Glycemic control and cardiovascular mortality in hemodialysis patients with diabetes: a 6-year cohort study

Previous observational studies using differing methodologies have yielded inconsistent results regarding the association between glycemic control and outcomes in diabetic patients receiving maintenance hemodialysis (MHD). We examined mortality predictability of A1C and random serum glucose over time in a contemporary cohort of 54,757 diabetic MHD patients (age 63 ± 13 years, 51% men, 30% African Americans, 19% Hispanics). Adjusted all-cause death hazard ratio (HR) for baseline A1C increments of 8.0-8.9, 9.0-9.9, and ≥10%, compared with 7.0-7.9% (reference), was 1.06 (95% CI 1.01-1.12), 1.05 (0.99-1.12), and 1.19 (1.12-1.28), respectively, and for time-averaged A1C was 1.11 (1.05-1.16), 1.36 (1.27-1.45), and 1.59 (1.46-1.72). A symmetric increase in mortality also occurred with time-averaged A1C levels in the low range (6.0-6.9%, HR 1.05 [95% CI 1.01-1.08]; 5.0-5.9%, 1.08 [1.04-1.11], and ≤5%, 1.35 [1.29-1.42]) compared with 7.0-7.9% in fully adjusted models. Adjusted all-cause death HR for time-averaged blood glucose 175-199, 200-249, 250-299, and ≥300 mg/dL, compared with 150-175 mg/dL (reference), was 1.03 (95% CI 0.99-1.07), 1.14 (1.10-1.19), 1.30 (1.23-1.37), and 1.66 (1.56-1.76), respectively. Hence, poor glycemic control (A1C ≥8% or serum glucose ≥200 mg/dL) appears to be associated with high all-cause and cardiovascular death in MHD patients. Very low glycemic levels are also associated with high mortality risk.