By Ted Bosworth
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(MI) (ie, heart attack), 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
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).
History of prediabetes was also an independent risk factor for percutaneous intervention and coronary artery bypass grafting, with an 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 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 have the potential to alter the risk, according to 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 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 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 Thota cited. In 2020, the Centers for Disease Control and Prevention estimated that 38% of the adult population has prediabetes. By 2030, one model predicts a further 25% growth.
Screening for hyperglycemia is part of routine patient evaluations at Thota’s center. In an interview, she said that once a diagnosis of prediabetes enters into the electronic medical record, the history carries forward so that changes in status could monitor continually.
Worsening Prediabetes Should Be Addressed
“Medication is not the treatment for Prediabetes, at least initially,” Thota explained. Rather, patients are educated about important lifestyle changes, such as diet and physical activity, that can reverse the diagnosis. However, patients who remain on a path of worsening hyperglycemia are candidates for more intensive lifestyle intervention and might be considered selectively for metformin.
“Early recognition of prediabetes through screening is important,” Thota emphasized. The benefit of preventing patients from progressing to diabetes is well recognized, but these data provide the basis for incentivizing lifestyle changes in patients with prediabetes by telling them that it can reduce their risk for MI.
These data have an important message, but they are not surprising, according to Deepak L. Bhatt, MD, executive director, interventional cardiovascular programs, Brigham and Women’s Hospital Heart & Vascular Center, Boston.
“In fact, in daily practice, we see a substantial percentage of patients with MI who have prediabetes that had not been previously recognized or formally diagnosed,” Bhatt said in an interview.
“Identifying these patients – preferably prior to coming in with cardiovascular complications – is important both to reduce cardiovascular risk but also to try and prevent progression at diabetes,” he added.
Bhatt went on to say that this large analysis, confirming that prediabetes is independently associated with MI, should prompt clinicians to screen patients rigorously for this condition.
“At a minimum, such patients would be candidates for intensive lifestyle modification aimed at weight loss and treatment of frequent coexistent conditions, such as hypertension and dyslipidemia,” Bhatt said.
Thota reports no potential conflicts of interest. Bhatt has financial relationships with more than 30 pharmaceutical companies, many of which make products relevant to the management of diabetes and cardiovascular disease.