Blood glucose and heart failure in nondiabetic patients.

OBJECTIVE: Nondiabetic patients were studied to determine whether increasing blood glucose is associated with subsequent incidence of heart failure. RESEARCH DESIGN AND METHODS: Baseline morning blood glucose determinations were evaluated with respect to subsequent heart failure using records from 20,810 nondiabetic patients. The onset of heart failure >1 year after initial glucose determinations was evaluated for patients who had 2-12 years of care. Patients were excluded if they had ever had the diagnosis of diabetes, had a diagnosis of heart failure <1 year after initial blood glucose determinations, had a blood glucose determination >125 mg/dl, or used corticosteroids, loop diuretics, insulin, or oral hypoglycemics.
RESULTS: Of the 20,810 patients studied, 916 patients developed heart failure over a total analysis time of 71,890 years at risk. Higher baseline morning glucose levels were associated with increased heart failure from 3.5% (glucose <90 mg/dl) to 3.8% (90-99 mg/dl) to 4.8% (100-109 mg/dl) to 6% (110-125 mg/dl) over a mean 4- to 5-year evaluation period. The incidence rate increased from 7.5 cases per 1,000 person-years (glucose <90 mg/dl) to 8.4 (90-99 mg/dl, NS) to 11.1 (100-109 mg/dl, P < 0.001) to 13.7 (110-125 mg/dl, P < 0.0001), an 83% increase in heart failure if baseline glucose was >109 mg/dl compared with <90 mg/dl. A Cox proportionate hazards model including age, sex, BMI, creatinine, hypertension, lipids, smoking, medications, and coronary disease showed a progressive increase in hazard ratio from 1.25 (glucose 90-99 mg/dl, P < 0.05) to 1.46 (100-109 mg/dl, P < 0.001) to 1.55 (110-125 mg/dl, P < 0.001) compared with glucose <90 mg/dl. Kaplan-Meier analysis showed increased glucose- associated risk with time.
CONCLUSIONS: Patients with higher baseline blood glucose levels in the absence of diabetes and after adjustment for covariants have a significantly increased risk of heart failure.