Parity, breastfeeding and risk of coronary heart disease: A pan-European case–cohort study

Abstract

67Objective: There is uncertainty about the direction and magnitude of the associations between parity, breastfeeding and the 68 risk of coronary heart disease (CHD). We examined the separate and combined associations of parity and breastfeeding 69 practices with the incidence of CHD later in life among women in a large pan-European cohort study. 70Methods: Data were used from EPIC-CVD, a case-cohort study nested within the EPIC prospective study of 520,000 71 participants from 10 countries. Information on reproductive history was available for 14,917 women, including 5,138 incident 72 cases of CHD. Using Prentice-weighted Cox regression separately for each country followed by random-effects meta-analysis, 73we calculated hazard ratios (HRs) and 95% confidence intervals (CIs) for CHD, after adjustment for age, study centre, and 74 several socioeconomic and biological risk factors. Key messages 86What is already known about this subject? 87 -Pregnancy poses a substantial challenge to the cardiovascular system of the mother and breastfeeding has been 88 suggested to reverse some of the pro-atherogenic changes. 89 -The direction and magnitude of the associations between parity, breastfeeding, and their combined effects, and the 90 risk of coronary heart disease (CHD) are uncertain. 91 92What does this study add? 93 -Compared with nulliparous women, parous women were at 20% increased risk of CHD and the excess risk was higher 94 with increasing number of children. 95 -Breastfeeding was associated with a 30% lower risk of CHD, compared with parous women who did not breastfeed. 96 -Compared with nulliparous women, childbearing was more strongly associated with a higher risk of CHD among 97 women who had never breastfed. This is despite the higher number of children among women who had ever 98

Breastfeeding and the Risk of Maternal Cardiovascular Disease: A Prospective Study of 300 000 Chinese Women

“…Among women younger than 65 years, there was some evidence of a U‐shaped relationship between lifetime duration of breastfeeding and the risk of CVD death, with women who reported lifetime breastfeeding duration of 7 to 12 months having half the risk than those who had breastfed for ≥2 years. In contrast, the EPIC (European Prospective Investigation into Cancer and Nutrition)‐CVD case‐cohort study, among 15 000 women with 5000 incident cases of CHD, found an inverse association between breastfeeding and the risk of CHD at all ages 12. The risk of CHD was the lowest among those who had breastfed for the longest durations, suggesting that prolonged durations of breastfeeding confer additional coronary benefits.…”

“…Previous studies of mostly Western populations have reported conflicting results on the relationship between breastfeeding and the risk of CVD. [10][11][12][13][14] In the US Nurses' Health Study of 90 000 parous women with 2500 cases of CHD, there was a threshold in the association between breastfeeding and CHD; only women with a lifetime duration of breastfeeding of ≥2 years had a significantly lower risk of CHD than those who never breastfed. 13 The HUNT trial (Nord-Trøndelag Health Study) 14 of 20 000 Norwegian women reported that the inverse association between a history of breastfeeding and CVD mortality was modified by age.…”

“…A few previous studies of mostly Western populations have assessed the association between breastfeeding duration and maternal risk of cardiovascular diseases (CVDs),10, 11, 12, 13, 14 but with inconclusive findings about the direction, magnitude, and shape of any putative relationship. Some of these discrepancies may be explained by methodological differences between studies, such as variation in study design, small sample sizes, different exposure definitions, or varying levels of covariate adjustment.…”

“…Some of these discrepancies may be explained by methodological differences between studies, such as variation in study design, small sample sizes, different exposure definitions, or varying levels of covariate adjustment. Moreover, some studies were restricted to fatal CVD end points,10, 11, 14 whereas others only examined specific types of CVD,12, 13 typically coronary heart disease (CHD), without evaluating other major types of incident CVD, such as ischemic and hemorrhagic stroke.…”

Breastfeeding: A bystander marker of improvement in multiparity-induced cardiometabolic disease risk?

“…In the current issue of this journal, the paper by Peters and associates 22 presents a case-cohort study that tracked 14,917 women from ten European countries who had no known history of CHD or stroke at baseline and who provided reproductive histories. Incidence rates of fatal and nonfatal CHD over 11 years of follow-up with regards to parity, number of children, breastfeeding and duration of breastfeeding were analysed.…”