Prediabetes is not only a predictor of diabetes and the cardiovascular complications that ensue, but it is also a risk factor by itself for myocardial infarction, according to data drawn from almost 1.8 million patients hospitalized for MI.
“Our study serves as a wakeup call for clinicians and patients to shift the focus to preventing prediabetes, and not just diabetes, said Geethika Thota, MD, at the annual meeting of the Endocrine Society.
There are plenty of data suggesting that prediabetes places patients on a trajectory toward cardiovascular disease. In a meta-analysis of 129 studies published 2 years ago, prediabetes was not only associated with a statistically significant 16% increase in coronary heart disease, but also a 13% increased risk of all-cause mortality relative to those with normoglycemia.
Data drawn from 1.8 million patients
In this study, 1,794,149 weighted patient hospitalizations for MI were drawn from the National Inpatient Sample database. Excluding patients who eventually developed diabetes, roughly 1% of these patients had a history of prediabetes in the past, according to a search of ICD-10 codes.
Before adjustment for other risk factors, prediabetes was linked to a greater than 40% increased odds of MI (odds ratio, 1.41; P < .01). After adjustment for a large array of known MI risk factors – including prior history of MI, dyslipidemia, hypertension, nicotine dependence, and obesity – prediabetes remained an independent risk factor, corresponding with a 25% increased risk of MI (OR, 1.25; P < .01).
A history of prediabetes was also an independent risk factor for percutaneous intervention and coronary artery bypass grafting, with increased risk of 45% and 95%, respectively.
As a retrospective study looking at prediabetes as a risk factor in those who already had a MI, it is possible that not all patients with prediabetes were properly coded, but Dr. Thota said that was unlikely to have been an issue of sufficient magnitude to have affected the major conclusions.
Relevance seen for community care
Although the study was drawn from hospitalized patients, its relevance is for the community setting, where screening and intervention for prediabetes has the potential to alter the risk, according to Dr. Thota.
Most clinicians are likely aware of the value of screening for prediabetes, which was defined in this study as a hemoglobin A1c of 5.7%-6.4%, but Dr. Thota suggested that many might not fully grasp the full scope of goals. Early detection and prevention will prevent diabetes and, by extension, cardiovascular disease, but her data suggest that control of prediabetes with lower cardiovascular risk by a more direct route.
“Despite mounting evidence, many clinicians are unaware that prediabetes is also a major risk factor for atherosclerotic cardiovascular disease,” said Dr. Thota, an internal medicine resident at Saint Peter’s University Hospital, New Brunswick, N.J.
Like diabetes, the prevalence of prediabetes is growing rapidly, according to data from the Centers for Disease Control that Dr. Thota cited. In 2020, the Centers for Disease Control and Prevention estimated that 38% of the adult population have prediabetes. By 2030, one model predicts a further 25% growth.
Screening for hyperglycemia is part of routine patient evaluations at Dr. Thota’s center. In an interview, she said that once a diagnosis of prediabetes is entered in the electronic medical record, the history is carried forward so that changes in status are continually monitored.