Association between anemia and mortality in hemodialysis patients is modified by the presence of diabetes.

Abstract

The prevalence and severity of anemia differ between diabetic and non-diabetic patients. We investigated whether the effect of hemoglobin (Hb) on patient outcome was affected by the presence or absence of diabetes among Japanese patients receiving chronic hemodialysis (HD). We enrolled 149,308 patients from a nationwide dialysis registry in Japan at the end of 2012 (mean age, 67.6 ± 12.3years; male, 61.7%; diabetes, 43.5%; median dialysis duration, 65months) who underwent three HD sessions weekly. One-year all-cause and cardiovascular (CV) mortality were assessed using Cox regression analysis and competing-risks regression analysis. We used multiple imputation to deal with missing covariate data. Baseline Hb and serum ferritin levels were independently associated with all-cause and CV mortality. In non-diabetic patients, a significantly higher risk for all-cause mortality compared to the reference group (10 to 11g/dL) was observed in patients with Hb < 8g/dL (hazard ratio (HR): 1.266; 95% confidence interval (CI) 1.097-1.460) and 8 to 9g/dL(HR: 1.153; 95% CI 1.030-1.290). On the other hand, diabetic HD patients in the same Hb category group did not have increased risk of all-cause mortality. We found that non-diabetic HD patients had an increased risk of all-cause mortality if they had lower Hb levels, whereas the effect of Hb levels on mortality was attenuated in diabetic HD patients. These data suggest that the association between Hb levels and mortality rate could be different between diabetic and non-diabetic HD patients.