Association of Glycemic Status During Progression of Chronic Kidney Disease With Early Dialysis Mortality in Patients With Diabetes

OBJECTIVE Although early trials suggested that intensive glycemic targets reduce the number of complications with diabetes, contemporary trials indicate no cardiovascular benefit and potentially higher mortality risk. As patients with advanced chronic kidney disease (CKD) transitioning to treatment with dialysis were excluded from these studies, the optimal glycemic level in this population remains uncertain. We hypothesized that glycemic status, defined by hemoglobin A1c (HbA1c) and random glucose levels, in the pre–end-stage renal disease (ESRD) period is associated with higher 1-year post-ESRD mortality among patients with incident diabetes who have ESRD. RESEARCH DESIGN AND METHODS Among 17,819 U.S. veterans with diabetic CKD transitioning to dialysis from October 2007 to September 2011, we examined the association of mean HbA1c and random glucose levels averaged over the 1-year pre-ESRD transition period with mortality in the first year after dialysis initiation. All-cause mortality hazard ratios (HRs) were estimated using multivariable survival models. Secondary analyses examined cardiovascular mortality using competing risks methods. RESULTS HbA1c levels ≥8% (≥64 mmol/mol) were associated with higher mortality in the first year after dialysis initiation (reference value 6% to <7% [42–53 mmol/mol]): adjusted HRs [aHRs] 1.19 [95% CI 1.07–1.32] and 1.48 (1.31–1.67) for HbA1c 8% to <9% [64–75 mmol/mol] and ≥9% [≥75 mmol/mol], respectively). Random glucose levels ≥200 mg/dL were associated with higher mortality (reference value 100 to <125 mg/dL): aHR 1.34 [95% CI 1.20–1.49]). Cumulative incidence curves showed that incrementally higher mean HbA1c and random glucose levels were associated with increasingly higher cardiovascular mortality. CONCLUSIONS In patients with diabetes and CKD transitioning to dialysis, higher mean HbA1c and random glucose levels during the pre-ESRD prelude period were associated with higher 1-year post-ESRD mortality. Clinical trials are warranted to examine whether modulating glycemic status improves survival in this population.