Presentation blood glucose and death, hospitalization, and future diabetes risk in patients with acute heart failure syndromes

Purpose The prognostic implications of blood glucose on a wide range of outcomes including early mortality, hospitalizations, and incident diabetes diagnoses have not been fully elucidated in acute heart failure syndromes (AHFS). Methods In a population-based cohort of 16 524 AHFS patients presenting to the emergency department (ED) in Ontario, Canada between 2004 and 2007, we performed a competing risk analysis for 30-day mortality, new diabetes diagnoses, and hospitalization outcomes. Presentation blood glucose concentrations were categorized as follows: 3.9-6.1 [referent], >6.1-7.8, >7.8-9.4, >9.4-11.1, and >11.1 mmol/L. Results Among AHFS patients without diabetes presenting to the ED (n = 9275), blood glucose >6.1 mmol/L (n = 5252, 56.6%) was associated with increased risks of all-cause death [hazard ratio (HR) range: 1.26 (95% CI 1.05-1.50) to 1.50 (95% CI 1.11-2.02)], and cardiovascular death [HR range: 1.28 (95% CI 1.03-1.59) to 1.64 (95% CI 1.16-2.33)]. Among AHFS patients with diabetes (n = 7249), presenting blood glucose >11.1 mmol/L (n = 2286, 31.5%) was associated with increased risks of all-cause death (HR 1.48, 95% CI 1.10-2.00) and diabetes-related hospitalizations (HR 1.39, 95% CI; 1.20-1.61). Presentation blood glucose >9.4 mmol/L was associated with increased risks of hospitalization for HF or cardiovascular causes [HR range: 1.09 (95% CI 1.02-1.17) to 1.15 (95% CI 1.07-1.24)] in all patients. With higher presentation blood glucose, the risk of incident diabetes diagnosis increased, with adjusted HRs of 1.61 (>6.1-7.8 mmol/L) to 3.61 (>11.1 mmol/L) among those without the condition at baseline (all P < 0.001). Conclusions Mildly elevated presentation blood glucose was associated with early death, future diabetes, and hospitalizations for diabetes, HF, and cardiovascular causes among patients with AHFS.