mg/dL, P < 0.001), fasting triglycerides (+1.2 vs +1.0 mg/dL, P = 0.027), triglycerides regardless of fasting status (+1.2 vs -0.9 mg/dL, P < 0.001), uric acid (+0.5 vs +0.2 mg/dL, P = 0.008), hemoglobin (+0.9 vs -0.3 g/dL, P < 0.001), aspartate aminotransferase (+2.9 vs -2.7 IU/L, P < 0.001), and alanine aminotransferase (+2.9 vs -2.6 IU/L, P < 0.001). No differences were found in the changes in body mass index, systolic and diastolic blood pressures, and hemoglobin A 1c between the women and the matched men.

CONCLUSIONS

Menopause may be a crucial factor related to changes in serum total cholesterol, non-high-density lipoprotein cholesterol, triglycerides, uric acid, hemoglobin, and liver enzymes.

Association of life-course reproductive duration with mortality: a population-based twin cohort study

BACKGROUND

Although age at menopause has been linked to mortality, the association between the entire reproductive lifespan and mortality remains unclear.

OBJECTIVE

This study aimed to examine to what extent life-course reproductive duration is associated with all-cause mortality and explore the role of a healthy lifestyle and familial background in such an association.

STUDY DESIGN

A total of 11,669 women (mean age, 63.54 years) from the Swedish Twin Registry were followed for up to 19 years. Information on reproductive duration (the interval between ages at menarche and menopause) and lifestyle factors (including smoking, alcohol consumption, and physical activity; divided into unfavorable/intermediate/favorable) was collected on the basis of a structured questionnaire. Survival status was obtained from the Sweden Cause of Death Register. The data were analyzed using generalized estimating equation models, Laplace regression, and conditional logistic regression.

RESULTS

In the generalized estimating equation model, compared with those with ≤34 reproductive years, the odds ratio (95% confidence interval) of all-cause mortality was 0.79 (0.68-0.90) for those with ≥40 reproductive years, which prolonged survival time by 0.84 (0.24-1.43) years. Women with ≥40 reproductive years plus a favorable lifestyle (odds ratio, 0.28; 95% confidence interval, 0.23-0.35) were at a lower risk of all-cause mortality than those with <40 reproductive years plus an unfavorable lifestyle. An additive interaction between ≥40 reproductive years and a favorable lifestyle on all-cause mortality was observed (attributable proportion, 0.584; 95% confidence interval, 0.016-1.151). The odds ratios in conditional logistic regression and generalized estimating equation models did not differ significantly (P=.67).

CONCLUSION

A longer reproductive lifespan is associated with reduced all-cause mortality and prolongs survival by 0.84 years. A favorable lifestyle may amplify the beneficial effect of longer reproductive lifespan on mortality. Familial background does not account for the observed association.

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.

Breastfeeding Is Associated With a Reduced Maternal Cardiovascular Risk: Systematic Review and Meta-Analysis Involving Data From 8 Studies and 1 192 700 Parous Women

Background

Breastfeeding has been robustly linked to reduced maternal risk of breast cancer, ovarian cancer, and type 2 diabetes. We herein systematically reviewed the published evidence on the association of breastfeeding with maternal risk of cardiovascular disease (CVD) outcomes.

Methods and Results

Our systematic search of PubMed and Web of Science of articles published up to April 16, 2021, identified 8 relevant prospective studies involving 1 192 700 parous women (weighted mean age: 51.3 years at study entry, 24.6 years at first birth; weighted mean number of births: 2.3). A total of 982 566 women (82%) reported having ever breastfed (weighted mean lifetime duration of breastfeeding: 15.6 months). During a weighted median follow‐up of 10.3 years, 54 226 CVD, 26 913 coronary heart disease, 30 843 stroke, and 10 766 fatal CVD events were recorded. In a random‐effects meta‐analysis, the pooled multivariable‐adjusted hazard ratios comparing parous women who ever breastfed to those who never breastfed were 0.89 for CVD (95% CI, 0.83–0.95; I²=79.4%), 0.86 for coronary heart disease (95% CI, 0.78–0.95; I²=79.7%), 0.88 for stroke (95% CI, 0.79–0.99; I²=79.6%), and 0.83 for fatal CVD (95% CI, 0.76–0.92; I²=47.7%). The quality of the evidence assessed with the Grading of Recommendations Assessment, Development, and Evaluation tool ranged from very low to moderate, which was mainly driven by high between‐studies heterogeneity. Strengths of associations did not differ by mean age at study entry, median follow‐up duration, mean parity, level of adjustment, study quality, or geographical region. A progressive risk reduction of all CVD outcomes with lifetime durations of breastfeeding from 0 up to 12 months was found, with some uncertainty about shapes of associations for longer durations.

Conclusions

Breastfeeding was associated with reduced maternal risk of CVD outcomes.

The association of reproductive history with hypertension and obesity according to menopausal status: the J-MICC Study

Previous studies have reported that the number of pregnancies and childbirths affected the risk of cardiovascular diseases (CVDs). However, the influence of reproductive history on hypertension and obesity, which are important risk factors for CVDs, is still unclear. Moreover, this association may vary depending on menopausal status. We evaluated the association of reproductive history with hypertension and obesity using a large cross-sectional dataset from the Japan Multi-Institutional Collaborative Cohort Study (J-MICC Study). At the baseline survey, physical data, blood samples, and self-reported health questionnaires were collected. Participants with insufficient data were excluded, and 24,558 women from eight study regions were included in this study. Logistic regression analysis was conducted to evaluate the association of reproductive history with hypertension and obesity using multivariable-adjusted odds ratios. In premenopausal women, childbirth showed a generally protective effect on hypertension but not on obesity. In postmenopausal women, childbirth was positively associated with obesity and hypertension but not with hypertension after adjusting for BMI. In conclusion, reproductive history was associated with hypertension and obesity in a large Japanese population, and this association differed between premenopausal and postmenopausal women.

Idiopathic early ovarian aging: is there a relation with premenopausal accelerated biological aging in young women with diminished response to ART?

PURPOSE

To evaluate whether young women with idiopathic early ovarian aging, as defined by producing fewer oocytes than expected for a given age over multiple in vitro fertilization (IVF) cycles, have changes in telomere length and epigenetic age indicating accelerated biological aging (i.e., increased risk of morbidity and mortality).

METHODS

A prospective cohort study was conducted at two Danish public fertility clinics. A total of 55 young women (≤ 37 years) with at least two IVF cycles with ≤ 5 harvested oocytes despite sufficient stimulation with follicle-stimulating hormone (FSH) were included in the early ovarian aging group. As controls, 52 young women (≤ 37 years) with normal ovarian function, defined by at least eight harvested oocytes, were included. Relative telomere length (rTL) and epigenetic age acceleration (AgeAccel) were measured in white blood cells as markers of premenopausal accelerated biological aging.

RESULTS

rTL was comparable with a mean of 0.46 (± SD 0.12) in the early ovarian aging group and 0.47 (0.14) in the normal ovarian aging group. The AgeAccel of the early ovarian aging group was, insignificantly, 0.5 years older, but this difference disappeared when adjusting for chronological age. Sub-analysis using Anti-Müllerian hormone (AMH) as selection criterion for the two groups did not change the results.

CONCLUSION

We did not find any indications of accelerated aging in whole blood from young women with idiopathic early ovarian aging. Further investigations in a similar cohort of premenopausal women or other tissues are needed to fully elucidate the potential relationship between premenopausal accelerated biological aging and early ovarian aging.

Menstrual and reproductive factors and limitations in activities of daily living: A case-control study within the Japan Public Health Center-based Prospective Study

AIM

Although menstrual/reproductive factors are known to be associated with physical disability, little is known about these associations in relation to activities of daily living (ADL). This study aimed to clarify associations between menstrual/reproductive factors and ADL limitations in peri- and postmenopausal women.

STUDY DESIGN

A nested case-control study of the Japan Public Health Center-based Prospective (JPHC) Study.

METHODS

The main outcome measure was self-reported ADL levels in the 10-year follow-up questionnaire survey of the JPHC Study conducted between 2000 and 2004 (N = 36 460). Women who "live inside almost independently, but go out with assistance" or had a lower level of activity were considered to have ADL limitations ("cases"), and all others served as controls. Candidate menstrual/reproductive predictors were as follows: menarcheal age, menopausal status, menopausal age, regularity of menses, menstrual cycle, number of pregnancies, age at first pregnancy, number of deliveries, age at first delivery, and breast feeding. Multiple logistic regression analyses were conducted, and odds ratios adjusted for age and past lifestyle were calculated.

RESULTS

Mean ages of cases (N = 592) and controls (N = 38 656) were 68.3 (SD = 7.6) and 61.1 (SD = 7.7) years, respectively. With respect to menopausal age, groups aged <45 and ≥55 years had significantly higher adjusted ORs (1.44, 95% CI: 1.09-1.90 and 1.55, 95%CI: 1.09-2.18, respectively) than the reference group (50-54 years). Multiparous women had significantly lower ORs than nulliparous women.

CONCLUSION

Our findings suggest that menopausal age and parity may predict future ADL limitations in women.

Early ovarian ageing: is a low number of oocytes harvested in young women associated with an earlier and increased risk of age-related diseases?

STUDY QUESTION

Do young women with early ovarian ageing (EOA), defined as unexplained, and repeatedly few oocytes harvested in ART have an increased risk of age-related events?

SUMMARY ANSWER

At follow-up, women with idiopathic EOA had an increased risk of age-related events compared to women with normal ovarian ageing (NOA).

WHAT IS KNOWN ALREADY

Early and premature menopause is associated with an increased risk of cardiovascular diseases (CVDs), osteoporosis and death. In young women, repeated harvest of few oocytes in well-stimulated ART cycles is a likely predictor of advanced menopausal age and may thus serve as an early marker of accelerated general ageing.

STUDY DESIGN, SIZE, DURATION

A register-based national, historical cohort study. Young women (≤37 years) having their first ART treatment in a public or private fertility clinic during the period 1995-2014 were divided into two groups depending on ovarian reserve status: EOA (n = 1222) and NOA (n = 16 385). Several national registers were applied to assess morbidity and mortality.

PARTICIPANTS/MATERIALS, SETTING, METHODS

EOA was defined as ≤5 oocytes harvested in a minimum of two FSH-stimulated cycles and NOA as ≥8 oocytes in at least one cycle. Cases with known causes influencing the ovarian reserve (endometriosis, ovarian surgery, polycystic ovary syndrome, chemotherapy etc.) were excluded. To investigate for early signs of ageing, primary outcome was an overall risk of ageing-related events, defined as a diagnosis of either CVD, osteoporosis, type 2 diabetes, cancer, cataract, Alzheimer's or Parkinson's disease, by death of any-cause as well as a Charlson comorbidity index score of ≥1 or by registration of early retirement benefit. Cox regression models were used to assess the risk of these events. Exposure status was defined 1 year after the first ART cycle to assure reliable classification, and time-to-event was measured from that time point.

MAIN RESULTS AND THE ROLE OF CHANCE

Median follow-up time from baseline to first event was 4.9 years (10/90 percentile 0.7/11.8) and 6.4 years (1.1/13.3) in the EOA and NOA group, respectively. Women with EOA had an increased risk of ageing-related events when compared to women with a normal oocyte yield (adjusted hazard ratio 1.24, 95% CI 1.08 to 1.43). Stratifying on categories, the EOA group had a significantly increased risk for CVD (1.44, 1.19 to 1.75) and osteoporosis (2.45, 1.59 to 3.90). Charlson comorbidity index (1.15, 0.93 to 1.41) and early retirement benefit (1.21, 0.80 to 1.83) was also increased, although not reaching statistical significance.

LIMITATIONS, REASONS FOR CAUTION

Cycles never reaching oocyte aspiration were left out of account in the inclusion process and we may therefore have missed women with the most severe forms of EOA. We had no information on the total doses of gonadotrophin administered in each cycle.

WIDER IMPLICATIONS OF THE FINDINGS

These findings indicate that oocyte yield may serve as marker of later accelerated ageing when, unexpectedly, repeatedly few oocytes are harvested in young women. Counselling on life-style factors as a prophylactic effort against cardiovascular and other age-related diseases may be essential for this group of women.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was received for this study. All authors declare no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Reproductive Factors and Lung Cancer Risk among Never-Smoking Japanese Women with 21 Years of Follow-Up: A Cohort Study

BACKGROUND

Previous studies have reported inconsistent associations between reproductive factors and lung cancer.

METHODS

We used data from the Japan Public Health Center-based Prospective Study, which included 400 incident lung cancer cases (305 adenocarcinoma) among 42,615 never-smoking women followed for a median of 21 years, to examine the associations of reproductive and hormonal factors with lung cancer by histological type using Cox proportional hazards models.

RESULTS

Longer fertility span (≥36 years vs. ≤32 years) was associated with increased risk of lung adenocarcinoma (HR, 1.48; 95% CI, 1.07-2.06, P _trend = 0.01) but not with all lung cancer or nonadenocarcinoma. Similarly, late age at menopause (≥ 50 years) was associated with increased adenocarcinoma risk (vs. ≤ 47 years, HR, 1.41; 95% CI, 1.01-1.96, P _trend 0.04). Compared with premenopausal women, women with natural menopause (HR, 1.99; 95% CI, 1.02-3.88) or surgical menopause (HR, 2.75; 95% CI, 1.33-5.67) were at increased risk of adenocarcinoma. In contrast, breastfeeding was associated with reduced risk of nonadenocarcinoma (HR, 0.51; 95% CI, 0.28-0.92). No significant association with parity, age at first birth, exogenous hormone use, or length of menstrual cycle was detected.

CONCLUSIONS

Reproductive factors may play a role in lung carcinogenesis. Future studies that include estrogen and progesterone biomarkers may help clarify the role of endogenous hormones in lung carcinogenesis.

IMPACT

Fertility span and age at menopause may be useful variables in developing risk prediction models for lung adenocarcinoma among nonsmoking women.

Colorectal and gastric metastases from lobular breast cancer that resembled superficial neoplastic lesions

Breast cancer is the most common malignancy in women and has a risk of late recurrence. We report a case of metastasis to the stomach and colon 23 years after surgery, with characteristic findings. A 74-year-old woman underwent breast cancer resection at the age of 51. At the time, no additional therapy was performed despite the histological diagnosis of invasive lobular carcinoma with lymph node metastasis. Upper gastrointestinal endoscopy, which was performed as a follow-up for her chronic gastritis, revealed multiple erosions. Histology revealed diffuse proliferation of signet ring cell-like atypical cells, that were positive for cytokeratin CAM5.2 and estrogen receptor. These findings suggested metastasis from the invasive lobular breast carcinoma. Positron-emission tomography revealed sternal and vertebral metastases. Colonoscopy also performed to screen for intestinal metastasis revealed several lesions that resembled hyperplastic polyps. Although these lesions were not strongly suspected of metastasis, histology surprisingly revealed the same findings as the gastric metastasis. This case involved gastric and colorectal superficial metastases that were synchronously detected 23 years after primary treatment. We report that early-stage colorectal metastasis may resemble hyperplastic polyps, and biopsy should always be considered in patients with a history of breast cancer, regardless of years elapsed since treatment.

Duration of estrogen exposure during reproductive years, age at menarche and age at menopause, and risk of cardiovascular disease events, all-cause and cardiovascular mortality: a systematic review and meta-analysis

BACKGROUND

Little is known about the estrogen exposure measurement and mutual effect of age at menarche and age at menopause in the risk of cardiovascular disease (CVD) events.

OBJECTIVES

To evaluate estrogen exposure measurement and describe mutual effect of age at menarche and age at menopause in the risk of CVD events.

SEARCH STRATEGY

Systematic review of literature in PubMed, Embase and Web of Science for studies published up to 28 June 2020.

SELECTION CRITERIA

Observational studies related to estrogen exposure measurement, including mutual effect of age at menarche and age at menopause and risk of CVD events.

DATA COLLECTION AND ANALYSIS

Synthesis of evidence was conducted by reviewing individual estimates, followed by meta-analysis. The study received no external funding.

MAIN RESULTS

A total of 75 studies were included in synthesis of evidence, of which 17 studies were included in meta-analysis. Reproductive lifespan (age at menopause - age at menarche), endogenous estrogen exposure and total estrogen exposure were used for estrogen exposure measurement. Reproductive lifespan was by far the most commonly used method for estrogen exposure measurement. A shorter reproductive lifespan was associated with a higher risk of CVD events; the pooled relative risk (95% CI) was 1.31 (1.25-1.36) for stroke events. Robust epidemiological studies with measurement of estrogen exposure and associated health risk would strengthen the evidence.

CONCLUSIONS

Reproductive lifespan was the most commonly used method for estrogen exposure measurement in epidemiological studies. A shorter reproductive lifespan was associated with a higher risk of CVD events, particularly stroke.

TWEETABLE ABSTRACT

A systematic review and meta-analysis found that women with a shorter reproductive lifespan have a higher risk of stroke events.

Female reproductive factors and risk of external causes of death among women: The Japan Public Health Center-based Prospective Study (JPHC Study)

Although empirical data suggest a possible link between female reproductive events and risk of nonfatal accidents and suicidal behaviors, evidence to determine these effects on mortality is scarce. This study investigated the association between female reproductive factors and the risk of external causes of death among middle-aged Japanese women. We used a population-based cohort study consisting of 71 698 women residing in 11 public health center areas across Japan between 1990 and 1994. Multivariable-adjusted Cox proportional hazard regression models were used to estimate hazard ratios (HRs) of the risk of all external causes, suicide, and accidents according to female reproductive factors at the baseline survey. During 1 028 583 person-years of follow-up for 49 279 eligible subjects (average 20.9 years), we identified 328 deaths by all injuries. Among parous women, ever versus never breastfeeding [0.67 (95% CI: 0.49–0.92)] was associated with a decreased risk of all injuries. Risk of suicide was inversely associated with ever versus never parity [0.53 (95% CI: 0.32–0.88)]. A lower risk of death by accidents was seen in ever breastfeeding [0.63 (95% CI: 0.40–0.97)] compared to never breastfeeding. This study suggests that parity and breastfeeding are associated with reduced risk of death by all external causes, suicide and/or accidents among Japanese women.

Age at natural menopause and mortality: A survival analysis of elderly residents of São Paulo, Brazil

OBJECTIVE

To conduct a survival analysis according to age at natural menopause (NM) in a representative sample of elderly women from the municipality of São Paulo, Brazil.

STUDY DESIGN

We analyzed data from the Health, Well-Being and Aging study (SABE), a cohort that started in 2000. Mortality data up to September 2016 were obtained by linkage from the Program for Mortality Information of São Paulo (PRO-AIM).

MAIN OUTCOME MEASURES

We used Cox regression to analyze all-cause and cause-specific mortality rates for cardiovascular diseases, respiratory diseases and cancer, according to age at menopause, categorized as <40, 41-44, 45-49, 50-54 (reference) and ≥55.

RESULTS

After 16 years of follow-up, there were 444 deaths, of which 199 were from cardiovascular diseases, 73 from respiratory diseases and 65 from cancer. After adjustment for socioeconomic, reproductive and lifestyle factors, having an early menopause (at age 41-44) was associated with an increased risk of all-cause mortality (HR = 1.48, 95% IC: 1.03, 2.14) relative to NM at 50-54 years. Women aged 41-44 and 45-49 at NM had twice the risk of cancer mortality of the reference group. We did not find significant associations between age at NM and cause-specific mortality for respiratory and cardiovascular diseases.

CONCLUSIONS

Our findings suggest that early menopause is associated with all-cause mortality in the largest city of Latin America. In addition, earlier age at NM was associated with cancer mortality. These results suggest that age at NM may be a biomarker for mortality, irrespective of country of residence.