Competing-risk analysis of ESRD and death among patients with type 1 diabetes and macroalbuminuria

Abstract

Patients with both type 1 diabetes and CKD have an increased risk of adverse outcomes. The competing risks of death and ESRD may confound the estimates of risk for each outcome. Here, we sought to determine the major predictors of the cumulative incidence of ESRD and pre-ESRD mortality in patients with type 1 diabetes and macroalbuminuria while incorporating the competing risk for the alternate outcome into a Fine-Gray competing-risks analysis. We followed 592 patients with macroalbuminuria for a median of 9.9 years. During this time, 56 (9.5%) patients died and 210 (35.5%) patients developed ESRD. Predictors of incident ESRD, taking baseline renal function and the competing risk for death into account, included an elevated HbA(1c), elevated LDL cholesterol, male sex, weight-adjusted insulin dose, and a shorter duration of diabetes. By contrast, predictors of pre-ESRD death, taking baseline renal function and the competing risk for ESRD into account, included only age, the presence of established macrovascular disease, and elevated cholesterol levels. This competing-risks approach has potential to highlight the appropriate targets and strategies for preventing premature mortality in patients with type 1 diabetes.

Figure 1.

Incidence of ESRD and pre-ESRD mortality, stratified for renal function at baseline, shows the impact of competing risks.

Figure 2.

Increasing cumulative incidence of ESRD with lower baseline levels of eGFR, stratified for gender [men (A) women (B)], adjusted to the mean of other variables. Estimated GFR has been stratified by percentiles: 5th (eGFR = 14.6; solid line); 10th (eGFR = 18.5; short dashed line); 25th (eGFR = 31.8; dotted line); 50th (eGFR = 52.6; long-dash dot line); 75th (eGFR = 75.6; long-dash line); 90th (eGFR = 91.6; short-dash dot line); men, left panel; women, right panel.

Figure 3.

Cumulative incidence of pre-ESRD death increases with increasing age (A), total cholesterol levels (B), and increasing eGFR (C). Data is adjusted to the mean of other variables.