Parenthood and the risk of cardiovascular diseases among 0.5 million men and women: findings from the China Kadoorie Biobank

Fatherhood and Cardiovascular Health, Disease, and Mortality: Associations From the Multi-Ethnic Study of Atherosclerosis

Introduction

Emerging literature links fatherhood to men's health but lacks comprehensive assessment of health outcomes, especially among multiethnic populations. This study's objective was to evaluate the associations of fatherhood (age at onset and status) with cardiovascular health scores, incident cardiovascular disease, cardiovascular disease death, and all-cause mortality, examining differences by race/ethnicity.

Methods

The study sample included men from Multi-Ethnic Study of Atherosclerosis, prospective cohort study that enrolled adults aged 45-84 years without known cardiovascular disease at baseline. Cardiovascular health was defined using the American Heart Association's Life's Essential 8 scores (0-100), excluding sleep (cardiovascular health score).

Results

In this sample of 2,814 men, mean age at cardiovascular health assessment was 62.2 years, 82% were fathers, 24% self-identified as Black, 13% self-identified Chinese, 22% self-identified Hispanic, and 41% self-identified White. Fathers who were aged <20 years and 20-24 years at their oldest child's birth had worse overall cardiovascular health than fathers who were aged >35 years (adjusted mean score of 61.1 vs 64.7 [p=0.01] and 61.0 vs 64.7 [p<0.001], respectively). Fathers had worse overall cardiovascular health (adjusted mean score of 63.2 vs 64.7, p=0.03) and more nicotine exposure (63.1 vs 66.6, p=0.04) than nonfathers. In age-adjusted models, fathers overall (hazard ratio=0.82; 95% CI=0.69, 0.98) and Black fathers (hazard ratio=0.73; 95% CI=0.53, 0.999) had a lower rate of all-cause mortality rate than nonfathers, but these associations were no longer significant in fully adjusted models.

Conclusions

Fatherhood is a social determinant of health, and understanding its influence may provide opportunities to improve men's health, particularly among men of color.

Child rearing or childbearing? Risk of cardiovascular diseases associated to parity and number of children

BACKGROUND

An increased risk of cardiovascular diseases (CVD) has been associated with women's parity, but whether or not this association reflects a direct pregnancy effect, or exposure to factors related to childrearing, still appears unclear. We assessed the CVD risk associated with number of children separately by gender and tested effect modification by socioeconomic position (SEP) and employment status, in order to elucidate the possible mechanisms underlying this association.

METHODS

The study population was composed of 20,904 men and 25,246 women who were interviewed in one of two National Health Surveys conducted in 2000 and 2005 in Italy. These subjects were followed for CVD incidence up to 2014 through record-linkage with national archives of mortality and hospitalisations. CVD risk was estimated by Cox regression models that were adjusted for socio-demographics, perceived health, lifestyles, biological CVD risk factors and for other potential confounders.

RESULTS

CVD incidence was significantly increased among men with 3 or more children (HR = 1.26, 95% CI: 1.02-1.56) and among women with 2 and with 3 or more children (HR = 1.42, 95% CI: 1.10-1.83; and HR = 1.39, 95% CI: 1.03-1.87, respectively) compared to subjects without children and no significant gender differences were observed. Subjects with lower SEP displayed stronger associations with parity and a higher number of children for both genders; by contrast, no modifying effect of employment status was observed.

CONCLUSIONS

Taken together, the significant association between higher parity and CVD risk in both genders, and the higher risk of CVD associated with higher parity among lower SEP parents, suggests that childrearing has a potential effect on the development of CVD that is more pronounced among disadvantaged families, although a concurrent effect of childbearing cannot be completely excluded.

Activity Behaviors Before and During Pregnancy Are Associated With Women's Device-Measured Physical Activity and Sedentary Time in Later Parenthood: A Longitudinal Cohort Analysis

PURPOSE

To explore how activity behaviors before/during pregnancy relate to those in later parenthood, we assessed associations between sitting and moderate-/strenuous exercise before/during pregnancy, and sedentary time (SED) and moderate to vigorous physical activity (MVPA) 4-7 years postpartum ("later parenthood").

METHODS

Longitudinal data were from the Southampton Women's Survey, United Kingdom. Women reported time spent sitting (in hours per day), in moderate-strenuous exercise (hours per week), and in strenuous exercise (hours per week) at 3 time points before/during pregnancy (ie, preconception, at ∼12-wk and ∼34-wk gestation). From this, we derived 3 behavior trajectories for each woman. In later parenthood, women wore an accelerometer for ≤7 days (mean: 5.4 [SD: 1.8] d), which we used to derive 2 outcomes: minutes per day SED and in MVPA. Multilevel linear regression was used to explore associations between trajectories before/during pregnancy and device-measured SED/MVPA in later parenthood.

RESULTS

A total of 780 women provided valid data before/during pregnancy and in later parenthood. Consistent high sitters (vs low) were more sedentary 4-7 years postpartum (β = 39.5 min/d [95% confidence interval, 23.26 to 55.82]), as were women in groups who sat more in later pregnancy. Consistently high moderate/-strenuous exercisers (vs low) were 22% (95% confidence interval, 2%-47%) more active in later parenthood; those engaging in strenuous activity preconception tended to have higher MVPA as parents.

CONCLUSIONS

Trajectories of sitting and exercise before/during pregnancy are associated with SED and MVPA, respectively, in later parenthood. Interventions to reduce sitting in pregnancy and to encourage higher intensity activity preconception may benefit maternal and child health.

Parity and hypertension risk in couples: does number of parity matter: findings from Tehran Lipid and Glucose Study

BACKGROUND AND AIMS

As reported, hypertension (HTN) plays a leading role in explaining mortality worldwide, but it still has many confounding factors. This study explored whether the number of parity and age matters for HTN among couples from the Tehran Lipid and Glucose Study (TLGS).

METHODS

This study was conducted on 2851 couples from TLGS. All the variables were collected based on the standard protocol. The participants were categorized into four and five categories according to the number of parity (childless, one, two, three, or more parities) and age (18-30y, 30-40y, 40-50y, 50-60y, and 60-70y), respectively. Spline regression models via log link function for the binary outcome and linear link function for continuous outcomes were applied to evaluate the effect of interaction term age and parity categories on the desired outcome.

RESULTS

Among the total of 2851 pairs, 2.3% had no child, 9.5% had 1 child, 38.4% had 2 children, and 49.8% had ≥ 3 children. The adjusted risk (95% CI) of HTN in females aged 40-50y with 1 child, 2 and ≥ 3 children compared to no child were 1.14(1.04, 1.26), 1.05(1.01, 1.10), 1.12(1.07, 1.17), respectively (p < 0.05). Moreover, in those aged 50-60y with 2 and ≥ 3 children, the risk of HTN significantly increased by 4%. In females aged 60-70y with ≥ 3 children compared to those without children, the risk of HTN increased by 2%. For males aged 30-40y with 2 children compared to the no child group, the adjusted risk of HTN increased by 17%, while for those with ≥ 3 children in the same age group, this risk significantly decreased by 13%. Moreover, in males aged 30-40y with 2 children, risk ratio of HTN increased by 17%, but in males with ≥ 3 children, it decreased by 13% and in those in the same groups but aged 40-50y the risk increased by 6% and 11%, respectively.

CONCLUSION

Our findings suggest that gender, childlessness, having one child, and multi-parity had different impacts on HTN. Further research is needed to confirm our findings.

Assessment of Cardiovascular Risk in Women: Progress so Far and Progress to Come

Cardiovascular disease is the leading cause of death in women worldwide. Nonetheless, there exist several uncertainties in the prediction, diagnosis, and treatment of cardiovascular disease in women. A cornerstone in the prediction of cardiovascular disease is the implementation of risk scores. A variety of pregnancy- and reproductive-factors have been associated with lower or higher risk of cardiovascular disease. Consequently, the question has been raised, whether these female-specific factors also provide added value to cardiovascular risk prediction. In this review, we provide an overview of the existing literature on sex differences in the association of established cardiovascular risk factors with cardiovascular disease and the relation between female-specific factors and cardiovascular risk. Furthermore, we systematically reviewed the literature for studies that assessed the added value of female-specific factors beyond already established cardiovascular risk factors. Adding female-specific factors to models containing established cardiovascular risk factors has led to little or no significant improvement in the prediction of cardiovascular events. However, analyses primarily relied on data from women aged ≥40 years. Future investigations are needed to quantify whether pregnancy-related factors improve cardiovascular risk prediction in young women in order to support adequate treatment of risk factors and enhance prevention of cardiovascular disease in women.

Number of Births and Later-Life Depression in Older Adults: Evidence from China

Previous studies on the number of births and the health of the elderly have been highly focused on physical health and used samples from developed countries. Therefore, this study aimed to explore the effect of the lifetime number of births on depression in Chinese older adults. We used panel data for men and women aged 50 and over from the 2013-2018 China Health and Retirement Longitudinal Study. Depressive symptoms were assessed through a short form of the Center for Epidemiologic Studies Depression Scale. We found that depression levels in women were significantly higher than in men, with a mean difference of 2.44 (p < 0.001). The model estimation results indicated that the number of births affected depression in older adults, and its increase could exacerbate depression in older adults. The number of births significantly impacted depression among the elderly aged 50-69. Furthermore, there was a negative relationship between the proportion of sons and older adults' depression, which was significant in older males; the number of abortions may exacerbate depression in older adults, especially in females.

Motherhood Health Penalty: Impact of Fertility on Physical and Mental Health of Chinese Women of Childbearing Age

Background

The negative consequences of childbearing on mothers are called the motherhood penalty, and it manifests in the aspects of women's physical and mental health. In May 2021, China relaxed its birth policy that allowed a married couple to have three children. It gives women the opportunity to have more children, but also may increase more risks to mothers' physical and mental health.

Objectives

The objectives of this study were to clarify the relationships between the fertility and the physical/mental health of women of childbearing age and empirically confirm the existence of the motherhood health penalty in China.

Materials and Methods

Using a nationally representative dataset from the China Labor-force Dynamics Survey 2018, we examined the effects of fertility on the physical and mental health of Chinese women of childbearing age. Physical health was self-rated, and mental health was assessed according to the Center for Epidemiological Studies Depression scale. The instrumental variable approach and the models of inverse probability of treatment weighting of propensity scores and regression adjustment were employed to overcome the endogeneity between fertility and health of women.

Results

The empirical results showed that the total number of births had significant adverse impacts on the physical and mental health of women of childbearing age, which empirically demonstrated the existence of the motherhood health penalty in China. The results of heterogeneity analysis indicated that the physical and mental health of the rural women was more easily affected by childbearing compared with that of the urban samples. In a mechanism analysis, the pathways of income and the multiple roles played by mothers were found to mediate the impacts of the total number of births on the physical and mental health of women. The robustness checks showed that the results of this study were robust.

Conclusions

The findings of this study extend the motherhood penalty to the health domain, and they have important implications for improving healthcare policy for women of childbearing age in China and other countries and regions and promoting gender equality in the healthcare field.

Cumulative triglyceride-glucose index is a risk for CVD: a prospective cohort study

BACKGROUND

Previous studies has shown a significant relationship between baseline triglyceride-glucose (TyG) index and cardiovascular disease (CVD). However, the long-term effect of TyG index and incident CVD remains uncertain. This study aimed to investigate the association between cumulative TyG index and the risk of CVD.

METHOD

In this study, we recruited individuals participating in Kailuan Study from 2006 to 2013 without stroke, myocardial infarction, and cancer in the four consecutive examinations. Cumulative TyG index was calculated by multiplying the average TyG index and the time between the two consecutive examinations. Cumulative TyG index levels were categorized into four quartile groups: Q1 group, ≤ 50.65 (as reference group), Q2 group, 50.65-53.86, Q3 group, 53.86-57.44, Q4 group, > 57.44. The association between cumulative TyG index and the risk of CVD was estimated by multivariable Cox proportional hazard models.

RESULT

A total of 44,064 individuals participated in the final analysis. After a mean follow-up of 6.52 ± 1.14 years, incident CVD, MI and stroke occurred in 2057, 395 and 1695, respectively. The risk of developing CVD increased with the quartile of cumulative in TyG index, after adjustment for multiple potential confounders, the HR for CVD events were 1.25 (1.08-1.44) in Q2, 1.22 (1.05-1.40) in Q3 and 1.39 (1.21-1.61) in Q4, compared to Q1 group. The longer duration of higher TyG index exposure was significantly associated with increased CVD risk. Similar results were obtained in the subgroup and sensitivity analysis.

CONCLUSION

Cumulative TyG index was associated with increased risk of CVD. Maintaining an appropriate level of TG and FBG within the desirable range and better control of cumulative TyG index are important for prevention of CVD.

Time-to-pregnancy and risk of cardiovascular disease among men and women

A few studies indicate that women with prolonged time-to-pregnancy (TTP) have an increased risk of cardiovascular disease (CVD). This has not been studied in men. We evaluated CVD risk by self-reported TTP among parous women (n = 64,064) and men (n = 50,533) participating in the Norwegian Mother, Father and Child Cohort Study. TTP was categorized as 0–3 (reference), 4–12 and > 12 months. CVD diagnosed between 2008 and 2017 were available from the national patient and general practitioner databases. Risk of CVD by TTP was estimated using Cox regression adjusting for baseline age, education, BMI, smoking, diabetes, and number of offspring in both sexes, and history of endometriosis, ovarian cysts, preterm birth and pre-eclampsia for women. Mean age was 33 for women and 35 for men at baseline (years). The rate of any CVD was 24 per 1000 person years among women and 22 per 1000 person years among men. Longer TTP was associated with increased rate of CVD among women, with adjusted hazard ratios (HRs) of 1.07 (95% CI: 1.03, 1.09) for TTP 4–12 months and 1.14 (1.08, 1.20) for TTP > 12 months. Among men, respective HRs for CVD were 1.06 (1.00, 1.10) for TTP 4–12 months and 1.07 (1.01, 1.14) for TTP > 12 months. We observed sex-differences in the relationship with CVD subtypes but none were statistically significant. In conclusion, both men and women with a prolonged TTP had a small increased risk of CVD, clinical significance of which is unclear. Further studies are necessary to investigate in detail what underlying causes of prolonged TTP might be reflected in the increased risk of CVD. Longer follow-up is required to confirm these preliminary findings.

Number of parity/live birth(s) and cardiovascular disease among Iranian women and men: results of over 15 years of follow-up

Background

Most previous studies conducted in non-Middle Eastern populations have suggested that an increase in the number of parity/live birth(s) leads to cardiovascular disease (CVD) development, although their findings were inconclusive on this issue for both sexes. Biologic and socioeconomic pathways were suggested to explain this association. We studied this issue among urban Iranian men and women.

Methods

In this population-based cohort study, which included 3929 women and 2571 men aged ≥30 years, data for the number of parity/live birth(s) were obtained by a standard questionnaire. Participants were then annually followed for CVD events. Multivariable Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the number of parity/live birth(s) and other traditional CVD risk factors.

Results

During more than 15 years of follow-up, 456 and 524 CVD events have occurred among women and men, respectively. Among women, a J-shaped association was found between the number of live births and incident CVD with the lowest risk for women with two live births. Among women in multivariable analyses, each unit increase in parity had a HR of 1.05 (CI: 1.01–1.10), and having ≥4 parity was associated with a HR of 1.86 (0.97–3.56, p-value = 0.061). Among men, in comparison with participants who had 1 child, multivariable HRs of having 2, 3, and ≥ 4 children were 1.97 (1.24–3.12), 2.08 (1.31–3.31), and 2.08 (1.30–3.34), respectively.

Conclusion

To the best of our knowledge, the current study is the first report on this issue in the Middle East and North Africa region, a region with a high burden of CVD. It can now be suggested that the number of parity/live birth(s) is linked to CVD among the Iranian population, with this issue being more prominent among men. Further research is needed to support our results and clarify the pathways between the number of parity/live birth(s) and CVD development among Iranian populations by considering potential risk factors, especially psycho-socio-economic risk factors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-020-03499-2.

Risk Factors for Incident Stroke and Its Subtypes in China: A Prospective Study

Background

Managing risk factors is crucial to prevent stroke. However, few cohort studies have evaluated socioeconomic factors together with conventional factors affecting incident stroke and its subtypes in China.

Methods and Results

A 2014 to 2016 prospective study from the China National Stroke Screening and Intervention Program comprised 437 318 adults aged ≥40 years without stroke at baseline. There were 2429 cases of first‐ever stroke during a median follow‐up period of 2.1 years, including 2206 ischemic strokes and 237 hemorrhagic strokes. The multivariable Cox regression analysis indicated that age 50 to 59 years (versus 40–49 years), primary school or no formal education (versus middle school), having >1 child (versus 1 child), living in Northeast, Central, East, or North China (versus Southwest China), physical inactivity, hypertension, diabetes mellitus, and obesity were positively associated with the risk of total and ischemic stroke, whereas age 60 to 69 years and living with spouse or children (versus living alone) were negatively associated with the risk of total and ischemic stroke. Men, vegetable‐based diet, underweight, physical inactivity, hypertension, living in a high‐income region, having Urban Resident Basic Medical Insurance, and New Rural Cooperative Medical System were positively associated with the risk of hemorrhagic stroke, whereas age 60 to 69 years was negatively associated with the risk of hemorrhagic stroke.

Conclusions

We identified socioeconomic factors that complement traditional risk factors for incident stroke and its subtypes, allowing targeting these factors to reduce stroke burden.

Number of children and the prevalence of later-life major depression and insomnia in women and men: findings from a cross-sectional study of 0.5 million Chinese adults

BACKGROUND

Pregnancy and parenthood have been associated with physical and mental health. Previous literature concerning the impacts of parity on mental health was inconsistent and lack epidemiolocal evidence. China, with growing mental health problems and changing fertility patterns, faces unique challenges. This study aims to examine the relationship between parity and the prevalence of major depression and insomnia among men and women in the Chinese population.

METHODS

Baseline data from a Chinese population-based study of 512,891 adults (59.01% women) from 10 areas, aged 30-79 were analyzed. Number of children was based on self-report by the participants. Major depression (MD) was assessed using the Composite International Diagnostic Inventory. Insomnia symptoms were accessed by a questionnaire comparable to that used in the Diagnostic and Statistical Manual of Mental Disorders. Logistic regression was used to assess the relationship between MD/Insomnia and number of children, after stratifications and adjustments.

RESULTS

For women, each additional child was associated with a 9% decreased odds of MD (OR: 0.91, 95%CI: 0.88-0.96), with the associations significant for those who lived in urban areas (OR: 0.76, 95%CI: 0.70-0.83), or had a lower education (OR: 0.90, 95%CI: 0.85-0.94), or had lower household income (OR: 0.89, 95%CI: 0.85-0.94), or had ever used alcohol (OR: 0.89, 95%CI: 0.84-0.93). The association between per additional children and MD was not significant in men (OR: 1.02, 95%CI: 0.97-1.07), but a decreased odd of MD with per additional child was found in men who lived in urban areas (OR: 0.81, 95%CI: 0.71-0.96). For women, each additional child was associated with a 4% decreased odds of insomnia (OR: 0.96, 95%CI: 0.95-0.96). Each additional child was also associated with a 2% decreased odds of insomnia in men (OR: 0.98, 95%CI: 0.97-1.00).

CONCLUSIONS

MD and insomnia were inversely associated with number of children in women while the association was not overall significant in men. The association was mediated by socioeconomic and lifestyle factors. Future mental health public health programs should address parity and sex differences when designing interventions.

Pregnancy, pregnancy loss and the risk of diabetes in Chinese women: findings from the China Kadoorie Biobank

Pregnancy and pregnancy loss may be associated with increased risk of diabetes in later life. However, the evidence is inconsistent and sparse, especially among East Asians where reproductive patterns differ importantly from those in the West. We examined the associations of pregnancy and pregnancy loss (miscarriage, induced abortion, and still birth) with the risk of incident diabetes in later life among Chinese women. In 2004-2008, the nationwide China Kadoorie Biobank recruited 302 669 women aged 30-79 years from 10 (5 urban, 5 rural) diverse localities. During 9.2 years of follow-up, 7780 incident cases of diabetes were recorded among 273,383 women without prior diabetes and cardiovascular disease at baseline. Cox regression yielded multiple-adjusted hazard ratios (HRs) for the risk of diabetes associated with pregnancy and pregnancy loss. Overall, 99% of women had been pregnant, of whom 10%, 53%, and 6% reported having a history of miscarriage, induced abortion, and stillbirth, respectively. Among ever pregnant women, each additional pregnancy was associated with an adjusted HR of 1.04 (95% CI 1.03; 1.06) for diabetes. Compared with those without pregnancy loss, women with a history of pregnancy loss had an adjusted HR of 1.07 (1.02; 1.13) and the HRs increased with increasing number of pregnancy losses, irrespective of the number of livebirths; the adjusted HR was 1.03 (1.00; 1.05) for each additional pregnancy loss. The strength of the relationships differed marginally by type of pregnancy loss. Among Chinese women, a higher number of pregnancies and pregnancy losses were associated with a greater risk of diabetes.

Rationale and tutorial for analysing and reporting sex differences in cardiovascular associations

Cardiovascular disease (CVD) is the leading cause of death in women and men. Yet biological and social factors differ between the sexes, while the importance of CVD in women may be underestimated due to the higher age-specific rates in men and the historical bias towards the male model of CVD. Consequently, sex differences in risk factor associations with CVD occur, but these are not always recognised. This article argues that sex disaggregation should be the norm in CVD research, for both humanitarian and clinical reasons. A tutorial on how to design and analyse sex comparisons is provided, including ways of reducing bias and increasing efficiency. This is presented both in the context of analysing individual participant data from a single study and a meta-analysis of sex-specific summary data. Worked examples are provided for both types of research. Fifteen key recommendations are included, which should be considered when undertaking sex comparisons of CVD associations. Paramount among these is the need to estimate sex differences, as ratios of relative risks or differences in risk differences, rather than merely test them for statistical significance. Conversely, when there is no evidence of statistical or clinical significance of a sex difference, the conclusions from the research should not be sex-specific.

Cardiovascular Disease and the Female Disadvantage

Age-standardised rates of cardiovascular disease (CVD) are substantially higher in men than women. This explains why CVD has traditionally been seen as a "man's problem". However, CVD is the leading cause of death in women, worldwide, and is one of the most common causes of disability-adjusted life-years lost. In general, this is under-recognised and, in several ways, women are disadvantaged in terms of CVD. Both in primary and secondary prevention, there is evidence that women are undertreated, compared to men. Women often experience heart disease in a different way compared to men, and lack of recognition of this has been shown to have adverse consequences. Female patients of male cardiac physicians have been found to have worse outcomes than their male counterparts, with no such gender differential for female cardiologists. Clinical trials in CVD primarily recruit male patients, yet, it is well recognised that some drugs act differently in women and men. Diabetes and smoking, and perhaps other risk factors, confer a greater proportional excess cardiovascular risk to women than to men, whilst adverse pregnancies and factors concerned with the female reproductive cycle give women added vulnerability to CVD. However, women's health research is skewed towards mother and child health, an area where, arguably, the greatest public health gains have already been made, and breast cancer. Hence there is a need to redefine what is meant by "women's health" to encompass the whole lifecycle, with a stronger emphasis on CVD and other non-communicable diseases. Sex-specific analyses of research data should be the norm, whenever feasible.

Number of Offspring and Cardiovascular Disease Risk in Men and Women: The Role of Shared Lifestyle Characteristics

Supplemental Digital Content is available in the text.

Background:

Previous studies of the number of offspring and cardiovascular disease (CVD) report conflicting findings. We re-examined this association in both sexes to clarify the role of the cardiometabolic changes that women experience during pregnancy versus shared lifestyle characteristics.

Methods:

We studied 180,626 women and 133,259 men participating in the UK Biobank cohort who were free of CVD at baseline. CVD events were obtained from hospital and death registers. Analyses were conducted using Cox proportional hazards regression.

Results:

The incidence rates of overall CVD were six per 1000 person-years for women and nine per 1000 person-years for men. Number of children showed an association with risk of CVD among women; the adjusted HR (95% CI) was 1.2 (1.1, 1.3) for one, 1.1 (1.0, 1.2) for two, 1.2 (1.1, 1.3) for three, and 1.2 (1.1, 1.4) for four or more as compared to none. Number of children was also associated with CVD among men; the adjusted HR (95% CI) was 1.1 (1.0, 1.2) for one, 1.0 (0.96, 1.1) for two, 1.1 (1.0, 1.2) for three, and 1.1 (1.0, 1.3) for four or more as compared to none. There was no evidence of heterogeneity in the associations between sexes (P_interaction = 0.80). Number of offspring also showed similar associations with ischemic heart disease and hypertensive disorders in both sexes.

Conclusions:

We observed similar associations between number of offspring and CVD in both sexes. The association among women might therefore be largely explained by unobserved behavioral and lifestyle characteristics.