Reproductive history and mortality from cardiovascular disease among women textile workers in Shanghai, China

BACKGROUND: Few studies have examined the possible effects of reproductive factors on cardiovascular disease (CVD) risks in Asian women. METHODS: A cohort of 267,400 female textile workers in Shanghai, China, was administered a questionnaire at enrolment (1989-91) and followed for mortality through 2000. Relative risks (hazard ratios) for ischaemic heart disease (IHD), ischaemic stroke and haemorrhagic stroke were calculated using Cox proportional hazards modelling, adjusting for relevant co-variates. RESULTS: Risks were not consistently associated with age at menopause, parity, stillbirths, miscarriages or duration of lactation. An increasing trend in IHD mortality risk, but not stroke, was observed with decreasing age at menarche. There was no evidence of increased CVD mortality risk by oral or injectable contraceptive use or induced abortions. As expected, greater mortality rates from CVD and increased CVD risks were also observed with smoking. CONCLUSIONS: Use of steroid contraceptives, induced abortions and reduced parity from China's one-child-per-family policy has not had an adverse effect on risk of CVD mortality in this cohort.