Nondiabetic heart failure patients who arrive at the emergency department with an elevated blood glucose level may be at risk for death within a month or for developing diabetes later on.
A study published Jan. 7 in the European Heart Journal reported these results from a three-year Canadian study. From 2004 to 2007, researchers analyzed outcomes of 16,524 acute heart failure patients in Ontario, Canada.
More than half the patients (56 percent) did not have pre-existing diabetes. Outcomes were compared to a reference set of acute heart failure patients whose blood glucose ranged from 3.9-6.1 millimoles per liter (mmol/L).
Researchers found that nondiabetic heart failure patients with a blood glucose level of greater than 6.1 mmol/L may be at risk for death or developing diabetes. In the U.S., that's equivalent to about 110 milligrams per deciliter (mg/dL).
"It is a rapid, readily available and inexpensive test that could be used to enable doctors to quickly assess a patient’s risk for a wide range of possible outcomes and to suggest appropriate screening strategies that should be put in place," said Dr. Douglas Lee, the study's lead researcher and a an associate professor at the Institute for Clinical Evaluative Sciences.
Of acute heart failure patients studied, those without pre-existing diabetes were 26 percent more likely to die within 30 days from any cause when their blood glucose levels were between 6.1-7.8 millimoles per liter (mmol/L). The risk of death was 50 percent higher if their blood glucose levels exceeded 11.1 mmol/L.
Risk of death from cardiovascular causes was 28 percent higher when blood glucose levels were between 6.1-7.8 mmol/L and increased to 64 percent when levels were between 9.4-11.1 mmol/L.
The study also found that nondiabetic heart failure patients with elevated blood glucose have an increased risk of developing diabetes later in life.
"Although diabetes is a known risk factor for developing heart failure, this is the first time that it has been shown that heart failure predisposes people to developing diabetes," Lee said.
Upon arrival at the emergency department, the majority of nondiabetic acute heart failure patients had blood glucose levels that were within "normal" limits, but still greater than the 6.1 mmol/L, which the study indicated increases risk of developing diabetes.
- With blood glucose levels between 6.1-7.8 mmol/L, patients' risk of subsequent diabetes was 61 percent higher
- Patients' risk increased by 14 percent for every 1 mmol/L of increase between 7.8 and 11.0 mmol/L
- Heart-failure patients whose blood glucose levels were greater than 11.1 mmol/L have a 261 percent higher risk of developing diabetes
Lee stressed that acute heart failure patients should have their blood glucose levels tested upon arrival at the emergency department so the results can be incorporated into the inpatient care plan and considered in future outpatient screenings.
"Our results suggest that all such patients should undergo further testing for diabetes before discharge," Lee said. "If the hospital tests show that their fasting blood glucose is not elevated, then they should be monitored subsequently for the development of diabetes as outpatients."
