Disappearance of association in diabetic patients on hemodialysis between anemia and mortality risk: the Japan dialysis outcomes and practice pattern study

We previously demonstrated that anemia was not associated with mortality in hemodialysis patients with cardiovascular disease (CVD). Since diabetes mellitus (DM) accelerates CVD, the influence of DM on the relationship between anemia and mortality was examined using the data obtained from 1,385 DM patients and 2,583 non-DM hemodialysis patients recruited into the Dialysis Outcomes Practice Pattern Study in Japan (J-DOPPS). When all patients were stratified into four groups on their hematocrit levels, mortality rate was significantly and steadily lower in the subgroups with the higher levels of hematocrit by the Kaplan-Meier method (p = 0.0003 by log-rank test). When DM and non-DM patients were analyzed separately, a significant association of lower hematocrit levels with higher mortality disappeared in DM patients (p = 0.6280), in contrast with its retention in non-DM counterparts (p < 0.0001). Multivariable-adjusted Cox proportional hazards models demonstrated a significant association between hematocrit with all-cause mortality in non-DM patients after adjustment for age, gender, BMI, hemodialysis duration, SBP, DBP, albumin, total cholesterol, calcium, phosphorus, and intact PTH (p = 0.046), whereas this association disappeared in DM patients in the same model (p = 0.583). In conclusion, these results suggested that the association between anemia and higher mortality disappeared in DM hemodialysis patients, in contrast with non-DM counterparts.