Relationships Between Reproductive History and Mortality From Cardiovascular Diseases Among Japanese Women: The Japan Collaborative Cohort Study for Evaluation of Cancer Risk (JACC) Study.

Kanami Tanigawa,Akiko Tamakoshi,Takashi Kimura,Satoyo Ikehara,Kokoro Shirai,Isao Muraki,Hiroyasu Iso,Hironori Imano

doi:10.2188/jea.je20190020

Abstract

BackgroundReproductive history has been addressed as a risk factor for cardiovascular disease (CVD). We examined the relationship between reproductive history and CVD mortality in Japanese women.MethodsWe followed 53,836 women without previous CVD or cancer history from 1988–1990 to 2009 in a prospective cohort study. Hazard ratios (HRs) and 95% confidence intervals (CIs) of CVD mortality were estimated according to the number of deliveries and maternal age at first delivery.ResultsDuring the follow-up, 2,982 CVD-related deaths were identified. There was U-shaped association between the number of deliveries and risk of CVD mortality with reference to three deliveries, although the excess risk of CVD mortality associated with ≥5 deliveries was of borderline statistical significance. The corresponding multivariable HRs were 1.33 (95% CI, 1.12–1.58) and 1.11 (95% CI, 0.99–1.24). In addition, higher CVD mortality was associated with maternal age ≥28 years at first delivery than maternal age of 24–27 years at first delivery. The multivariable HRs were 1.22 (95% CI, 1.10–1.36) for 28–31 years at first delivery and 1.26 (95% CI, 1.04–1.52) for ≥32 years at first delivery. Moreover, among women with ≥3 deliveries, maternal age ≥28 years at first delivery was associated with 1.2- to 1.5-fold increased CVD mortality.ConclusionThe number of deliveries showed a U-shaped association with risk of CVD mortality. Higher maternal age at first delivery was associated with an increased risk of CVD mortality, and excessive risk in women aged ≥28 years at first delivery was noted in those with ≥3 deliveries.

Highlights

Cardiovascular disease (CVD) is the leading cause of death and disability in the world, and 17.9 million deaths due to cardiovascular disease (CVD) occurred worldwide in 2016.1 The latest guidelines on CVD prevention in women from the American Heart Association have indicated that reproductive history related to pregnancy should be taken account to identify high-risk women for CVD.[2]
The higher maternal age at first delivery was associated with risk of mortality from subarachnoid hemorrhage[18] and incidence of coronary heart disease (CHD).[19]
We examined the association of the number of deliveries and maternal age at first delivery with mortality from CVD, stroke, and CHD among Japanese women in a nationwide prospective cohort study

Summary

Introduction

Cardiovascular disease (CVD) is the leading cause of death and disability in the world, and 17.9 million deaths due to CVD occurred worldwide in 2016.1 The latest guidelines on CVD prevention in women from the American Heart Association have indicated that reproductive history related to pregnancy should be taken account to identify high-risk women for CVD.[2]. The association between reproductive history and risk of CVD remains controversial. Some prospective cohort studies have shown a U-shaped relationship between the number of deliveries and risks of CVD incidence[3] and CVD mortality.[4,5,6,7,8] other studies have found positive association with risks of CVD incidence[9,10] and CVD mortality,[11] inverse association with risk of CVD mortality,[12] and no association with risk of CVD mortality.[13,14] In addition to the association with the number of deliveries, a number of prospective cohort studies have shown that early maternal age at first delivery was a risk factor for risk of CVD mortality,[4,14,15,16] but other studies showed no inverse association between maternal age at first delivery and risk of CVD mortality.[15,16,17] The higher maternal age at first delivery was associated with risk of mortality from subarachnoid hemorrhage[18] and incidence of coronary heart disease (CHD).[19]. Reproductive history has been addressed as a risk factor for cardiovascular disease (CVD). We examined the relationship between reproductive history and CVD mortality in Japanese women

Methods

Results

Conclusion