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.