MedWire News: Persistent hyperglycemia determined by multiple glucose assessments during hospitalization for acute myocardial infarction (AMI) better predicts mortality than hyperglycemia on admission, research shows.
Mikhail Kosiborod (University of Missouri-Kansas City, USA) and colleagues compared three different metric measures of glucose control, namely mean glucose, time-averaged glucose, and hyperglycemic index, over three time windows, with admission glucose for their ability to predict in-hospital death among patients hospitalized with AMI.
The researchers evaluated 16,871 AMI patients hospitalized from January 2000 to December 2005 who had comprehensive laboratory data.
They report in the journal Circulation that all three glucose control metrics, for all three time windows (first 24 hours, first 48 hours, and the entire hospitalization period), predicted in-hospital mortality better than did admission hyperglycemia.
The ability of each glucose control metric to predict mortality improved as the time window increased. Thus, the authors write: "There was no 'critical time window' that was most associated with death; glucose assessments over the entire hospitalization were incrementally better than assessments over shorter durations of time."
Kosiborod et al say that mean glucose was the most practical summary metric of glucose control given "its ease of calculation."
There was a J-shaped relationship between average glucose over hospitalization and mortality, with both persistent hyperglycemia and hypoglycemia associated with adverse prognosis.
The odds for in-hospital mortality increased gradually and significantly with each 10-mg/dl rise in mean hospitalization glucose levels above the threshold of 120 mg/dl. For example, the odds ratio for patients with mean glucose concentrations of 120 to <230 mg/dl versus 100 to <110 mg/dl was 1.80 (p=0.003).
And the odds ratio for patients with glucose levels <70 mg/dl, compared with those with levels of 100 to <110 mg/dl, was 6.4.
The slope of these relationships was steeper in those with versus those without diabetes.
The researchers write: "Summary measures of average glucose control at any time point during hospitalization offer a significant, incremental advantage in their ability to predict mortality compared with admission glucose."
They conclude that average glucose control during hospitalization "could be used routinely for prognosis and, if an intervention is demonstrated to be prognostically beneficial, as a modifiable therapeutic target."
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