ORLANDO — Treatment of diabetic patients who had a myocardial infarction with a second-generation sulfonylurea did not boost mortality, compared with treating patients by diet alone or with insulin, in a study of about 450 patients in a community-based cohort.
In fact, the results suggested that treatment with a second-generation sulfonylurea may have increased survival, compared with other treatments. However, the investigators preferred a conservative interpretation, which concluded only that sulfonylurea drugs produced no excess of deaths, Dr. Richard K. Patch III said at the annual scientific sessions of the American Heart Association.
The safety of sulfonylurea drugs in patients with diabetes who have an MI has been a subject of controversy, said Dr. Patch, a researcher at the Mayo Clinic, Rochester, Minn. The study was designed to investigate this.
The findings also showed that following an MI, the prognosis of patients with diabetes was significantly worse than it was for those without diabetes.
The study included patients from Olmsted County, Minn., a community of about 125,000 people, who were enrolled in the Rochester Epidemiology Project.
During 1979–2002, a total of 2,732 people had an MI, including 487 patients who had diabetes and 2,245 patients without diabetes. Their average age was 68 years, and they were followed for an average of almost 6 years.
Patients were identified as having diabetes based on criteria from the National Diabetes Data Group.
In an analysis that controlled for age and gender, patients with diabetes who had an MI were 33% more likely to die during the first year than were patients without diabetes, a statistically significant difference.
A second analysis looked at the link between treatment and survival. Patients were divided into three groups: those treated with diet only, those treated with insulin, and those treated with a sulfonylurea. Early during the study, first-generation sulfonylureas were used, but starting in the mid-1980s this practice shifted toward second-generation drugs, such as glipizide.
The analysis excluded the 30 patients treated with a first-generation sulfonylurea, and focused on the remaining 457 patients.
In an analysis that controlled for age, gender, duration of MI, renal function, and several other variables, treatment with a second-generation sulfonylurea drug was linked with a halving of the mortality rate compared with diet alone, a statistically significant difference. (See box.)
Treatment with insulin was linked with a small, nonsignificant increase in mortality. Data on hemoglobin A1c levels were not available for all patients, so it was impossible to assess the role of tighter glycemic control on survival rates, Dr. Patch said.
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