A. Abundances in significant plasma proteins at baseline that mediated the association between baseline RDW and 15-year all-cause mortality. B. Abundances in significant changes in plasma proteins that mediated the association between change in RDW and 6-year all-cause mortality. Bar graphs represent least-squares means and standard errors from a linear regression model adjusted for age, sex, body mass index, smoking status, years of education, and haemoglobin level (black bars, deceased; white bars, censored). † secondary axis.