Annual all-cause mortality rate for patients with diabetic kidney disease in Singapore

BACKGROUND: The prognosis of diabetic kidney disease is poor because epidemiological data have shown that all-cause mortality increases with declining renal function. This study aims to estimate the annual mortality rate of diabetic kidney disease stratified by chronic kidney disease (CKD) stages and to identify the predictors of mortality. METHODS: Patients with Stage 3–5 CKD (estimated glomerular filtration rate [eGFR] less than 60 mL/min per 1.73 m(2)) with diabetic kidney disease from the National Healthcare Group CKD Registry from 1 January 2007 to 31 December 2007 were included in this study. The patients were followed up till 30 November 2013. Cox's proportional hazards regression modelling was used to assess the factors associated with all-cause mortality. RESULTS: Over a median follow up period of 6.0 years, 985 out of 3008 patients (32.8%) died. Of those who died, 363 (36.9%) died from cardiovascular causes. The annual mortality rate was 64.1 per 1000 individuals (95% confidence interval [CI] 60.2–68.3) and the mortality rate increased with severity of CKD [Stage 3A (37.0), Stage 3B (57.5), Stage 4 (98.3) and Stage 5 (198.5)]. Predictors of mortality were age, male gender, CKD stages, albuminuria, comorbid conditions such as peripheral vascular disease, neuropathy, retinopathy and the use of antiplatelet agents. CONCLUSION: Our study estimated the annual all-cause mortality rate for Singaporean patients with diabetic kidney disease by CKD stages and identified predictors of all-cause mortality. This study has affirmed the poor prognosis of these patients and an urgency to intervene early so as to retard the progression to later stages of CKD.