Blood glucose and heart failure in nondiabetic patients

Nondiabetic patients were studied to determine whether increasing blood glucose is associated with subsequent incidence of heart failure.

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.

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.

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.