Type 2 diabetes in patients with end-stage kidney disease: influence on cardiovascular disease-related mortality risk

OBJECTIVES: To examine the association between type 2 diabetes mellitus, with and without diabetic nephropathy, and cardiovascular disease-related mortality in dialysis-dependent patients with end-stage kidney disease (ESKD); to determine whether this association is affected by the age of the patient. DESIGN, SETTING, PARTICIPANTS: Prospective population cohort analysis of Australia and New Zealand Dialysis and Transplant Registry data for all patients with incident ESKD who commenced dialysis in Australia or New Zealand during 1980-2014. OUTCOME MEASURES: Primary outcome: cardiovascular disease-related mortality; secondary outcome: all-cause mortality. RESULTS: Of 56 552 patients followed for a median 2.5 years (total, 193 549 person-years), 15 829 (28.0%) had type 2 diabetes and diabetic nephropathy; 4993 (8.8%) had type 2 diabetes and non-diabetic nephropathy. Cardiovascular disease-related mortality during the first 10 years of dialysis was significantly higher for patients with diabetes/diabetic nephropathy (277 deaths per 1000 patients; 95% CI, 270-284) or diabetes/non-diabetic nephropathy (220 deaths per 1000 patients; 95% CI, 208-231) than for patients without type 2 diabetes (136 deaths per 1000 patients; 95% CI, 133-140). The risk of cardiovascular disease-related mortality was greater for patients with diabetes/diabetic nephropathy (adjusted hazard ratio [aHR], 1.63; 95% CI, 1.56-1.72) or diabetes/non-diabetic nephropathy (aHR, 1.31; 95% CI, 1.23-1.41) than for patients without diabetes. The excess risk associated with having diabetes was greater for younger than for older patients. CONCLUSIONS: Mortality risk is higher for patients with incident ESKD commencing dialysis who also have type 2 diabetes than for patients without diabetes, particularly among patients under 50 years of age, and the risk was more pronounced in patients for whom ESKD was attributed to diabetic nephropathy.