Reproductive factors and risk of mortality in the European Prospective Investigation into XXXX and Nutrition; a cohort study.

@entity1 @entity249 @entity204 @entity5
BACKGROUND: Reproductive events are associated with important physiologic changes, yet little is known about how reproductive factors influence long-term health in @entity1 . Our objective was to assess the relation of reproductive characteristics with all-cause and cause-specific mortality risk. METHODS: The analysis was performed within the European Investigation into @entity5 and Nutrition prospective cohort study, which enrolled >500,000 @entity1 and @entity1 from 1992 to 2000, who were residing in a given town/geographic area in 10 European countries. The current analysis included 322,972 eligible @entity1 aged 25-70 years with 99  % complete follow-up for vital status. We assessed reproductive characteristics reported at the study baseline including parity, age at the first birth, breastfeeding, @entity249 , oral contraceptive use, age at menarche and menopause, total ovulatory years, and history of oophorectomy/hysterectomy. Hazard ratios (HRs) and 95  % confidence intervals (CIs) for mortality were determined using Cox proportional hazards regression models adjusted for menopausal status, body mass index, physical activity, education level, and smoking status/intensity and duration. RESULTS: During a mean follow-up of 12.9  years, 14,383 @entity204 occurred. The HR (95  % CI) for risk of all-cause mortality was lower in parous versus nulliparous @entity1 (0.80; 0.76-0.84), in @entity1 who had ever versus never breastfed (0.92; 0.87-0.97), in ever versus never users of oral contraceptives (among non-smokers; 0.90; 0.86-0.95), and in @entity1 reporting a later age at menarche (>= 15  years versus <12; 0.90; 0.85-0.96; P for trend   =   0.038). CONCLUSIONS: Childbirth, breastfeeding, oral contraceptive use, and a later age at menarche were associated with better health outcomes. These findings may contribute to the development of improved strategies to promote better long-term health in @entity1 .
