Parity and later life adherence to healthy lifestyles concerning all-cause and cause-specific mortality

Background and Aims: Whether parity related mortality risk can be mitigated by healthy lifestyles in later life remains unclear. We aimed to examine the combined association and interaction between parity and lifestyle factors in later life on all-cause and cause-specific mortality. Methods: : 96,170 women aged ≥ 40 years were included. Parity and lifestyle factors were obtained at baseline. Mortality status was assessed during a follow-up of up to 5 years. Results: : The multivariable adjusted hazard ratio (HR) for all-cause mortality was 1.40 (95% confidence interval (CI), 1.08-1.81) among women with four births and 1.82 (95% CI, 1.38-2.41) among women with five births or more, compared with women with one birth. In parous women, four births or more was associated with the greatest risk of all-cause mortality (HR, 1.79; 95% CI, 1.22-2.62; compared with 1-3 births) among women who with 0-1 healthy lifestyle factor, but such association was substantially attenuated among women with four healthy lifestyle factors (HR, 1.21; 95% CI, 0.74 to 1.97; p-interaction=0.005). Conclusions: : Most mortality risk associated with high-level parity could be modified by a healthier lifestyle in later life among Chinese women.