Anaemia, independent of chronic kidney disease, predicts all-cause and cardiovascular mortality in type 2 diabetic patients

Abstract

Objective: There is limited and controversial information on whether anaemia is a risk factor for cardiovascular mortality in type 2 diabetes, and whether this risk is modified by the presence of chronic kidney disease (CKD). We assessed the predictive role of lower hemoglobin concentrations on all-cause and cardiovascular mortality in a cohort of type 2 diabetic individuals.

Methods: The cohort included 1153 type 2 diabetic outpatients, who were followed for a mean period of 4.9 years. The independent association of anaemia (i.e., hemoglobin <120 g/l in women and <130 g/l in men) with all-cause and cardiovascular mortality was evaluated by Cox proportional hazards regression models and adjusted for several potential confounders, including kidney function measures.

Results: During follow-up, 166 (14.4%) patients died, 42.2% (n=70) of them from cardiovascular causes. In univariate analysis, anaemia was associated with increased risk of all-cause (hazard ratio HR 2.62, 95% confidence intervals 1.90-3.60, p<0.001) and cardiovascular mortality (HR 2.70, 1.67-4.37, p<0.001). After adjustment for age, sex, body mass index, smoking, hypertension, dyslipidemia, diabetes duration, hemoglobin A1c, medication use (hypoglycemic, anti-hypertensive, lipid-lowering and anti-platelet drugs) and kidney function measures, the association of anaemia with all-cause (adjusted HR 2.11, 1.32-3.35, p=0.002) and cardiovascular mortality (adjusted HR 2.23, 1.12-4.39, p=0.020) remained statistically significant.

Conclusions: Anaemia is associated with increased risk of all-cause and cardiovascular mortality in type 2 diabetic individuals, independently of the presence of CKD and other potential confounders. The advantage to treat anaemia in type 2 diabetes for reducing the risk of adverse cardiovascular outcomes remains to be demonstrated.