Diabetes, glycaemic control and mortality risk in patients on haemodialysis: the Japan Dialysis Outcomes and Practice Pattern Study

Aims/hypothesis There are few data on the target level of glycaemic control among patients with diabetes on haemodialysis. We investigated the impact of glycaemic control on mortality risk among diabetic patients on haemodialysis. Subjects and methods Data were analysed from the Dialysis Outcomes Practice Pattern Study (DOPPS) for randomly selected patients on haemodialysis in Japan. The diagnosis of diabetes at baseline and information on clinical events during follow-up were abstracted from the medical records. A Cox proportional hazards model was used to evaluate the association between presence or absence of diabetes, glycaemic control (HbA(1c) quintiles) and mortality risk. Results Data from 1,569 patients with and 3,342 patients without diabetes on haemodialysis were analysed. Among patients on haemodialysis, those with diabetes had a higher mortality risk than those without (multivariable hazard ratio 1.37, 95% CI 1.08-1.74). Compared with those in the bottom quintile of HbA(1c) level, the multivariable-adjusted hazard ratio for mortality was not increased in the bottom second to fourth quintiles of HbA(1c) (HbA(1c) 5.0-5.5% to 6.2-7.2%), but was significantly increased to 2.36 (95% CI 1.02-5.47) in the fifth quintile (HbA(1c)>= 7.3%). The effect of poor glycaemic control did not statistically correlate with baseline mortality risk (p=0.27). Conclusions/interpretation Among dialysis patients, poorer glycaemic control in those with diabetes was associated with higher mortality risk. This suggests a strong effect of poor glycaemic control above an HbA(1c) level of about 7.3% on mortality risk, and that this effect does not appear to be influenced by baseline comorbidity status.